Document:

<PAGE>

                                                                    Exhibit 4(a)

                    TRUST INDENTURE AND SECURITY AGREEMENT
                            (UTC Trust No. 2000-A)
                                    (L-16)

                              Dated June 29, 2000

                                    Between

                 Norwest Bank Minnesota, National Association

                                                                as Owner Trustee

                                      And

                       LaSalle Bank National Association

                                                            as Indenture Trustee

                         COVERED HOPPERS AND TANK CARS

                             ____________________

                  Filed with the Surface Transportation Board of the Department
                  of Transportation pursuant to 49 U.S.C.(S) 11301 on June 29,
                  2000 at ___ [a.m./p.m.], Recordation Number ___, and deposited
                  in the Office of the Registrar General of Canada pursuant to
                  Section 105 of the Canada Transportation Act on June 29, 2000.
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                               Table of Contents
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                                                                                                    Page
                                                                                                    ----

                                                 GRANTING CLAUSE 1

                                                 HABENDUM CLAUSE 4

                                                    Article I.
                                                    DEFINITIONS
<S>                                                                                                 <C>
     Section 1.01.     Certain Definitions; Construction..........................................     5

                                                    Article II.
                                                THE EQUIPMENT NOTES

     Section 2.01.     Form of Equipment Notes....................................................     6
     Section 2.02.     Term of Equipment Notes....................................................     9
     Section 2.03.     Payment from Indenture Estate Only.........................................     9
     Section 2.04.     Method of Payment..........................................................     9
     Section 2.05.     Application of Payments to Principal Amount and Interest...................    10
     Section 2.06.     Termination of Interest in Indenture Estate................................    10
     Section 2.07.     Transfer of Equipment Notes................................................    10
     Section 2.08.     Mutilated, Destroyed, Lost or Stolen Equipment Notes.......................    11
     Section 2.09.     Payment of Transfer Taxes..................................................    12
     Section 2.10.     Prepayments................................................................    12
     Section 2.11.     Equally and Ratably Secured................................................    14

                                                   Article III
                                     RECEIPT, DISTRIBUTION AND APPLICATION OF
                                         INCOME FROM THE INDENTURE ESTATE

     Section 3.01.     Basic Rent Distribution....................................................    14
     Section 3.02.     Payments in the Event of Prepayment........................................    15
     Section 3.03.     Payments after Indenture Event of Default..................................    15
     Section 3.04.     Other Payments.............................................................    17
     Section 3.05.     Distribution of Excepted Property..........................................    17

                                                   Article IV.
                                   OF OBLIGATIONS OF OWNER TRUSTEE BY LESSEE

     Section 4.01.     Assumption of Obligations of Owner Trustee by Lessee.......................    17
</TABLE>

                                      -i-
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<TABLE>
                                                            Article V.
                                                 REMEDIES OF THE INDENTURE TRUSTEE
                                                UPON AN INDENTURE EVENT OF DEFAULT
<S>                                                                                                                  <C>
         Section 5.01.     Indenture Events of Default...........................................................    19
         Section 5.02.     Acceleration; Rescission and Annulment................................................    20
         Section 5.03.     Remedies with Respect to Indenture Estate.............................................    21
         Section 5.04.     Right to Cure; Option to Purchase; Etc................................................    23
         Section 5.05.     Rights of Lessee......................................................................    26
         Section 5.06.     Waiver of Existing Defaults...........................................................    26

                                                            Article VI.
                                                  DUTIES OF THE INDENTURE TRUSTEE

         Section 6.01.     Action upon Indenture Event of Default................................................    26
         Section 6.02.     Action upon Instructions..............................................................    27
         Section 6.03.     Indemnification.......................................................................    28
         Section 6.04.     No Duties Except as Specified in Indenture or Instructions............................    28
         Section 6.05.     No Action Except under Lease, Indenture or Instructions...............................    28
         Section 6.06.     Disposition of Units..................................................................    29
         Section 6.07.     Indenture Supplements for Replacements................................................    29
         Section 6.08.     Effect of Replacements................................................................    29
         Section 6.09.     Withholding Taxes.....................................................................    29
         Section 6.10.     Lessee's Right of Quiet Enjoyment.....................................................    29
         Section 6.11.     Compensation and Indemnity............................................................    30

                                                           Article VII.
                                            THE OWNER TRUSTEE AND THE INDENTURE TRUSTEE

         Section 7.01.     Acceptance of Trusts and Duties.......................................................    30
         Section 7.02.     Absence of Duties.....................................................................    31
         Section 7.03.     No Representations or Warranties as to the Equipment or Documents.....................    31
         Section 7.04.     No Segregation of Moneys; No Interest; Investments....................................    31
         Section 7.05.     Reliance; Agents; Advice of Counsel...................................................    32
         Section 7.06.     Not Acting in Individual Capacity.....................................................    33

                                                           Article VIII.
                                              CERTAIN LIMITATIONS ON OWNER TRUSTEE'S
                                                  AND INDENTURE TRUSTEE'S RIGHTS

         Section 8.01.     Certain Limitations on Owner Trustee's and Indenture Trustee's Rights.................    33
</TABLE>

                                     -ii-
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<TABLE>
<CAPTION>
                                                            Article IX.
                                                        SUCCESSOR TRUSTEES
<S>                                                                                                        <C>
         Section 9.01.     Notice of Successor Owner Trustee...........................................    33
         Section 9.02.     Resignation of Indenture Trustee; Appointment of Successor..................    33

                                                            Article X.
                                              SUPPLEMENTS AND AMENDMENTS TO THIS
                                                  INDENTURE AND OTHER DOCUMENTS

         Section 10.01.    Supplemental Indentures without Consent of Holders..........................    35
         Section 10.02.    Indenture Trustee Protected.................................................    36
         Section 10.03.    Request of Substance, Not Form..............................................    37
         Section 10.04.    Documents Mailed to Holders.................................................    37
         Section 10.05.    Amendments, Waivers, Etc. of Other Documents................................    37

                                                            Article XI.
                                                           MISCELLANEOUS

         Section 11.01.    Termination of Indenture....................................................    39
         Section 11.02.    No Legal Title to Indenture Estate in Holders...............................    40
         Section 11.03.    Sale of Equipment by Indenture Trustee is Binding...........................    40
         Section 11.04.    Remedies Cumulative.........................................................    40
         Section 11.05.    Discontinuance of Proceedings...............................................    40
         Section 11.06.    Indenture and Equipment Notes for Benefit of Owner Trustee, Indenture
                           Trustee, Owner Participant and Holders Only.................................    41
         Section 11.07.    Notices.....................................................................    41
         Section 11.08.    Severability................................................................    41
         Section 11.09.    Separate Counterparts.......................................................    41
         Section 11.10.    Successors and Assigns......................................................    42
         Section 11.11.    Headings....................................................................    42
         Section 11.12.    Governing Law...............................................................    42
         Section 11.13.    Normal Commercial Relations.................................................    42
         Section 11.14.    No Recourse Against Others..................................................    42
         Section 11.15.    Identity of Note Purchasers.................................................    42
</TABLE>

EXHIBIT A  -               Form of Trust Indenture Supplement
EXHIBIT B  -               Terms of Equipment Notes
APPENDIX A -               Definitions

                                     -iii-
<PAGE>

                    TRUST INDENTURE AND SECURITY AGREEMENT
                         (UTC Trust No. 2000-A)(L-16)

     This TRUST INDENTURE AND SECURITY AGREEMENT (UTC Trust No. 2000-A) (L-16)
dated June 29, 2000 (this "Indenture"), between Norwest Bank Minnesota, National
Association, not in its individual capacity, except as otherwise expressly set
forth in Section 7.03 hereof, but solely as trustee under the Trust Agreement
referred to below and any successor appointed in accordance with the terms
hereof and of the Trust Agreement (herein in such trustee capacity called the
"Owner Trustee"), and LaSalle Bank National Association as Indenture Trustee
hereunder and any successor appointed in accordance with the terms hereof
(herein called the "Indenture Trustee");

                                  WITNESSETH:

     WHEREAS, the Owner Participant and the Owner Trustee in its individual
capacity have entered into the Trust Agreement whereby, among other things, (i)
the Owner Trustee establishes a certain trust for the use and benefit of the
Owner Participant subject, however, to the Indenture Estate created pursuant
hereto for the use and benefit of, and with the priority of payment to, the
holders of the Equipment Notes, and (ii) the Owner Trustee is authorized and
directed to execute and deliver this Indenture;

     WHEREAS, the Owner Trustee and the Indenture Trustee desire by this
Indenture, among other things, (i) to provide in accordance with this Indenture
for the issuance by the Owner Trustee of the Equipment Notes on the Closing Date
and (ii) to provide for the assignment, mortgage and pledge by the Owner Trustee
to the Indenture Trustee, as part of the Indenture Estate hereunder, among other
things, of, and the grant of a security interest in, certain of the Owner
Trustee's right, title and interest in and to the Equipment and the Lease and
certain payments and other amounts received hereunder or thereunder, in
accordance with the terms hereof, in trust, as security for, among other things,
the Owner Trustee's obligations for the equal and ratable benefit of the holders
of the Equipment Notes; and

     WHEREAS, all things necessary to make this Indenture the legal, valid and
binding obligation of the Owner Trustee and the Indenture Trustee, for the uses
and purposes herein set forth, in accordance with its terms, have been done and
performed and have happened.

                                GRANTING CLAUSE

     NOW, THEREFORE, THIS TRUST INDENTURE AND SECURITY AGREEMENT WITNESSETH,
that, to secure the prompt payment of the principal of and interest and Make-
Whole Amount, if any, on and all other amounts due with respect to, the
Equipment Notes, as provided in this Indenture, from time to time outstanding
hereunder and the performance and observance by the
<PAGE>

Owner Trustee of all the agreements, covenants and provisions herein and in the
Equipment Notes all for the benefit of the holders of the Equipment Notes, and
for the uses and purposes and subject to the terms and provisions hereof, and in
consideration of the premises and of the covenants herein contained, and of the
acceptance of the Equipment Notes by the purchasers thereof, the Owner Trustee
does hereby sell, assign, transfer, convey, mortgage, pledge, and confirm unto
the Indenture Trustee, its successors and assigns, for the security and benefit
of the holders of the Equipment Notes from time to time, a security interest in
and mortgage lien on all right, title and interest of the Owner Trustee in and
to the following described property, rights, interests and privileges insofar as
it does not constitute Excepted Property (which collectively, including all
property hereafter required to be subjected to the Lien of this Indenture by any
instrument supplemental hereto, but excluding Excepted Property, being herein
called the "Indenture Estate"), to wit:

          (1)  the Lease, including, without limitation, all amounts of Basic
     Rent, Supplemental Rent, insurance proceeds and other payments of any kind
     for or with respect to the Equipment, subject to Lessee's rights under the
     Lease, including, without limitation, Lessee's right of quiet enjoyment;

          (2)  the Equipment, the Replacement Units and all substitutions
     therefor in which the Owner Trustee shall from time to time acquire an
     interest under the Lease, all as more particularly described in the
     Indenture Supplements and Lease Supplements executed and delivered with
     respect to the Equipment or any such Replacement Units or any substitutions
     therefor, as provided in this Indenture and the Lease;

          (3)  all requisition proceeds with respect to the Equipment or any
     Unit thereof (to the extent of the Owner Trustee's interest therein
     pursuant to the terms of the Lease);

          (4)  all monies and securities now or hereafter paid or deposited or
     required to be paid or deposited with the Indenture Trustee pursuant to any
     term of this Indenture, the Lease or the Participation Agreement or
     required to be held by the Indenture Trustee hereunder or thereunder;

          (5)  all proceeds of the foregoing;

          (6)  the right to make all waivers and agreements and to enter into
     any amendments relating to the Lease and to give and receive duplicate
     copies of all notices and other instruments or communications; and

          (7)  the right to take such action upon the occurrence of an Event of
     Default under the Lease, including the commencement, conduct and
     consummation of legal, administrative or other proceedings, as shall be
     permitted by the Lease or by law, and to do any and all other things
     whatsoever which the Lessor is or may be entitled to do under the Lease in
     connection therewith.

                                      -2-
<PAGE>

     Notwithstanding the foregoing provisions:

          (a)  there shall be excluded from the foregoing sale, assignment,
     transfer, conveyance, mortgage, pledge or security interest granted by this
     Indenture and from the Indenture Estate all Excepted Property;

          (b)  (i)    the Owner Trustee and the Owner Participant shall at all
     times retain the right, to the exclusion of the Indenture Trustee (A) to
     Excepted Property and to commence an action at law to obtain such Excepted
     Property and (B) to adjust Basic Rent and the percentages relating to
     Stipulated Loss Value and Termination Value as provided in Section 3.4 of
     the Lease and Section 2.6 of the Participation Agreement;

               (ii)   the Owner Trustee and the Indenture Trustee shall each
     retain the right to receive from the Lessee all notices, certificates,
     reports, filings, opinions of Counsel, copies of all documents and all
     information which the Lessee is permitted or required to give or furnish to
     the Lessor or to the Owner Trustee pursuant to the Lease or pursuant to any
     other Operative Agreement and to exercise the inspection rights provided
     for in Section 13.2 of the Lease, to give any notice of default under
     Section 14 of the Lease and to retain the right to cause the Lessee to take
     any action and execute and deliver such documents and assurances as the
     Lessor may from time to time reasonably request pursuant to Section 16.2 of
     the Lease;

               (iii)  so long as no Indenture Event of Default shall have
     occurred and be continuing (but subject to the provisions of Section
     10.05), the Owner Trustee shall retain the right, to the exclusion of the
     Indenture Trustee, to exercise all rights of the Lessor under the Lease
     (other than the right to receive any funds to be delivered to the Lessor
     under the Lease (except funds which constitute or are delivered with
     respect to Excepted Property)); and

          (c)  the leasehold interest granted to the Lessee under the Lease
     shall not be subject to the security interest granted by this Indenture,
     and nothing in this Indenture shall affect the rights of the Lessee under
     the Lease so long as no Lease Event of Default has occurred and is
     continuing; and

          (d)  as between the Owner Trustee and the Indenture Trustee, nothing
     contained in this Granting Clause shall prevent the Owner Trustee, as the
     Lessor under the Lease, from seeking specific performance of the covenants
     of the Lessee under the Lease relating to the insurance, maintenance,
     possession and use of the Units and from maintaining separate insurance
     with respect to the Units to the extent permitted by Section 12.5 of the
     Lease.

                                      -3-
<PAGE>

     Notwithstanding the foregoing, the Indenture Trustee shall at all times
have the right, to the exclusion of the Owner Trustee and the Owner Participant,
to (i) declare the Lease to be in default pursuant to Section 15 of the Lease
and (ii) to exercise the remedies set forth in Section 15 of the Lease and in
Section 5 (except for Section 5.04) hereof.

                                HABENDUM CLAUSE

     TO HAVE AND TO HOLD all and singular the aforesaid property unto the
Indenture Trustee, its successors and assigns, in trust for the benefit and
security of the holders of the Equipment Notes from time to time, without any
priority of any one Equipment Note over any other Equipment Note, and for the
uses and purposes, and subject to the terms and provisions, set forth in this
Indenture.

     It is expressly agreed that anything herein contained to the contrary
notwithstanding, the Owner Trustee shall remain liable under each of the
Operative Agreements to which it is a party to perform all of the obligations,
if any, assumed by it thereunder, all in accordance with and pursuant to the
terms and provisions thereof, and the Indenture Trustee and the holders of the
Equipment Notes shall have no obligation or liability under any of the Operative
Agreements to which the Owner Trustee is a party by reason of or arising out of
this assignment, nor shall the Indenture Trustee (unless the Indenture Trustee
shall have become the "Lessor" under the Lease) or the holders of the Equipment
Notes be required or obligated in any manner to perform or fulfill any
obligations of the Owner Trustee under or pursuant to any of the Operative
Agreements to which the Owner Trustee is a party or, except as herein expressly
provided, to make any payment, or to make any inquiry as to the nature or
sufficiency of any payment received by it, or present or file any claim, or take
any action to collect or enforce the payment of any amounts which may have been
assigned to it or to which it may be entitled at any time or times.

     Subject to the terms and conditions hereof, the Owner Trustee does hereby
constitute the Indenture Trustee the true and lawful attorney of the Owner
Trustee, irrevocably, with full power (in the name of the Owner Trustee or
otherwise), upon the occurrence and during the continuation of an Indenture
Event of Default, to ask, require, demand, receive, compound and give
acquittance for any and all moneys and claims for moneys due and to become due
to the Owner Trustee (other than Excepted Property), under or arising out of the
Lease, or to endorse any checks or other instruments or orders in connection
therewith and to file any claims or take any action or institute any proceedings
which the Indenture Trustee may deem to be necessary or advisable in the
premises.  The Owner Trustee has directed the Lessee to make all payments of
Rent (other than Excepted Property) payable to the Owner Trustee by the Lessee
and all other amounts which are required to be paid to or deposited with the
Owner Trustee pursuant to the Lease directly to the Indenture Trustee at such
address as the Indenture Trustee shall specify, for application as provided in
this Indenture.  The Owner Trustee agrees that promptly on receipt thereof, it
will transfer to the Indenture Trustee any and all moneys from time to time
received by it constituting part of the

                                      -4-
<PAGE>

Indenture Estate, for distribution by the Indenture Trustee pursuant to this
Indenture, except that the Owner Trustee shall accept for distribution pursuant
to the Trust Agreement any amounts distributed to it by the Indenture Trustee as
expressly provided in this Indenture and any Excepted Property.

     The Owner Trustee agrees that at any time and from time to time, upon the
written request of the Indenture Trustee, the Owner Trustee will promptly and
duly execute and deliver or cause to be executed and delivered any and all such
further instruments and documents as the Indenture Trustee may reasonably deem
to be necessary in order to obtain the full benefits of this assignment and of
the rights and powers herein granted.

     The Owner Trustee does hereby warrant and represent that it has not
assigned or pledged, and hereby covenants that it will not assign or pledge, so
long as the assignment hereunder shall remain in effect, any of its right, title
or interest hereby assigned, to anyone other than the Indenture Trustee, and
that it will not (other than in respect of Excepted Property), except as
provided in or permitted by this Indenture, accept any payment from the Lessee,
enter into an agreement amending or supplementing any of the Operative
Agreements, execute any waiver or modification of, or consent under the terms of
any of the Operative Agreements (other than the Tax Indemnity Agreement), settle
or compromise any claim (other than claims in respect of Excepted Property)
against the Lessee arising under any of the Operative Agreements, or submit or
consent to the submission of any dispute, difference or other matter arising
under or in respect of any of the Operative Agreements, to arbitration
thereunder.

     IT IS HEREBY COVENANTED AND AGREED by and between the parties hereto as
follows:

                                  Article I.
                                  DEFINITIONS

     Section 1.01.  Certain Definitions; Construction.  Unless the context
otherwise requires, all capitalized terms used herein and not otherwise defined
shall have the meanings set forth in Appendix A hereto for all purposes of this
Indenture, and include the plural as well as the singular.  All references to
articles, sections, clauses, schedules and appendices in this Indenture are to
articles, sections, clauses, schedules and appendices in and to this Indenture
unless otherwise indicated.  All accounting terms not otherwise defined herein
or in Appendix A hereto have the meanings assigned to them in accordance with
generally accepted accounting principles.  The words herein, hereof and
                                                     ------  ------
hereunder and other words of similar import refer to this Indenture as a whole
---------
and not to any particular Article, Section or other subdivision.  Whenever any
matter set forth herein requires the consent, direction or approval of the
holders of Equipment Notes or a specified number thereof, any Equipment Notes
held by the Owner Trustee, Owner Participant, Lessee, or any of their respective
Affiliates shall be disregarded in determining whether such consent, direction
or approval has been granted, unless all of the Equipment Notes are held by such
Person.

                                      -5-
<PAGE>

                                  Article II.
                              THE EQUIPMENT NOTES

     Section 2.01.  Form of Equipment Notes.  The Equipment Notes shall be
substantially in the form set forth below:

                          2000-A 8.13% EQUIPMENT NOTE

                (Secured by, among others, Lease Obligations of
                            Union Tank Car Company)

           Issued in Connection with Certain Railroad Rolling Stock

No.______                                                      Chicago, Illinois
                                                                   June 29, 2000
$________________

     Norwest Bank Minnesota, National Association, not in its individual
capacity, but solely as owner trustee (herein in such capacity called the "Owner
Trustee") under that certain Trust Agreement (UTC Trust No. 2000-A) (L-16),
dated June 29, 2000, as from time to time supplemented and amended (herein
called the "Trust Agreement"), between the Owner Trustee in its individual
capacity and the institution referred to therein as the "Owner Participant",
hereby promises to pay to _______________________________, or registered
assigns, the principal sum of $____________ in lawful currency of the United
States of America, in installments payable on the dates set forth in Exhibit A
hereto, commencing January 15, 2001, and thereafter to and including [June 29],
2016 each such installment to be in an amount equal to the corresponding
percentage (if any) of the remaining principal amount hereof set forth in
Exhibit A hereto, together with interest thereon on the amount of such principal
amount remaining unpaid from time to time from and including the date hereof
until such principal amount shall be due and payable, payable on January 15,
2001 and on each July 15 and January 15 thereafter to the maturity date hereof
at the rate of 8.13% per annum (computed on the basis of a 360-day year of
twelve 30-day months).  Interest on any overdue principal and (to the extent
legally enforceable) on overdue interest shall be paid from the due date thereof
at the rate of 10.13% per annum (computed on the basis of a 360-day year of
twelve 30-day months), payable on demand.

     All payments of principal and interest and Make-Whole Amount, if any, to be
made hereunder and under the Trust Indenture and Security Agreement (UTC Trust
No. 2000-A) (L-16), dated June 29, 2000 as from time to time amended and
supplemented (herein called the "Indenture", the defined terms therein not
otherwise defined herein being used herein with the same meanings), between the
Owner Trustee and LaSalle National Bank, as Indenture Trustee thereunder for the
holder of this Equipment Note and the holders of other Equipment Notes
outstanding thereunder

                                      -6-
<PAGE>

(herein in such capacity called the "Indenture Trustee") shall be made only from
the income and proceeds from the Indenture Estate and only to the extent that
the Indenture Trustee shall have sufficient income or proceeds from the
Indenture Estate to make such payments in accordance with the terms of Article
III of the Indenture. Each holder hereof, by its acceptance of this Equipment
Note, agrees that it will look solely to the income and proceeds from the
Indenture Estate to the extent available for distribution to the holder hereof
as provided in the Indenture and that none of the Owner Trustee, the Owner
Participant, the Indenture Trustee or their permitted successors and assigns is
or shall be personally liable to the holder hereof for any amount payable under
this Equipment Note or the Indenture or, except as expressly provided in the
Participation Agreement or the Indenture, for any liability under the
Participation Agreement or (in the case of the Owner Trustee or the Indenture
Trustee) the Indenture.

     Payments with respect to the principal amount hereof, Make-Whole Amount, if
any, and interest thereon shall be payable in U.S. dollars in immediately
available funds at the principal bond and trustee administration office of the
Indenture Trustee, or as otherwise provided in the Indenture.  Each such payment
shall be made on the date such payment is due and without any presentment or
surrender of this Equipment Note.  Whenever the date scheduled for any payment
to be made hereunder or under the Indenture shall not be a Business Day, then
such payment need not be made on such scheduled date but may be made on the next
succeeding Business Day with the same force and effect as if made on such
scheduled date and (provided such payment is made on such next succeeding
Business Day) no interest shall accrue on the amount of such payment from and
after such scheduled date to the time of such payment on such next succeeding
Business Day.

     Each holder hereof, by its acceptance of this Equipment Note, agrees that
each payment received by it hereunder shall be applied, first, to the payment of
                                                        -----
accrued but unpaid interest on this Equipment Note then due, second, to the
                                                             ------
payment of the unpaid principal amount of this Equipment Note then due, third,
                                                                        -----
to the payment of any Make-Whole Amount then due, and fourth, to the payment of
                                                      ------
the remaining outstanding principal amount of this Equipment Note; provided,
that the Owner Trustee may only prepay this Equipment Note as provided in
Sections 2.10, 3.02 and 3.03 of the Indenture.

     This Equipment Note is one of the Equipment Notes referred to in the
Indenture which have been or are to be issued by the Owner Trustee pursuant to
the terms of the Indenture and relates to the Units described in Lease
Supplement No. 1.  The Indenture Estate is held by the Indenture Trustee as
security for the Equipment Notes.  Reference is hereby made to the Indenture for
a statement of the rights of the holder of, and the nature and extent of the
security for, this Equipment Note, as well as for a statement of the terms and
conditions of the trusts created by the Indenture, to all of which terms and
conditions in the Indenture each holder hereof agrees by its acceptance of this
Equipment Note.

     This Equipment Note is not subject to redemption or prepayment except as
provided in Sections 2.10, 3.02 and 3.03 of the Indenture.  This Equipment Note
is subject to purchase by the

                                      -7-
<PAGE>

Owner Trustee without a Make-Whole Amount as provided in Section 5.04(b) of the
Indenture. The holder hereof, by its acceptance of this Equipment Note, agrees
to be bound by said provisions.

     This Equipment Note is a registered Equipment Note and is transferable, as
provided in the Indenture, only upon surrender of this Equipment Note for
registration of transfer duly endorsed by, or accompanied by a written statement
of transfer duly executed by, the registered holder hereof or his attorney duly
authorized in writing. Prior to the due presentation for registration of
transfer of this Equipment Note, the Owner Trustee and the Indenture Trustee may
deem and treat the registered holder of this Equipment Note as the absolute
owner and holder hereof for the purpose of receiving payment of all amounts
payable with respect hereto and for all other purposes and shall not be affected
by any notice to the contrary.

     THIS EQUIPMENT NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
1933 AND MAY NOT BE TRANSFERRED IN VIOLATION OF SUCH ACT.  THIS EQUIPMENT NOTE
SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF
NEW YORK.

     Unless the certificate of authentication hereon has been executed by or on
behalf of the Indenture Trustee by manual signature, this Equipment Note shall
not be entitled to any benefit under the Indenture or be valid or obligatory for
any purpose.

     In Witness Whereof, the Owner Trustee has caused this Equipment Note to be
executed by one of its authorized officers as of the date hereof.

                         Norwest Bank Minnesota, National Association, not in
                         its individual capacity, but solely as Owner Trustee

                         By:____________________________________________________

          [FORM OF INDENTURE TRUSTEE'S CERTIFICATE OF AUTHENTICATION]

     This is one of the Equipment Notes referred to in the within-mentioned
     Indenture.

                              LaSalle Bank National Association, as Indenture
                               Trustee

                                       By:______________________________________
                                              Authorized Officer

     [Insert the related Amortization Schedule]

                                      -8-
<PAGE>

     Section 2.02.  Term of Equipment Notes.  There shall be issued and
delivered to each holder one or more Equipment Notes on the Closing Date in the
maturity and bearing the interest rate as set forth in Exhibit B hereto, in an
aggregate principal amount equal to the loan made by the holder of such
Equipment Note to the Owner Trustee pursuant to Section 2 of the Participation
Agreement.  Such Equipment Note shall evidence the loan made by the holder of
such Equipment Note in connection with the purchase of the Equipment by the
Owner Trustee from the Lessee, shall be substantially in the form set forth in
Section 2.01, with deletions and insertions as appropriate, and shall be duly
authenticated by the Indenture Trustee and dated the Closing Date.

     The principal amount of and interest on each Equipment Note issued pursuant
to the provisions of this Indenture shall be payable as set forth in the form
thereof contained in Section 2.01.  Interest accrued on the Equipment Notes
shall be computed on the basis of a 360-day year of twelve 30-day months on the
principal amount thereof remaining unpaid from time to time from and including
the date thereof to but excluding the date of payment.  The Owner Trustee shall
furnish to the Indenture Trustee a copy of each Equipment Note issued pursuant
to the provisions of this Indenture.  The aggregate principal amount of
Equipment Notes which may be outstanding at any one time shall be limited to the
aggregate amount set forth in Exhibit B hereto.

     No Equipment Note shall be entitled to any benefit under this Indenture or
be valid or obligatory for any purpose, unless it shall have been authenticated
by or on behalf of the Indenture Trustee by manual signature.

     Section 2.03.  Payment from Indenture Estate Only.  Notwithstanding any
other provision herein or in the Equipment Notes to the contrary, all payments
to be made under the Equipment Notes and this Indenture and the relevant
Indenture Supplement shall be made only from the income and the proceeds from
the Indenture Estate and only to the extent that the Indenture Trustee shall
have received sufficient income or proceeds from the Indenture Estate to make
such payments in accordance with the terms of Article III hereof.  Each holder
of an Equipment Note, by its acceptance of such Equipment Note, agrees that it
will look solely to the income and proceeds from the Indenture Estate to the
extent available for distribution to such holder as herein provided and that
none of the Owner Trustee, the Owner Participant, the Indenture Trustee or their
permitted successors and assigns is or shall be personally liable to the holder
of any Equipment Note for any amount payable under such Equipment Note or the
Indenture or except as expressly provided in the Participation Agreement or the
Indenture for any liability under the Participation Agreement or (in the case of
the Owner Trustee or the Indenture Trustee) the Indenture.

     Section 2.04.  Method of Payment.  (a)  The principal of and Make-Whole
Amount, if any, and interest on each Equipment Note will be payable in U.S.
dollars in immediately available funds at the principal corporate trust
administration office of the Indenture Trustee or as otherwise directed in the
manner provided herein.  Notwithstanding the foregoing or any provision in any
Equipment Note to the contrary, the Indenture Trustee will pay, or cause to be
paid, all amounts payable by the Owner Trustee hereunder to such holder or a
nominee therefor either (i) by transferring by wire in

                                      -9-
<PAGE>

immediately available funds to an account maintained by such holder with a bank
in the United States the amount to be distributed to such holder or (ii) by
mailing a check denominated in U.S. dollars to such holder in either case as
specified by such holder in such holder's Schedule 2 attached to the
Participation Agreement or in any subsequent written notice to the Owner Trustee
and the Indenture Trustee, in any case without any presentment or surrender of
any Equipment Note, except that the holder of an Equipment Note shall surrender
such Equipment Note to the Indenture Trustee upon payment in full of the
principal amount of and interest on such Equipment Note and such other sums
payable to such holder hereunder or under the Equipment Note.

     (b) Whenever the date scheduled for any payment to be made hereunder or
under any Equipment Note shall not be a Business Day, then such payment need not
be made on such scheduled date but may be made on the next succeeding Business
Day with the same force and effect as if made on such scheduled date and
(provided such payment is made on such next succeeding Business Day) no interest
shall accrue on the amount of such payment from and after such scheduled date to
the time of such payment on such next succeeding Business Day.

     Section 2.05.  Application of Payments to Principal Amount and Interest.
In the case of each Equipment Note, each payment of principal thereof and Make-
Whole Amount, if any, and interest thereon shall be applied, first, to the
                                                             -----
payment of accrued but unpaid interest on such Equipment Note then due
thereunder, second, to the payment of the unpaid principal amount of such
            ------
Equipment Note then due thereunder, third, to the payment of any Make-Whole
                                    -----
Amount then due thereon and fourth, to the payment of the remaining outstanding
                            ------
principal amount of such Equipment Note; provided, that the Owner Trustee may
only prepay such Equipment Note in accordance with the provisions of Section
2.10, 3.02 and 3.03 hereof.

     Section 2.06.  Termination of Interest in Indenture Estate.  A holder of an
Equipment Note shall have no further interest in, or other right with respect
to, the Indenture Estate when and if the principal amount of and interest on all
Equipment Notes held by such holder and all other sums payable to such holder
hereunder and under such Equipment Notes and under the Participation Agreement
shall have been paid in full.

     Section 2.07.  Transfer of Equipment Notes.  The Indenture Trustee shall
maintain at its corporate trust administration office in Chicago, Illinois or in
the city in which the corporate trust office of a successor Indenture Trustee is
located, a register for the purpose of registering transfers and exchanges of
Equipment Notes, copies of which shall be made available to any holder of
Equipment Notes upon reasonable notice.  A holder of an Equipment Note intending
to transfer such Equipment Note to a new payee, or to exchange any Equipment
Note or Equipment Notes held by it for an Equipment Note or Equipment Notes of a
different denomination or denominations, may surrender such Equipment Note or
Equipment Notes to the Indenture Trustee at such principal corporate trust
administration office of the Indenture Trustee, together with a written request
from such holder for the issuance of a new Equipment Note or Equipment Notes,
specifying the denomination or denominations (each of which shall be not less
than $500,000 or a whole multiple

                                      -10-
<PAGE>

thereof or such smaller denomination as may be necessary due to the original
issuance of Equipment Notes of the applicable maturity in an aggregate principal
amount not evenly divisible by $500,000) of the same, and, in the case of a
surrender for registration of transfer, the name and address of the transferee
or transferees. Promptly upon receipt of such documents, the Owner Trustee will
issue and the Indenture Trustee will authenticate a new Equipment Note or
Equipment Notes in the form set forth in Section 2.01 in the same aggregate
principal amount and dated the same date or dates, with the same payment
schedule, in the same maturity, and bearing the same interest rate as the
Equipment Note or Equipment Notes surrendered, in such denomination or
denominations and payable to such payee or payees as shall be specified in the
written request from such holder. All Equipment Notes issued upon any
registration of transfer or exchange of Equipment Notes shall be the valid
obligations of the Owner Trustee evidencing the same respective obligations, and
entitled to the same security and benefits under this Indenture, as the
Equipment Notes surrendered upon such registration of transfer or exchange. The
Indenture Trustee shall make a notation on each new Equipment Note or Equipment
Notes of the amount of all payments or prepayments of principal and interest
previously made on the old Equipment Note or Equipment Notes with respect to
which such new Equipment Note or Equipment Notes is or are issued. From time to
time, the Indenture Trustee will provide the Owner Trustee and the Lessee with
such information as it may request as to the registered holders of Equipment
Notes. The Owner Trustee shall not be required to exchange any surrendered
Equipment Notes as above provided during the 10-day period preceding the due
date of any payment on such Equipment Notes.

     Prior to the due presentment for registration of transfer or exchange of an
Equipment Note, the Owner Trustee and the Indenture Trustee may deem and treat
the registered holder of such Equipment Note as the absolute owner and holder of
such Equipment Note for the purpose of receiving payment of all amounts payable
with respect to such Equipment Note and for all other purposes and shall not be
affected by any notice to the contrary.

     The Indenture Trustee will promptly notify the Owner Trustee and the Lessee
of each request for a registration of transfer or exchange of an Equipment Note.
The Indenture Trustee will promptly cancel and destroy all Equipment Notes
surrendered for transfer or exchange pursuant to this Section.

     Section 2.08.  Mutilated, Destroyed, Lost or Stolen Equipment Notes.  If
any Equipment Note shall become mutilated, destroyed, lost or stolen, the Owner
Trustee shall, upon the written request of the holder of such Equipment Note,
issue, and the Indenture Trustee shall authenticate and deliver in replacement
thereof, a new Equipment Note in the form set forth in Section 2.01, payable to
the same holder in the same principal amount, of the same maturity, with the
same payment schedule, bearing the same interest rate and dated the same date as
the Equipment Note so mutilated, destroyed, lost or stolen.  The Indenture
Trustee shall make a notation on each new Equipment Note of the amount of all
payments or prepayments of principal and interest theretofore made on the
Equipment Note so mutilated, destroyed, lost or stolen and the date to which
interest on such old Equipment Note has been paid.  If the Equipment Note being
replaced has become mutilated, such

                                      -11-
<PAGE>

Equipment Note shall be surrendered to the Indenture Trustee and forwarded to
the Owner Trustee by the Indenture Trustee. If the Equipment Note being replaced
has been destroyed, lost or stolen, the holder of such Equipment Note shall
furnish to the Owner Trustee and the Indenture Trustee such security or
indemnity as may be required by them to save the Owner Trustee and the Indenture
Trustee harmless and evidence satisfactory to the Owner Trustee and the
Indenture Trustee of the destruction, loss or theft of such Equipment Note and
of the ownership thereof (provided, that if such holder is an institutional
investor, its written agreement shall be sufficient).

     Section 2.09.  Payment of Transfer Taxes.  Upon the transfer or exchange of
any Equipment Note or Equipment Notes pursuant to Section 2.07, the Owner
Trustee or the Indenture Trustee may require from the party requesting such new
Equipment Note or Equipment Notes payment of a sum to reimburse the Owner
Trustee or the Indenture Trustee for, or to provide funds for the payment of,
any tax or other governmental charge in connection therewith.

     Section 2.10.  Prepayments.  (a)  Each Equipment Note shall be prepaid in
whole or in part by the Owner Trustee on a Rent Payment Date (or, in the
circumstance provided in Section 10.1 and the last sentence of Section 10.3 of
the Lease, on the Termination Date) upon at least 25 days' prior notice from the
Owner Trustee (or the Lessee on its behalf) to the Indenture Trustee in the
event that the Lease as applicable to any Unit or Units related to such
Equipment Note is terminated pursuant to Section 10 thereof, at a price equal to
the sum of (i) as to principal thereof, an amount equal to the product obtained
by multiplying the unpaid principal amount of such Equipment Note, as of such
prepayment date (after deducting therefrom the principal installment, if any,
due on or prior to the date of such prepayment), by a fraction, the numerator of
which shall be the Equipment Cost of such Unit or Units and the denominator of
which shall be the aggregate Equipment Cost of all Units included in the
Indenture Estate under the Indenture Supplement immediately prior to the date of
such prepayment, (ii) as to interest, the aggregate amount of interest accrued
and unpaid in respect of the principal amount to be prepaid pursuant to clause
(i) above on the date of such payment (after giving effect to the application of
any Basic Rent paid on or prior to the date of such prepayment) and (iii) the
Make-Whole Amount, if any, applicable in respect of the principal amount to be
prepaid pursuant to clause (i) above on the date of such prepayment.

     (b) Each Equipment Note shall be prepaid in whole or in part by the Owner
Trustee on a Rent Payment Date upon at least 15 days' prior notice from the
Owner Trustee (or the Lessee on its behalf) to the Indenture Trustee in
connection with the occurrence of an Event of Loss with respect to any Unit or
Units related to such Equipment Note if such Unit or Units are not replaced
pursuant to Section 11.2(i) of the Lease, or in the event Lessee shall be
required to settle for 10 or more Units on the date of payment therefor
determined pursuant to Section 11.2 of the Lease, such prepayment shall be made
on such date, at a price equal to the sum of (i) as to principal thereof, an
amount equal to the product obtained by multiplying the aggregate unpaid
principal amount of such Equipment Note, as of such prepayment date (after
deducting therefrom the principal installment, if any, due on such date), by a
fraction, the numerator of which shall be the Equipment Cost of such Unit or
Units and the denominator of which shall be the aggregate Equipment Cost of all
Units

                                      -12-
<PAGE>

included in the Indenture Estate under the Indenture Supplement immediately
prior to such date, and (ii) as to interest, the aggregate amount of interest
accrued and unpaid in respect of the principal amount to be prepaid pursuant to
clause (i) above to but not including the date of prepayment after giving effect
to the application of any Basic Rent paid on or prior to the date of such
prepayment, but without the payment of any Make-Whole Amount.

     (c)  Unless Lessee shall have elected to assume all of the rights and
obligations of the Owner Trustee under this Indenture in respect of the
Equipment Notes, each Equipment Note shall be prepaid in whole by the Owner
Trustee on the Business Day specified by Lessee to Owner Trustee and Indenture
Trustee in accordance with Section 6.9 of the Participation Agreement, in the
event that Lessee exercises the purchase option under Section 6.9 of the
Participation Agreement with respect to the Equipment, at a price equal to the
sum of (i) as to principal thereof, an amount equal to the unpaid principal
amount of such Equipment Note as at the date of any prepayment under Section 6.9
of the Participation Agreement (after deducting therefrom the principal
installment, if any, due on the prepayment date), (ii) as to interest, the
aggregate amount of interest accrued and unpaid in respect of the principal
amount to be prepaid pursuant to clause (i) above on the date of such prepayment
after giving effect to the application of any Basic Rent paid on or prior to the
date of such prepayment, and (iii) the Make-Whole Amount, if any, applicable in
respect of the principal amount to be prepaid pursuant to clause (i) above on
the date of such payment.

     (d)  Unless Lessee shall have elected to assume all of the rights and
obligations of the Owner Trustee under this Indenture in respect of the
Equipment Notes, each Equipment Note shall be prepaid in whole or in part by the
Owner Trustee on the Early Purchase Date in the event that Lessee exercises the
purchase option under Section 22.1 of the Lease with respect to the Equipment,
at a price equal to the sum of (i) as to principal thereof, an amount equal to
the product obtained by multiplying the aggregate unpaid principal amount of
such Equipment Note allocable to the Equipment Group of which such Units are a
part, as of the Early Purchase Date (after deducting therefrom the principal
installment, if any, due on the prepayment date), by a fraction, the numerator
of which shall be the Equipment Cost of such Unit or Units to be purchased and
the denominator of which shall be the aggregate Equipment Cost of all Units in
such Equipment Group included in the Indenture Estate immediately prior to the
date of such prepayment, (ii) as to interest, the aggregate amount of interest
accrued and unpaid in respect of the principal amount to be prepaid pursuant to
clause (i) above on the date of such prepayment after giving effect to the
application of any Basic Rent paid on or prior to the date of such prepayment,
and (iii) the Make-Whole Amount, if any, applicable in respect of the principal
amount to be prepaid pursuant to clause (i) above on the date of such payment.

     (e)  Each Equipment Note shall be prepaid in whole but not in part on the
Refunding Date specified by the Lessee to the Owner Trustee and to the Indenture
Trustee in accordance with Sections 10.2(a) and (f) of the Participation
Agreement, in the event of a refunding or refinancing pursuant to Section 10.2
of the Participation Agreement, at a price in addition to any other amounts

                                      -13-
<PAGE>

due to the holders of the Equipment Notes under this Indenture equal to the
unpaid principal amount thereof together with accrued but unpaid interest
thereon, plus the Make-Whole Amount, if any.

     (f)  The Indenture Trustee shall give prompt notice of any prepayment of
any of the Equipment Notes to all holders of the Equipment Notes as soon as the
Indenture Trustee shall have knowledge that such prepayment is to occur, which
notice shall specify the Equipment Note or Notes to be prepaid, the principal
amount of such Equipment Note or Notes to be prepaid and the date of prepayment;
provided that any notice of prepayment given pursuant to Section 2.10(a),
2.10(c), 2.10(d) or 2.10(e) shall be revocable and shall be deemed revoked in
the event that (x) the Lease does not terminate or the Lessee does not pay all
amounts then due to the Lessor under the Operative Documents, in the case of any
notice of prepayment given to Section 2.10(a), 2.10(c) or 2.10(d) or (y) the
subject refinancing does not in fact occur in the case of any notice of
prepayment given pursuant to Section 2.10(e).

     Section 2.11.  Equally and Ratably Secured.  All Equipment Notes at any
time outstanding under this Indenture shall be equally and ratably secured
hereby without preference, priority or distinction on account of the date or
dates or the actual time or times of the issue or maturity of such Equipment
Notes so that all Equipment Notes at any time issued and outstanding hereunder
shall have the same rights, Liens and preferences under and by virtue of this
Indenture.

                                 Article III.
                RECEIPT, DISTRIBUTION AND APPLICATION OF INCOME
                           FROM THE INDENTURE ESTATE

     Section 3.01.  Basic Rent Distribution.  Except as otherwise provided in
Section 3.03, each installment of Basic Rent as well as any installment of
interest on overdue installments of Basic Rent, and any other moneys paid over
by the Lessee or the Owner Trustee to the Indenture Trustee for such purpose,
shall be distributed by the Indenture Trustee as promptly as possible (it being
understood that any payments of Basic Rent received by the Indenture Trustee by
11:00 a.m. Eastern time on the date due and in accordance with the provisions of
Section 3.6 of the Lease shall be distributed no later than 12:00 p.m. on the
date received in the funds so received, and that funds received after 11:00 a.m.
Eastern time will be deemed to be late and will be distributed on the next
business day together with interest at the overdue rate) in the following order
of priority: first, so much of such installment as shall be required for the
             -----
purpose shall be distributed and paid to the holders of the Equipment Notes to
pay in full the aggregate amount of the payment or payments of principal, Make-
Whole Amount, if any, and interest (as well as any interest on overdue principal
or interest) then due, such distribution to be made ratably, without priority of
one over the other, in the proportion that the amount of such payment or
payments then due with respect to each such Equipment Note bears to the
aggregate amount of payments then due under all such Equipment Notes; and
second, the balance, if any, of such installment remaining thereafter shall be
------
distributed to the Owner Trustee for distribution in accordance with the terms
of the Trust Agreement.  The

                                      -14-
<PAGE>

portion of each such installment distributed to a holder of an Equipment Note
shall be applied by such holder in payment of such Equipment Note in accordance
with the terms of Section 2.05.

     Section 3.02.  Payments in the Event of Prepayment.  (a)  Except as
otherwise provided in Section 3.03 or 3.05, in the event of any prepayment of an
Equipment Note or Notes, in whole or in part, in accordance with the provisions
of Section 2.10 any amount received by the Indenture Trustee shall in each case
be distributed and paid by the Indenture Trustee as promptly as possible in the
following order of priority: first, so much of such amount as shall be required
                             -----
for the purpose of prepayment shall be distributed and paid to the holders of
such Equipment Note or Notes to pay the aggregate amount of the payment of
principal, Make-Whole Amount, if any, and interest to be prepaid on such
Equipment Note or Notes pursuant to Section 2.10, such prepayment to be made
ratably to such Equipment Note or Notes to which such prepayment relates,
without priority of one over any other, in the proportion that the amount to be
prepaid on each such Equipment Note bears to the aggregate amount to be paid on
all such Equipment Notes; and second, the balance, if any, of such amount
                              ------
remaining thereafter shall be distributed to the Owner Trustee for distribution
in accordance with the terms of the Trust Agreement.

     (b)  Except as otherwise provided in Section 3.03 or 3.05 hereof, any
amounts received  by the Indenture Trustee directly or through the Lessee from
any governmental authority or other party pursuant to Section 11 of the Lease
with respect to any Unit as the result of an Event of Loss, to the extent that
such amounts are not at the time required to be paid to the Lessee pursuant to
said Section 11, and any amounts of insurance proceeds for damage to the
Indenture Estate received directly or though the Lessee from any insurer
pursuant to Section 12 of the Lease with respect thereto as the result of an
Event of Loss, to the extent such amounts are not at the time required to be
paid to the Lessee pursuant to said Section 12, shall be applied by the
Indenture Trustee as provided in clause (a) of this Section 3.02.

     Section 3.03.  Payments after Indenture Event of Default.  (a)  Except as
provided in Section 3.05, all payments received and amounts realized by the
Indenture Trustee from any source after an Indenture Event of Default shall have
occurred and be continuing and after the Indenture Trustee has declared (as
assignee from the Owner Trustee of the Lease) the Lease to be in default
pursuant to Section 15 thereof or has declared the Equipment Notes to be
accelerated pursuant to Section 5.02, as the case may be, or has elected to
foreclose or otherwise exercise any remedies under this Indenture (including any
amounts realized by the Indenture Trustee from the exercise of any remedies
pursuant to Section 15 of the Lease, or Article V), as well as all payments or
amounts then held or thereafter received by the Indenture Trustee as part of the
Indenture Estate while such Indenture Event of Default shall be continuing,
shall be distributed forthwith by the Indenture Trustee in the following order
of priority:

          First, so much of such payments or amounts as shall be required to
     reimburse the Indenture Trustee for any fees which are due and payable for
     its services under this Indenture and any tax, expense (including
     reasonable attorney's fees) or other loss incurred by the

                                      -15-
<PAGE>

     Indenture Trustee (to the extent reimbursable and not previously reimbursed
     and to the extent incurred in connection with its duties as Indenture
     Trustee) shall be distributed to the Indenture Trustee;

          Second, so much of such payments or amounts as shall be required to
     reimburse the holders of the Equipment Notes for payments made by them to
     the Indenture Trustee pursuant to Section 6.03 (to the extent not
     previously reimbursed), and to pay such holders of the Equipment Notes the
     amounts payable to them pursuant to the provisions of the Participation
     Agreement, shall be distributed to such holders of the Equipment Notes,
     without priority of one over the other, in accordance with the amount of
     the payment or payments made by, or payable to, each such holder;

          Third, so much of such payments or amounts remaining as shall be
     required to pay the principal of, accrued interest, including interest at
     the overdue rate (to the date of distribution) on all Equipment Notes, and
     Make-Whole Amount, if any (but only to the extent received from the Lessee
     as Supplemental Rent) in each case as is then due and payable to the
     holders of the Equipment Notes, whether by declaration of acceleration
     pursuant to Section 5.02 or otherwise, and in case the aggregate amount so
     to be distributed shall be insufficient to pay in full the aforesaid
     amounts, then, ratably, without priority of one over the other, in the
     proportion that the aggregate unpaid principal amount of, and Make-Whole
     Amount, if any, on, all Equipment Notes held by each such holder, plus the
     accrued but unpaid interest thereon to the date of distribution, bears to
     the aggregate unpaid principal amount of all Equipment Notes, plus the
     accrued but unpaid interest thereon to the date of distribution; and

          Fourth, the balance, if any, of such payments or amounts remaining
     thereafter shall be distributed to the Owner Trustee for distribution in
     accordance with the terms of the Trust Agreement.

     (b)  Except as provided in Sections 3.03(a) and 3.05, if an Indenture
Default or Indenture Event of Default shall have occurred and be continuing, the
Indenture Trustee shall not make any distribution to the Owner Trustee but shall
hold amounts otherwise distributable to the Owner Trustee as collateral security
for the obligations secured hereby and invested as provided in Section 7.04(b)
until the earliest to occur of (a) the date on which such Indenture Default or
Indenture Event of Default shall have been cured or waived and (b) the Indenture
Trustee shall have declared the unpaid principal amount of all Equipment Notes
then outstanding to be due and payable pursuant to Section 5.02 hereof and such
amounts are applied pursuant to Section 3.03(a); provided, that if any amounts
are held pursuant to this Section 3.03(b) for a period of 180 days during which
time the Equipment Notes could, but shall not have been, accelerated, then all
amounts then held by the  Indenture Trustee under this Section 3.03(b) with
respect to such Indenture Default or Indenture Event of Default shall on the
181/st/ day be distributed to the Owner Trustee for distribution in accordance
with the terms of the Trust Agreement.

                                      -16-
<PAGE>

     Section 3.04.  Other Payments.  Except as otherwise provided in Section
3.03 or 3.05, (a) any payments received by the Indenture Trustee for which no
provision as to the application thereof is made in the Lease or the
Participation Agreement or elsewhere in this Article III, and (b) all payments
received and amounts realized by the Indenture Trustee under the Lease or
otherwise with respect to the Equipment to the extent received or realized at
any time after payment in full of the principal of and interest and Make-Whole
Amount, if any, on all Equipment Notes, as well as any other amounts remaining
as part of the Indenture Estate after payment in full of the principal of and
interest and Make-Whole Amount, if any, and all other amounts due to the holders
of Equipment Notes under the Operative Documents, shall be distributed forthwith
by the Indenture Trustee in the order of priority set forth in Section 3.03(a),
except that in the case of any payment described in clause (b) above, such
payment shall be distributed omitting clause "third" of such Section 3.03(a) on
all Equipment Notes issued hereunder.

     Any payments received by the Indenture Trustee for which provision as to
the application thereof is made in the Lease or the Participation Agreement but
not elsewhere in this Indenture shall be applied to the purposes for which such
payments were made in accordance with the provisions of the Lease or the
Participation Agreement, as the case may be.

     Section 3.05.  Distribution of Excepted Property.  All amounts constituting
Excepted Property received by the Indenture Trustee shall be paid promptly by
the Indenture Trustee to the Person or Persons entitled thereto.

                                  Article IV.
             ASSUMPTION OF OBLIGATIONS OF OWNER TRUSTEE BY LESSEE

     Section 4.01.  Assumption of Obligations of Owner Trustee by Lessee.   In
the event that the Lessee shall have elected to assume all of the rights and
obligations of the Owner Trustee under this Indenture in respect of the
Equipment Notes in connection with the purchase by Lessee of Equipment pursuant
to Section 6.9 of the Participation Agreement or Section 22.1 of the Lease and,
if on or prior to the purchase date:

     (a)  Lessee shall have delivered to the Indenture Trustee a certificate,
dated the date of such purchase, of a Responsible Officer stating that Lessee
has paid to the Owner Trustee all amounts required to be paid to the Owner
Trustee pursuant to Section 3.3 of the Lease in connection with such purchase
and assumption;

     (b)  no event which constitutes or, with the lapse of time or notice, or
both, would become, an Event of Default under this Agreement after giving effect
to the indenture supplement referred to below shall have occurred and be
continuing immediately subsequent to such purchase

                                      -17-
<PAGE>

or assumption and the Indenture Trustee shall have received a certificate, dated
the date of such purchase, of a Responsible Officer of the Lessee to such
effect;

     (c)  the Indenture Trustee shall have received, on or prior to the date of
such purchase, evidence of all filings, recordings and other action referred to
in the Opinion or Opinions of Counsel referred to below;

     (d)  the Indenture Trustee shall have received an Opinion or Opinions of
Counsel for Lessee, dated the date of such purchase which without unusual
qualification shall be to the effect that, after giving effect to the indenture
supplement referred to below:

          (i)  this Indenture constitutes the legal, valid and binding
     obligation of Lessee, enforceable against Lessee in accordance with its
     terms, except as the same may be limited by applicable bankruptcy,
     insolvency, reorganization, moratorium or similar laws affecting the rights
     of creditors generally and by general principles of equity, and except as
     limited by applicable laws which may affect the remedies provided for in
     this Indenture, which laws, however, do not in the opinion of such counsel
     make the remedies provided for in this Agreement inadequate for the
     practical realization of the rights and benefits provided for in this
     Indenture; and

          (ii) the Lien on the Equipment constitutes a fully-perfected Lien and
     all filing, recording or other action (specifying the same) necessary to
     perfect and protect the Lien of this Agreement has been accomplished.

     (e)  upon delivery of an indenture supplement giving effect to such
assumption reasonably satisfactory to the Indenture Trustee, dated the date of
such purchase;

then, automatically and without the requirement of further action by any Person,
effective as of the date of such purchase, the Owner Trustee shall be released
from all of its obligations under the Equipment Notes and under this Indenture
in respect of the Equipment Notes or otherwise (other than any obligations or
liabilities of the Owner Trustee in its individual capacity incurred on or prior
to the date of such purchase or arising out of or based upon events occurring on
or prior to the date of such purchase, which obligations and liabilities shall
remain the sole responsibility of the Owner Trustee) and the Lien of this
Indenture upon the sale proceeds paid or payable to the Owner Trustee shall be
discharged.  If requested by the Owner Trustee, the Indenture Trustee shall
execute and deliver an instrument, in form and substance satisfactory to the
Owner Trustee, confirming such release and discharge.

                                      -18-
<PAGE>

                                  Article V.
              REMEDIES OF THE INDENTURE TRUSTEE UPON AN INDENTURE
                               EVENT OF DEFAULT

     Section 5.01.  Indenture Events of Default.  The following events shall
constitute "Indenture Events of Default" and each such Indenture Event of
Default shall be deemed to exist and continue so long as, but only so long as,
it shall not have been remedied:

     (a)  subject to Section 5.04(a), a Lease Event of Default (other than a
Lease Event of Default by reason of a default by the Lessee to pay any amounts
which are part of the Excepted Property); or

     (b)  default by the Owner Trustee in making any payment when due of
principal of, Make-Whole Amount, if any, or interest on, the Equipment Notes or
any Equipment Note or Equipment Notes, and the continuance of such default
unremedied for 10 Business Days after the same shall have become due and
payable; or

     (c)  any failure by the Owner Trustee or the Owner Participant to observe
or perform in any material respect any covenant or obligation of them or any of
them, in this Indenture or the Equipment Notes (other than as set forth in
clause (b) above) or in the Participation Agreement, if such failure is not
remedied within a period of 30 days after there has been given to the Owner
Trustee, the Owner Participant and the Lessee by the Indenture Trustee or by any
holder of an Equipment Note a written notice specifying such failure and
requiring it to be remedied; or

     (d)  any representation or warranty made by the Owner Trustee (except to
the extent made with respect to Norwest Bank Minnesota, National Association in
its individual capacity) or the Owner Participant under the Participation
Agreement, or by the Owner Trustee hereunder, or by any representative of the
Owner Trustee or the Owner Participant in any document or certificate furnished
to the Indenture Trustee or the holders of Equipment Notes in connection
herewith or therewith or pursuant hereto or thereto, shall prove at any time to
have been incorrect in any material respect as of the date made and, if capable
of cure, such incorrectness shall remain material and continue unremedied for a
period of 30 days after there has been given to the Owner Trustee and the Owner
Participant a written notice specifying such incorrectness, stating that such
incorrectness is a default hereunder and requiring it to be remedied by the
Indenture Trustee or by any holder of an Equipment Note; or

     (e)  the Owner Trustee (as Owner Trustee and not in its individual
capacity) or the Owner Participant shall consent to the appointment of a
custodian, receiver, trustee or liquidator of itself or of a substantial part of
its property or shall make a general assignment for the benefit of creditors; or

                                      -19-
<PAGE>

     (f)  the Owner Trustee (as Owner Trustee and not in its individual
capacity) or the Owner Participant shall file, or consent by answer or otherwise
to the filing against it of, a petition for relief or reorganization or
arrangement or any other petition in bankruptcy, for liquidation or to take
advantage of any bankruptcy or insolvency law of any jurisdiction; or

     (g)  an order, judgment or decree shall be entered by any court of
competent jurisdiction appointing, without the consent of the Owner Trustee (as
Owner Trustee and not in its individual capacity) or the Owner Participant, a
receiver, trustee or liquidator of the Indenture Estate, the Owner Trustee (as
Owner Trustee and not in its individual capacity) or the Owner Participant, or
of any substantial part of its property, or granting any order for relief in
respect of the Owner Trustee (as Owner Trustee and not in its individual
capacity) or the Owner Participant under the Federal bankruptcy laws, and any
such order, judgment or decree of appointment shall remain in force undismissed,
unstayed or unvacated for a period of 60 days after the date of entry thereof;
or

     (h)  a petition against the Owner Trustee (as Owner Trustee and not in its
individual capacity) or the Owner Participant, in a proceeding under the Federal
bankruptcy laws or other insolvency law, as now or hereafter in effect, shall be
filed and shall not be withdrawn or dismissed within 60 days thereafter, or if,
under the provisions of any law providing for reorganization or winding-up of
corporations which may apply to the Owner Trustee (as Owner Trustee and not in
its individual capacity) or the Owner Participant, any court of competent
jurisdiction shall assume jurisdiction, custody or control of the Indenture
Estate, the Owner Trustee (as Owner Trustee and not in its individual capacity)
or the Owner Participant or of any substantial part of its property and such
jurisdiction, custody or control shall remain in force unrelinquished, unstayed
or unterminated for a period of 60 days; or

Notwithstanding any provision herein to the contrary, if an Indenture Event of
Default described in clause (e), (f), (g) or (h) of this Section 5.01 results
solely from the bankruptcy, reorganization, compromise, arrangement, insolvency,
readjustment of debt, dissolution or liquidation of Owner Trustee solely in its
individual capacity, and can be cured by the appointment of a substitute Owner
Trustee without adversely affecting the rights of the Indenture Trustee
hereunder, then Indenture Trustee shall refrain from the exercise of any of the
rights, powers or remedies pursuant to this Article V for a period of 45 days
from the date of the filing or entry of the first applicable document or
pleading, provided Owner Participant is diligently seeking to, and does, replace
the bank or trust company then serving as Owner Trustee which replacement shall
be deemed to cure such Indenture Event of Default.

     Section 5.02.  Acceleration; Rescission and Annulment.  If an Indenture
Event of Default occurs and is continuing, the Indenture Trustee may, and upon
the written directions of a Majority in Interest shall, subject to Section 5.04,
declare the unpaid principal amount of all Equipment Notes then outstanding and
accrued interest thereon to be due and payable, but without any Make-Whole
Amount.  At any time after the Indenture Trustee has declared the unpaid
principal amount of all Equipment Notes then outstanding to be due and payable
and prior to the sale of any of the Indenture

                                      -20-
<PAGE>

Estate pursuant to this Article V, a Majority in Interest, by written notice to
the Owner Trustee, the Lessee and the Indenture Trustee, may rescind and annul
such declaration and thereby annul its consequences if: (i) there has been paid
to or deposited with the Indenture Trustee an amount sufficient to pay all
overdue installments of interest on all of the Equipment Notes, and the
principal of and Make-Whole Amount, if any, on any Equipment Notes that have
become due otherwise than by such declaration of acceleration, (ii) the
rescission would not conflict with any judgment or decree, and (iii) all other
Indenture Defaults and Indenture Events of Default, other than nonpayment of
principal or interest on any of the Equipment Notes that have become due solely
because of such acceleration, have been cured or waived.

     Section 5.03.  Remedies with Respect to Indenture Estate.  (a)  After an
Indenture Event of Default shall have occurred and so long as such Indenture
Event of Default shall be continuing, then and in every such case the Indenture
Trustee, as assignee hereunder of the Lease or as mortgagee hereunder of the
Equipment or otherwise, may, and when required pursuant to the provisions of
Article VI hereof shall, subject to Sections 5.04 and 5.05, exercise any or all
of the rights and powers and pursue any and all of the remedies pursuant to
Section 15 of the Lease and this Article V and may recover judgment in its own
name as Indenture Trustee against the Indenture Estate and may take possession
of all or any part of the Indenture Estate, and may exclude the Owner Trustee
and the Owner Participant and all persons claiming under any of them wholly or
partly therefrom; provided, however, that nothing in this Indenture shall permit
or require the Indenture Trustee to take any action contrary to, or to disturb,
the Lessee's rights under the Lease, except in accordance with the provisions of
the Lease.  The Indenture Trustee, after the occurrence of any Indenture Event
of Default, shall give the Owner Participant and the Owner Trustee 5 Business
Days' (or such shorter period as practical) prior notice of the date before
which the Indenture Trustee shall not exercise any remedy which would result in
the exclusion of the Owner Trustee from the Indenture Estate or any part
thereof; provided, that the failure to give such notice shall have no effect on
any action taken by the Indenture Trustee.

     (b)  Subject to Section 5.04 and Section 5.05, the Indenture Trustee may,
if at the time such action may be lawful and always subject to compliance with
any mandatory legal requirements, either with or without taking possession, and
either before or after taking possession, and without instituting any legal
proceedings whatsoever, and having first given notice of such sale by registered
mail to the Owner Trustee, the Owner Participant and the Lessee once at least 20
days prior to the date of such sale or the date on which the Indenture Trustee
enters into a binding contract for a private sale, and any other notice which
may be required by law, sell and dispose of the Indenture Estate, or any part
thereof, or interest therein, at public auction to the highest bidder or at
private sale in one lot as an entirety or in separate lots, and either for cash
or on credit and on such terms as the Indenture Trustee may determine, and at
any place (whether or not it be the location of the Indenture Estate or any part
thereof) and time designated in the notice above referred to; provided, however,
that, notwithstanding any provision herein to the contrary, the Indenture
Trustee shall not sell any of the Indenture Estate or exercise any other
remedies which would result in the exclusion of the Owner Trustee from the
Indenture Estate or any part thereof unless a declaration of acceleration has

                                      -21-
<PAGE>

been made pursuant to Section 5.02; provided, further, that, in the event the
circumstances contemplated by Section 5.04(c) exist, the Indenture Trustee shall
not be allowed to deliver the notice required by this Section 5.03(b) until the
earlier of (x) such time as such circumstances no longer exist or (y) the
expiration of the 90 day period set forth in Section 5.04(c).  Any such public
sale or sales may be adjourned from time to time by announcement at the time and
place appointed for such sale or sales, or for any such adjourned sale or sales,
without further notice, and the Indenture Trustee or the holder or holders of
any Equipment Notes, or any interest therein, may bid and become the purchaser
at any such public sale.  The Indenture Trustee may exercise such right without
possession or production of the Equipment Notes or proof of ownership thereof,
and as representative of the holders may exercise such right without including
the holders as parties to any suit or proceeding relating to foreclosure of any
property in the Indenture Estate.  The Owner Trustee hereby irrevocably
constitutes the Indenture Trustee the true and lawful attorney-in-fact of the
Owner Trustee (in the name of the Owner Trustee or otherwise) for the purpose of
effectuating any sale, assignment, transfer or delivery for enforcement of the
Lien of this Indenture, whether pursuant to foreclosure or power of sale or
otherwise, to execute and deliver all such bills of sale, assignments and other
instruments as the Indenture Trustee may consider necessary or appropriate, with
full power of substitution, the Owner Trustee hereby ratifying and confirming
all that such attorney or any substitute shall lawfully do by virtue hereof.
Nevertheless, if so requested by the Indenture Trustee or any purchaser, the
Owner Trustee shall ratify and confirm any such sale, assignment, transfer or
delivery, by executing and delivering to the Indenture Trustee or such purchaser
all bills of sale, assignments, releases and other proper instruments to effect
such ratification and confirmation as may be designated in any such request.

     (c)  Subject to Section 5.04 and Section 5.05, the Owner Trustee agrees, to
the fullest extent that it lawfully may, that, in case one or more of the
Indenture Events of Default shall have occurred and be continuing, then, in
every such case, the Indenture Trustee may take possession of all or any part of
the Indenture Estate and may exclude the Owner Trustee and the Owner Participant
and all persons claiming under any of them wholly or partly therefrom.  At the
request of the Indenture Trustee, the Owner Trustee shall promptly execute and
deliver to the Indenture Trustee such instruments of title and other documents
as the Indenture Trustee may deem necessary or advisable to enable the Indenture
Trustee or an agent or representative designated by the Indenture Trustee, at
such time or times and place or places as the Indenture Trustee may specify, to
obtain possession of all or any part of the Indenture Estate.  If the Owner
Trustee shall fail for any reason to execute and deliver such instruments and
documents to the Indenture Trustee, the Indenture Trustee may pursue all or part
of the Indenture Estate wherever it may be found and may enter any of the
premises of the Lessee wherever the Indenture Estate may be or be supposed to be
and search for the Indenture Estate and, subject to Section 5.05, take
possession of and remove the Indenture Estate.  Upon every such taking of
possession, the Indenture Trustee may, from time to time, at the expense of the
Indenture Estate, make all such expenditures for maintenance, insurance,
repairs, replacements, alterations, additions and improvements to any of the
Indenture Estate, as it may deem proper.  In each such case, the Indenture
Trustee shall have the right to use, operate, store, control or manage the
Indenture Estate, and to carry on the business and to exercise all rights and
powers

                                      -22-
<PAGE>

of the Owner Trustee relating to the Indenture Estate, as the Indenture Trustee
shall deem best, including the right to enter into any and all such agreements
with respect to the maintenance, operation, leasing or storage of the Indenture
Estate or any part thereof as the Indenture Trustee may determine; and the
Indenture Trustee shall be entitled to collect and receive all tolls, rents,
revenues, issues, income, products and profits of the Indenture Estate and every
part thereof, without prejudice, however, to the right of the Indenture Trustee
under any provision of this Indenture to collect and receive all cash held by,
or required to be deposited with, the Indenture Trustee hereunder. Such tolls,
rents, revenues, issues, income, products and profits shall be applied to pay
the expenses of holding and operating the Indenture Estate and of conducting the
business thereof, and of all maintenance, repairs, replacements, alterations,
additions and improvements, and to make all payments which the Indenture Trustee
may be required or may elect to make, if any, for taxes, assessments, insurance
or other proper charges upon the Indenture Estate or any part thereof (including
the employment of engineers and accountants to examine, inspect and make reports
upon the properties and books and records of the Indenture Estate), and all
other payments which the Indenture Trustee may be required or authorized to make
under any provision of this Indenture, as well as just and reasonable
compensation for the services of the Indenture Trustee, and of all persons
properly engaged and employed by the Indenture Trustee, including the reasonable
expenses of the Indenture Trustee.

     (d)  If an Indenture Event of Default occurs and is continuing and the
Indenture Trustee shall have obtained possession of a Unit, the Indenture
Trustee shall not be obligated to use or operate such Unit or cause such Unit to
be used or operated directly or indirectly by itself or through agents or other
representatives or to lease, license or otherwise permit or provide for the use
or operation of such Unit or Equipment by any other Person unless (i) the
Indenture Trustee shall have been able to obtain insurance in kinds, at rates
and in amounts satisfactory to it in its reasonable discretion to protect the
Indenture Estate and the Indenture Trustee, as trustee and individually, against
any and all liability for loss or damage to such Unit and for public liability
and property damage resulting from use or operation of such Unit and (ii) funds
are available in the Indenture Estate to pay for all such insurance or, in lieu
of such insurance, the Indenture Trustee is furnished with indemnification from
the holders of the Equipment Notes or any other Person upon terms and in amounts
satisfactory to the Indenture Trustee in its reasonable discretion to protect
the Indenture Estate and the Indenture Trustee, as trustee and individually,
against any and all such liabilities.

     Section 5.04.  Right to Cure; Option to Purchase; Etc.

     (a)  Right to Cure.  (A)  If there shall occur a Lease Event of Default in
respect of the payment of Basic Rent pursuant to Section 14(a) of the Lease,
then as long as no other Indenture Event of Default (other than arising from
such failure to pay Basic Rent or which is concurrently being cured pursuant to
this Section 5.04(a)) shall have occurred and be continuing the Owner
Participant or the Owner Trustee may (but need not) pay to the Indenture
Trustee, at any time prior to the expiration of a period of 10 Business Days (a
"10-Day Period") after receiving written notice of such default from the
Indenture Trustee (prior to the expiration of which 10-Day Period the

                                      -23-
<PAGE>

Indenture Trustee shall not declare the Lease in default pursuant to Section 15
thereof or exercise any of the rights, powers or remedies pursuant to such
Section 15 or this Article V), an amount equal to the full amount of such
payment of Basic Rent, together with any interest due thereon on account of the
delayed payment thereof, and such payment by the Owner Participant or the Owner
Trustee shall be deemed to cure any Indenture Event of Default which arose from
such failure of the Lessee (but such cure shall not relieve the Lessee of any of
its obligations and shall not cure any other Indenture Event of Default) or (B)
if there shall occur a Lease Event of Default in respect of any other payment of
Rent (other than Basic Rent) or a Lease Event of Default shall have occurred and
be continuing, which Lease Event of Default is curable by the payment of money
(it being understood that actions such as the obtaining of insurance or the
procuring of maintenance services can be so effected), then as long as no other
Indenture Event of Default (other than arising from such Lease Event of Default
or which is concurrently being cured pursuant to this Section 5.04(a)) shall
have occurred and be continuing the Owner Participant or the Owner Trustee may
(but need not) pay to the Indenture Trustee, at any time prior to the expiration
of a period of 30 days (a "30-Day Period") after receiving written notice of
such Lease Event of Default from the Indenture Trustee (prior to the expiration
of which 30-Day Period the Indenture Trustee shall not declare the Lease in
default pursuant to Section 15 thereof or exercise any of the rights, powers or
remedies pursuant to such Section 15 or this Article V), an amount equal to the
full amount of such payment of Rent, together with any interest due thereon on
account of the delayed payment thereof or otherwise make such payment as shall
effect such cure, and such payment by the Owner Participant or the Owner Trustee
shall be deemed to cure any Indenture Event of Default which arose from such
Lease Event of Default (but such cure shall not relieve the Lessee of any of its
obligations); provided however, Owner Participant and Owner Trustee,
collectively, shall not be entitled to (x) cure more than three consecutive or
six total defaults in the payment of Basic Rent, or (y) cure other Lease Events
of Default if the outstanding amount which has been paid by the Owner
Participant or the Owner Trustee and not reimbursed to such parties by the
Lessee pursuant to this clause (y) exceeds in the aggregate $2,500,000, as
adjusted annually for inflation as of January 1 of each calendar year, by the
percentage change in the Consumer Price Index, All Urban Consumers, All Cities,
as compared to the prior calendar year as published by the Bureau of Labor
Statistics of the United States Department of Labor. Upon any cure by the Owner
Participant or the Owner Trustee in accordance with the first sentence of this
Section 5.04(a), the Owner Participant or the Owner Trustee shall, to the extent
of their respective payments, be subrogated to the rights of the Indenture
Trustee, as assignee hereunder of the Owner Trustee to receive such payment of
Rent (and any interest due thereon on account of the delayed payment thereof) or
right of reimbursement, and shall be entitled to receive such payment upon its
receipt by the Indenture Trustee as aforesaid (but in each case only if all
amounts of principal and interest at the time due and payable on the Equipment
Notes shall have been paid in full); provided that neither the Owner Participant
nor the Owner Trustee shall attempt to recover any such amount paid by it on
behalf of the Lessee pursuant to this Section 5.04(a) except by demanding of the
Lessee payment of such amount or by commencing an action against the Lessee to
require the payment of such amount.

                                      -24-
<PAGE>

     (b)  Option to Purchase Equipment Notes.  In the event that (i) at any time
one or more Lease Events of Default shall have occurred and any such Lease Event
of Default shall have continued for a period of 180 days or more during which
time the Equipment Notes could, but shall not, have been accelerated pursuant to
Section 5.02, (ii) the Equipment Notes shall have been accelerated pursuant to
Section 5.02, (iii) the Indenture Trustee, as assignee hereunder of the Lease,
shall have exercised (or given notice of its intention to exercise) any remedy
in respect of the Units under the Lease, or (iv) the Indenture Trustee shall
commence foreclosure of the Lien of this Indenture or otherwise exercise
remedies which would result in the exclusion of the Owner Trustee from the
Indenture Estate or any part thereof (or give notice of its intention to
foreclose or exercise remedies), then and in any such case, so long as the
Lessee and its Affiliates do not individually or in the aggregate own more than
20% of the Beneficial Interest, upon 30 days' notice from the Owner Trustee to
the Indenture Trustee designating a date of purchase (the "Purchase Date") which
shall be the fifteenth day of any month, each holder of an Equipment Note agrees
that it will, upon and subject to receipt by the Indenture Trustee from the
Owner Trustee or its nominee of an amount equal to the aggregate unpaid
principal amount of all Equipment Notes, together with accrued interest thereon
to the Purchase Date, plus all other sums then due and payable to such holder of
an Equipment Note hereunder, but, except in the case of purchase of the
Equipment Notes pursuant to clause (iv) above if the right to exercise any
remedies arises because of an Indenture Event of Default arising from action
attributable to the Owner Trustee or the Owner Participant, without any Make-
Whole Amount, forthwith sell, assign, transfer and convey to the Owner Trustee
or its nominee on the Purchase Date all of the right, title and interest of such
holder in and to the Equipment Notes then held by such holder, and the Owner
Trustee or its nominee shall assume all of such holder's obligations under the
Participation Agreement; provided that the Owner Trustee or its nominee must
purchase all and not less than all of the Equipment Notes then outstanding.

     (c)  Restrictions on Certain Actions. Notwithstanding any provision of this
Indenture to the contrary, the Indenture Trustee shall not foreclose the Lien of
this Indenture or otherwise exercise remedies hereunder which would result in
the exclusion of the Owner Trustee from the Indenture Estate or any part thereof
as a result of an Indenture Event of Default that constitutes or occurs solely
by virtue of one or more Lease Events of Default (at a time when no other
Indenture Event of Default unrelated to any Lease Event of Default shall have
occurred and be continuing) unless the Indenture Trustee as security assignee of
the Owner Trustee has proceeded or is then currently proceeding, to the extent
it is then entitled to do so hereunder and under the Lease and is not then
stayed or otherwise prevented from doing so by operation of law, to exercise one
(or more, as it shall in its good faith discretion determine) of the comparable
remedies provided for in Section 15 of the Lease with respect to the Equipment,
provided that in the event the Indenture Trustee shall be so stayed or otherwise
prevented from exercising such remedies under the Lease, it shall in any event
refrain from so foreclosing or exercising such other remedies hereunder for a
period of not less than 90 days from the date such stay first went into effect,
and further provided that in the event the Lessee as debtor in a proceeding
under Chapter 11 of the Bankruptcy Code (or any trustee appointed for the Lessee
as debtor in any such bankruptcy case) shall have affirmed the Lease and no
Lease Event of Default other than as specified in Section 14(g) or Section 14(h)
of the Lease has occurred

                                      -25-
<PAGE>

and is continuing, with the approval of the bankruptcy court having jurisdiction
over such case, under Section 365 of the Bankruptcy Code or any amended or
successor version thereof, the Indenture Trustee shall refrain from so
foreclosing or exercising such other remedies hereunder.

     Section 5.05.  Rights of Lessee.  Notwithstanding the provisions of this
Indenture, including, without limitation, Section 5.03, so long as no Lease
Event of Default shall have occurred and be continuing, neither the Indenture
Trustee nor the Owner Trustee shall take any action contrary to, or disturb, the
Lessee's rights under the Lease, except in accordance with the provisions of the
Lease, including, without limitation, (i) the right to receive all monies due
and payable to it in accordance with the provisions of the Lease and (ii) the
Lessee's rights to possession and use of, and of quiet enjoyment of, the
Equipment.

     Section 5.06.  Waiver of Existing Defaults.  A Majority in Interest by
notice to the Indenture Trustee on behalf of all holders of the Equipment Notes
may waive any past default hereunder and its consequences, except a default: (i)
in the payment of the principal of, Make-Whole Amount, if any, or interest on
any Equipment Note, or (ii) in respect of a covenant or provision hereof which
under Article X hereof cannot be modified or amended without the consent of the
holder of each Equipment Note affected.  Upon any such waiver, such default
shall cease to exist, and any Indenture Event of Default arising therefrom shall
be deemed to have been cured for every purpose of this Indenture; but no such
waiver shall extend to any subsequent or other default or impair any right
consequent thereon.

                                  Article VI.
                        DUTIES OF THE INDENTURE TRUSTEE

     Section 6.01. Action upon Indenture Event of Default. If any payments of
Basic Rent or payments of the principal or interest or Make-Whole Amount, if
any, on the Equipment Notes due and payable on any Rent Payment Date shall not
have been paid in full on such Rent Payment Date, the Indenture Trustee shall
give telephonic notice within one Business Day (followed by prompt written
notice) to the Owner Trustee, the Owner Participant, the holders of the
Equipment Notes and the Lessee specifying the amount and nature of such
deficiency in payment. In the event a Responsible Officer of the Indenture
Trustee shall have actual knowledge of an Indenture Default, the Indenture
Trustee shall give prompt notice of such Indenture Default to the Lessee, the
Owner Trustee, the Owner Participant and the holders of the Equipment Notes by
facsimile or telephone (to be promptly confirmed in writing). In the event the
Owner Trustee shall have knowledge of an Indenture Default, the Owner Trustee
shall give notice of such Indenture Default in the same manner to the Lessee,
the Indenture Trustee, the Owner Participant and the holders of the Equipment
Notes. Subject to the terms of Section 6.03, the Indenture Trustee shall take
such action, or refrain from taking such action, with respect to such Indenture
Default as the Indenture Trustee shall be instructed in writing by a Majority in
Interest. If the Indenture Trustee shall not have received instructions as above
provided within 20 days after the mailing of notice of such Indenture Event of
Default or such

                                      -26-
<PAGE>

Indenture Default to the holders of the Equipment Notes by the Indenture
Trustee, the Indenture Trustee may, but shall not be obligated to, take such
action, or refrain from taking such action, with respect to such Indenture Event
of Default or Indenture Default as it shall determine to be advisable in the
best interests of the holders of the Equipment Notes. Any provision of this
Section 6.01 to the contrary notwithstanding, the Indenture Trustee shall not
declare the Lease to be in default solely in respect of the Lessee's failure to
make any payment of Basic Rent within 10 Business Days after the same shall have
become due, unless the 10-Day Period within which, pursuant to Section 5.04(a),
the Owner Participant or the Owner Trustee are entitled to cure such failure
shall have expired. For all purposes of this Indenture, in the absence of actual
knowledge, neither the Owner Trustee nor the Indenture Trustee shall be deemed
to have knowledge of an Indenture Event of Default (except, in the case of the
Indenture Trustee, the failure of the Lessee to pay any installment of Basic
Rent that is required to be paid directly to the Indenture Trustee within the 10
Business Days after the same shall become due or the failure of the Lessee to
maintain insurance as required under Section 12 of the Lease if the Indenture
Trustee shall receive written notice thereof from an insurer or insurance
broker) unless notified in writing by the Lessee, the Owner Trustee, one or more
Loan Participant or the Owner Participant; and "actual knowledge" (as used in
the foregoing clause) of the Owner Trustee or the Indenture Trustee shall mean
actual knowledge of an officer in the Corporate Trust Administration of the
Owner Trustee or the Corporate Trust Department of the Indenture Trustee, as the
case may be.

     Section 6.02. Action upon Instructions. Subject to the terms of Sections
6.01 and 6.03, upon the written instructions at any time and from time to time
of a Majority in Interest, the Indenture Trustee shall take such of the
following actions as may be specified in such instructions (subject to the
rights of the other parties thereto, except to the extent assigned hereunder):
(i) subject to and solely to the extent permitted by the terms hereof and of the
Lease, give such notice, direction or consent, or exercise such right, remedy or
power hereunder or under the Lease or in respect of any part or all of the
Indenture Estate or take such other action as shall be specified in such
instructions; and (ii) after an Indenture Event of Default shall have occurred
and so long as such Indenture Event of Default shall be continuing, approve as
satisfactory to it all matters required by the terms of the Lease to be
satisfactory to the Owner Trustee, it being understood that without the written
instructions of a Majority in Interest the Indenture Trustee shall not take any
action described in clauses (i) or (ii) above.

     Upon the expiration or earlier termination of the Lease Term with respect
to any Unit under the Lease and after payment of the portion of the principal
of, together with interest and Make-Whole Amount, if any, on the Equipment Notes
in accordance with the terms of this Indenture, or, if and so long as no
Indenture Event of Default shall have occurred and be continuing, upon the
transfer by the Owner Trustee to the Lessee or its designee of any Unit pursuant
to Section 10 or 11 of the Lease or the retention by the Owner Trustee of any
Unit pursuant to Section 10.3 of the Lease, then the Indenture Trustee shall in
either such case, upon the written request of the Owner Trustee, and receipt by
the Indenture Trustee of funds necessary to prepay the Equipment Notes required
to be prepaid in connection with such purchase, termination, retention or Event
of Loss, execute and

                                      -27-
<PAGE>

deliver to, or as directed in writing by, the Owner Trustee an appropriate
instrument (in due form for recording) furnished by the Owner Trustee or the
Lessee releasing such property from the Lien of this Indenture.

     Section 6.03. Indemnification. (a) The Indenture Trustee shall not be
required to take any action or refrain from taking any action under Section 6.01
(other than the first two sentences thereof) or 6.02 or Article V if it shall
have reasonable grounds for believing that repayment of any funds which may be
expended in taking any action or refraining from taking any action or adequate
indemnification against any risk of loss, cost or liability is not reasonably
assured to it. The Indenture Trustee shall not be required to take any action
under Section 6.01 or 6.02 or Article V, nor shall any other provision of this
Indenture be deemed to impose a duty on the Indenture Trustee to take any
action, if the Indenture Trustee shall have been advised in writing by
independent counsel that such action is contrary to the terms hereof or of the
Lease or the Participation Agreement, or is otherwise contrary to law.

     (b)  Each holder of an Equipment Note may, but shall not be required to,
participate in any indemnification of the Indenture Trustee given pursuant to
paragraph (a) of this Section 6.03. Each holder of an Equipment Note so
participating shall be entitled to reimbursement for such participation in
accordance with Article III.

     Section 6.04. No Duties Except as Specified in Indenture or Instructions.
The Indenture Trustee shall not have any duty or obligation to manage, control,
use, sell, dispose of or otherwise deal with the Equipment or any other part of
the Indenture Estate, or to otherwise take or refrain from taking any action
under, or in connection with, this Indenture, the Lease, or the Participation
Agreement, except as expressly provided by the terms of this Indenture or as
expressly provided in written instructions received pursuant to the terms of
Section 6.01 or 6.02; and no implied duties or obligations shall be read into
this Indenture against the Indenture Trustee. Each of the Owner Trustee (only in
its individual capacity) and the Indenture Trustee nevertheless agrees that it
will, at its own cost and expense, promptly take such action as may be necessary
duly to discharge any liens or encumbrances on any part of the Indenture Estate,
or on any properties of the Owner Trustee assigned, pledged or mortgaged as part
of the Indenture Estate, which result from claims against it in its individual
capacity not related to the ownership of the Equipment (in the case of the Owner
Trustee), administration of the Indenture Estate (in the case of the Indenture
Trustee) or any other transaction under this Indenture or the Trust Agreement or
any document included in the Indenture Estate.

     Section 6.05. No Action Except under Lease, Indenture or Instructions. The
Indenture Trustee agrees that it will not manage, control, use, sell, dispose of
or otherwise deal with the Equipment or other property constituting part of the
Indenture Estate except (i) as required by the terms of the Lease and the
Participation Agreement, (ii) in accordance with the powers granted to, or the
authority conferred upon, the Indenture Trustee pursuant to this Indenture, or
(iii) in

                                      -28-
<PAGE>

accordance with the express terms hereof or with written instructions pursuant
to Section 6.01 or 6.02.

     Section 6.06.  Disposition of Units.  At any time and from time to time
prior to the expiration of the Lease Term, any Unit for which the provisions of
Section 11.4(a) of the Lease has been satisfied may be disposed of in accordance
with the provisions of Section 11.4(a) of the Lease, and the Owner Trustee
shall, from time to time, direct the Indenture Trustee to, provided no Lease
Event of Default shall have occurred and be continuing, execute and deliver to
it, or as directed in writing by the Owner Trustee, an appropriate instrument
furnished by the Owner Trustee or the Lessee releasing such Unit from the Lien
of the Indenture, but only in respect of such Unit.

     Section 6.07.  Indenture Supplements for Replacements.  In the event of a
Replacement Unit being substituted as contemplated by Section 11.2 of the Lease,
the Owner Trustee and the Indenture Trustee agree for the benefit of the holders
of the Equipment Notes and the Lessee, subject to compliance by the Lessee with
its obligations set forth in Section 11 of the Lease, to execute and deliver an
Indenture Supplement substantially in the form of Exhibit A hereto and, provided
no Lease Default shall have occurred and be continuing, execute and deliver to
the Lessee an appropriate instrument releasing the Unit being replaced from the
Lien of the Indenture.

     Section 6.08.  Effect of Replacements.  In the event of the substitution of
a Replacement Unit, all provisions of this Indenture relating to the Unit or
Units being replaced shall be applicable to such Replacement Unit with the same
force and effect as if such Replacement Unit was the same Unit being replaced.

     Section  6.09.  Withholding Taxes.  The Indenture Trustee, as agent for the
Owner Trustee, shall exclude and withhold from each payment of principal, Make-
Whole Amount, if any, and interest and other amounts due hereunder or under the
Equipment Notes any and all withholding taxes applicable thereto as required by
law.  The Indenture Trustee agrees to act as such withholding agent and, in
connection therewith, whenever any present or future taxes or similar charges
are required to be withheld with respect to any amounts payable in respect of
any of the Equipment Notes, to withhold such amounts and timely pay the same to
the appropriate authority in the name of and on behalf of the holders of such
Equipment Notes, that it will file any necessary withholding tax returns or
statements when due, and that, as promptly as possible after the payment
thereof, it will deliver to each holder of an Equipment Note appropriate
documentation showing the payment thereof, together with such additional
documentary evidence as such holders may reasonably request from time to time.
The Owner Trustee agrees that the provisions of Section 6.13 of the
Participation Agreement are intended for the benefit of the Indenture Trustee.

     Section 6.10.  Lessee's Right of Quiet Enjoyment.  Notwithstanding any of
the provisions of this Indenture to the contrary, so long as Lessee is in
compliance with its obligations under the Lease (including applicable grace
periods) and no Lease Event of Default has occurred and is continuing
unremedied, the Indenture Trustee will comply with Section 8 of the
Participation

                                      -29-
<PAGE>

Agreement to the same extent as if it were the Lessor under the Lease. Each
holder of an Equipment Note, by its acceptance thereof, consents in all respects
to the terms of the Lease and the Participation Agreement and agrees to the
provisions of this Section 6.10.

     Section 6.11.  Compensation and Indemnity.  (a)  The Owner Trustee shall
pay to the Indenture Trustee, from time to time, on demand, all funds received
for such purposes from the Lessee for (i) reasonable compensation for the
Indenture Trustee's services, which compensation shall not be limited by any law
on compensation of a trustee of an express trust, (ii) reimbursement for all
reasonable out-of-pocket expenses incurred by the Indenture Trustee in
connection with the performance of its duties under this Indenture (including
the reasonable compensation and expenses of the Indenture Trustee's counsel and
any agent appointed in accordance with Section 7.05) and (iii) in respect of any
loss or liability incurred by it arising out of or in connection with its
acceptance or administration of the trust or trusts hereunder except (A) as such
expenses or loss or liability might result from the gross negligence or wilful
misconduct of the Indenture Trustee or the inaccuracy of any representation or
warranty of the Indenture Trustee in Section 3.3 of the Participation Agreement,
and (B) as otherwise excluded by the terms of Sections 7.1 and 7.2 of the
Participation Agreement from the Lessee's indemnities under said sections;
provided that, so long as the Lease is in effect, the Indenture Trustee shall
--------
not make any claim under this Section 6.11 for any claim or expense indemnified
against by the Lessee under the Participation Agreement (or otherwise as for
which the Lessee has agreed to reimburse the Indenture Trustee pursuant to the
Owner Participant Agreements, including Section 2.5(b) of the Participation
Agreement) without first making demand on the Lessee for payment of such claim
or expense.  The Indenture Trustee shall notify the Owner Trustee and the Lessee
promptly of any claim for which it may seek indemnity.  The Owner Trustee shall
have the right to defend the claim and the Indenture Trustee shall cooperate in
the defense.  The Indenture Trustee may have separate counsel and the Owner
Trustee, subject to limitations set forth in the preceding sentence, shall pay
the reasonable fees and expenses of such counsel.  The Owner Trustee need not
pay for any settlement made without its and the Lessee's consent.

                                 Article VII.
                  THE OWNER TRUSTEE AND THE INDENTURE TRUSTEE

     Section 7.01.  Acceptance of Trusts and Duties.  The Indenture Trustee
accepts the trusts hereby created and applicable to it and agrees to perform the
same but only upon the terms of this Indenture and agrees to receive and
disburse all moneys received by it constituting part of the Indenture Estate in
accordance with the terms hereof.  The Indenture Trustee shall not be answerable
or accountable under any circumstances, except for its own willful misconduct or
gross negligence (or negligence or willful misconduct in the case of application
or investment of moneys constituting the Indenture Estate) or breach of any of
its representations or warranties or covenants set forth herein or in the
Participation Agreement, or the performance of its obligations under the last
sentence of Section 6.04; and the Owner Trustee shall not be liable for any
action or inaction of the Indenture Trustee and the Indenture Trustee shall not
be liable for any action or inaction of the Owner Trustee.

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<PAGE>

The Owner Trustee shall not be deemed a trustee for, or agent of, the holders of
the Equipment Notes for any purpose.

     Section 7.02.  Absence of Duties.  Except in accordance with written
instructions or requests furnished pursuant to Section 6.01 or Section 6.02 and
except as provided in, and without limiting the generality of, Section 6.04, the
Indenture Trustee shall have no duty (i) to see to any registration of the
Equipment or any recording or filing of the Lease, or of this Indenture or any
other document, or to see to the maintenance of any such registration, recording
or filing, (ii) to see to any insurance on the Equipment or to effect or
maintain any such insurance, whether or not the Lessee shall be in default with
respect thereto, (iii) to confirm, verify or inquire into the failure to receive
any financial statements of the Lessee or (iv) to inspect the Equipment at any
time or ascertain or inquire as to the performance or observance of any of the
Lessee's covenants under the Lease with respect to the Equipment.
Notwithstanding the foregoing, the Indenture Trustee will furnish to any holder
of an Equipment Note, so long as such holder of an Equipment Note or its
nominees shall hold any of the Equipment Notes, promptly upon receipt thereof,
duplicates or copies of all reports, notices, requests, demands, certificates,
financial statements and other instruments furnished to the Indenture Trustee
under this Indenture, to the extent that the same shall not have been furnished
to the Indenture Trustee and the holder of an Equipment Note pursuant to the
Lease.

     Section 7.03.  No Representations or Warranties as to the Equipment or
Documents.  Neither the Owner Trustee nor the Owner Trustee in its individual
capacity nor the Indenture Trustee makes or shall be deemed to have made (i) any
representation or warranty, express or implied, as to the value, condition,
design, operation, merchantability or fitness for use of the Equipment or as to
their title thereto, or any other representation or warranty with respect to the
Equipment whatsoever, or (ii) any representation or warranty as to the validity,
legality or enforceability of this Indenture, the Trust Agreement, the
Participation Agreement, the Equipment Notes, the Lease, any Lease Supplement,
any Indenture Supplement or any other document or instrument or as to the
correctness of any statement contained in any thereof (except as to the
representations and warranties made by the Owner Trustee in its individual
capacity as set forth in Section 3.1 of the Participation Agreement), except
that the Owner Trustee and the Indenture Trustee each in its individual capacity
hereby confirms the representations and warranties made by it in its individual
capacity in Sections 3. 1 and 3.3, respectively, of the Participation Agreement.

     Section 7.04.  No Segregation of Moneys; No Interest; Investments.  (a)
Subject to Section 7.04(b), no moneys received by the Indenture Trustee
hereunder need be segregated in any manner except to the extent required by law,
and any such moneys may be deposited under such general conditions for the
holding of trust funds as may be prescribed by law applicable to the Indenture
Trustee, and, except as otherwise agreed by the Owner Trustee or the Indenture
Trustee, as the case may be, neither the Owner Trustee nor the Indenture Trustee
shall be liable for any interest thereon.

     (b)  Any amounts held by the Indenture Trustee pursuant to the express
terms of this Indenture or the Lease and not required to be distributed as
herein provided shall be invested and

                                      -31-
<PAGE>

reinvested by the Indenture Trustee from time to time in Specified Investments
at the written direction and at the risk and expense of the Lessee, except that
in the absence of any such direction, such amounts need not be invested and
reinvested and except that after a Lease Event of Default shall have occurred
and be continuing, such amounts shall be so invested and reinvested by the
Indenture Trustee in Indenture Investments. Any net income or gain realized as a
result of any such investments or reinvestment shall be held as part of the
Indenture Estate and shall be applied by the Indenture Trustee at the same
times, on the same conditions and in the same manner as the amounts in respect
of which such income or gain was realized are required to be distributed in
accordance with the provisions hereof or of the Lease pursuant to which such
amounts were required to be held and if no Lease Event of Default shall have
occurred and be continuing any excess shall be paid to the Lessee. Any such
Specified Investments or Indenture Investments may be sold or otherwise reduced
to cash (without regard to maturity date) by the Indenture Trustee whenever
necessary to make any application as required by such provisions. The Indenture
Trustee shall have no liability for any loss resulting from any such investment
or reinvestment other than by reason of the willful misconduct or gross
negligence of the Indenture Trustee.

     Section 7.05.  Reliance; Agents; Advice of Counsel.  The Indenture Trustee
shall incur no liability to anyone acting upon any signature, instrument,
notice, resolution, request, consent, order, certificate, report, opinion, bond
or other document or paper believed by it to be genuine and believed by it to be
signed by the proper party or parties.  The Indenture Trustee may accept a copy
of a resolution of the Board of Directors of any party to the Participation
Agreement, certified by the Secretary or an Assistant Secretary of such party as
duly adopted and in full force and effect, as conclusive evidence that such
resolution has been duly adopted by said Board and that the same is in full
force and effect.  As to any fact or matter the manner of ascertainment of which
is not specifically described herein, the Indenture Trustee may for all purposes
hereof rely on a certificate, signed by an officer of the Lessee, as to such
fact or matter, and such certificate shall constitute full protection to the
Indenture Trustee for any action taken or omitted to be taken by it in good
faith in reliance thereon.  The Indenture Trustee shall furnish to the Owner
Trustee upon request such information and copies of such documents as the
Indenture Trustee may have and as are necessary for the Owner Trustee to perform
its duties under Article II hereof.  The Indenture Trustee shall assume, and
shall be fully protected in assuming, that the Owner Trustee is authorized by
the Trust Agreement to enter into this Indenture and to take all action
permitted to be taken by it pursuant to the provisions hereof, and need not
inquire into the authorization of the Owner Trustee with respect thereto.  In
the administration of the trusts hereunder, the Indenture Trustee may execute
any of the trusts or powers hereof and perform its powers and duties hereunder
directly or through agents or attorneys and may, at the reasonable expense of
the Indenture Estate, consult with independent counsel, accountants and other
skilled persons to be selected and employed by it, and the Indenture Trustee
shall not be liable for anything done, suffered, or omitted in good faith by it
in accordance with the written advice or opinion of any such independent
counsel, accountants or other skilled persons acting within such persons' area
of competence (so long as the Indenture Trustee shall have exercised reasonable
care in selecting such persons).

                                      -32-
<PAGE>

     Section 7.06.  Not Acting in Individual Capacity.  The Owner Trustee and
the Indenture Trustee each acts hereunder solely as trustee hereunder and, in
the case of the Owner Trustee, under the Trust Agreement and not in its
individual capacity unless otherwise expressly provided; and all Persons, other
than the holders of Equipment Notes to the extent expressly provided in this
Indenture, having any claim against the Owner Trustee or the Indenture Trustee
by reason of the transactions contemplated hereby shall, subject to the Lien and
priorities of payment as herein provided, look only to the Indenture Estate for
payment or satisfaction thereof.

                                 Article VIII.
                    CERTAIN LIMITATIONS ON OWNER TRUSTEE'S
                        AND INDENTURE TRUSTEE'S RIGHTS

     Section  8.01.  Certain Limitations on Owner Trustee's and Indenture
Trustee's Rights.  Each  of the Owner Trustee and the Indenture Trustee agree
that it shall have no right against the holders of the Equipment Notes or the
Indenture Estate (except in the case of the Indenture Trustee as expressly
provided in Section 3.03 or 5.03 hereof) for any fee as compensation for its
services hereunder or any expenses or disbursements incurred in connection with
the exercise and performance of its powers and duties hereunder or any
indemnification against liability which it may incur in the exercise and
performance of such powers and duties but, on the contrary, shall look solely to
the Lessee for such payment and indemnification and that neither the Owner
Trustee nor the Indenture Trustee shall have any lien on nor security interest
in the Indenture Estate as security for such compensation, expenses, reasonable
counsel fees, if any, disbursements and indemnification.

                                  Article IX.
                              SUCCESSOR TRUSTEES

     Section 9.01.  Notice of Successor Owner Trustee.  In the case of any
appointment of a successor Owner Trustee pursuant to the Trust Agreement or any
merger, conversion, consolidation or sale of substantially all the business
involving the Owner Trustee pursuant to the Trust Agreement, the successor Owner
Trustee shall give prompt written notice thereof to the Indenture Trustee, the
Lessee and the holders of all Equipment Notes at the time outstanding.

     Section 9.02.  Resignation of Indenture Trustee; Appointment of Successor.
The resignation or removal of the Indenture Trustee and the appointment of a
successor Indenture Trustee shall become effective only upon the successor
Indenture Trustee's acceptance of appointment as provided in this Section 9.02.
The Indenture Trustee or any successor thereto may resign at any time without
cause by giving at least 30 days' prior written notice to the Owner Trustee, the
Owner Participant, the Lessee and the holders of the Equipment Notes.  A
Majority in Interest may at any time remove the Indenture Trustee without cause
by an instrument in writing delivered to the Owner Trustee, the

                                      -33-
<PAGE>

Owner Participant, the Lessee and the Indenture Trustee. The Owner Trustee may
remove the Indenture Trustee if: (1) the Indenture Trustee fails to comply with
Section 9.02(c); (2) the Indenture Trustee is adjudged a bankrupt or an
insolvent; (3) a receiver or public officer takes charge of the Indenture
Trustee or its property; or (4) the Indenture Trustee becomes incapable of
performing its duties hereunder.

     (a)  In the case of the resignation or removal of the Indenture Trustee,
the Owner Trustee shall provide notice thereof to the holders of the Equipment
Notes, and the Owner Trustee shall, unless otherwise directed by a Majority in
Interest, promptly appoint a successor Indenture Trustee, provided that a
Majority in Interest may appoint, within one year after such resignation or
removal, a successor Indenture Trustee which may be other than the successor
Indenture Trustee appointed as provided above, and such successor Indenture
Trustee appointed as provided above shall be superseded by the successor
Indenture Trustee so appointed by a Majority in Interest. If a successor
Indenture Trustee shall not have been appointed and accepted its appointment
hereunder within 60 days after the Indenture Trustee gives notice of resignation
or is removed as provided above, the retiring Indenture Trustee, the Lessee, the
Owner Trustee or a Majority in Interest may petition any court of competent
jurisdiction for the appointment of a successor Indenture Trustee. Any successor
Indenture Trustee so appointed by such court shall immediately and without
further act be superseded by any successor Indenture Trustee appointed as
provided in the proviso to the first sentence of this paragraph (a) within one
year from the date of the appointment by such court.

     (b)  Any successor Indenture Trustee, however appointed, shall execute and
deliver to the Owner Trustee and the Lessee and to the predecessor Indenture
Trustee an instrument accepting such appointment, and thereupon such successor
Indenture Trustee, without further act, shall become vested with all the
estates, properties, rights, powers, duties and trusts of the predecessor
Indenture Trustee hereunder in the trusts hereunder applicable to it with like
effect as if originally named the Indenture Trustee herein; but nevertheless,
upon the written request of such successor Indenture Trustee, such predecessor
Indenture Trustee shall execute and deliver an instrument transferring to such
Indenture Trustee, upon the trusts herein expressed applicable to it, all the
estates, properties, rights, powers and trusts of such predecessor Indenture
Trustee, and such Indenture Trustee shall duly assign, transfer, deliver and pay
over to such successor Indenture Trustee all moneys or other property then held
by such predecessor Indenture Trustee hereunder.

     (c)  The Indenture Trustee shall be a bank or trust company organized under
the laws of the United States or any State thereof having a combined capital and
surplus of at least $250,000,000, if there be such an institution willing, able
and legally qualified to perform the duties of the Indenture Trustee hereunder
upon reasonable or customary terms.

     (d)  Any corporation into which the Indenture Trustee may be merged or
converted or with which it may be consolidated, or any corporation resulting
from any merger, conversion or consolidation to which the Indenture Trustee
shall be a party, or any corporation to which substantially all the corporate
trust business of the Indenture Trustee may be transferred, shall,

                                      -34-
<PAGE>

subject to the terms of paragraph (c) of this Section, be the Indenture Trustee
under this Indenture without further act.

                                  Article X.
                          SUPPLEMENTS AND AMENDMENTS
                     TO THIS INDENTURE AND OTHER DOCUMENTS

     Section 10.01. Supplemental Indentures without Consent of Holders.  (a)
The Owner Trustee and the Indenture Trustee, at any time and from time to time,
without notice to or the consent of any holders of any Equipment Notes, may
enter into one or more indentures supplemental hereto for any of the following
purposes:

          (i)    to correct or amplify the description of any property at any
     time subject to the Lien of this Indenture or better to assure, convey and
     confirm unto the Indenture Trustee any property subject or required to be
     subject to the Lien of this Indenture or to subject to the Lien of this
     Indenture any Unit or Units substituted for any Unit or Units in accordance
     with the Lease; provided, however, that indenture supplements entered into
     for the purpose of subjecting to the Lien of this Indenture any Unit or
     Units substituted for any in accordance with the Lease need only be
     executed by the Owner Trustee; or

          (ii)   to evidence the succession of another trustee to the Owner
     Trustee and the assumption by any such successor of the covenants of the
     Owner Trustee herein and in the Equipment Notes contained, or to evidence
     (in accordance with Article IX) the succession of a new Indenture Trustee
     hereunder; or

          (iii)  to add to the covenants of the Owner Trustee, for the benefit
     of the holders of any of the Equipment Notes, or to surrender any right or
     power herein conferred upon the Owner Trustee; or

          (iv)   to cure any ambiguity, to correct or supplement any provision
     herein which may be defective or inconsistent with any other provision
     herein, or to make any other provisions with respect to matters or
     questions arising hereunder so long as any such action does not adversely
     affect the interests of the holders of any of the Equipment Notes;

provided that no such supplement to this Indenture or waiver or modification of
the terms hereof shall adversely affect in a substantive manner the interests of
the Lessee without the Lessee's prior written consent, and in no event shall the
terms of Section 5.05 be so altered or modified without such Lessee consent.

     (b) Supplemental Indentures with Consent of Majority In Interest.  With the
written consent of a Majority in Interest, the Owner Trustee (but only on the
written request of the Owner

                                      -35-
<PAGE>

Participant) may, and the Indenture Trustee, subject to Section 10.02 hereof,
shall, at any time and from time to time, enter into an indenture or indentures
supplemental hereto for the purpose of adding any provisions to or changing in
any manner or eliminating any of the provisions of this Indenture or of
modifying in any manner the rights and obligations of holders of any of the
Equipment Notes and of the Owner Trustee under this Indenture; provided,
however, without the consent of each holder of an Equipment Note affected
thereby, no such supplemental indenture shall:

          (1) except as expressly provided by Section 10.01(c), change the final
     maturity of the principal of any Equipment Note, or change the dates or
     amounts of payment of any installment of the principal of, Make-Whole
     Amount, if any, or interest on any Equipment Note, or change the principal
     amount thereof or the Make-Whole Amount, if any, or interest thereon, or
     change to a location outside the United States the place of payment where,
     or the coin or currency in which, any Equipment Note or the Make-Whole
     Amount, if any, or interest thereon is payable, or impair the right to
     institute suit for the enforcement of any such payment of principal or
     Make-Whole Amount, if any, or interest on or after the date such principal
     or Make-Whole Amount, if any, or interest becomes due and payable; or

          (2) create any Lien with respect to the Indenture Estate ranking prior
     to, or on a parity with, the security interest created by this Indenture
     except such as are permitted by this Indenture, or deprive any holder of an
     Equipment Note of the benefit of the Lien on the Indenture Estate created
     by this Indenture; or

          (3) reduce the percentage in principal amount of any of the Equipment
     Notes, the consent of whose holders is required for any such supplemental
     indenture, or the consent of whose holders is required for any waiver (of
     compliance with certain provisions of this Indenture, or of certain
     defaults hereunder and their consequences) provided for in this Indenture;
     or

          (4) modify any provisions of this Section 10.01(b), except to provide
     that certain other provisions of this Indenture cannot be modified or
     waived without the consent of the holder of each Equipment Note affected
     thereby; or

          (5) modify Sections 3.01, 3.02 or 3.03 hereof;

provided that no such supplement to this Indenture or waiver or modification of
the terms hereof shall adversely affect in a substantive manner the interests of
the Lessee without the Lessee's prior written consent unless otherwise provided
in the Operative Documents, and in no event shall the terms of the proviso to
Section 5.05 be so altered or modified without such Lessee consent.

     Section 10.02. Indenture Trustee Protected.  If in the opinion of the
Indenture Trustee any document required to be executed pursuant to the terms of
Section 10.01 adversely affects any right, duty, immunity or indemnity in favor
of the Indenture Trustee under this Indenture, the Participation

                                      -36-
<PAGE>

Agreement or the Lease, the Indenture Trustee may in its discretion decline to
execute such document.

     Section 10.03. Request of Substance, Not Form.  It shall not be necessary
for the consent of the holders of Equipment Notes under Section 10.01(b) to
approve the particular form of any proposed supplemental indenture, but it shall
be sufficient if such consent shall approve the substance thereof.

     Section 10.04. Documents Mailed to Holders.  Promptly after the execution
by the Indenture Trustee of any document entered into pursuant to Section
10.01(b), the Indenture Trustee shall mail, by first-class mail, postage
prepaid, a conformed copy thereof to each holder of an Equipment Note at its
address last known to the Indenture Trustee, but the failure of the Indenture
Trustee to mail such conformed copies shall not impair or affect the validity of
such document.

     Section 10.05. Amendments, Waivers, Etc. of Other Documents.  (a)  Without
the consent of a Majority in Interest, the respective parties to the Lease and
the Trust Agreement may not modify, amend or supplement any of such agreements,
or give any consent, waiver, authorization or approval thereunder, for the
purpose of adding any provisions to or changing in any manner or eliminating any
of the provisions thereof or of modifying in any manner the rights of the
respective parties thereunder; provided, however, that the actions specified in
subsection (b) of this Section 10.05 may be taken, except as otherwise expressly
provided therein, without the consent of the Indenture Trustee or of a Majority
in Interest or any holder of an Equipment Note.

     (b)  Subject to the provisions of subsection (c) of this Section 10.05, the
respective parties to the Lease and the Trust Agreement, at any time and from
time to time without the consent of the Indenture Trustee or of a Majority in
Interest or any holder of an Equipment Note, may:

          (1)  so long as no Indenture Event of Default shall have occurred and
     be continuing, modify, amend or supplement the Lease, or give any consent,
     waiver, authorization or approval with respect thereto, except that without
     the consent of a Majority in Interest, the parties to the Lease shall not
     modify, amend or supplement, or give any consent, waiver, authorization or
     approval for the purpose of adding any provisions to or changing in any
     manner or eliminating any of the provisions thereof or of modifying in any
     manner the rights of the respective parties thereunder, with respect to the
     following provisions of the Lease: Sections 2, 3.1 (if the result thereof
     would be to shorten the Basic Term to a period shorter than the period
     ending with the final maturity of the Equipment Notes), 3.2, 3.3, 3.4, 3.5,
     3.6 (except insofar as it relates to the address or account information of
     the Owner Trustee or Indenture Trustee) (other than as such Sections 3.1
     through 3.6 may be amended pursuant to Section 3.4 of the Lease as
     originally executed), 4, 5, 6 (but only to the extent such Section is made
     operative by Section 15), 7, 8, 9, 10 (except that additional requirements
     may be imposed on the Lessee's ability to terminate the Lease with respect
     to a Unit), 11 (except that additional requirements may be imposed on the

                                      -37-
<PAGE>

     Lessee's ability to replace a Unit subject to an Event of Loss), 12
     (including the Letter Agreement referred to therein) (except that
     additional insurance requirements may be imposed on the Lessee), 13, 14,
     15, 16, 17, 18, 19, 20, 21, 22, 24, 25, and any definition of terms used in
     the Lease, to the extent that any modification of such definition would
     result in a modification of the Lease not permitted as aforesaid in this
     clause (1) of subsection (b); provided that, in the event an Indenture
     Event of Default shall have occurred and be continuing, the Indenture
     Trustee shall have all rights of the Owner Trustee as "Lessor" under the
     Lease to modify, amend or supplement the Lease or give any consent, waiver,
     authorization or approval thereunder, for the purpose of adding any
     provisions to or changing in any manner or eliminating any of the
     provisions thereof or of modifying in any manner the rights of the "Lessor"
     thereunder; provided further that, whether or not an Indenture Event of
     Default shall have occurred and be continuing, the Owner Trustee shall
     retain the right (A) to exercise all rights of the Owner Trustee under
     Section 17 (to the extent permitted by Section 5.04) of the Lease; (B) to
     consent to any amendment, modification, or supplement of, or the granting
     of any waiver in respect of (w) any provisions of the Lease if the effect
     thereof is to decrease the amount or defer the payment of any Rent,
     including any amounts payable under Sections 3, 10, 11, 15 or 22 of the
     Lease or Section 10.2 of the Participation Agreement, (x) Section 6 of the
     Lease, (y) Section 12 of the Lease in respect of insurance policies and the
     proceeds thereof which by the terms of such policies are payable to the
     Owner Participant or the Owner Trustee and not to the Indenture Trustee,
     and (z) any other provision of the Lease if such amendment, modification,
     supplement or waiver would impose any additional affirmative obligations
     upon the Owner Trustee or the Owner Participant;

          (2)  modify, amend or supplement the Trust Agreement, or give any
     consent, waiver, authorization or approval with respect thereto, except
     that without the consent of a Majority of Interest, the parties to the
     Trust Agreement shall not modify, amend or supplement, or give any consent,
     waiver, authorization or approval for the purpose of adding any provisions
     to or changing in any manner or eliminating any of the provisions thereof
     or of modifying in any manner the rights of the respective parties
     thereunder, with respect to Sections 2.1, 2.2 (or the definition of
     Accepted Equipment or Accepted Unit), 3.1, 4.1, 4.4, 7.1, 7.2, 9.1, 10.1,
     10.2, 10.7, 10.11 or any other Section of the Trust Agreement if such
     action would materially adversely affect the interest of the Loan
     Participants, and any definition of terms used in the Trust Agreement, to
     the extent that any modification of such definition would result in a
     modification of the Trust Agreement not permitted pursuant to this
     subsection (b); and

          (3)  modify, amend or supplement any of said agreements in order to
     cure any ambiguity, to correct or supplement any provision thereof which
     may be defective or inconsistent with any other provision thereof or any
     provision of this Indenture, or to make any other provision with respect to
     matters or questions arising thereunder or under this Indenture which shall
     not be inconsistent with the provisions of this Indenture, provided any

                                      -38-
<PAGE>

     such action shall not adversely affect the interests of the holders of any
     of the Equipment Notes.

     (c)  No modification, amendment, supplement, consent, waiver, authorization
or approval with respect to the Lease, whether effected pursuant to subsection
(a) or pursuant to subsection (b) of this Section 10.05, and anything in such
subsections or elsewhere in this Indenture to the contrary notwithstanding,
shall, without the consent of the holder of each Equipment Note affected
thereby:

          (1)  modify, amend or supplement the Lease in such a way as to change
     the time of payment of Basic Rent, Supplemental Rent or Stipulated Loss
     Value and any other amounts payable under, or as provided in, the Lease
     upon the occurrence of an Event of Loss or Termination Value and any other
     amounts payable under, or as provided in, the Lease upon termination
     thereof or reduce the amount of any installment of Basic Rent so that the
     same is less than the payment of interest and principal on such Equipment
     Notes, as the case may be, to be made from such installment of Basic Rent
     or reduce the aggregate amount of Stipulated Loss Value and any other
     amounts payable under, or as provided in, the Lease upon the occurrence of
     an Event of Loss so that the same is less than the accrued interest on and
     principal of the Equipment Notes required to be paid at the time of such
     payments, or reduce the amount of Termination Value and any other amounts
     payable under, or as provided in, the Lease upon termination thereof so
     that the same is less than the accrued interest on and principal of such
     Equipment Notes required to be paid at the time of such payments; or

          (2)  modify, amend or supplement the Lease in such a way as to, or
     consent to any assignment of the Lease or give any consent, waiver,
     authorization or approval which would, release the Lessee from its
     obligation in respect of payment of Basic Rent, Supplemental Rent or
     Stipulated Loss Value and any other amounts payable under, or as provided
     in, the Lease upon the occurrence of an Event of Loss, or Termination Value
     and any other amounts payable under, or as provided in, the Lease upon
     termination thereof, except for any such assignment pursuant to Section 6.8
     of the Participation Agreement, and except as provided in the Lease.

                                  Article XI.
                                 MISCELLANEOUS

     Section 11.01. Termination of Indenture.  With respect to each Unit, this
Indenture and the trusts created hereby shall terminate and this Indenture shall
be of no further force or effect upon the earliest to occur of (i) the
termination of the Lease Term with respect to such Unit by Lessee pursuant to
Section 10 or Section 22.1 thereof and upon payment in full to the Indenture
Trustee of the amounts required to be paid pursuant to Section 2.10(a) in
respect of such Unit, (ii) the termination of the Lease with respect to such
Unit pursuant to Section 11 thereof and upon payment

                                      -39-
<PAGE>

in full to the Indenture Trustee of the amounts required to be paid pursuant to
Section 2. 10(b) in respect of such Unit, (iii) the termination of the Lease
with respect to all Units pursuant to Section 6.9 of the Participation Agreement
and upon payment in full to the Indenture Trustee of the amounts required to be
paid pursuant to Section 2.10(c) in respect of such Units and (iv) the payment
in full of the principal amount of and interest on all Equipment Notes
outstanding hereunder and all other sums payable to the Indenture Trustee and
the holders of all of the Equipment Notes hereunder and under such Equipment
Notes and under the Participation Agreement.

     Section 11.02. No Legal Title to Indenture Estate in Holders.  No holder of
an Equipment Note shall have legal title to any part of the Indenture Estate.
No transfer, by operation of law or otherwise, of any Equipment Note or other
right, title and interest of any holder of an Equipment Note in and to the
Indenture Estate or hereunder shall operate to terminate this Indenture or the
trusts hereunder or entitle any successor or transferee of such holder to an
accounting or to the transfer to it of legal title to any part of the Indenture
Estate.

     Section 11.03. Sale of Equipment by Indenture Trustee is Binding.  Any sale
or other conveyance of the Equipment by the Indenture Trustee made pursuant to
the terms of this Indenture or the Lease shall bind the holders of any Equipment
Notes, the Owner Trustee and the Owner Participant and shall be effective to
transfer or convey all right, title and interest of the Indenture Trustee, the
Owner Trustee, the Owner Participant and such holders of the Equipment Notes in
and to the Equipment.  No purchaser or other grantee shall be required to
inquire as to the authorization, necessity, expediency or regularity of such
sale or conveyance or as to the application of any sale or other proceeds with
respect thereto by the Indenture Trustee.

     Section 11.04. Remedies Cumulative.  Each and every right, power and remedy
herein specifically given to the Indenture Trustee or otherwise in this
Indenture shall be cumulative and shall be in addition to every other right,
power and remedy herein specifically given or now or hereafter existing at law,
in equity or by statute, and each and every right, power and remedy whether
specifically herein given or otherwise existing may be exercised from time to
time and as often and in such order as may be deemed expedient by the Indenture
Trustee, and the exercise or the beginning of the exercise of any power or
remedy shall not be construed to be a waiver of the right to exercise at the
time or thereafter any other right, power or remedy.  No delay or omission by
the Indenture Trustee in the exercise of any right, remedy or power or in the
pursuance of any remedy shall impair any such right, power or remedy or be
construed to be a waiver of any default on the part of the Owner Trustee or the
Lessee or to be an acquiescence therein.

     Section 11.05. Discontinuance of Proceedings.  In case the Indenture
Trustee shall have proceeded to enforce any right, power or remedy under this
Indenture by foreclosure, entry or otherwise, and such proceedings shall have
been discontinued or abandoned for any reason or shall have been determined
adversely to the Indenture Trustee, then and in every such case the Owner
Trustee, the Owner Participant, the Indenture Trustee and the Lessee shall be
restored to their former positions and rights hereunder with respect to the
Indenture Estate, and all rights, remedies and

                                      -40-
<PAGE>

powers of the Indenture Trustee shall continue as if no such proceedings had
been undertaken (but otherwise without prejudice).

     Section 11.05.  Indenture and Equipment Notes for Benefit of Owner Trustee,
Indenture Trustee, Owner Participant and Holders Only. Nothing in this
Indenture, whether express or implied, shall be construed to give to any Person
other than the Owner Trustee (individually and as trustee), the Indenture
Trustee, the Owner Participant (as set forth herein) and the holders of any
Equipment Notes any legal or equitable right, remedy or claim under or in
respect of this Indenture or any such Equipment Note.

     Section 11.06.  Notices.  Unless otherwise expressly specified or permitted
by the terms hereof, all notices required or permitted under the terms and
provisions hereof shall be in writing, and shall become effective when deposited
in the United States mail, with proper postage for first class registered or
certified mail prepaid, when delivered personally, or, if promptly confirmed by
mail as provided above, when dispatched by telegram, telex or other written
telecommunication addressed (i) if to the Owner Trustee, at its office at Sixth
and Marquette, MAC N9303-120, Minneapolis, MN 55479, Attention: Corporate Trust
Services, (ii) if to the Indenture Trustee, at its office at 135 S.  LaSalle
St., Suite 1690, Chicago, IL 60603, Attention: Ms.  Margaret Muir, (iii) if to a
holder of an Equipment Note, at such address as is set forth on Schedule 2 of
the Participation Agreement or, if not so specified, at the address set forth in
the register maintained pursuant to Section 2.07 hereof, or at such address as
such Loan Participant shall have furnished by notice to the Owner Trustee and
the Indenture Trustee, (iv) if to the Lessee, at 225 West Washington Street,
19th Floor, Chicago, Illinois 60606, Attention: Treasurer, (v) if to the Owner
Participant, 1290 Avenue of the Americas, New York, New York 10104, Attention:
Chief Financial Officer, and (vi) if to any of the foregoing Persons, at such
other address as such Person shall from time to time designate by written notice
to the other parties hereto in accordance with this Section 11.07.

     Notwithstanding the foregoing provisions, for purposes of Sections 5.01,
5.02, 5.04, 6.01 and 6.02, written notice shall be deemed given when it is in
fact received (by mail, confirmed facsimile or otherwise) by any addressee at
the respective addresses specified above.

     Section 11.07.  Severability.  Any provision of this Indenture which is
prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction,
be ineffective to the extent of such prohibition or unenforceability without
invalidating the remaining provisions hereof, and any such prohibition or
unenforceability in any jurisdiction shall not invalidate or render
unenforceable such provision in any other jurisdiction.  In the event of any
inconsistency or conflict between any provision of this Indenture and any
provision of the Trust Agreement, such provision in this Indenture shall govern
and control.

     Section 11.08.  Separate Counterparts.  This Indenture may be executed in
any number of counterparts (and each of the parties hereto shall not be required
to execute the same counterpart).  Each counterpart of this Indenture including
a signature page executed by each of the parties hereto

                                      -41-
<PAGE>

shall be an original counterpart of this Indenture, but all of such counterparts
together shall constitute one instrument.

     Section 11.10. Successors and Assigns.  All covenants and agreements
contained herein shall be binding upon, and inure to the benefit of, the Owner
Trustee and its successors and permitted assigns, the Owner Participant and its
successors and permitted assigns, and the Indenture Trustee and its successors
and permitted assigns, and each holder of an Equipment Note, all as herein
provided.  Any request, notice, direction, consent, waiver or other instrument
or action by any holder of an Equipment Note shall bind the successors and
assigns of such holder.

     Section 11.11. Headings.  The headings of the various Articles and Sections
herein are for convenience of reference only and shall not define or limit any
of the terms or provisions hereof.

     Section 11.12. Governing Law.  This Indenture shall in all respects be
governed by, and construed in accordance with, the laws of the State of New
York, including all matters of construction, validity and performance.

     Section 11.13. Normal Commercial Relations.  Anything contained in this
Indenture to the contrary notwithstanding, the Owner Participant, the Owner
Trustee or the Indenture Trustee or any affiliate of the Owner Participant, the
Owner Trustee or the Indenture Trustee may enter into commercial banking or
other financial transactions, and conduct banking or other commercial
relationships, with the Lessee, any holder of an Equipment Note or the Indenture
Trustee (in its individual capacity or otherwise) fully to the same extent as if
this Indenture were not in effect, including, without limitation, the making of
loans or other extensions of credit for any purpose whatsoever.

     Section 11.14. No Recourse Against Others.  No director, officer, employee
or stockholder, as such, of the Lessee, the Owner Trustee, the Owner Participant
or the Indenture Trustee shall have any liability for any obligations of Lessee,
the Owner Participant, the Owner Trustee or the Indenture Trustee or under the
Equipment Notes or the Indenture or for any claim based on, in respect of or by
reason of such obligations or their creation.  Each holder of an Equipment Note
by accepting an Equipment Note waives and releases all such liability.  The
waiver and release are part of the consideration of such Equipment Note.

     Section 11.15. Identity of Note Purchasers.  Upon the written request for
a valid business purpose by any holder of an Equipment Note, the Indenture
Trustee shall provide as soon as reasonably practicable to such holder the names
and addresses of all other registered holders of Equipment Notes.

                                      -42-
<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this Indenture to be
duly executed by their respective officers or attorneys-in-fact, as the case may
be, thereunto duly authorized, on the day and year first above written.

                                NORWEST BANK MINNESOTA, NATIONAL
                                 ASSOCIATION, not in its individual capacity
                                 except as set forth in Section 7.03 hereof, but
                                 solely as Owner Trustee

                                By: /s/ Timothy P. Mowdy
                                   --------------------------------------------
                                Name:  Tim Mowdy
                                Title: Corporate Trust Officer

                                LASALLE BANK NATIONAL ASSOCIATION,
                                 as Indenture Trustee

                                By: /s/ Margaret M. Muir
                                   ---------------------------------------------
                                Name:  Margaret M. Muir
                                Title: Vice President

                                      -43-
<PAGE>

State of Minnesota  )
                    ) SS
County of Hennepin  )

     On this 26th day of June, 2000 before me personally appeared Timothy P.
Mowdy, to me personally known, who being by me duly sworn, say that he is
Corporate Trust Officer of Norwest Bank Minnesota, National Association, that
said instrument was signed on such date on behalf of said corporation by
authority of its Board of Directors, and he acknowledged that the execution of
the foregoing instrument was the free act and deed of said corporation.

                                                   /s/ Jeffery T. Rose
                                              ----------------------------------
                                              Notary Public

[Notarial Seal]

My commission expires:  01/31/2005

State of Illinois  )
                   ) SS
County of Cook     )

     On this 26th day of June, 2000, before me personally appeared Margaret M.
Muir, to me personally known, who being by me duly sworn, say that he is the
Vice President of LaSalle Bank National Association, that said instrument was
signed on such date on behalf of said corporation by authority of its Board of
Directors, and he acknowledged that the execution of the foregoing instrument
was the free act and deed of said corporation.

                                                   /s/ Vernita L. Anderson
                                              ----------------------------------
                                              Notary Public

[Notarial Seal]

My commission expires:   07/13/2001

                                      -44-
<PAGE>

                                                                       EXHIBIT A

                       TRUST INDENTURE SUPPLEMENT NO.__
                            (UTC Trust No. 2000-A)
                                    (L-16)

     This Indenture Supplement No. __ (UTC Trust No. 2000-A) (L-16), dated
_________________, 2000 (this "Indenture Supplement"), of Norwest Bank
Minnesota, National Association, not in its individual capacity but solely as
trustee (the "Owner Trustee") under the Trust Agreement (UTC Trust No. 2000-A)
(L-16), dated June 29, 2000 (the "Trust Agreement"), between the Owner Trustee
in its individual capacity and BNY Capital Funding LLC, as Owner Participant:

                                  WITNESSETH:

     WHEREAS, the Trust Indenture and Security Agreement (UTC Trust No. 2000-A)
(L-16) dated June 29, 2000 (the "Indenture"), between the Owner Trustee and
LaSalle Bank National Association, as Indenture Trustee (the "Indenture
Trustee"), provides for the execution and delivery of Indenture Supplements
thereto substantially in the form hereof each of which shall particularly
describe the Units covered by a related Lease Supplement under the Lease, by
having attached thereto a copy of such related Lease Supplement, and shall
specifically mortgage such Units to the Indenture Trustee;

     WHEREAS, the Indenture includes the Units described in the copy of Lease
Supplement No. __ attached hereto and made a part hereof; and

     WHEREAS, an executed counterpart of the Indenture is attached to this
Indenture Supplement;

     NOW, THEREFORE, in order to secure the prompt payment of the principal of,
and Make-Whole Amount, if any, and interest on all of the Equipment Notes from
time to time outstanding under the Indenture and the performance and observance
by the Owner Trustee of all the agreements, covenants and provisions in the
Indenture for the benefit of the holders of the Equipment Notes and in the
Equipment Notes, subject to the terms and conditions of the Indenture, and in
consideration of the premises and of the covenants contained in the Indenture
and of the acceptance of the Equipment Notes by the holders thereof, and of the
sum of $1.00 paid to the Owner Trustee by the Indenture Trustee at or before the
delivery hereof, the receipt whereof is hereby acknowledged, the Owner Trustee
(i) has sold, assigned, transferred, pledged and confirmed, and does hereby
sell, assign, transfer, pledge and confirm, a security interest in and mortgage
lien on all right, title and interest of the Owner Trustee in and to the
property comprising the Equipment described in the copy of Lease Supplement No.
__ attached hereto, and (ii) has sold, assigned, transferred and set over, a
security interest in and mortgage lien on all of the right, title and interest
of the Owner Trustee under, in and to such Lease Supplement (excluding, however,
any rights to Excepted Property thereunder),

                                      A-1
<PAGE>

referred to above, to the Indenture Trustee, its successors and assigns, in the
trust created by the Indenture for the benefit of the holders from time to time
of the Equipment Notes.

     To have and to hold all and singular the aforesaid property unto the
Indenture Trustee, its successors and assigns, in trust for the benefit and
security of the holders from time to time of the Equipment Notes and for the
uses and purposes and subject to the terms and provisions set forth in the
Indenture.

     It is the intention of the parties hereto that all Equipment Notes issued
and outstanding under this Indenture Supplement rank on a parity with each other
Equipment Note and that, as to each other Equipment Note, they be secured
equally and ratably by the collateral described herein, without preference,
priority or distinction of any one thereof over any other by reason of
difference in time of issuance or otherwise, and that each such Equipment Note
be entitled to the same benefits and security in the Indenture and this
Indenture Supplement as each other.

     The Equipment Notes issued under this Indenture Supplement shall be
designated as Equipment Notes 2000-A. The Equipment Notes shall be substantially
in the form set forth in Section 2.01 of the Indenture. The Equipment Notes
issued under this Indenture Supplement shall be dated the date of issuance
thereof, shall be issued in the maturity and aggregate principal amount and
shall bear interest as specified in Exhibit B hereto. The principal of each
Equipment Note shall be payable in installments, on each Installment Payment
Date and the Maturity Date, in amounts equal to the Installment Payment Amount
for each such Installment Payment Date and Maturity Date as set forth for such
Equipment Notes.

     This Supplement shall be construed as supplemental to the Indenture and
shall form a part of it, and the Indenture is hereby incorporated by reference
herein and is hereby ratified, approved and confirmed.

     This Supplement may be executed by the Owner Trustee in separate
counterparts, each of which when so executed and delivered is an original, but
all such counterparts shall together constitute but one and the same Supplement.

     AND FURTHER, the Owner Trustee hereby acknowledges that the Equipment
referred to in the aforesaid Lease Supplement attached hereto and made a part
hereof has been delivered to the Owner Trustee and is included in the property
of the Owner Trustee covered by all the terms and conditions of the Trust
Agreement, subject to the pledge or mortgage thereof under the Indenture.

                                      A-2
<PAGE>

     IN WITNESS WHEREOF, the Owner Trustee has caused this Indenture Supplement
to be duly executed by one of its duly authorized officers, on the day and year
first above written.

                              NORWEST BANK MINNESOTA, NATIONAL
                               ASSOCIATION, not in its individual capacity, but
                               solely as Owner Trustee

                              By:_______________________________________________
                              Name:
                              Title:

                                      A-3
<PAGE>

State of       )
               ) SS
County of      )

     On this ____ day of _____________________, 2000, before me personally
appeared ___________________, to me personally known, who being by me duly
sworn, say that he is __________________ of Norwest Bank Minnesota, National
Association, that said instrument was signed on such date on behalf of said
corporation by authority of its Board of Directors, and he acknowledged that the
execution of the foregoing instrument was the free act and deed of said
corporation.

                                             __________________________________
                                             Notary Public

[Notarial Seal]

My commission expires:

                                      A-4
<PAGE>

                                                                       EXHIBIT B
                                                                       ---------

                            Terms of Equipment Notes
                            -----------------------

     Aggregate Principal Amount         Interest Rate       Final Maturity
     --------------------------         -------------       --------------

         $108,423,245.65                    8.13%            June 29, 2016<PAGE>

                                                                Exhibit 4(b)

================================================================================
                             EXSIF WORLDWIDE, INC.

                          ___________________________

                       INDENTURE AND SECURITY AGREEMENT

                           Dated September 28, 2000

                                     Among

                                BANK ONE, N.A.,

                                                       Trustee,

                            EXSIF WORLDWIDE, INC.,

                                                       Issuer,

                                      and

                            UNION TANK CAR COMPANY,

                                                       Guarantor,

                          ___________________________

================================================================================
                                 $180,000,000
                      7.68% Senior Secured Notes Due 2015
<PAGE>

                               TABLE OF CONTENTS
                               -----------------

                                   ARTICLE I
                                   ---------
                                  DEFINITIONS
                                  -----------

<TABLE>
<CAPTION>
                                                                                                              Page
                                                                                                              ----
<S>                                                                                                           <C>
Section 1.01    Definitions...................................................................................   5
Section 1.02    Compliance Certificates and Opinions..........................................................  11
Section 1.03    Form of Documents Delivered to Trustee........................................................  12
Section 1.04    Acts of Noteholders...........................................................................  12

                                                 ARTICLE II
                                                 ----------
                               AMORTIZATION OF PRINCIPAL; INTEREST; REDEMPTION
                               -----------------------------------------------

Section 2.01    Principal and Interest Payments; Maturity; Redemption.........................................   14
Section 2.02    Form, Execution and Characteristics of Notes..................................................   15
Section 2.03    Authentication of Notes.......................................................................   16
Section 2.04    Registration of Transfer and Exchange of Notes................................................   17
Section 2.05    Persons Deemed Owners.........................................................................   17
Section 2.06    Cancellation..................................................................................   17
Section 2.07    Replacement of Lost Notes.....................................................................   17

                                                    ARTICLE III
                                                    -----------
                                                     COLLATERAL
                                                     ----------

Section 3.01    Additional and Substituted Equipment and Related Leasehold Interests Subject Hereto...........   18
Section 3.02    Termination of Security.......................................................................   18
Section 3.03    Indemnity.....................................................................................   19
Section 3.04    Substitution and Replacement of Collateral....................................................   19
Section 3.05    Maintenance of Equipment; Casualty Occurrences................................................   21
Section 3.06    Possession of Collateral......................................................................   22
Section 3.07    Marking of Equipment..........................................................................   22
Section 3.08    Modifications and Improvements................................................................   22

                                                       ARTICLE IV
                                                       ----------
                                              EVENTS OF DEFAULT AND REMEDIES
                                              -----------------------------

Section 4.01    Events of Default.............................................................................   23
</TABLE>

                                      -i-
<PAGE>

<TABLE>
<CAPTION>
                                                                                                                 Page
                                                                                                                 ----
<S>                                                                                                               <C>
Section 4.02    Incidents of Sale of Collateral..................................................................  25
Section 4.03    Judicial Proceedings Instituted by Trustee.......................................................  25
Section 4.04    Control by Noteholders...........................................................................  26
Section 4.05    Waivers of Default...............................................................................  26
Section 4.06    Undertaking to Pay Court Costs...................................................................  27
Section 4.07    Unconditional Right of Holders of Notes To Sue for Principal, Interest and Make-Whole Amount.....  27
Section 4.08    Remedies.........................................................................................  28
Section 4.09    Application of Proceeds..........................................................................  28
Section 4.10    Obligations of Company and the Guarantor Not Affected by Remedies................................  29
Section 4.11    Company To Deliver Collateral to Trustee.........................................................  29
Section 4.12    Limitations on Suits by Holders of Notes.........................................................  29
Section 4.13    Remedies Cumulative; Subject to Mandatory Requirements of Law....................................  30

                                                    ARTICLE V
                                                    ---------
                                         CERTAIN AGREEMENTS OF THE COMPANY
                                         ---------------------------------

Section 5.01    Discharge of Liens...............................................................................  30
Section 5.02    Further Assurances...............................................................................  30
Section 5.03    Payment of Expenses; Financing Statements........................................................  30

                                                  ARTICLE VI
                                                  ----------
                                    ADDITIONAL AGREEMENTS OF THE GUARANTOR
                                    --------------------------------------
                                                 AND THE COMPANY
                                                 ---------------

Section 6.01    Guarantee........................................................................................  31
Section 6.02    Compliance with Law..............................................................................  35
Section 6.03    Insurance........................................................................................  36
Section 6.04    Maintenance of Properties........................................................................  37
Section 6.05    Payment of Taxes and Claims......................................................................  37
Section 6.06    Maintenance of Corporate Existence...............................................................  37
Section 6.07    Consolidation, Merger or Sale of Assets Permitted................................................  37

                                                       ARTICLE VII
                                                       -----------
                                              CONCERNING THE HOLDERS OF NOTES
                                              -------------------------------

Section 7.01    Company to Furnish Trustee with Names and Addresses of Noteholders...............................  38
</TABLE>

                                      -ii-
<PAGE>

<TABLE>
<CAPTION>
                                                                            Page
                                                                            ----
<S>                                                                         <C>
Section 7.02  Preservation of Information; Communications to Noteholders... 39
Section 7.03  Financial Statements and Other Information................... 39
Section 7.04  Inspection................................................... 40

                                 ARTICLE VIII
                                 ------------
                                  THE TRUSTEE
                                  -----------

Section 8.01  Certain Duties and Responsibilities.......................... 41
Section 8.02  Notice of Defaults........................................... 42
Section 8.03  Certain Rights of Trustee.................................... 42
Section 8.04  Not Responsible for Recitals or Issuance of Notes............ 43
Section 8.05  May Hold Notes............................................... 43
Section 8.06  Money Held by Trustee........................................ 44
Section 8.07  Compensation and Reimbursement............................... 44
Section 8.08  Trustee Required; Eligibility................................ 45
Section 8.09  Resignation and Removal; Appointment of Successor............ 45
Section 8.10  Acceptance of Appointment by Successor....................... 47
Section 8.11  Merger, Conversion, Consolidation or Succession to Business.. 47
Section 8.12  Maintenance of Agencies...................................... 47
Section 8.13  Money for Note Payments to Be Held by Trustee................ 49

                                  ARTICLE IX
                                  ----------
                           SUPPLEMENTS TO INDENTURE
                           ------------------------

Section 9.01  Supplements to Indenture Without Consent of Noteholders...... 49
Section 9.02  Supplements to Indenture with Consent of Noteholders......... 50
Section 9.03  Documents Affecting Immunity or Indemnity.................... 50
Section 9.04  Execution of Supplements to Indentures....................... 51
Section 9.05  Effect of Supplements to Indenture........................... 51
Section 9.06  Reference in Notes to Supplements to Indentures.............. 51

                                   ARTICLE X
                                   ---------
                                 MISCELLANEOUS
                                 -------------

Section 10.01  Rights Confined to Parties and Holders...................... 51
Section 10.02  No Recourse................................................. 51
Section 10.03  Binding Upon Assigns........................................ 51
Section 10.04  Notices..................................................... 52
</TABLE>

                                     -iii-
<PAGE>

<TABLE>
<CAPTION>
                                                                          Page
                                                                          ----
<S>                                                                       <C>
Section 10.05  Effect of Headings; Date Executed; and Governing Law.....   52
Section 10.06  Legal Holidays...........................................   52
Section 10.07  Counterparts.............................................   52
</TABLE>

Schedule 1    -  Description of Equipment
Schedule 2    -  Insurance Provisions

                                      -iv-
<PAGE>

     This INDENTURE AND SECURITY AGREEMENT (this "Indenture") dated September
                                                  ---------
28, 2000, among BANK ONE, N.A., solely in its capacity as Trustee, a national
banking association organized and existing under the laws of the United States
of America (the "Trustee"), EXSIF WORLDWIDE, INC., a Delaware corporation (the
                 -------
"Company"), and UNION TANK CAR COMPANY, a Delaware corporation (the
--------
"Guarantor");
 ---------

                             W I T N E S S E T H:

     WHEREAS EXSIF Worldwide, Inc. 7.68% Senior Secured Notes due 2015 (the
"Notes") are to be issued and sold, at a price not less than their principal
------
amount, in an aggregate principal amount not exceeding $180,000,000;

     WHEREAS, the Company's prompt payment when due of the principal of the
Notes and interest thereon and the Make-Whole Amount, if any, all in accordance
with the terms of the Notes, has been unconditionally and irrevocably guaranteed
by the Guarantor; and

     WHEREAS the text of the Notes is to be substantially in the following form:

                                [Form of Note]

          THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
AMENDED (THE "ACT"), OR APPLICABLE STATE SECURITIES LAWS.  THIS NOTE MAY NOT BE
SOLD OR TRANSFERRED IN THE ABSENCE OF SUCH REGISTRATION OR EXEMPTION THEREFROM
UNDER THE FEDERAL OR STATE SECURITIES LAWS.  THIS NOTE IS SUBJECT TO THE TERMS
AND CONDITIONS OF AN INDENTURE AND SECURITY AGREEMENT AMONG EXSIF WORLDWIDE,
INC., UNION TANK CAR COMPANY AND BANK ONE, N.A., AS TRUSTEE, AS MORE FULLY SET
FORTH HEREIN.

                      7.68% SENIOR SECURED NOTE DUE 2015

          Secured by certain ISO Tank Containers and Wheeled Chassis
                 and the Leasehold Interests Relating Thereto

No. S-_____                                                    Chicago, Illinois
PPN 302228 AA9                                                            , 2000

$______________

     EXSIF WORLDWIDE, INC., a Delaware corporation (the "Company"), hereby
                                                         -------
promises to pay to _______________________________, or registered assigns, the
principal sum of $____________ in lawful currency of the United States of
America, in installments payable on the dates set forth in Exhibit A hereto,
commencing October 1, 2001, and thereafter to and including October 1, 2015,
each such installment to be in an amount equal to the corresponding
<PAGE>

percentage, if any, of the remaining principal amount hereof set forth in
Exhibit A hereto, together with interest thereon on the amount of such principal
amount remaining unpaid from time to time from and including the date hereof
until such principal amount shall be due and payable, payable commencing on
April 1, 2001 and on each October 1 and April 1 thereafter to the maturity date
hereof at the rate of 7.68% per annum (computed on the basis of a 360-day year
of twelve 30-day months). Interest on any overdue principal, any overdue Make-
Whole Amount, and (to the extent legally enforceable) on overdue interest shall
be paid from the due date thereof at the rate of 9.68% per annum (computed on
the basis of a 360-day year of twelve 30-day months), payable on demand.

     Payments with respect to the principal amount hereof, Make-Whole Amount, if
any, and interest thereon shall be payable in U.S. dollars in immediately
available funds at the principal bond and trustee administration office of Bank
One, N.A. (the "Trustee"), or as otherwise provided in the Indenture and
                -------
Security Agreement dated September 28, 2000, among the Company, Union Tank Car
Company, a Delaware corporation (the "Guarantor"), and the Trustee (the
                                      ---------
"Indenture").  Each such payment shall be made on the date such payment is due
----------
and without any presentment or surrender of this Note.  Whenever the date
scheduled for any payment to be made hereunder or under the Indenture shall not
be a Business Day, then such payment need not be made on such scheduled date but
may be made on the next succeeding Business Day with the same force and effect
as if made on such scheduled date and (provided such payment is made on such
next succeeding Business Day) no interest shall accrue on the amount of such
payment from and after such scheduled date to the time of such payment on such
next succeeding Business Day.

     Each holder hereof, by its acceptance of this Note, agrees that each
payment received by it hereunder shall be applied, first, to the payment of
                                                   -----
accrued but unpaid interest on this Note then due, second, to the payment of any
                                                   ------
Make-Whole Amount then due, and third, to the payment of the remaining
                                -----
outstanding principal amount of this Note.

     This Note is one of the Notes referred to in the Indenture and those
certain separate Note Purchase Agreements, dated September 28, 2000, among the
Company, the Guarantor and the respective Purchasers named therein (the "Note
                                                                         ----
Purchase Agreements") which have been or are to be issued by the Company
-------------------
pursuant to the terms of the Indenture and the Note Purchase Agreements.
Reference is hereby made to the Indenture for a statement of the rights of the
holder of, and the nature and extent of the security for, this Note, as well as
for a statement of the terms and conditions of the Indenture, to all of which
terms and conditions in the Indenture each holder hereof agrees by its
acceptance of this Note.

     This Note is subject to redemption, in whole or in part, at any time upon
at least 30 days advance notice at a price equal to the sum of (a) accrued and
unpaid interest to the date of redemption on the principal amount of this Note
to be redeemed, (b) the principal amount of this Note being redeemed and (c) the
Make-Whole Amount, if any.  The holder hereof, by its acceptance of this Note,
agrees to be bound by said provisions.

     This Note is a registered Note and is transferable, as provided in the
Indenture, only upon surrender of this Note for registration of transfer duly
endorsed by, or accompanied by a written

                                      -2-
<PAGE>

statement of transfer duly executed by, the registered holder hereof or his
attorney duly authorized in writing, and accompanied by an opinion of counsel
reasonably satisfactory to the Company, that such transfer may properly be made
without registration under the Securities Act of 1933, as amended. Prior to the
due presentation for registration of transfer of this Note, the Company and the
Trustee may deem and treat the registered holder of this Note as the absolute
owner and holder hereof for the purpose of receiving payment of all amounts
payable with respect hereto and for all other purposes and shall not be affected
by any notice to the contrary.

     The Guarantor, for good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, unconditionally and irrevocably
guarantees to the registered holder of this Note the prompt payment when due of
the principal of this Note and interest thereon and the Make-Whole Amount, if
any, specified in this Note, with interest on any overdue principal and on any
overdue interest, to the extent legally enforceable, at the rate specified in
this Note, all in accordance with the terms of this Note and the Indenture.

     THIS NOTE SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF
THE STATE OF NEW YORK.

     All terms used in this Note which are defined in the Indenture shall have
the meanings assigned to them in the Indenture.

     Unless the Certificate of Authentication hereon has been executed by or on
behalf of the Trustee by manual signature, this Note shall not be entitled to
any benefit under the Indenture or be valid or obligatory for any purpose.

     In Witness Whereof, each of the Company and the Guarantor has caused this
Note to be executed by one of its authorized officers as of the date hereof.

                                   EXSIF WORLDWIDE, INC.

                                   By:_______________________________
                                   Name:
                                   Title:

Attest:

_______________________________
Secretary

                                      -3-
<PAGE>

                                   PROMPT PAYMENT HEREOF WHEN DUE
                                   GUARANTEED BY:

                                   UNION TANK CAR COMPANY

                                   By:_______________________________
                                   Name:
                                   Title:

Attest:

_______________________________
Secretary

               [FORM OF TRUSTEE'S CERTIFICATE OF AUTHENTICATION]

    This is one of the Notes referred to in the within-mentioned Indenture.

                                   BANK ONE, N.A., as Trustee

                                   By:_______________________________
                                     Authorized Officer

[Insert Exhibit A - Amortization Schedule]

     WHEREAS, it is desired to secure to the holders of the Notes the payment of
the principal thereof when due, whether by declaration or otherwise, and
interest thereon and the Make-Whole Amount, if any, as hereinafter provided;

                                GRANTING CLAUSE

     NOW, THEREFORE, THIS INDENTURE AND SECURITY AGREEMENT WITNESSETH, that, to
secure the prompt payment of the principal of and interest on and Make-Whole
Amount, if any, on and all other amounts due with respect to the Notes from time
to time outstanding hereunder and the performance and observance by the Company
of all the agreements, covenants and provisions herein and in the Notes all for
the benefit of the holders of the Notes, and for the uses and purposes and
subject to the terms and provisions hereof, and in consideration of the premises
and of the covenants herein contained, and of the acceptance of the Notes by the
holders thereof, the Company does hereby assign, transfer, mortgage and pledge
and confirm unto the Trustee, its successors and assigns, for the security and
benefit of the holders of the Notes from time to time, a security interest in
and mortgage lien on all right, title and interest of the Company in and to the
following described property, rights, interests and privileges (which
collectively, including all property hereafter required to be subjected to the

                                      -4-
<PAGE>

Lien of this Indenture by any instrument supplemental hereto, being herein
called the "Indenture Estate"), to wit:
            ----------------

          (1)  the Equipment and all substitutions therefor, all as more
  particularly described in this Indenture and in any Indenture Supplements
  executed and delivered with respect to the Equipment or any such substitutions
  therefor, as provided in this Indenture;

          (2)  all monies and securities now or hereafter paid or deposited or
  required to be paid or deposited with the Trustee pursuant to any term of this
  Indenture, or required to be held by the Trustee hereunder, including, without
  limitation, all Permitted Investments held by the Trustee from time to time;

          (3)  the Leasehold Interests and all substitutions therefor, all as
  more particularly described in this Indenture and in any Indenture Supplements
  executed and delivered with respect to the Leasehold Interests or any
  substitutions therefor; and

          (4)  all proceeds of the foregoing.

                                HABENDUM CLAUSE

     TO HAVE AND TO HOLD all and singular the aforesaid property unto the
Trustee, its successors and assigns, in trust for the benefit and security of
the holders of the Notes from time to time, without any priority of any one Note
over any other Note, and for the uses and purposes, and subject to the terms and
provisions, set forth in this Indenture.

     The Company agrees that at any time and from time to time, upon the written
request of the Trustee, the Company will promptly and duly execute and deliver
or cause to be executed and delivered any and all such further instruments and
documents as the Trustee may reasonably deem to be necessary in order to obtain
the full benefits of this assignment and of the rights and powers herein
granted.

     The Company does hereby warrant and represent that it has not assigned or
pledged, and hereby covenants that it will not assign or pledge, so long as the
assignment hereunder shall remain in effect, any of its right, title or interest
hereby assigned, to anyone other than the Trustee.

     IT IS HEREBY COVENANTED AND AGREED by and among the parties hereto as
follows:

                                   ARTICLE I

                                  Definitions
                                  -----------

     Section 1.01  Definitions.  The following terms (except as otherwise
                   -----------
expressly provided or unless the context otherwise requires) for all purposes of
this Indenture shall have the respective meanings hereinafter specified:

                                      -5-
<PAGE>

          Affiliate of any Person shall mean any Person which, directly or
          ---------
     indirectly, controls or is controlled by, or is under common control with,
     such Person.  For the purposes of this definition, control (including
     controlled by and under common control with), as used with respect to any
     Person, shall mean the possession, directly or indirectly, of the power to
     direct or cause the direction of the management and policies of such
     Person, whether through the ownership of voting securities or by contract
     or otherwise.

          Business Day shall mean any day, other than a Saturday or Sunday or a
          ------------
     day on which commercial banking institutions or trust companies are
     authorized or required by law, regulation or executive order to be closed
     in New York, New York or Chicago, Illinois or, so long as any Note is
     outstanding, a city and state in which the Corporate Trust Office of the
     Trustee is located.

          Casualty Occurrence shall have the meaning set forth in Section 3.05
          -------------------
     hereof.

          Collateral shall mean all Equipment, Leasehold Interests and all
          ----------
     monies and securities at the time subject to the terms of this Indenture.

          Company shall mean EXSIF Worldwide, Inc., a Delaware corporation
          -------
     (whose chief place of business and chief executive office is currently
     located at 225 West Washington Street, 19/th/ Floor, Chicago, Illinois
     60606), and any successor or successors to it complying with the provisions
     of Section 6.07.

          Corporate Trust Office shall mean the principal office of the Trustee,
          ----------------------
     at which the corporate trust business of the Trustee shall, at the time in
     question, be administered, which office is, on the date of execution of
     this Indenture, located at 1 Bank One Plaza, Suite IL10126, Chicago,
     Illinois 60670.

          Cost shall mean the actual cost of Equipment to the Company.
          ----

          Default shall mean:
          -------

               (i)  any Event of Default; and

               (ii) any event or condition, the occurrence or existence of
          which, with the giving of notice or the passage of time or both, could
          constitute an Event of Default.

          The Company shall be considered to "be in Default" if a Default shall
     have occurred and be continuing.

          Environmental Laws shall mean any and all federal, state, local, and
          ------------------
     foreign statutes, laws, regulations, ordinances, rules, judgments, orders,
     decrees, permits, concessions, grants, franchises, licenses, agreements or
     governmental restrictions relating to pollution and the protection of the
     environment or the release of any materials into the

                                      -6-
<PAGE>

     environment, including but not limited to those related to hazardous
     substances or wastes, air emissions and discharges to waste or public
     systems.

          Equipment shall mean the ISO tank containers and wheeled chassis
          ---------
     described on Schedule 1 hereto and having an aggregate Cost of not less
                  ----------
     than $240,000,000.

          Event of Default shall mean any event specified in Section 4.01 to be
          ----------------
     an Event of Default.

          GAAP shall mean generally accepted accounting principles as in effect
          ----
     from time to time in the United States of America.

          Guarantor shall mean Union Tank Car Company, a Delaware corporation
          ---------
     (whose chief place of business and chief executive office is currently
     located at 225 West Washington Street, Chicago, Illinois 60606), and any
     successor or successors to it complying with the provisions of Section
     6.07.

          The word "holder", when used with respect to Notes, shall include the
                    ------
     plural as well as the singular number.

          Indebtedness shall mean, with respect to the Company on any date of
          ------------
     determination (without duplication), (i) the principal of and premium (if
     any) in respect of indebtedness for borrowed money, (ii) the principal of
     and premium (if any) in respect of obligations evidenced by bonds,
     debentures, notes or other similar instruments, (iii) all obligations in
     respect of letters of credit or other similar instruments (including
     obligations with respect to letters of credit securing obligations (other
     than obligations described in clauses (i), (ii) and (v)) entered into in
     the ordinary course of business to the extent that such letters of credit
     are not drawn upon or, if and to the extent drawn upon, such drawing is
     reimbursed no later than the third business day following receipt of a
     demand for reimbursement following payment on the letter of credit), (iv)
     all obligations to pay the deferred and unpaid purchase price of property
     or services (other than accounts payable to trade creditors arising in the
     ordinary course of business), (v) all capitalized lease obligations, (vi)
     all Indebtedness of other Persons secured by a Lien on any asset of the
     Company whether or not such Indebtedness is assumed by such Person;
     provided, however, that the amount of such Indebtedness shall be the lesser
     --------  -------
     of (A) the fair market value of such asset at such date of determination or
     (B) the amount of such Indebtedness of such other Persons, and (viii) all
     Indebtedness of other Persons to the extent guaranteed by the Company.  The
     amount of Indebtedness at any date shall be the outstanding balance at such
     date of all unconditional obligations as described above and the maximum
     liability, upon the occurrence of the contingency giving rise to the
     obligation, of any contingent obligations at such date.

          Independent Engineer shall mean an engineer, appraiser or other expert
          --------------------
     appointed by the Company and approved by the Trustee in the exercise of
     reasonable care, who (a) is in fact independent, (b) does not have any
     substantial interest, direct or indirect, in the Company or in any other
     obligor on the Notes or in any Affiliate of the Company or

                                      -7-
<PAGE>

     any such other obligor and (c) is not connected with the Company or any
     other obligor on the Notes or any Affiliate of the Company or any such
     other obligor as an officer, employee, promoter, underwriter, trustee,
     partner, director or person performing similar functions.

          Institutional Investor shall mean (a) any original purchaser of a
          ----------------------
     Note, (b) any Noteholder holding more than 5% of the aggregate principal
     amount of the Notes then outstanding, and (c) any bank, trust company,
     savings and loan association or other financial institution, any pension
     plan, any investment company, any insurance company, any broker or dealer,
     or any other similar financial institution or entity, regardless of legal
     form.

          Leasehold Interests shall mean all interests of the Company as lessor
          -------------------
     under all leases to which the units of Equipment are subject from time to
     time, solely to the extent such leases relate to the Equipment.

          Liens shall mean, as to any Person, any mortgage, lien, pledge,
          -----
     adverse claim, charge, security interest or other encumbrance in or on, or
     interest or title of any vendor, lessor (excluding lessors under non-
     capitalized leases), lender or other secured party to or of such Person
     under conditional sale or other title retention agreement or capital lease
     with respect to any property or asset of such Person, or the signing or
     filing of a financing statement which names such Person as debtor, or the
     signing of any security agreement authorizing any other party as the
     secured party thereunder to file any financing statement.

          Make-Whole Amount shall mean, with respect to any Note, an amount
          -----------------
     equal to the excess, if any, of the Discounted Value of the Remaining
     Scheduled Payments with respect to the Called Principal of such Note over
     the amount of such Called Principal.  For the purposes of determining the
     Make-Whole Amount, the following terms have the following meanings:

               Called Principal means, with respect to any Note, the principal
               ----------------
     of such Note that is to be redeemed pursuant to Section 2.01.

               Discounted Value means, with respect to the Called Principal of
               ----------------
          any Note, the amount obtained by discounting all Remaining Scheduled
          Payments with respect to such Called Principal from their respective
          scheduled due dates to the Settlement Date with respect to such Called
          Principal, in accordance with accepted financial practice and at a
          discount factor (applied on the same periodic basis as that on which
          interest on the Notes is payable) equal to the Reinvestment Yield with
          respect to such Called Principal.

               Reinvestment Yield means, with respect to the Called Principal of
               ------------------
          any Note, 0.50% over the yield to maturity implied by (i) the yields
                                                                 -
          reported, as of 10:00 A.M. (New York City time) on the second Business
          Day preceding the Settlement Date with respect to such Called
          Principal, on the display designated

                                      -8-
<PAGE>

          as "Page 678" on the Telerate Access Service (or such other display as
          may replace Page 678 on Telerate Access Service) for actively traded
          U.S. Treasury securities having a maturity equal to the Remaining
          Average Life of such Called Principal as of such Settlement Date, or
          (ii) if such yields are not reported as of such time or the yields
           --
          reported as of such time are not ascertainable, the Treasury Constant
          Maturity Series Yields reported, for the latest day for which such
          yields have been so reported as of the second Business Day preceding
          the Settlement Date with respect to such Called Principal, in Federal
          Reserve Statistical Release H.15 (519) (or any comparable successor
          publication) for actively traded U.S. Treasury securities having a
          constant maturity equal to the Remaining Average Life of such Called
          Principal as of such Settlement Date. Such implied yield will be
          determined, if necessary, by (a) converting U.S. Treasury bill
                                        -
          quotations to bond-equivalent yields in accordance with accepted
          financial practice and (b) interpolating linearly between (1) the
                                  -                                  -
          actively traded U.S. Treasury security with the duration closest to
          and greater than the Remaining Average Life and (2) the actively
                                                           -
          traded U.S. Treasury security with the duration closest to and less
          than the Remaining Average Life.

               Remaining Average Life means, with respect to any Called
               ----------------------
          Principal, the number of years (calculated to the nearest one-twelfth
          year) obtained by dividing (i) such Called Principal into (ii) the sum
                                      -                              --
          of the products obtained by multiplying (a) the principal component of
                                                   -
          each Remaining Scheduled Payment with respect to such Called Principal
          by (b) the number of years (calculated to the nearest one-twelfth
              -
          year) that will elapse between the Settlement Date with respect to
          such Called Principal and the scheduled due date of such Remaining
          Scheduled Payment.

               Remaining Scheduled Payments means, with respect to the Called
               ----------------------------
          Principal of any Note, all payments of such Called Principal and
          interest thereon that would be due after the Settlement Date with
          respect to such Called Principal if no payment of such Called
          Principal were made prior to its scheduled due date, provided that if
                                                               --------
          such Settlement Date is not a date on which interest payments are due
          to be made under the terms of the Notes, then the amount of the next
          succeeding scheduled interest payment will be reduced by the amount of
          interest accrued to such Settlement Date and required to be paid on
          such Settlement Date pursuant to Section 2.01.

               Settlement Date means, with respect to the Called Principal of
               ---------------
          any Note, the date on which such Called Principal is to be redeemed
          pursuant to Section 2.01.

          Material Adverse Effect shall mean a material adverse effect on (a)
          -----------------------
     the business, operations, affairs, financial condition, assets or
     properties of the Company or the Guarantor or (b) the ability of the
     Company or the Guarantor to perform its obligations under this Indenture,
     the Note Purchase Agreement or the Notes, or (c) the validity or
     enforceability of this Indenture, the Note Purchase Agreement or the Notes.

                                      -9-
<PAGE>

          Maturity Date shall mean October 1, 2015.
          -------------

          Note Purchase Agreement shall mean each of those certain Note Purchase
          -----------------------
     Agreements, dated September 28, 2000, among the Company, the Guarantor and
     the respective original purchasers of the Notes.

          Noteholder shall mean the Person in whose name a Note is registered in
          ----------
     the Register.

          Notes shall mean the Senior Secured Notes issued hereunder.
          -----

          Officers' Certificate shall mean a Certificate signed by the Chairman
          ---------------------
     of the Board, or the President or any Vice President and by the Treasurer
     or any Assistant Treasurer or the Secretary or any Assistant Secretary of
     the Company or the Guarantor, as applicable, which officer is in a position
     to know the truth and accuracy thereof.

          Opinion of Counsel shall mean an opinion in writing signed by legal
          ------------------
     counsel who shall be acceptable to the Trustee and who may, unless in a
     particular instance the Trustee shall otherwise require, be an employee of
     or counsel to the Company or the Guarantor, as applicable, or an Affiliate
     of the Company or the Guarantor, as applicable.  The acceptance by the
     Trustee of, and its action on, an Opinion of Counsel shall be sufficient
     evidence that such counsel is satisfactory to the Trustee.

          Penalty Rate shall mean 2% per annum over the rate specified in the
          ------------
     Notes.

          Permitted Investments shall mean bonds, notes or other direct
          ---------------------
     obligations of the United States of America or obligations for which the
     full faith and credit of the United States is pledged to provide for the
     payment of the interest and principal of such obligations and which mature
     within one year of the date of purchase.

          Person shall mean an individual, partnership, corporation, limited
          ------
     liability company, association, trust, unincorporated organization or a
     government or agency or political subdivision thereof.

          Record Date shall mean with respect to any Scheduled Payment Date, the
          -----------
     close of business on the March 15 or September 15 (whether or not a
     Business Day), as the case may be, next preceding such Scheduled Payment
     Date.

          Request shall mean a written request for the action therein specified,
          -------
     delivered to the Trustee, dated not more than 10 days prior to the date of
     delivery to the Trustee and signed on behalf of the Company by the Chairman
     of the Board, the President, a Vice President or the Treasurer of the
     Company or the Guarantor, as the case may be.

          Responsible Officer shall mean (i) with respect to the initial
          -------------------
     Trustee, any officer assigned by the Trustee to administer corporate trust
     matters; (ii) with respect to any successor Trustee, the chairman or vice-
     chairman of the board of directors or trustees, the chairman or vice-
     chairman of the executive or standing committee of the board of

                                      -10-
<PAGE>

     directors or trustees, the president, the chairman of the committee on
     trust matters, any vice-president, any second vice-president, the
     secretary, any assistant secretary, the treasurer, any assistant treasurer,
     the cashier, any assistant cashier, any trust officer or assistant trust
     officer, the comptroller and any assistant comptroller; and (iii) with
     respect to the Company or the Guarantor, as applicable, the chief financial
     officer, principal accounting officer, treasurer or comptroller, and any
     other officer with responsibility for the administration of the relevant
     portion of this Indenture. Responsible Officer also means, with respect to
     any Trustee, any other officer of the Trustee customarily performing
     functions similar to those performed by the persons who at the time shall
     be any of the above designated officers, and with respect to a particular
     corporate trust matter, any other officer to whom such matter is referred
     because of his knowledge of and familiarity with the particular subject.

          Scheduled Payment Date shall have the meaning set forth in Section
          ----------------------
     2.01.

          SEC shall mean the United States Securities and Exchange Commission.
          ---

          Senior Financial Officer shall mean the chief financial officer,
          ------------------------
     principal accounting officer, treasurer or comptroller of the Company or
     the Guarantor, as the case may be.

          Subordinated Indebtedness shall mean any Indebtedness of the Company
          -------------------------
     (whether outstanding on the date of issuance of the Notes or thereafter
     incurred) that is subordinate or junior in right of payment to the Notes or
     any other senior Indebtedness of the Company pursuant to a written
     agreement.

          Trustee shall mean Bank One, N.A., solely in its capacity as Trustee,
          -------
     and, subject to the provisions of Article VII, any successor as trustee
     hereunder.

          Value, as used herein, shall mean the fair market value thereof.
          -----

     The words herein, hereof, hereby, hereto, hereunder and words of similar
import refer to this Indenture as a whole and not to any particular Article,
Section, paragraph or subdivision hereof.

     Section 1.02  Compliance Certificates and Opinions.  Upon any application
                   ------------------------------------
or request by the Company to the Trustee to take any action under any provision
of this Indenture, the Company shall furnish to the Trustee an Officer's
Certificate stating that, in the opinion of the signers, all conditions
precedent, if any, provided for in this Indenture relating to the proposed
action have been complied with and an Opinion of Counsel stating that in the
opinion of such counsel all such conditions precedent, if any, have been
complied with, except that in the case of any such application or request as to
which the furnishing of such documents is specifically required by any provision
of this Indenture relating to such particular application or request, no
additional Certificate or opinion need be furnished.

                                      -11-
<PAGE>

     Every certificate or opinion with respect to compliance with a condition or
covenant provided for in this Indenture (other than a certificate provided
pursuant to Section 7.03(b)) shall include:

          (a)  a statement that each individual signing such certificate or
     opinion has read such covenant or condition and the definitions herein
     relating thereto;

          (b)  a brief statement as to the nature and scope of the examination
     or investigation upon which the statements or opinions contained in such
     certificate or opinion are used;

          (c)  a statement that, in the opinion of each such individual, he or
     she has made such examination or investigation as necessary to enable him
     or her to express an informed opinion as to whether or not such covenant or
     condition has been complied with; and

          (d)  a statement as to whether, in the opinion of each such
     individual, such condition or covenant has been complied with.

     Section 1.03  Form of Documents Delivered to Trustee.  In any case where
                   --------------------------------------
several matters are required to be certified by, or covered by an opinion of,
any specified Person, it is not necessary that all such matters be certified by,
or covered by the opinion of, only one such Person, or that they be so certified
or covered by only one document, but one such Person may certify or give an
opinion with respect to some matters and one or more other such Persons as to
other matters and any such Person may certify or give an opinion as to such
matters in one or several documents.

     Any Opinion of Counsel stated to be based on the opinion of other counsel
shall be accompanied by a copy of such other opinion.

     Where any Person is required to make, give or execute two or more
applications, requests, consents, certificates, statements, opinions or other
instruments under this Indenture, they may, but need not, be consolidated and
form one instrument.

     Section 1.04  Acts of Noteholders.
                   -------------------

          (a)  Any direction, consent, waiver or other action provided by this
     Indenture to be given or taken by Noteholders may be embodied in and
     evidenced by one or more instruments of substantially similar tenor signed
     by such Noteholders in person or by an agent duly appointed in writing;
     and, except as herein otherwise expressly provided, such action shall
     become effective when such instrument or instruments are delivered to the
     Trustee and, where it is hereby expressly required, to the Company.  Such
     instrument or instruments (and the action embodied therein and evidenced
     thereby) are herein sometimes referred to as the "Act" of the Noteholders
                                                       ---
     signing such instrument or instruments.  Proof of execution of any such
     instrument or of a writing appointing any such agent shall be sufficient
     for any purpose of this Indenture and conclusive in favor of the Trustee
     and the Company, if made in the manner provided in this Section.

                                      -12-
<PAGE>

          (b)  The fact and date of the execution by any Person of any such
     instrument or writing may be proved by the certificate of any notary public
     or other officer of any jurisdiction authorized to take acknowledgments of
     deeds or administer oaths that the Person executing such instrument
     acknowledged to him the execution thereof, or by an affidavit of a witness
     to such execution sworn to before any such notary or such other officer and
     where such execution is by an officer of a corporation or association or a
     member of a partnership, on behalf of such corporation, association or
     partnership, such certificate or affidavit shall also constitute sufficient
     proof of his authority.  The fact and date of the execution of any such
     instrument or writing, or the authority of the Person executing the same,
     may also be proved in any other reasonable manner which the Trustee deems
     sufficient.  In the absence of bad faith on the part of the Trustee, an
     Officer's Certificate may be deemed to be conclusively proved.

          (c)  In determining whether the Noteholders of the requisite aggregate
     unpaid principal then outstanding have given any direction, consent or
     waiver (a "Direction"), under this Indenture, Notes owned by the Company or
                ---------
     any Affiliate of the Company shall be disregarded and deemed not to be
     outstanding under this Indenture for purposes of any such determination.
     In determining whether the Trustee shall be protected in relying upon any
     such Direction, only Notes which the Trustee knows to be so owned shall be
     so disregarded. Notwithstanding the foregoing, if any such Person owns 100%
     of the Notes outstanding, such Notes shall not be so disregarded as
     aforesaid.

          (d)  The Company may at its option by delivery of an Officer's
     Certificate to the Trustee set a record date to determine the Noteholders
     entitled to give any consent, request, demand, authorization, direction,
     notice, waiver or other Act.  Such record date shall be the record date
     specified in such Officer's Certificate which shall be a date not more than
     30 nor less than 15 days prior to the first solicitation of Noteholders in
     connection therewith.  If such a record date is fixed, such consent,
     request, demand, authorization, direction, notice, waiver or other Act may
     be given before or after such record  date, but only the Noteholders of
     record at the close of business on such record date shall be deemed to be
     Noteholders for the purposes of determining whether Noteholders of the
     requisite aggregate principal amount then outstanding have authorized or
     agreed or consented to such consent, request, demand, authorization,
     direction, notice, waiver or other Act, and for that purpose the
     outstanding Notes shall be computed as of such record date; provided that
                                                                 --------
     no such consent, request, demand, authorization, direction, notice, waiver
     or other Act by the Noteholders on such record date shall be deemed
     effective unless it shall become effective pursuant to the provisions of
     this Indenture not later than one year after the record date.

          (e)  Any direction, consent, waiver or other action by the registered
     holder of any Note shall bind the registered holder of every Note issued
     upon the transfer thereof or in exchange thereof or in lieu thereof,
     whether or not notation of such action is made upon such Note.

                                      -13-
<PAGE>

          (f)  Except as otherwise provided in Section 1.04(c), Notes owned by
     or pledged to any Person shall have an equal and proportionate benefit
     under the provisions of this Indenture, without preference, priority, or
     distinction as among all of the Notes.

                                  ARTICLE II

                Amortization of Principal; Interest; Redemption
                -----------------------------------------------

     Section 2.01  Principal and Interest Payments; Maturity; Redemption.  The
                   -----------------------------------------------------
Notes shall bear interest at 7.68% per annum and shall be payable as follows
(unless payment thereof is accelerated pursuant to Article IV of this
Indenture):  principal shall be paid in installments on the dates set forth in
Exhibit A to the form of Note set forth in the third Whereas clause of this
Indenture, commencing October 1, 200l, and thereafter to and including October
1, 2015, each such installment to be in an amount equal to the corresponding
percentage, if any, of the remaining principal amount set forth in Exhibit A to
the form of Note, and interest on the outstanding principal shall be paid in
semiannual installments on April 1 and October 1 in each year (each, a
"Scheduled Payment Date") commencing April 1, 2001.  Interest on the Notes shall
 ----------------------
accrue from the date of original issue and shall be calculated on the basis of a
360-day year of twelve 30-day months.  Interest shall be payable on overdue
installments of principal and, to the extent legally enforceable, interest at
the Penalty Rate.

     The Company may, at its option, upon notice as provided below, redeem at
any time all, or from time to time any part of, the Notes, in an amount not less
$5,000,000 in the case of a partial redemption, for the sum of (a) accrued
interest to the date of redemption, (b) the principal amount of the Notes being
redeemed and (c) the Make-Whole Amount, if any, determined as of the redemption
date with respect to such principal amount.  The Company will give each holder
of Notes written notice of each optional redemption under this Section 2.01 not
less than 30 days and not more than 60 days prior to the date fixed for such
redemption.  Each such notice shall specify such date, the aggregate principal
amount of the Notes to be redeemed on such date, the principal amount of each
Note held by such holder to be redeemed (determined in accordance with the
following paragraph), and the interest to be paid on the redemption date with
respect to such principal amount being redeemed, and shall be accompanied by a
certificate of a Senior Financial Officer of the Company as to the estimated
Make-Whole Amount due in connection with such redemption (calculated as if the
date of such notice were the date of the redemption), setting forth the details
of such computation.  Two Business Days prior to such redemption, the Company
shall deliver to each holder of Notes a certificate of a Senior Financial
Officer of the Company specifying the calculation of such Make-Whole Amount as
of the specified redemption date.

     The Company and the Guarantor acknowledge, and the parties hereto agree,
that each holder of a Note has the right to maintain its investment in the Notes
free from repayment by the Company (except as herein specifically provided for)
and that the provision for payment of a Make-Whole Amount by the Company in the
event that the Notes are redeemed, is intended to provide compensation for the
deprivation of such right under such circumstances.

                                      -14-
<PAGE>

     In the case of a partial redemption of the Notes, the principal amount of
the Notes to be redeemed shall be allocated among all of the Notes at the time
outstanding in proportion, as nearly as practicable, to the respective unpaid
principal amounts thereof not theretofore called for redemption.

     In the case of each redemption of Notes pursuant to this Section 2.01, the
principal amount of each Note to be redeemed shall mature and become due and
payable on the date fixed for such redemption, together with interest on such
principal amount accrued to such date and the applicable Make-Whole Amount, if
any.  From and after such date, unless the Company or the Guarantor shall fail
to pay such principal amount when so due and payable, together with interest and
Make-Whole Amount, if any, as aforesaid, interest on such principal amount shall
cease to accrue.  Any Note redeemed in full shall be surrendered to the Company
and cancelled and shall not be reissued, and no Note shall be issued in lieu of
any redeemed principal amount of any Note.

     The Guarantor will not and will not permit the Company or any other
Affiliate to purchase, redeem, prepay or otherwise acquire, directly or
indirectly, any of the outstanding Notes except (a) upon the payment or
                                                 -
redemption of the Notes in accordance with the terms of this Indenture or (b)
pursuant to an offer to purchase made by the Guarantor, the Company or any
Affiliate pro rata to the holders of all Notes at the time outstanding upon the
same terms and conditions.  Any such offer shall provide each holder with
sufficient information to enable it to make an informed decision with respect to
such offer, and shall remain open for at least 20 Business Days.  If the holders
of more than 25% of the principal amount of the Notes then outstanding accept
such offer, the Guarantor, the Company or the Affiliate making the offer shall
promptly notify the remaining holders of such fact and the expiration date for
the acceptance by holders of Notes of such offer shall be extended by the number
of days necessary to give each such remaining holder at least 10 Business Days
from its receipt of such notice to accept such offer.  The Company will promptly
cancel all Notes acquired by it, the Guarantor or any Affiliate pursuant to any
payment, prepayment or purchase of Notes pursuant to any provision of this
Agreement and no Notes may be issued in substitution or exchange for any such
Notes.

     Payment of the principal, Make-Whole Amount, if any, and interest on the
Notes shall be made by the Company at the Corporate Trust Office in such coin or
currency of the United States of America as at the time of payment shall be
legal tender for the payment of public and private debts.

     Section 2.02  Form, Execution and Characteristics of Notes.
                   --------------------------------------------

          (a)  The Notes shall be in substantially the form hereinbefore set
     forth.

          (b)  The Notes shall be signed in the name and on behalf of each of
     the Company and the Guarantor by the manual or facsimile signature of one
     of its officers and its corporate seal or a facsimile thereof shall be
     affixed or imprinted thereon and attested by the manual signature of one of
     its officers. In case any officer of the Company or the Guarantor whose
     signature, whether facsimile or not, shall appear on any of the Notes shall
     cease to be such officer of the Company or the Guarantor, as

                                      -15-
<PAGE>

     applicable, before the Notes shall have been issued and delivered by the
     Company or shall not have been acting in such capacity on the date of the
     Notes, such Notes may be adopted by the Company or the Guarantor, as
     applicable, and be issued and delivered as though such person had not
     ceased to be or had then been such officer of the Company or the Guarantor,
     as applicable.

          (c)  The Notes (i) shall be issuable in denominations of U.S. $1,000
     or any multiple thereof; (ii) shall be registered, as to both principal and
     interest, in the name of the holders; (iii) shall be transferable in whole
     or in part upon presentation and surrender thereof for transfer at the
     Corporate Trust Office, accompanied by appropriate instruments of
     assignment and transfer, duly executed by the registered holder of the
     surrendered Note or by duly authorized attorney, in form satisfactory to
     the Trustee; (iv) shall be dated as of the date of issue unless issued in
     exchange for another Note bearing unpaid interest from an earlier date, in
     which case they shall be dated as of such earlier date; (v) shall entitle
     the registered holder to interest from the date thereof; and (vi) shall be
     exchangeable for an aggregate principal amount of Notes of authorized
     denominations of like tenor and maturity equal to the then unpaid principal
     amount of Notes being exchanged.

          (d)  Intentionally Omitted.

          (e)  Each Note delivered pursuant to any provision of this Indenture
     in exchange or substitution for, or upon the transfer of the whole or any
     part, as the case may be, of one or more other Notes shall carry all the
     rights to principal and to interest accrued and unpaid and to accrue, which
     were carried by the whole or such part, as the case may be, of such one or
     more other Notes, and, notwithstanding anything contained in this
     Indenture, such Note shall be so dated that neither gain nor loss in
     interest or principal shall result from such exchange, substitution or
     transfer and a notation of all previous principal payments shall be
     endorsed on the reverse side thereof.

          The Trustee shall not be required to issue, transfer or exchange Notes
     for a period of 10 days next preceding any principal or interest payment
     date.

          (f)  The definitive Notes shall be printed, lithographed, typewritten
     or engraved or produced by any combination of these methods, all as
     determined by the officer executing such Notes as evidenced by such
     execution.

          (g)  The Notes shall in all respects rank senior to all Subordinated
     Indebtedness of the Company.  The Notes shall rank pari passu with all
     existing and future secured Indebtedness of the Company that by its terms
     constitutes senior Indebtedness of the Company.  The obligations of the
     Guarantor under Section 6.01 hereof shall rank pari passu with all senior
     unsecured obligations of the Guarantor.

     Section 2.03  Authentication of Notes.  The Trustee shall duly authenticate
                   -----------------------
and deliver Notes in authorized denominations equaling in the aggregate the
aggregate principal amount of the Notes to be issued hereunder.

                                      -16-
<PAGE>

     Section 2.04  Registration of Transfer and Exchange of Notes.  The Trustee
                   ----------------------------------------------
shall cause to be kept at the Corporate Trust Office or the office or agency to
be maintained by it in accordance with the provisions of Section 8.12 a register
(the "Register") in which, subject to such reasonable regulations as it may
      --------
prescribe, the Trustee shall provide for the registration of Notes and of
transfers and exchanges of Notes as herein provided.  The Trustee shall
initially be the registrar (the "Registrar") for the purpose of registering
                                 ---------
Notes and transfers and exchanges of Notes as herein provided.

     Upon presentation for registration of transfer of any Note at the Corporate
Trust Office or such other office or agency, the Trustee shall execute,
authenticate and deliver, in the name of the designated transferee or
transferees, one or more new Notes in authorized denominations of a like
aggregate unpaid principal amount.

     At the option of a Noteholder, Notes may be exchanged for other Notes of
authorized denominations of a like aggregate unpaid principal amount, upon
surrender of the Notes to be exchanged at any such office or agency. Whenever
any Notes are so surrendered for exchange, the Trustee shall promptly execute,
authenticate and deliver the Notes that the Noteholder making the exchange is
entitled to receive.  Every Note presented or surrendered for registration of
transfer or exchange shall be duly endorsed or accompanied by a written
instrument of transfer in form satisfactory to the Trustee and the Registrar
duly executed by the Noteholder thereof or its attorney duly authorized in
writing.

     No service charge shall be made to a Noteholder for any registration of
transfer or exchange of Notes, but the Trustee shall require payment of a sum
sufficient to cover any tax or governmental charge that may be imposed in
connection with any transfer or exchange of Notes.

     All Notes surrendered for registration of transfer and exchange shall be
canceled and subsequently destroyed by the Trustee.  The Trustee shall provide
the Company with written certification as to the destruction of all such Notes.

     Section 2.05  Persons Deemed Owners.  Prior to due presentation of a Note
                   ---------------------
for registration of transfer, the Trustee, the Registrar, and any paying agent
of the Trustee may treat the Person in whose name any Note is registered as the
owner of such Note for all purposes whatsoever, and neither the Trustee, the
Registrar, nor any paying agent of the Trustee shall be affected by any notice
to the contrary.

     Section 2.06  Cancellation.  All Notes surrendered for payment or transfer
                   ------------
or exchange shall, if surrendered to any Person party hereto other than the
Registrar, be delivered to the Registrar for cancellation.  No Notes shall be
authenticated in lieu of or in exchange for any Notes canceled as provided in
this Section, except as expressly permitted by this Indenture.  All canceled
Notes held by the Registrar shall be destroyed in due course and a certification
of their destruction delivered to the Trustee and the Company.

     Section 2.07  Replacement of Lost Notes.  In case any Note shall become
                   -------------------------
mutilated or defaced or be lost, destroyed or stolen, then on the terms herein
set forth, and not otherwise, the Trustee shall promptly execute and deliver a
new Note in the then unpaid principal amount of the

                                      -17-
<PAGE>

predecessor Note and bearing such identifying number or designation as the
Trustee may determine, in exchange and substitution for, and upon cancellation
of, the mutilated or defaced Note, or in lieu of and in substitution for the
same if lost, destroyed or stolen. The applicant for a new Note pursuant to this
Section shall furnish to the Trustee and to the Company evidence to their
satisfaction of the loss, destruction or theft of such Note alleged to have been
lost, destroyed or stolen and of the ownership and authenticity of such
mutilated, defaced, lost, destroyed or stolen Note, and also shall furnish such
security or indemnity as may be required by the Trustee and the Company in their
discretion, and shall pay all expenses and charges of such substitution or
exchange. In the case of each of the original purchasers of Notes or any
Institutional Investor transferee, a letter of indemnity in form reasonably
satisfactory to the Company and the Trustee from such holder shall be sufficient
security and indemnity. All Notes are held and owned upon the express condition
that the foregoing provisions are exclusive in respect of the replacement of
mutilated, defaced, lost, destroyed or stolen Notes and shall preclude any and
all other rights and remedies, any law or statute now existing or hereafter
enacted to the contrary notwithstanding.

                                  ARTICLE III

                                  Collateral
                                  ----------

     Section 3.01  Additional and Substituted Equipment and Related Leasehold
                   ----------------------------------------------------------
Interests Subject Hereto.  In the event that the Company shall, as provided in
------------------------
Section 3.04, cause to be transferred to the Trustee other Equipment or cash in
addition to or in substitution for any of the Equipment herein specifically
described or subjected hereto, as a condition to any release of Collateral
contemplated in connection with such transfer, such other Equipment or cash, as
well as all Leasehold Interests relating to such Equipment, shall be included as
part of the Collateral by supplement hereto to be executed by the Trustee, the
Guarantor and the Company in accordance with Article IX and shall be subject to
all the terms and conditions hereof in all respects as though it had been part
of the Collateral herein specifically described.

     Section 3.02  Termination of Security.
                   -----------------------

          (a)  After all payments which are required to be made on the Notes
     pursuant to this Indenture have been completed and fully made by the
     Company or the Guarantor, (1) any moneys or Permitted Investments remaining
     in the hands of the Trustee after providing for all outstanding Notes and
     after paying the expenses of the Trustee, including its reasonable
     compensation, shall be paid to the Company or the Guarantor (to the extent
     that the Guarantor has made payments hereunder), and (2) the Trustee shall
     execute for record in public offices, at the expense of the Company, such
     instrument or instruments in writing as reasonably shall be requested by
     the Company in order to make clear upon public records the release of the
     Collateral from the security interest granted hereunder, under the laws of
     any jurisdiction.

          (b)  Provided that no Default or Event of Default shall have occurred
     or be continuing, on each principal payment date beginning on October 1,
     2008, the Trustee shall execute for record in public offices, at the
     expense of the Company, such instrument or instruments in writing as
     reasonably shall be requested by the Company in order to

                                      -18-
<PAGE>

     make clear upon public records the release from the security interest
     granted hereunder, under the laws of any jurisdiction, of any item of
     Equipment which reached 18 years of age (determined by reference to the
     month and year in which such item of Equipment was built) during the
     calendar year in which such principal payment is made (as so certified to
     the Trustee by a Responsible Officer of the Company), together with all
     Leasehold Interests relating to such Equipment, except as set forth in
     Sections 3.04 or 3.05 hereof.

     Section 3.03  Indemnity.  The Company covenants and agrees to indemnify the
                   ---------
Trustee against any and all claims arising out of or connected with the use of
any of the Equipment, and particularly against any and all claims arising out of
the use of any patented inventions in and about the Equipment, and to comply in
all respects with the laws of the United States of America and of all the
states, foreign countries and other jurisdictions in which the Equipment, or any
unit thereof, may be operated, and with all lawful acts, rules, regulations and
orders of any commissions, boards and other legislative, executive,
administrative or judicial bodies or officers having power to regulate or
supervise any of the Equipment, provided, however, that the Company may in good
                                --------  -------
faith contest the validity of any such law, act, rule, regulation or order, or
the application thereof to the Equipment or any part thereof, in any manner
which does not contest the validity of the Notes, the Note Purchase Agreements,
the Indenture or the security interests granted to the Trustee hereunder, and
which will not in the judgment of the Trustee otherwise endanger the rights or
interests of the Trustee or of the holders of the Notes.  The Company shall not
be relieved from any of its obligations hereunder by reason of the assertion or
enforcement of any such claims or the commencement or prosecution of any
litigation in respect thereof.  The Company's obligation to indemnify the
Trustee under this Section 3.03 shall survive the termination of this Indenture.

     Section 3.04  Substitution and Replacement of Collateral.  At any time and
                   ------------------------------------------
from time to time, as required for valid business reasons arising in the
ordinary course of the Company's business (as determined in the Company's
reasonable discretion), the Company may issue to the Trustee a Request, and upon
such Request, the Trustee shall execute and deliver a release of all the right
and interest of the Trustee in and to any of the units of Equipment and the
related Leasehold Interests as provided herein; provided, however, that, at the
                                                --------  -------
option of the Company, (a) there shall be paid to the Trustee cash in an amount
not less than the Value, as of the date of such Request, of the units of
Equipment to be released by the Trustee or (b) there shall be conveyed to the
Trustee, at the time of release of any units of Equipment and the related
Leasehold Interests, a security interest in (i) other units of Equipment with a
Value not less than the Value, and a remaining useful life not less than that as
of the date of such Request, of the units of Equipment to be released and (ii)
the Leasehold Interests relating to such other units of Equipment.

     At the time of delivery of any Request pursuant to the first paragraph of
this Section, the Company shall, if other Equipment and related Leasehold
Interests are to be conveyed to the Trustee in substitution for the Collateral
to be released by the Trustee, deliver to the Trustee the following papers:

                                      -19-
<PAGE>

          (a)  an Officers' Certificate stating (i) the Value, as of the date of
     said Request, of the Equipment so to be released by the Trustee, and the
     year in which such Equipment was built, (ii) that the requested release by
     the Trustee will not impair the security under this Indenture in
     contravention of the provisions hereof, (iii) a description of the
     Equipment to be substituted, the Value thereof as of such date and the year
     in which such substituted Equipment was built, (iv) that each such unit so
     to be substituted is Equipment as defined herein, and (v) that the Company
     is not in Default;

          (b)  an Opinion of Counsel to the effect that a proper supplement
     hereto in respect of each substituted unit of Equipment and the related
     Leasehold Interest has been duly executed by the Trustee, the Guarantor and
     the Company as required by Section 9.04; and

          (c)  if the Value of the Equipment to be released by the Trustee, plus
     the Value of all other Equipment so released within the prior twelve
     months, is more than 10% of the aggregate principal amount of Notes then
     outstanding, a certificate by an Independent Engineer stating, as of the
     date of said Request, both the Value of the Equipment so to be released by
     the Trustee and the Value of such substituted Equipment; and

          (d)  a supplemental indenture in accordance with Section 3.01 and
     Article IX.

     At the time of delivery of any Request pursuant to the first paragraph of
this Section, the Company shall, if only cash is to be paid to the Trustee in
respect of the Equipment to be released by the Trustee, deliver to the Trustee
an Officers' Certificate stating to the effect set forth in clauses (i), (ii)
and (v) of subparagraph (a) as well as the certificate required by subparagraph
(c), if applicable, of the second paragraph of this Section.

     At any time, and from time to time, the Trustee, on Request, shall invest
and reinvest cash deposited with it pursuant to this Section or Section 3.05 in
Permitted Investments, at such prices, including any premium and accrued
interest, as are set forth in such Request.

     The Trustee shall send statements to the Company monthly reflecting
activity for the account created hereunder for the preceding month.  The Company
hereby agrees that confirmations of investments are not required to be issued by
the Trustee for each month in which a monthly statement is rendered.  The
Trustee shall have no liability with respect to any investment made pursuant to
this Section 3.04, other than by reason of the willful conduct or gross
negligence of the Trustee.  The Permitted Investments and all earnings from such
investments shall be held by the Trustee subject to the provisions of this
Indenture.  Permitted Investments shall be liquidated by the Trustee and the
cash proceeds thereof shall, from time to time, be paid over by the Trustee to
the Company upon Request, against granting to the Trustee of a security interest
hereunder in units of Equipment having a Value, as of the date of said Request,
not less than the amount of cash so paid, together with all Leasehold Interests
relating to such Equipment, and upon delivery to the Trustee of papers
corresponding to those set forth in the second paragraph of this Section, with
such appropriate modifications as may be approved by the Trustee.

                                      -20-
<PAGE>

     Section 3.05  Maintenance of Equipment; Casualty Occurrences.  The Company
                   ----------------------------------------------
agrees that it will maintain and keep all the Equipment in good order and proper
repair at its own cost and expense, unless and until it becomes worn out,
unsuitable for use or lost or destroyed (such occurrences being hereinafter
called "Casualty Occurrences").  Whenever any of the Equipment shall suffer a
        --------------------
Casualty Occurrence, the Company shall on or before the next following May 15,
deliver to the Trustee an Officer's Certificate describing such Equipment and
stating the Value thereof as of the date such Equipment suffered such Casualty
Occurrence.  When the total Value of all units of Equipment having suffered a
Casualty Occurrence (exclusive of units having suffered a Casualty Occurrence in
respect of which a payment or substitution shall have been made to the Trustee
pursuant to this Section) shall exceed $1,000,000 or 1% of the principal amount
of the Notes then outstanding, whichever is less, the Company, within 30 days
after it shall have been informed of such event, shall deliver to the Trustee an
Officer's Certificate describing such Equipment and stating the Value thereof as
of the date such Equipment suffered such Casualty Occurrence and either (i)
deposit with the Trustee an amount in cash equal to the Value of such units of
Equipment as of the date of the Casualty Occurrence in respect of each thereof
or (ii) convey to the Trustee, in accordance with the procedures and
requirements of Section 3.04, a security interest in (A) units of Equipment with
a Value, as of the date of such conveyance, not less than the Value of the units
of Equipment suffering such Casualty Occurrence(s), as of the date of the
Casualty Occurrence in respect of each thereof, and with a remaining useful life
not less than that of the units of Equipment suffering such Casualty
Occurrence(s) immediately prior to such Casualty Occurrence(s) and (B) the
Leasehold Interests relating to such units of Equipment.  The rights and
remedies of the Trustee to enforce its security interest hereunder shall not be
affected by reason of any Casualty Occurrence.  Cash deposited with the Trustee
pursuant to this Section shall be held, invested and applied as provided in the
fourth paragraph of Section 3.04.
                    ------------

     Upon the deposit of cash with the Trustee pursuant to this Section 3.05,
                                                                ------------
the Trustee shall execute and deliver a release in the form reasonably requested
by the Company releasing to the Company all the right, title and interest of the
Trustee in and to the Equipment which has suffered a Casualty Occurrence and in
respect of which such deposit is made and all related Leasehold Interests.

     The Company agrees to furnish to the Trustee on or before May 15 in every
calendar year commencing May 15, 2001, and during the continuance of the
security interest granted hereunder, an Officers' Certificate, dated as of the
preceding February 14, (1) stating the description and numbers of all units of
Equipment that may have suffered a Casualty Occurrence or which have been
withdrawn from use pending major repairs since the date of the last preceding
statement (or the date of this Indenture in the case of the first such
statement), (2) that no Event of Default has occurred and is continuing, (3)
that, in the opinion of the signers, the Company is in compliance with all of
the terms of this Indenture and (4) covering such other matters as the Trustee
may reasonably request.

     The Trustee, by its agents, shall have the right at any reasonable time
(which may be more frequent than once in each calendar year), but shall be under
no duty, to inspect the Collateral at the then existing locations thereof.

                                      -21-
<PAGE>

     Section 3.06  Possession of Collateral.  Except as provided in this Section
                   ------------------------
3.06, without first obtaining the written consent of the Trustee and the holders
of not less than two-thirds of the principal amount of the Notes then
outstanding, the Company will not (a) assign or transfer its rights hereunder or
under the Note Purchase Agreements, (b) transfer the Collateral or any part
thereof (unless the Company complies with the substitution and replacement
requirements of Section 3.04 hereof) or (c) part with the possession of, or
suffer or allow to pass out of its possession and control, any of the
Collateral.  An assignment or transfer to any Person which shall acquire all or
substantially all the property of the Company (by merger, consolidation or
otherwise) and which, by execution of an appropriate instrument satisfactory to
the Trustee, shall assume and agree to perform each and all the obligations and
covenants of the Company hereunder, all in accordance with the provisions of
Section 6.07 hereof, shall not be deemed a breach of this covenant and such
assignment, transfer or assumption shall have the effect of releasing the
Company from its obligations hereunder and under the Note Purchase Agreements.

     Notwithstanding the foregoing, so long as the Company and the Guarantor
shall not be in Default, the Company shall be entitled to the possession and use
of the Collateral in accordance with the terms hereof, and the Company may also
lease or contract to others all or any part of the Equipment, subject to all the
terms and conditions of this Indenture and the Note Purchase Agreements.

     Any such lease or contract may provide that the party acquiring the use of
units of Equipment, so long as it shall not be in default under such lease or
contract, shall be entitled, subject to the rights of the Trustee and the
Noteholders hereunder, to the possession of such units and the use thereof.
Every such lease or contract entered into after the date of this Indenture shall
contain provisions which have the effect of subjecting the rights of the party
acquiring the use of units of Equipment under such lease or contract to the
rights and remedies of the Trustee and the Noteholders in respect of such units.

     Section 3.07  Marking of Equipment.  The Company shall not change, or
                   --------------------
permit to be changed, the prefixes or numbers of any of the Equipment at any
time covered hereby (or any numbers which may have been substituted as herein
provided) except in accordance with a statement of new numbers to be substituted
therefor which previously shall have been filed with the Trustee by the Company
and which shall be filed and recorded in like manner as this Indenture.

     The Equipment may be lettered or marked, in case of a lease of any
Equipment made pursuant to Section 3.06 hereof, in such manner as may be
appropriate for convenience of identification of the leasehold interest of the
lessee under such lease; but the Company, during the continuance of the security
interest provided for herein, will not allow any lettering or designation to be
placed on any of the Equipment claiming ownership thereof by any Person, firm,
association or corporation other than the Company.

     SECTION 3.08  Modifications and Improvements The Company may make
                   ------------------------------
modifications and improvements to the Equipment and may remove parts and
improvements (unless required by law or regulation) to the extent that the
Value, utility and remaining useful life of the Equipment is not materially
impaired. The Company shall make all modifications

                                      -22-
<PAGE>

required by law or regulation unless the modification is economically
impractical, in which case the Company may replace such Equipment by
substituting other Equipment in accordance with Section 3.04 hereof.

                                  ARTICLE IV

                        Events of Default and Remedies
                        ------------------------------

     Section 4.01  Events of Default.  The Company covenants and agrees that in
                   -----------------
case:

          (a)  the Company defaults in the payment of any principal or Make-
     Whole Amount, if any, on any Note when the same becomes due and payable,
     whether at maturity or at a date fixed for redemption or by declaration or
     otherwise; or

          (b)  the Company defaults in the payment of any interest on any Note
     for more than five Business Days after the same becomes due and payable; or

          (c)  the Company shall make or suffer any unauthorized assignment or
     transfer of its rights hereunder or shall make any unauthorized transfer or
     lease (including, for the purpose of this clause, contracts for the use
     thereof) of any of the Collateral, or, except as herein authorized, shall
     part with the possession of any of the Collateral, and shall fail or refuse
     either to cause such assignment or transfer or lease to be canceled by
     agreement of all parties having any interest therein and recover possession
     of such Collateral within 30 days after the Trustee shall have demanded in
     writing such cancellation and recovery of possession, or within said 30
     days to deposit with the Trustee a sum in cash equal to the Value, as of
     the date of such unauthorized action, of such Collateral (any sum so
     deposited to be returned to the Company upon the cancellation of such
     assignment, transfer or lease and the recovery of possession by the Company
     of such Collateral); or

          (d)  the Company or the Guarantor default in the performance of or
     compliance with any term contained herein (other than those referred to in
     paragraphs (a) or (b) of this Section 4.01) or in Section 7.1 of the Note
     Purchase Agreements and such default is not remedied within 30 days after
     the earlier of (i) a Responsible Officer obtaining actual knowledge of such
                     -
     default and (ii) the Company and the Guarantor receiving written notice of
                  --
     such default from the Trustee or any holder of a Note (any such written
     notice to be identified as a "notice of default" and to refer specifically
     to this paragraph (d) of Section 4.01); provided, however, that so long as
                                             --------  -------
     such failure is capable of being remedied other than through the payment of
     money, and the Company or the Guarantor is diligently proceeding to comply,
     the Company or the Guarantor may cure such failure within 60 days of
     receipt of such notice or obtaining such knowledge; or

          (e)  any representation or warranty made in writing by or on behalf of
     the Company or the Guarantor or by any officer of the Company or the
     Guarantor in the Note Purchase Agreements or in any writing furnished in
     connection with the transactions contemplated thereby or hereby proves to
     have been false or incorrect in any material respect on the date as of
     which made and such untruth or incorrectness shall continue to

                                      -23-
<PAGE>

     be material and unremedied for a period of 30 days after the earlier of (i)
     a Responsible Officer obtaining actual knowledge of such default and (ii)
     the Company and the Guarantor receiving written notice of such default from
     the Trustee or any Noteholder (any such written notice to be identified as
     a "notice of default" and to refer specifically to this Section 4.01(e));
     provided that, if such untruth or incorrectness is capable of being
     remedied, no such untruth or incorrectness shall constitute an Event of
     Default hereunder for a period of 60 days after receipt of such notice so
     long as the Company or the Guarantor is diligently proceeding to remedy
     such untruth or incorrectness and shall in fact remedy such untruth or
     incorrectness within such period, or

          (f)  the Company or the Guarantor (i) is generally not paying, or
     admits in writing its inability to pay, its debts as they become due, (ii)
     files, or consents by answer or otherwise to the filing against it of, a
     petition for relief or reorganization or arrangement or any other petition
     in bankruptcy, for liquidation or to take advantage of any bankruptcy,
     insolvency, reorganization, moratorium or other similar law of any
     jurisdiction, (iii) makes an assignment for the benefit of its creditors,
     (iv) consents to the appointment of a custodian, receiver, trustee or other
     officer with similar powers with respect to it or with respect to any
     substantial part of its property, (v) is adjudicated as insolvent or to be
     liquidated, or (vi) takes corporate action for the purpose of any of the
     foregoing, or

          (g)  a court or governmental authority of competent jurisdiction
     enters an order appointing, without consent by the Company or the
     Guarantor, a custodian, receiver, trustee or other officer with similar
     powers with respect to it or with respect to any substantial part of its
     property, or constituting an order for relief or approving a petition for
     relief or reorganization or any other petition in bankruptcy or for
     liquidation or to take advantage of any bankruptcy or insolvency law of any
     jurisdiction, or ordering the dissolution, winding-up or liquidation of the
     Company or the Guarantor, or any such petition shall be filed against the
     Company or the Guarantor and such petition shall not be dismissed within 60
     days; or

          (h)  this Indenture (including, without limitation, the provisions of
     Section 6.01 hereof), any Note or any Note Purchase Agreement, or any Liens
     granted under this Indenture relating to Equipment with an aggregate Value
     in excess of $1,000,000 or 1% of the principal amount of the Notes then
     outstanding, whichever is more, shall, taken as a whole, terminate, cease
     to be effective against, or cease to be the legal, valid, binding and
     enforceable obligation of the Company or Guarantor, as the case may be;
     provided that for purposes of this Section 4.01 any Lien granted under this
     Indenture shall not be deemed to have terminated or ceased to be effective
     unless such Lien terminates or ceases to be effective under the Uniform
     Commercial Code as adopted in the State of Illinois or in any other state
     in which the Company's chief executive office may subsequently be located;
     or

        (i)    the Company or the Guarantor shall contest the effectiveness,
     validity, binding nature or enforceability of this Indenture (including,
     without limitation, the

                                      -24-
<PAGE>

     provisions of Section 6.01 hereof), any Note or any Note Purchase Agreement
     or any Lien granted under this Indenture

(each herein sometimes called an "Event of Default"), then, (i) upon the
                                  ----------------
occurrence of an Event of Default described in Section 4.01(a) or (b), any
holder may declare its Note to be immediately due and payable in an amount equal
to such Note's outstanding principal amount plus all accrued interest thereon,
but without any Make-Whole Amount, (ii) upon the occurrence of an Event of
Default described in Sections 4.01(a) through (e), in addition to the right set
forth in the immediately preceding clause (i), the holder or holders of a
majority of the aggregate unpaid principal amount of the Notes may declare all
of the Notes to be immediately due and payable in an amount equal to the
outstanding principal amount thereof plus all accrued and unpaid interest
thereon, but without any Make-Whole Amount, and (iii) upon the occurrence of an
Event of Default described in Sections 4.01(f), (g), (h) or (i), all of the
Notes then outstanding shall automatically become immediately due and payable in
an amount equal to the outstanding principal amount thereof plus all accrued and
unpaid interest thereon, but without any Make-Whole Amount.  Upon any Notes
becoming due and payable under this Section 4.01, whether automatically or by
declaration, such Notes will forthwith mature and the entire unpaid principal
amount of such Notes plus all accrued and unpaid interest thereon shall be
immediately due and payable, in each and every case without presentment, demand,
protest or further notice, all of which are hereby waived.

     Section 4.02  Incidents of Sale of Collateral. Upon any sale of all or any
                   -------------------------------
part of the Collateral made under Section 4.08 of this Indenture or otherwise
for the enforcement of this Indenture, the following shall be applicable:

          (a)  Receipt of Trustee Shall Discharge Purchaser.  The receipt of the
               --------------------------------------------
     Trustee or of the officer making such sale shall be a sufficient discharge
     to any purchaser for his purchase money, and, after paying such purchase
     money and receiving such receipt, such purchaser or its personal
     representative or assigns shall not be obliged to see to the application of
     such purchase money, or be in any way answerable for any loss,
     misapplication or non-application thereof.

          (b)  Application of Moneys Received Upon Sale. Any moneys collected by
               ----------------------------------------
     the Trustee upon any sale made either under the power of sale given by this
     Indenture or otherwise for the enforcement of this Indenture, shall be
     applied as provided in Section 4.09.

     Section 4.03  Judicial Proceedings Instituted by Trustee.
                   ------------------------------------------

          (a)  Trustee May Bring Suit.  If there shall be a failure to make
               ----------------------
     payment of the principal of or interest on a Note or Make-Whole Amount, if
     any, when due and payable then the Trustee, in its own name, and as trustee
     of an express trust, shall be, to the extent permitted by and in accordance
     with the terms of this Indenture and the Notes, entitled and empowered to
     institute any suits, actions or proceedings at law, in equity or otherwise,
     for the collection of the sums so due and unpaid on such Notes or under
     this

                                      -25-
<PAGE>

     Indenture and may prosecute any such claim or proceeding to judgment or
     final decree with respect to the whole amount of any such sums so due and
     unpaid.

          (b)  Trustee May File Proofs of Claim; Appointment of Trustee as
               -----------------------------------------------------------
     Attorney-in-Fact in Judicial Proceedings.  The Trustee in its own name, or
     ----------------------------------------
     as trustee of an express trust, or as attorney-in-fact for the Noteholders,
     or in any one or more of such capacities (irrespective of whether
     distributions on the Notes shall then be due and payable as therein
     expressed or by declaration or otherwise) shall be entitled and empowered
     to file such proofs of claim and other papers or documents as may be
     necessary or advisable in order to have the claims of the Trustee and of
     the Noteholders allowed in any receivership, insolvency, bankruptcy,
     liquidation, readjustment, reorganization or any other judicial proceedings
     relative to the Company, the Guarantor or either of their creditors or
     property.  Any receiver, assignee, trustee, liquidator, sequestrator (or
     similar official) in any judicial proceeding is hereby authorized by each
     Noteholder to make payments in respect of such claim to the Trustee and, in
     the event that the Trustee shall consent to the making of such payments
     directly to the Noteholders, to pay to the Trustee any amount due to it for
     the reasonable compensation, expenses, disbursements and advances of the
     Trustee, its agents and counsel.  Nothing contained in this Indenture shall
     be deemed to give to the Trustee any right to accept or consent to any plan
     of reorganization or otherwise by action of any character in any such
     proceeding to waive or change in any way any right of any Noteholder.

     Section 4.04  Control by Noteholders.  The Noteholders holding Notes
                   ----------------------
representing more than 50% of the aggregate unpaid principal amount then
outstanding shall have the right to direct the time, method and place of
conducting any proceeding for any remedy available to the Trustee, or exercising
any trust or power conferred on the Trustee under this Indenture, provided that:
                                                                  --------

          (a)  such direction shall not be in conflict with any rule of law or
     with this Indenture and would not involve the Trustee in personal liability
     or expense,

          (b)  the Trustee shall not determine that the action so directed would
     be unjustly prejudicial to the Noteholders not taking part in such
     direction, and

          (c)  the Trustee may take any other action deemed proper by the
     Trustee which is not inconsistent with such direction.

     Section 4.05  Waivers of Default.  Prior to the declaration of the
                   ------------------
acceleration of the maturity of all the Notes as provided in Section 4.01, the
holders of more than 50% in aggregate unpaid principal amount of the Notes at
the time outstanding may, on behalf of the holders of all the Notes, waive any
past Default and its consequences, except a Default in the payment of the
principal of or interest on any of the Notes or Make-Whole Amount, if any, but
no such waiver shall extend to or affect any subsequent Default or impair any
right consequent thereon.

     At any time after any Notes have been declared due and payable or have
automatically become due and payable pursuant to Section 4.01, the holders of
not less than a majority of the

                                      -26-
<PAGE>

aggregate principal amount of the Notes then outstanding, by written notice to
the Company and the Trustee, may rescind and annul any such declaration and its
consequences if (a) the Company or the Guarantor has paid all overdue interest
                 -
on the Notes, all principal of and Make-Whole Amount, if any, on any Notes that
are due and payable and are unpaid other than by reason of such declaration, and
all interest on such overdue principal and Make-Whole Amount, if any, and (to
the extent permitted by applicable law) any overdue interest in respect of the
Notes, at the Default Rate, (b) all Events of Default and Defaults, other than
                             -
non-payment of amounts that have become due solely by reason of such
declaration, have been cured or have been waived pursuant to this Indenture, and
(c) no judgment or decree has been entered for the payment of any monies due
 -
pursuant hereto or to the Notes. No rescission and annulment under this Section
4.05 will extend to or affect any subsequent Event of Default or Default or
impair any right consequent thereon.

     No course of dealing and no delay on the part of any holder of any Note in
exercising any right, power or remedy shall operate as a waiver thereof or
otherwise prejudice such holder's rights, powers or remedies.  No right, power
or remedy conferred by this Agreement or by any Note upon any holder thereof
shall be exclusive of any other right, power or remedy referred to herein or
therein or now or hereafter available at law, in equity, by statute or
otherwise.  Without limiting the obligations of the Company and the Guarantor
under Section 7 of the Note Purchase Agreements, the Company or the Guarantor
will pay to the holder of each Note on demand such further amount as shall be
sufficient to cover all costs and expenses of such holder incurred in any
enforcement or collection under this Article IV, including, without limitation,
reasonable attorneys' fees, expenses and disbursements.

     Section 4.06  Undertaking to Pay Court Costs.  All parties to this
                   ------------------------------
Indenture, and each Noteholder by its acceptance of a Note, shall be deemed to
have agreed that any court may in its discretion require, in any suit, action or
proceeding for the enforcement of any right or remedy under this Indenture, or
in any suit, action or proceeding against the Trustee for any action taken or
omitted by it as Trustee hereunder, the filing by any party litigant in such
suit, action or proceeding of an undertaking to pay the costs of such suit,
action or proceeding, and that such court may, in its discretion, assess
reasonable costs, including reasonable attorney's fees, against any party
litigant in such suit, action or proceeding, having due regard to the merits and
good faith of the claims or defenses made by such party litigant; provided,
                                                                  --------
however, that the provisions of this Section shall not apply to (a) any suit,
-------
action or proceeding instituted by any Noteholder or group of Noteholders
representing more than 10% of the aggregate unpaid principal amount then
outstanding, (b) any suit, action or proceeding instituted by any Noteholder for
the enforcement of the payment of principal or interest on the Notes on or after
the respective due dates expressed herein or (c) any suit, action or proceeding
instituted by the Trustee.

     Section 4.07  Unconditional Right of Holders of Notes To Sue for Principal,
                   -------------------------------------------------------------
Interest and Make-Whole Amount.  Notwithstanding any other provision in this
------------------------------
Indenture, the right of any holder of any Note to receive payment of the
principal of and interest on such Note and Make-Whole Amount, if any, on or
after the due date expressed in such Note, or to institute suit for the
enforcement of any such payment on or after such date, shall not be impaired or
affected without the consent of such holder, except no such suit shall be
instituted if and to the extent that the

                                      -27-
<PAGE>

institution or prosecution thereof or the entry of judgment therein would, under
applicable law, result in the surrender, impairment, waiver or loss of the title
reserved under this Indenture upon any property subject hereto.

     Section 4.08  Remedies.  In case of the happening and continuance of any
                   --------
Event of Default, the Trustee may by its agents enter upon the premises of the
Company and any of its Affiliates or lessees of the Equipment (or other Persons
having acquired the use of the Equipment) where any of the Equipment may be and
take possession of all or any part of the Equipment and withdraw the same from
said premises, and shall be entitled to collect, receive and retain all unpaid
charges of any kind earned by the Collateral or any part thereof, and may lease
or otherwise contract for the use of the Collateral or any part thereof, or with
or without retaking possession thereof (but only after declaring due and payable
the entire amount of the principal of all the then outstanding Notes, as
provided in Section 4.01) may sell the same or any part thereof, free from any
and all claims of the Company or the Guarantor at law or in equity in one lot
and as an entirety or in separate lots, at public or private sale, for cash or
upon credit, in its discretion, and may proceed otherwise to enforce its rights
and the rights of the holders of then outstanding Notes, all subject to any
mandatory requirements of law applicable thereto.  Upon any such sale, the
Trustee itself may bid for the property offered for sale or any part thereof.
Any such sale may be held or conducted at such place and at such time as the
Trustee may specify, or as may be required by law, and without gathering at the
place of sale the Collateral to be sold, and in general in such manner as the
Trustee may determine, but so that the Company and the Guarantor may and shall
have a reasonable opportunity to bid at any such sale.  Upon such taking
possession or withdrawal or lease or sale of the Collateral, the Company and the
Guarantor shall cease to have any rights or remedies in respect of the
Collateral hereunder, but all such rights and remedies shall be deemed
thenceforth to have been waived and surrendered by the Company and the
Guarantor, and no payments theretofore made by the Company or the Guarantor for
the rent or use of the Collateral or any of it shall give to the Company or the
Guarantor any legal or equitable interest or title in or to the Collateral or
any of it or any cause or right of action at law or in equity in respect of the
Collateral against the Trustee or the holders of Notes hereunder.  No such
taking possession, withdrawal, lease or sale of the Collateral by the Trustee
shall be a bar to the recovery by the Trustee from the Company and the Guarantor
of the principal of and interest on the Notes or Make-Whole Amount, if any, and
the Company and the Guarantor shall be and remain liable for the same until such
sums have been realized as, with the proceeds of the lease or sale of the
Collateral, shall be sufficient for the discharge and payment in full of all the
obligations of the Company and the Guarantor under this Indenture.

     Section 4.09  Application of Proceeds.  If the Trustee shall exercise any
                   -----------------------
of the powers conferred upon it by this Article IV, all payments made by the
Company or the Guarantor to the Trustee, and the proceeds of any judgment
collected from the Company or the Guarantor by the Trustee, and the proceeds of
every sale or lease by the Trustee of any of the Collateral, together with any
other sums which may then be held by the Trustee under any of the provisions
hereof (other than sums held in trust for the payment of specific Notes or a
part thereof, or interest thereon), shall be applied by the Trustee to the
payment, in the following order of priority, (a) of all proper charges, expenses
or advances made or incurred by the Trustee in accordance with the provisions of
this Indenture and (b) of the interest then due, with interest on overdue
interest at

                                      -28-
<PAGE>

the Penalty Rate, to the extent legally enforceable, and of the Make-Whole
Amount then due, if any, with interest thereon at the Penalty Rate, to the
extent legally enforceable, and of the principal of all the outstanding Notes,
with interest thereon at the Penalty Rate, to the extent legally enforceable,
from the last preceding interest payment date, whether such Notes shall have
then matured by their terms or not, all such payments to be pro rata and in full
if such proceeds shall be sufficient, and if not sufficient, then first to
interest, then to the Make-Whole Amount and then to principal.

     After all such payments shall have been made in full, the title to any of
the Collateral remaining unsold shall be conveyed by the Trustee to the Company
free from any further liabilities or obligations to the Trustee hereunder.  If
after applying all such sums of money realized by the Trustee as aforesaid there
shall remain any amount due to the Trustee under the provisions hereof, the
Company and the Guarantor agree to pay the amount of such deficit to the
Trustee.  If after applying as aforesaid the sums of money realized by the
Trustee there shall remain a surplus in the possession of the Trustee, such
surplus shall be paid to the Company.

     Section 4.10  Obligations of Company and the Guarantor Not Affected by
                   --------------------------------------------------------
Remedies.  No retaking of possession of the Collateral by the Trustee, or any
--------
withdrawal, lease or sale thereof, nor any action or failure or omission to act
against the Company or the Guarantor or in respect of the Collateral, on the
part of the Trustee or on the part of the holder of any Note, nor any delay or
indulgence granted to the Company or the Guarantor by the Trustee or by any such
holder, shall affect the obligations of the Company or the Guarantor hereunder.
The Company and the Guarantor hereby waive presentation and demand in respect of
any of the Notes and waive notice of presentation, of demand and of any Default
in the payment of the principal of and interest on the Notes.

     Section 4.11  Company To Deliver Collateral to Trustee.  In case the
                   -----------------------------------------
Trustee shall rightfully demand possession of any of the Collateral under
Section 4.08, the Company will, at its own expense, forthwith and in the usual
manner and at usual speed, cause such Collateral to be delivered to such point
or points as shall reasonably be designated by the Trustee and will there
deliver or cause to be delivered the same to the Trustee; or, at the option of
the Trustee, the Trustee may keep such Collateral, at the expense of the Company
and the Guarantor, on any premises approved by the Trustee until the Trustee
shall have leased, sold or otherwise disposed of the same.  The performance of
the foregoing covenant is of the essence of this Indenture and upon application
to any court having jurisdiction in the premises, the Trustee shall be entitled
to a decree against the Company requiring the specific performance thereof.

     Section 4.12  Limitations on Suits by Holders of Notes.  No holder of any
                   ----------------------------------------
Note shall have any right by virtue or by availing of any provision of this
Indenture to institute any action or proceeding at law or in equity or in
bankruptcy or otherwise, upon or under or with respect to this Indenture, or for
the appointment of a receiver or trustee, or for any other remedy hereunder,
unless such holder previously shall have given to the Trustee written notice of
a Default and of the continuance thereof, as herein provided, and (i) with
respect to Events of Default set forth in Sections 4.01(c) through (i), the
holders of more than 50% in aggregate principal amount of the Notes then
outstanding or, (ii) with respect to an Event of Default set forth in Section
4.01(a) or (b), such Noteholder, shall have made written request to the Trustee
to institute such action or

                                      -29-
<PAGE>

proceeding in its own name as trustee hereunder and shall have offered to the
Trustee such reasonable indemnity as it may require against the costs, expenses
and liabilities to be incurred therein or thereby, and the Trustee for 20 days
after its receipt of such notice, request and offer of indemnity shall have
failed to institute any such action or proceeding and no direction inconsistent
with such written request shall have been given to the Trustee pursuant to
Section 4.04; and no one or more holders of Notes shall have any right in any
manner whatever to affect or prejudice the rights of any other holder of Notes,
or to obtain or seek to obtain priority over any other such holder or to enforce
any right under this Indenture, except in the manner herein provided and for the
equal, ratable and common benefit of all holders of Notes. For the protection
and enforcement of the provisions of this Section, each and every holder of a
Note and the Trustee shall be entitled to such relief as can be given either at
law or in equity.

     Section 4.13  Remedies Cumulative; Subject to Mandatory Requirements of
                   ---------------------------------------------------------
Law.  The remedies in this Indenture provided in favor of the Trustee and the
---
holders of the Notes shall not be deemed exclusive, but shall be cumulative, and
shall be in addition to all other remedies in their favor existing at law or in
equity; and such remedies shall be subject in all respects to any mandatory
requirements of law at the time applicable thereto, to the extent such
requirements may not be waived on the part of the Company.

                                   ARTICLE V

                       Certain Agreements of the Company
                       ---------------------------------

     Section 5.01  Discharge of Liens.  The Company agrees that it will, and the
                   ------------------
Guarantor agrees to cause the Company to, pay and discharge, or make adequate
provision for the payment or discharge of, any debt, tax, charge, assessment,
obligation or claim which if unpaid might become a Lien or charge upon or
against any of the Collateral; but this provision shall not require the payment
of any such debt, tax, charge, assessment, obligation or claim so long as the
validity thereof shall be contested in good faith and by appropriate legal
proceedings that do not materially endanger the rights or interests of the
Trustee or of the holders of the Notes and the Company shall have furnished the
Trustee with an Opinion of Counsel to such effect.

     If the Company or the Guarantor does not forthwith pay and discharge, or
cause to be paid and discharged, or make adequate provision for the satisfaction
or discharge of, any such debt, tax, charge, assessment, obligation or claim as
required by this Section, the Trustee may, but shall not be obligated to, pay
and discharge the same and any amounts so paid shall be secured by and under
this Indenture until reimbursed by the Company or the Guarantor.

     Section 5.02  Further Assurances.  The Company agrees to do, and the
                   ------------------
Guarantor shall cause the Company to do, all such acts and execute all such
instruments of further assurance as shall be reasonably requested by the Trustee
for the purpose of fully carrying out and effectuating this Indenture and the
intent hereof.

     Section 5.03  Payment of Expenses; Financing Statements.  The Company
                   -----------------------------------------
agrees to pay the expenses incident to the preparation and execution of the
Notes to be issued hereunder and the preparation, execution, recording and
filing of all financing statements required to be filed

                                      -30-
<PAGE>

pursuant to this Section 5.03 and all other instruments executed under the
provisions hereof. The Company shall (i) promptly after the execution and
delivery of this Indenture and each supplement hereto, respectively, cause
financing statements to be duly filed in the State of Illinois or in any other
state in which the Company's chief executive office may be subsequently located,
in accordance with the Uniform Commercial Code as adopted in such
jurisdiction(s), and (ii) from time to time file continuation statements and
perform any other act and will execute, acknowledge, deliver, file, register and
record any and all further instruments required by law or reasonably requested
by the Trustee for the purpose of proper protection of the security interest of
the Trustee in the Collateral and the rights of the holders of the Notes within
such jurisdiction(s) and of fully carrying out and effectuating this Indenture
and the intent hereof; provided, however, that the Company shall not be required
                       --------  -------
to take any action to protect the security interest of the Trustee in the
Collateral in any jurisdiction outside the United States.

                                  ARTICLE VI

            Additional Agreements of the Guarantor and the Company
            ------------------------------------------------------

     Section 6.01  Guaranty.
                   --------

          (a)  The Guarantor, as primary obligor and not as surety, hereby
     absolutely, unconditionally and irrevocably guarantees to each of the
     Noteholders and the Trustee (together, the "Guaranteed Parties") the
                                                 ------------------
     following obligations (collectively, the "Guaranteed Obligations"):
                                               ----------------------

               (i)  the due, punctual and full payment by the Company, whether
          at stated maturity, by required prepayment, declaration, acceleration,
          demand or otherwise, of all obligations and amounts to be paid by the
          Company pursuant to the Notes and this Indenture (including all such
          amounts which would become due but for any stay imposed by reason of a
          Company Bankruptcy (as defined below) or operation of law on any claim
          or exercise of remedy against or action affecting or relating to the
          Company, the Notes, this Indenture or the Collateral; and

               (ii) the due, prompt, complete and faithful performance of, and
          compliance with, all other obligations, covenants, terms, conditions
          and undertakings of the Company contained in the Notes, Note Purchase
          Agreements and this Indenture in accordance with the terms thereof and
          hereof.

          For purposes of this Section 6.01, "Company Bankruptcy" shall mean any
     voluntary or involuntary proceeding under the United States Bankruptcy Code
     or other state, federal or foreign law relating to insolvency, moratorium,
     reorganization, appointment of receivership or similar proceedings
     affecting creditors' rights generally and relating to or having
     jurisdiction over the Collateral, or the Company's obligations under the
     Notes, Note Purchase Agreements and this Indenture.

          If any of the Guaranteed Obligations become due, the Guarantor
     promises to pay

                                      -31-
<PAGE>

     or, to the extent guaranteed herein, cause the performance of such
     Guaranteed Obligation at the time required for payment or performance
     thereof (the "Guarantor Performance Due Date").
                   ------------------------------

          The Guarantor further agrees that it shall indemnify and hold harmless
     each Guaranteed Party for any and all reasonable costs and expenses
     (including reasonable attorney's fees and expenses) incurred after the
     Guarantor Performance Due Date by such Guaranteed Party in enforcing any
     rights under this Indenture.

          The Guarantor specifically agrees that it shall not be necessary or
     required that any Guaranteed Party exercise any right, assert any claim or
     demand or enforce any remedy whatsoever against the Company (or any other
     Person) before or as a condition to the obligations of the Guarantor
     hereunder.

          Notwithstanding any other provision of this Indenture to the contrary,
     the term Guaranteed Obligation as used herein shall not include any
     liability in excess of that imposed on the Company under the Notes, Note
     Purchase Agreements or this Indenture (as the same may be amended from time
     to time in accordance with their terms), provided, however, that if the
                                              --------  -------
     imposition of liability on the Company under the Notes, Note Purchase
     Agreements or this Indenture, or the realization on such liability, is
     limited as a result of a Company Bankruptcy or any other action by the
     Company, the Guarantor shall be responsible for and discharge any such
     liability in full; further provided, however, that nothing contained in
                        ------- --------  -------
     this paragraph or elsewhere in this Indenture shall prevent the Guarantor
     from bringing an action for damages suffered by the Guarantor (or by the
     Company if Guarantor shall be subrogated or otherwise become entitled to
     exercise the rights of the Company under the Notes, Note Purchase
     Agreements or this Indenture) as a result of a breach by any Person of any
     obligation owed by such Person or representation made by such Person to the
     Guarantor (or to the Company if Guarantor shall be subrogated or otherwise
     become entitled to exercise the rights of the Company under the Notes, Note
     Purchase Agreements or this Indenture) or for equitable relief to obtain
     compliance therewith.

          (b)  Guaranty Absolute, etc. The obligations of the Guarantor under
               ----------------------
     this Section 6.01 are primary obligations of the Guarantor and shall in all
     respects be a continuing, absolute, unconditional and irrevocable guaranty
     of payment and, to the extent guaranteed herein, guaranty to cause
     performance, and shall remain in full force and effect until all Guaranteed
     Obligations have been paid and, to the extent guaranteed herein, performed
     in full. Subject to the terms and provisions of this Section 6.01, the
     Guarantor guarantees that the Guaranteed Obligations will be paid and, to
     the extent guaranteed herein, performance will occur strictly in accordance
     with the terms of the Notes, the Note Purchase Agreements or this
     Indenture, as the case may be, in each case regardless of any law,
     regulation or order now or hereafter in effect in any jurisdiction
     affecting any of such terms or the rights of any Guaranteed Party. Subject
     to the terms and provisions of this Section 6.01, the liability of the
     Guarantor under this Section 6.01 shall be absolute, unconditional and
     irrevocable, and shall not be altered or impaired, irrespective of:

                                      -32-
<PAGE>

               (i)    any lack of validity, legality or enforceability of any
          Note, the Note Purchase Agreements or this Indenture or of the
          Guaranteed Obligations;

               (ii)   the failure of any Guaranteed Party:

                      (A)  to assert any claim or demand or to enforce any right
               or remedy or to take any other action against the Company or any
               other Person (including any other guarantor under the provisions
               of any agreement or otherwise or to perfect or enforce any
               security interest, or

                      (B)  to exercise any right or remedy against any other
               guarantor of, or Collateral securing, any Guaranteed Obligations;

               (iii)  any change in the time, manner or place of payment of, or
          in any other term of, all or any of the Guaranteed Obligations, or any
          other extension, waiver, compromise or renewal of any of the
          Guaranteed Obligations;

               (iv)   any reduction, limitation, impairment or termination of
          the Guaranteed Obligations for any reason, including any claim of
          waiver, release, surrender, alteration or compromise, and shall not be
          subject to (and the Guarantor hereby waives any right to or claim of)
          any defense or setoff, counterclaim, recoupment or termination
          whatsoever by reason of the invalidity, illegality, nongenuineness,
          irregularity, compromise, unenforceability of, or any other event or
          occurrence affecting, the Guaranteed Obligations;

               (v)    any amendment to, rescission, waiver, or other
          modification of, or any consent to departure from, any of the terms of
          any Note, Note Purchase Agreement or this Indenture;

               (vi)   any addition, exchange, release, surrender or
          nonperfection of any Collateral, or any amendment to or waiver or
          release or addition of, or consent to departure from, any other
          guaranty, held by any Guaranteed Party securing any of the Guaranteed
          Obligations;

               (vii)  any other circumstance which might otherwise constitute a
          defense available to, or a legal or equitable discharge of, the
          Company, any surety or any guarantor;

               (viii) any release, surrender, compromise, settlement, waiver,
          subordination or modification, with or without consideration, of any
          other guarantees or other credit support with respect to the
          Guaranteed Obligations or any part thereof, or any other obligation of
          any Person with respect to the Guaranteed Obligations or any part
          thereof;

               (ix)   any change in ownership of the Company or the insolvency,
          bankruptcy or any other change in the legal status of the Company or
          any

                                      -33-
<PAGE>

          rejection or modification of the obligations of the Company or those
          of any Person as a result of a Company Bankruptcy;

               (x)   the existence of any claim, set-off or other rights that
          the Guarantor may have at any time against the Company or any other
          Person in connection herewith or with an unrelated transaction;

               (xi)  any merger or consolidation of the Company or the Guarantor
          into or with any Person, or any sale, lease or transfer of any or all
          of the assets of the Company or the Guarantor to any other Person; or

               (xii) any other action, omission or occurrence or circumstance
          whatsoever which may in any manner or to any extent vary the risk or
          effect discharge of the Guarantor hereunder as a matter of law or
          otherwise.

          (c)  Reinstatement, etc. The Guarantor agrees that its obligations
               ------------------
     under this Section 6.01 shall continue to be effective or be reinstated, as
     the case may be, if at any time any payment (in whole or in part) of any of
     the Guaranteed Obligations is rescinded or must otherwise be restored by
     any Guaranteed Party, upon a Company Bankruptcy, as though such payment had
     not been made notwithstanding any termination of this Indenture or any
     other agreement.

          (d)  Waiver, etc.  The Guarantor hereby waives, to the fullest extent
               -----------
     permitted by law, promptness, diligence, notice of acceptance, presentment,
     demand of payment or performance and any other notice with respect to any
     of the Guaranteed Obligations and this Indenture and any requirement that
     any Guaranteed Party protect, secure, perfect or insure any security
     interest or lien, or any property subject thereto, or exhaust any right or
     take any action against the Company or any other Person (including any
     other guarantor) or entity or any Collateral securing the Guaranteed
     Obligations.

          (e)  Waiver of Subrogation.  The Guarantor hereby irrevocably waives
               ---------------------
     until all Guaranteed Obligations are satisfied in full any claim or other
     rights which it may now or hereafter acquire against the Company that arise
     from the existence, payment, performance or enforcement of the Guarantor's
     obligations under this Indenture or any Note or Note Purchase Agreement,
     including any right of subrogation, reimbursement, exoneration, or
     indemnification, any right to participate in the claim or remedy of the
     Guaranteed Parties against the Company or any Collateral which the Trustee
     now has or hereafter acquires, whether or not such claim, remedy or right
     arises in equity, or under contract, statute or common law, including the
     right to take or receive from the Company, directly or indirectly, in cash
     or other property or by set-off or in any manner, payment or security on
     account of such claim or other rights.  The Guarantor acknowledges that it
     will receive benefits from the financing and other arrangements
     contemplated by this Indenture, the Notes and Note Purchase Agreement and
     that the waiver set forth in this Section 6.01(e) is knowingly made in
     contemplation of such benefits.  The Guarantor further agrees that to the
     extent the waiver of its rights of subrogation as set forth herein is found
     by a court of competent jurisdiction to be void or voidable for any reason,
     any

                                      -34-
<PAGE>

     rights of subrogation the Guarantor may have against the Company or against
     such Collateral or security shall be junior and subordinate to any rights
     the Guaranteed Parties may have against the Company and to all right, title
     and interest the Guaranteed Parties may have in such Collateral or
     security. Subject to the terms and conditions set forth elsewhere in this
     Indenture, the Guaranteed Parties may use, sell or dispose of any item of
     Collateral or security as they see fit without regard to any subrogation
     rights that the Guarantor may have, and upon any disposition or sale of
     Collateral or security, any rights of subrogation the Guarantor may have
     with respect to such Collateral or security shall terminate. The Guaranteed
     Parties agree that, notwithstanding the foregoing waiver, reimbursement by
     the Company of amounts paid by the Guarantor under this Guaranty shall not
     constitute a breach of Guarantor's obligations herein.

          (f)  Bankruptcy. In the event of a rejection of the Notes, Note
               ----------
     Purchase Agreements or this Indenture in a Company Bankruptcy, the
     Guarantor agrees that it will pay or, to the extent guaranteed herein,
     cause the performance of all Guaranteed Obligations as if such rejection
     had not occurred.

          (g)  Waiver of Suretyship, etc.
               -------------------------

               (i)  The Guarantor further agrees that nothing contained herein
          shall prevent the Guaranteed Parties from suing on the Notes, Note
          Purchase Agreements or this Indenture, or from exercising any rights
          available to them thereunder or under any of such instruments, and
          that the exercise of any of the aforesaid rights shall not constitute
          a legal or equitable discharge of the Guarantor.  The Guarantor
          understands that the exercise by the Guaranteed Parties of certain
          rights and remedies contained in this Indenture may cause the
          Guarantor to incur a partially or totally non-reimbursable liability
          hereunder; nevertheless, the Guarantor hereby authorizes and empowers
          each Guaranteed Party to exercise, in its sole discretion, any rights
          and remedies, or any combination thereof, which may then be available,
          since it is the intent and purpose of the Guarantor that the
          obligations hereunder shall be absolute, independent and unconditional
          under any and all circumstances.  To the fullest extent permitted by
          law, the Guarantor waives all rights and defenses arising out of an
          election of remedies by the Guaranteed Parties.

     Section 6.02  Compliance with Law.  The Company and the Guarantor will, and
                   -------------------
the Guarantor will cause the Company to, comply with all laws, ordinances or
governmental rules or regulations to which either of them is subject, including,
without limitation, Environmental Laws, and will obtain and maintain in effect
all licenses, certificates, permits, franchises and other governmental
authorizations, necessary to the ownership of their respective properties or to
the conduct of their respective businesses, in each case to the extent necessary
to ensure that non-compliance with such laws, ordinances or governmental rules
or regulations or failures to obtain or maintain in effect such licenses,
certificates, permits, franchises and other governmental authorizations would
not, individually or in the aggregate, reasonably be expected to have a Material
Adverse Effect.

                                      -35-
<PAGE>

     Section 6.03  Insurance.
                   ---------

          (a)  The Company will, and the Guarantor will cause the Company to,
     maintain, as part of an insurance program which may include appropriate
     risk retention and self-insurance, insurance with respect to the Equipment
     in such amounts and against such risks not less than the insurance, if any,
     maintained by the Company with respect to similar equipment owned or leased
     by the Company, subject to specified minimum coverage levels set forth in
     Schedule 2 hereto.
     ----------

          (b)  If any public liability insurance policy or coverage thereunder
     which is required to be maintained under Section 6.03(a) shall not be
     available to the Company in the commercial insurance market on commercially
     reasonable terms, the Trustee shall not unreasonably withhold its agreement
     to waive such requirement to the extent the maintenance thereof is not so
     available upon application therefor as set forth herein.  The Company shall
     make written request for any such waiver in writing, accompanied by written
     reports prepared, at the Company's option, either by (i) one independent
     insurance advisor chosen by the Company and the Trustee or (ii) three
     independent insurance advisors, one chosen by the Trustee, one chosen by
     the Company and one chosen by the other two advisors (one of which may be
     the regular insurance broker or brokers of the Company), in either case,
     such independent insurance advisors being of recognized national standing.
     The fees and expenses of all such advisors shall be paid by the Company.
     The written reports required hereunder shall (x) state that such insurance
     (or the required coverage thereunder) is not reasonably available to the
     Company at commercially reasonable premiums in the commercial insurance
     markets within which the Company normally purchases its insurance from
     insurers, acceptable to the Company, with a Best's rating of A- or better
     for equipment of similar type and capacity and (y) explain in detail the
     basis for such conclusions.  Upon the granting of any such waiver, the
     Company shall within 15 days thereafter certify to the Trustee in writing
     the cost (for all equipment of a type similar to the Equipment) of
     liability insurance premiums for the coverage required by Section 6.03(a)
     for the immediately preceding fiscal year; and in the event that any such
     certificate is not received by the Trustee within such 15-day period, any
     such waiver shall be deemed revoked.  At any time after the granting of
     such waiver, but not more often than once a year, the Trustee may make a
     written request for a supplemental report (in form reasonably acceptable to
     the Trustee) from such insurance advisor(s) updating the prior report and
     reaffirming the conclusions set forth therein.  The Company shall provide
     any such required supplemental report within 60 days after receipt of the
     written request therefor.  Any such waiver shall be effective for only as
     long as such insurance is not reasonably available to the Company in the
     commercial markets in which the Company normally purchases its insurance at
     commercially reasonable rates, it being understood that the failure of the
     Company to furnish timely any such supplemental report shall be conclusive
     evidence that such condition no longer exists.  If such supplemental report
     shows that such coverage is available, the Company shall within 90 days of
     such report obtain such insurance coverage.  During any period with respect
     to which such waiver has been granted and remains in effect under this
     Section 6.03(b), the Company shall obtain public liability insurance as set
     forth under Section 6.03(a) from such carriers, in such amounts and with
     coverage limits and

                                      -36-
<PAGE>

     deductibles as is prudent under the circumstances, but in any event in an
     amount that may be purchased for a premium equal to 110% of the Company's
     cost (for all equipment of a type similar to the Equipment) of public
     liability insurance premiums for the coverage required by Section 6.03(a)
     for the fiscal year immediately preceding the fiscal year in which such
     waiver first was granted.

     Section 6.04  Maintenance of Properties.  The Company and the Guarantor
                   -------------------------
will, and the Guarantor will cause the Company to, maintain and keep, or cause
to be maintained and kept, their respective properties in good repair, working
order and condition (other than ordinary wear and tear), so that the business
carried on in connection therewith may be properly conducted at all times,
provided that this Section shall not prevent the Guarantor or the Company from
discontinuing the operation and the maintenance of any of its properties if such
discontinuance is desirable or appropriate in the conduct of its business and
the Guarantor has concluded that such discontinuance would not, individually or
in the aggregate, reasonably be expected to have a Material Adverse Effect.

     Section 6.05  Payment of Taxes and Claims.  The Company and the Guarantor
                   ---------------------------
will, and the Guarantor will cause the Company to, file all tax returns required
to be filed in any jurisdiction and to pay and discharge all taxes shown to be
due and payable on such returns and all other taxes, assessments, governmental
charges, or levies imposed on them or any of their properties, assets, income or
franchises, to the extent such taxes and assessments have become due and payable
and before they have become delinquent and all claims for which sums have become
due and payable that have or might become a Lien on properties or assets of the
Guarantor or the Company, provided that neither the Guarantor nor the Company
need pay any such tax or assessment or claims if (i) the amount, applicability
or validity thereof is contested by the Guarantor or the Company on a timely
basis in good faith and in appropriate proceedings, and the Guarantor or the
Company has established adequate reserves therefor in accordance with GAAP on
the books of the Guarantor or the Company, as applicable, or (ii) the nonpayment
of all such taxes and assessments in the aggregate could not reasonably be
expected to have a Material Adverse Effect.

     Section 6.06  Maintenance of Corporate Existence. Subject to compliance
                   ----------------------------------
with the provisions of Section 6.07, each of the Company and the Guarantor will,
and the Guarantor will cause the Company to, at all times preserve and keep in
full force and effect its corporate existence (unless the Company is merged into
the Guarantor or a subsidiary thereof) and all rights and franchises of the
Guarantor and the Company unless, in the good faith judgment of the Guarantor,
the termination of or failure to preserve and keep in full force and effect such
corporate existence, right or franchise would not, individually or in the
aggregate, have a Material Adverse Effect.

     Section 6.07  Consolidation, Merger or Sale of Assets Permitted.
                   -------------------------------------------------

          (a)  Neither the Company nor the Guarantor shall, nor shall the
     Guarantor permit or cause the Company to, consolidate with or merge into
     any other Person or convey, transfer or lease all or substantially all of
     its assets in a single transaction or series of transactions to any Person,
     unless (i) the successor formed by such consolidation

                                      -37-
<PAGE>

     or the survivor of such merger or the Person which acquires by conveyance,
     transfer or lease all or substantially all of the assets of the Company or
     the Guarantor as an entirety, as the case may be, shall be a Person
     organized and existing under the laws of the United States of America or
     any state thereof or the District of Columbia, and unless such Person is
     the Guarantor, such Person shall have executed and delivered to the Trustee
     an agreement in form reasonably satisfactory to the Trustee containing an
     assumption by such Person of the due and punctual performance and
     observance of each covenant and condition of this Indenture, the Note
     Purchase Agreements and the Notes applicable to the Company or the
     Guarantor, as the case may be, and (ii) immediately after giving effect to
     such transaction, no Event of Default, and no event that, after notice or
     lapse of time, or both, would become an Event of Default, shall have
     occurred and be continuing.

          (b)  Upon any consolidation or merger, or any conveyance, transfer or
     lease of all or substantially all of the assets of the Company or the
     Guarantor, the successor formed by such consolidation or the survivor of
     such merger or the Person to which such conveyance, transfer or lease is
     made shall succeed to, and be substituted for, and may exercise every right
     and power of, the Company or the Guarantor, as applicable, under this
     Indenture with the same effect as if such Person had been named as such
     party herein.  No such consolidation or merger or conveyance, transfer or
     lease of all or substantially all of the assets of the Company or the
     Guarantor as an entirety, as applicable, shall have the effect of releasing
     such party or any successor Person which shall theretofore have become such
     from its liability hereunder or under the Note Purchase Agreements or the
     Notes.

          (c)  The Company or the Guarantor, as applicable, shall deliver to the
     Trustee an Opinion of Counsel of the Company or the Guarantor that any such
     consolidation, merger, transfer, lease or conveyance, and any such
     assumption agreement complies with the provisions of this Section 6.07,
     including the enforceability of the Guarantor's obligations against such
     successor Person.

                                  ARTICLE VII

                        Concerning the Holders of Notes
                        -------------------------------

     Section 7.01  Company to Furnish Trustee with Names and Addresses of
                   ------------------------------------------------------
Noteholders.  The Company will furnish to the Trustee within 15 days after each
-----------
Record Date with respect to a Scheduled Payment Date, and at such other times as
the Trustee may request in writing, within 30 days after receipt by the Company
of any such request, a list, in such form as the Trustee may reasonably require,
of all information in the possession or control of the Company as to the names
and addresses of the Noteholders, in each case as of a date not more than 15
days prior to the time such list is furnished; provided, however, that so long
                                               --------  -------
as the Trustee is the sole Registrar, no such list need be furnished; and
provided further,  however, that no such list need be furnished for so long as a
-------- -------   -------
copy of the Register is being furnished to the Trustee pursuant to Section 8.12.

                                      -38-
<PAGE>

     Section 7.02  Preservation of Information; Communications to Noteholders.
                   ----------------------------------------------------------
The Trustee shall preserve, in as current a form as is reasonably practicable,
the names and addresses of Noteholders contained in the most recent Register or
list furnished to the Trustee as provided in Section 8.12 or Section 7.01, as
the case may be, and the names and addresses of holders of Notes received by the
Trustee in its capacity as Registrar, if so acting.  The Trustee may destroy any
Register or list furnished to it as provided in Section 8.12 or Section 7.01, as
the case may be, upon receipt of a new Register or list so furnished.

     Section 7.03  Financial Statements and Other Information.  The Guarantor
                   ------------------------------------------
will provide and with respect to the matters set forth in subsections (b) and
(c) will cause the Company to provide to the Trustee and each Noteholder that is
an Institutional Investor:

          (a)  Quarterly Statements - within 60 days after the end of each
               --------------------
     quarterly fiscal period in each fiscal year of the Guarantor (other than
     the last quarterly fiscal period of each such fiscal year), a copy of:

               (i)  a condensed consolidated balance sheet of the Guarantor and
          its subsidiaries as at the end of such quarter, and

               (ii) condensed consolidated statements of income and cash flows
          of the Guarantor and its subsidiaries, for such quarter and (in the
          case of the second and third quarters) for the portion of the fiscal
          year ending with such quarter,

     setting forth in each case in comparative form the figures for the
     corresponding periods in the previous fiscal year (as at the end of the
     most recent fiscal year in the case of the balance sheet), all in
     reasonable detail, prepared in accordance with GAAP applicable to quarterly
     financial statements generally, and certified by a Senior Financial Officer
     as fairly presenting, in the opinion of such Person, in all material
     respects, the consolidated financial position of the companies being
     reported on and their results of operations and cash flows, subject to
     changes resulting from year-end adjustments, provided that delivery within
                                                  --------
     the time period specified above of a copy of the Guarantor's Quarterly
     Report on Form 10-Q prepared in compliance with the requirements therefor
     and filed with the SEC shall be deemed to satisfy the requirements of this
     Section 7.03(a);

          (b)  Annual Statements - within 105 days after the end of each fiscal
               -----------------
     year of the Guarantor, a copy of:

               (i)  a consolidated balance sheet of the Guarantor and its
          subsidiaries, as at the end of such year, and

               (ii) consolidated statements of income, changes in stockholder's
          equity and cash flows of the Guarantor and its subsidiaries, for such
          year,

     setting forth in each case in comparative form the figures for the previous
     fiscal year, all in reasonable detail, prepared in accordance with GAAP,
     and accompanied by an opinion thereon of independent certified public
     accountants of recognized national standing, which opinion shall state
     that, in the opinion of such firm, such financial statements

                                      -39-
<PAGE>

     present fairly, in all material respects, the consolidated financial
     position of the companies being reported upon and their results of
     operations and cash flows and have been prepared in conformity with GAAP,
     and that the audits performed by such accountants in connection with such
     financial statements have been made in accordance with generally accepted
     auditing standards, and that such audits provide a reasonable basis for
     such opinion in the circumstances, provided that the delivery within the
                                        --------
     time period specified above of the Guarantor's Annual Report on Form 10-K
     for such fiscal year (together with the Guarantor's annual report to
     shareholders, if any, prepared pursuant to Rule 14a-3 under the Securities
     Exchange Act of 1934, as amended) prepared in accordance with the
     requirements therefor and filed with the SEC shall be deemed to satisfy the
     requirements of this Section 7.03(b);

          (c)  Each set of annual financial statements delivered pursuant to
     Section 7.03(b) hereof shall be accompanied by a certificate of a Senior
     Financial Officer of the Guarantor and of the Company as to the Company's
     or the Guarantor's, as applicable:

               (i)  Covenant Compliance - whether, in the opinion of the Person
                    -------------------
          signing such certificate, the Company or the Guarantor, as applicable,
          was in compliance with all of its obligations hereunder during the
          annual period covered by the statements then being furnished, and

               (ii) Event of Default - a statement that such officer has
                    ----------------
          reviewed the relevant terms hereof and has made, or caused to be made,
          under his or her supervision, a review of the transactions and
          conditions of the Guarantor or the Company, as applicable, from the
          beginning of the annual period covered by the statements then being
          furnished to the date of the certificate and that such review shall
          not have disclosed the existence during such period of any condition
          or event that constitutes a Default or an Event of Default or, if any
          such condition or event existed or exists (including, without
          limitation, any such event or condition resulting from the failure of
          the Guarantor or the Company to comply with any Environmental Law),
          specifying the nature and period of existence thereof and what action
          the Guarantor or the Company shall have taken or proposes to take with
          respect thereto;

          (d)  Within five (5) Business Days after a Responsible Officer of the
     Company or the Guarantor becomes aware of any Default, a written notice
     specifying the nature and period of existence thereof and what action the
     Company or the Guarantor is taking or proposes to take with respect
     thereto; and

          (e)  Other information relating to the business, operations, affairs,
     financial condition, assets or properties of the Guarantor or any of its
     subsidiaries as reasonably requested by any Noteholder.

     Section 7.04  Inspection.  The Guarantor shall permit each Noteholder that
                   ----------
is an Institutional Investor:

                                      -40-
<PAGE>

          (a)  Prior to the occurrence of an Event of Default, at the
     Noteholder's own expense and upon reasonable prior notice, to visit the
     principal executive office of the Guarantor and discuss the Guarantor's and
     the Company's business, operations, financial condition, assets and
     properties with their respective officers and, with the consent of the
     Guarantor (which shall not be unreasonably withheld), to visit other
     offices and properties of the Guarantor and the Company, all at such
     reasonable times during regular business hours and as often as may be
     reasonably requested in writing; and

          (b)  Following the occurrence of an Event of Default and during the
     continuance thereof, at the Guarantor's expense, to visit and inspect any
     offices or properties of the Guarantor or the Company, to examine their
     respective books and records, and make copies and extracts therefrom to the
     extent reasonably necessary under the circumstances and to discuss the
     Guarantor's and the Company's business, operations, financial condition,
     assets and properties with their respective officers and independent public
     accountants.

          (c)  The confidentiality of all information provided by the Guarantor
     or the Company pursuant to Section 7.04(a) or 7.04(b) shall be maintained
     by each Noteholder in strict accordance with the provisions of Section 12
     of the Note Purchase Agreements (regardless of whether such Noteholders are
     parties thereto).

                                 ARTICLE VIII

                                  The Trustee
                                  -----------

     Section 8.01  Certain Duties and Responsibilities.
                   -----------------------------------

          (a)  Except during the continuance of an Event of Default,

               (i)  the Trustee undertakes to perform only such duties as are
          specifically set forth in this Indenture, and no implied covenants,
          duties or obligations shall be read into this Indenture against the
          Trustee; and

               (ii) in the absence of bad faith on its part, the Trustee may
          conclusively rely, as to the truth of the statements and the
          correctness of the opinions expressed therein, upon certificates or
          opinions furnished to the Trustee and conforming to the requirements
          of this Indenture; but in the case of any such certificates or
          opinions which by any provision hereof are specifically required to be
          furnished to the Trustee, the Trustee shall be under a duty to examine
          the form of the same to determine whether or not they substantially
          conform to the requirements of this Indenture, but shall be under no
          duty to investigate the facts contained therein.

          (b)  In case an Event of Default has occurred and is continuing, the
     Trustee shall exercise such of the right and powers vested in it by this
     Indenture, and use the same

                                      -41-
<PAGE>

     degree of care and skill in its exercise, as a prudent man would exercise
     or use under the circumstances in the conduct of his own affairs.

          (c)  No provision of this Indenture shall be construed to relieve the
     Trustee from liability for its own negligent action, its own negligent
     failure to act, or its own willful misconduct, except that:

               (i)   this Subsection shall not be construed to limit the effect
          of Subsection (a) of this Section;

               (ii)  the Trustee shall not be liable for any error of judgment
          made in good faith by a Responsible Officer of the Trustee;

               (iii) the Trustee shall not be liable with respect to any action
          taken or omitted to be taken by it in good faith in accordance with
          the direction of the holders of Notes representing more than 50% of
          the aggregate unpaid principal amount of Notes then outstanding
          relating to the time, method and place of conducting any proceeding
          for any remedy available to the Trustee, or exercising any trust or
          power conferred upon the Trustee, under this Indenture; and

               (iv)  no provision of this Indenture shall require the Trustee to
          expend or risk its own funds in the performance of any of its duties
          hereunder, or in the exercise of any of its rights or powers, if it
          shall have reasonable grounds for believing that payment of such funds
          or adequate indemnity against such risk is not reasonably assured to
          it.

          (d)  Whether or not herein expressly so provided, every provision of
     this Indenture relating to the conduct or affecting the liability of or
     affording protection to the Trustee shall be subject to the provisions of
     this Section.

     Section 8.02  Notice of Defaults.  As promptly as practicable after, and in
                   ------------------
any event within 30 days after, the occurrence of any default (as such term is
defined below) hereunder, the Trustee shall transmit by mail to the Noteholders,
the Company and the Guarantor notice of such default hereunder actually known to
a Responsible Officer of the Trustee, unless such default shall have been cured
or waived; provided, however, that, except in the case of a default in the
           --------  -------
payment of the principal of or interest on a Note or the Make-Whole Amount, if
any, the Trustee shall be protected in withholding such notice if and so long as
the board of directors, the executive committee or a trust committee of
directors and/or Responsible Officers of the Trustee in good faith determine
that the withholding of such notice is in the interests of the registered
holders of the Notes.  Solely for the purpose of this Section, the term
"default" means the occurrence of any Event of Default, except that in
determining whether any such Event of Default has occurred, any grace period or
notice in connection therewith shall be disregarded.

     Section 8.03  Certain Rights of Trustee.  Except as otherwise provided in
                   -------------------------
Section 8.01:

          (a)  the Trustee may rely and shall be protected in acting or
     refraining from acting in reliance upon any resolution, certificate,
     statement, instrument, opinion, report,

                                      -42-
<PAGE>

     notice, request, direction, consent, order, bond, debenture or other paper
     or document believed by it to be genuine and to have been signed or
     presented by the proper party or parties;

          (b)  any request or direction of the Company or the Guarantor
     mentioned herein shall be sufficiently evidenced by a Request;

          (c)  whenever in the administration of this Indenture the Trustee
     shall deem it desirable that a matter be proved or established prior to
     taking, suffering or omitting any action hereunder, the Trustee (unless
     other evidence be herein specifically prescribed) may, in the absence of
     bad faith on its part, rely upon any Officer's Certificate;

          (d)  the Trustee may consult with counsel and the advice of such
     counsel or any Opinion of Counsel shall be full and complete authorization
     and protection in respect of any action taken, suffered or omitted by it
     hereunder in good faith and in reliance thereon;

          (e)  the Trustee shall be under no obligation to exercise any of the
     rights or powers vested in it by this Indenture at the request or direction
     of any of the Noteholders pursuant to this Indenture, unless such
     Noteholders shall have offered to the Trustee reasonable security or
     indemnity against the cost, expenses and liabilities which might be
     incurred by it in compliance with such request or direction;

          (f)  the Trustee shall not be bound to make any investigation into the
     facts or matters stated in any resolution, certificate, statement,
     instrument, opinion, report, notice, request, direction, consent, order,
     bond, debenture or other paper or document; and

          (g)  the Trustee may execute any of the trusts or powers hereunder or
     perform any duties hereunder either directly or by or through agents or
     attorneys and the Trustee shall not be responsible for any misconduct or
     negligence on the part of any agent or attorney appointed with due care by
     it hereunder.

     Section 8.04  Not Responsible for Recitals or Issuance of Notes.  The
                   -------------------------------------------------
recitals contained herein and in the Notes, except the certificates of
authentication, shall not be taken as the statements of the Trustee, and the
Trustee assumes no responsibility for their correctness.  The Trustee makes no
representations as to the validity or sufficiency of this Indenture or the
Notes, except that the Trustee hereby represents and warrants that this
Indenture has been executed and delivered by one of its officers who is duly
authorized to execute and deliver such document on its behalf, and that this
Indenture constitutes the legal, valid and binding obligation of the Trustee to
the extent so stated herein, enforceable against the Trustee in accordance with
its terms.

     Section 8.05  May Hold Notes.  The Trustee or any of its Affiliates, in
                   --------------
their respective individual or any other capacity, may become the owner or
pledgee of Notes and, subject to Sections 310(b) and 311 of the Trust Indenture
Act of 1939, as amended (the "Trust Indenture Act"), which shall be deemed to
                              -------------------
apply solely for the purposes of this Section and the second paragraph of
Section 8.08 hereof, may otherwise deal with the Company or the Guarantor with
the same rights it would have if it were not Trustee.

                                      -43-
<PAGE>

     Section 8.06  Money Held by Trustee.  Any money or Permitted Investments
                   ---------------------
held by the Trustee in trust hereunder need not be segregated from other funds
except to the extent required herein or by law, and the Trustee shall not have
any liability for interest upon any such moneys except as provided for herein.

     Section 8.07  Compensation and Reimbursement.  The Company and the
                   ------------------------------
Guarantor agree:

          (a)  to pay, or cause to be paid, to the Trustee from time to time
     reasonable compensation for all services rendered by it hereunder (which
     compensation shall not be limited by any provision of law in regard to the
     compensation of a trustee of an express trust);

          (b)  except as otherwise expressly provided herein, to reimburse, or
     cause to be reimbursed, the Trustee upon its request for all reasonable
     out-of-pocket expenses, disbursements and advances incurred or made by the
     Trustee in accordance with any provision of this Indenture (including the
     reasonable compensation and the expenses and disbursements of its agents
     and counsel), except any such expense, disbursement or advance as may be
     attributable to its negligence, willful misconduct or bad faith or as may
     be incurred due to the Trustee's breach of its representations and
     warranties set forth in Section 8.04;

          (c)  to indemnify, or cause to be indemnified, the Trustee for, and to
     hold it harmless against, any loss, liability or expense (other than for or
     with respect to any tax) incurred without negligence, willful misconduct or
     bad faith, on its part, arising out of or in connection with the acceptance
     or administration of this Indenture, including the costs and expenses of
     defending itself against any claim or liability in connection with the
     exercise or performance of any of its powers or duties hereunder, except
     for any such loss, liability or expense incurred by reason of the Trustee's
     breach of its representations and warranties set forth in Section 8.04.
     The Trustee shall notify the Company and the Guarantor promptly of any
     claim for which it may seek indemnity.  The Company and the Guarantor shall
     defend the claim and the Trustee shall cooperate in the defense.  The
     Trustee may have separate counsel with the consent of the Company, and the
     Company and the Guarantor will pay the reasonable fees and expenses of such
     counsel.  The Company and the Guarantor need not pay for any settlement
     made without their consent; and

          (d)  to indemnify, or cause to be indemnified, the Trustee for, and to
     hold it harmless against, any tax (other than for or with respect to any
     tax referred to in the next paragraph, provided that no indemnification
                                            --------
     shall be available with respect to any tax attributable to the Trustee's
     compensation for serving as such) incurred without negligence, willful
     misconduct or bad faith, on its part, arising out of or in connection with
     the acceptance or administration of this Indenture, including any costs and
     expenses reasonably incurred in contesting the imposition of any such tax.
     The Trustee, shall notify the Company and the Guarantor promptly of any tax
     for which it may seek indemnity.  The Company and the Guarantor shall
     defend against the imposition of such

                                      -44-
<PAGE>

     tax and the Trustee shall cooperate in the defense. The Trustee may have
     separate counsel with the consent of the Company, and the Company and the
     Guarantor will pay the reasonable fees and expenses of such counsel. The
     Company and the Guarantor need not pay for any taxes paid, in settlement or
     otherwise, without its consent.

     In addition, the Trustee shall be entitled to reimbursement from, and shall
have a Lien prior to the Notes upon, all property and funds held or collected by
the Trustee in its capacity as Trustee for any tax incurred without negligence,
bad faith or willful misconduct, on its part, arising out of or in connection
with the acceptance or administration of this Indenture (other than any tax
attributable to the Trustee's compensation for serving as such), including any
costs and expenses reasonably incurred in contesting the imposition of any such
tax.  If the Trustee reimburses itself for any such tax, it will within 30 days
mail a brief report setting forth the circumstances thereof to all Noteholders
as their names and addresses appear in the Register and to the Guarantor, and
the Guarantor shall promptly deliver funds to the Trustee equal to such amount,
such funds to be added to the Collateral pursuant to Section 3.04.

     Section 8.08  Trustee Required; Eligibility.  This Indenture shall at all
                   -----------------------------
times have a Trustee which shall have a combined capital and surplus of at least
$100,000,000 or the obligations of which, whether now in existence or hereafter
incurred, are fully and unconditionally guaranteed by a corporation organized
and doing business under the laws of the United States of America, any State or
Territory thereof or of the District of Columbia and having a combined capital
and surplus of at least $100,000,000.  Any successor Trustee shall have a
combined capital of at least $250,000,000 or shall have its obligations
unconditionally guaranteed by a corporation meeting the criteria set forth in
the immediately preceding sentence, and having a combined capital and surplus of
at least $250,000,000.  If such corporation publishes reports of condition at
least annually, pursuant to law or the requirements of federal, state,
territorial or District of Columbia supervising or examining authority, then for
the purposes of this Section 8.08, the combined capital and surplus of such
corporation shall be deemed to be its combined capital and surplus as set forth
in its most recent report of condition so published.

     The Trustee shall comply with Section 310(b) of the Trust Indenture Act
which shall be deemed to apply solely for the purposes of this sentence and
Section 8.05 hereof.

     In case at any time the Trustee shall cease to be eligible in accordance
with the provisions of this Section 8.08, the Trustee shall resign immediately
in the manner and with the effect specified in Section 8.09.

     Section 8.09  Resignation and Removal; Appointment of Successor.
                   -------------------------------------------------

          (a)  No resignation or removal of the Trustee and no appointment of a
     successor Trustee pursuant to this Article shall become effective until the
     acceptance of appointment by the successor Trustee under Section 8.10.

          (b)  The Trustee may resign at any time by giving written notice
     thereof to the Company.  If an instrument of acceptance by a successor
     Trustee shall not have been delivered to the Company, within 30 days after
     the giving of such notice of resignation,

                                      -45-
<PAGE>

     the resigning Trustee may petition any court of competent jurisdiction for
     the appointment of a successor Trustee.

          (c)  The Trustee may be removed at any time by Act of the Noteholders
     holding Notes representing more than 50% of the aggregate unpaid principal
     amount of Notes then outstanding delivered to the Trustee and the Company.

          (d)   If at any time:

               (i)  the Trustee shall cease to be eligible under Section 8.08
          and shall fail to resign after written request therefor by the
          Companies or by any such Noteholder; or

               (ii) the Trustee shall become incapable of acting or shall be
          adjudged a bankrupt or insolvent or a receiver of the Trustee or of
          its property shall be appointed or any public officer shall take
          charge or control of the Trustee or of its property or affairs for the
          purpose of rehabilitation, conservation or liquidation;

     then, in any case, (x) the Company may remove the Trustee or (y) subject to
     Section 4.06, any Noteholder who has been a bona fide Noteholder for at
     least six months may, on behalf of himself and all others similarly
     situated, petition any court of competent jurisdiction for the removal of
     the Trustee and the appointment of a successor Trustee.

          (e)  If a Responsible Officer of the Trustee shall obtain actual
     knowledge of an Avoidable Tax (as hereinafter defined) which has been or is
     likely to be asserted, the Trustee shall promptly notify the Company and
     shall, within 30 days of such notification, resign hereunder unless within
     such 30-day period the Trustee shall have received notice that the Company
     has agreed to pay such tax.  The Company shall promptly appoint a successor
     Trustee in a jurisdiction where there are no Avoidable Taxes.  As used
     herein, an "Avoidable Tax" means a state or local tax: (i) upon (w) the
                 -------------
     Indenture, (x) the Collateral, (y) Noteholders or (z) the Trustee for which
     the Trustee is entitled to seek reimbursement from the Collateral, and (ii)
     which would be avoided if the Trustee were located in another state, or
     jurisdiction within a state, within the United States.  A tax shall not be
     an Avoidable Tax if the Company shall agree to pay, and shall pay, such
     tax.

          (f)  If the Trustee shall resign, be removed or become incapable of
     acting, or if a vacancy shall occur in the office of the Trustee for any
     cause, the Company shall promptly appoint an interim successor Trustee. If,
     within one year after such resignation, removal or incapacity, or the
     occurrence of such vacancy, a successor Trustee shall be appointed by Act
     of the Noteholders representing more than 50% of the aggregate unpaid
     principal then outstanding delivered to the Company and the interim
     successor Trustee, the successor Trustee so appointed shall, forthwith upon
     its acceptance of such appointment, become the successor Trustee and
     supersede the interim successor Trustee.  If no successor Trustee shall
     have been so appointed as provided above and accepted appointment in the
     manner hereinafter provided, any Noteholder who has been a bona fide
     Noteholder for at least six months may, on behalf of himself and all others
     similarly

                                      -46-
<PAGE>

     situated, petition any court of competent jurisdiction for the appointment
     of a successor Trustee.

          (g)  The successor Trustee shall give notice of the resignation and
     removal of the Trustee and appointment of the successor Trustee by mailing
     written notice of such event by first-class mail, postage prepaid, to the
     Noteholders as their names and addresses appear in the Register.  Each
     notice shall include the name of such successor Trustee and the address of
     its Corporate Trust Office.

     Section 8.10  Acceptance of Appointment by Successor.  Every successor
                   --------------------------------------
Trustee appointed hereunder shall execute, acknowledge and deliver to the
Company and the retiring Trustee an instrument accepting such appointment, and
thereupon the resignation or removal of the retiring Trustee shall become
effective and such successor Trustee, without any further act, deed or
conveyance, shall become vested with all the rights, powers, trusts and duties
of the retiring Trustee; but, on request of the Company or the successor
Trustee, such retiring Trustee shall execute and deliver an instrument
transferring to such successor Trustee all the rights, powers and trusts of the
retiring Trustee and shall duly assign, transfer and deliver to such successor
Trustee all property and money held by such retiring Trustee hereunder, subject
nevertheless to its Lien, if any, provided for in Section 8.07.  Upon request of
any such successor Trustee, the Company, the retiring Trustee and such successor
Trustee shall execute and deliver any and all instruments containing such
provisions as shall be necessary or desirable to transfer and confirm to, and
for more fully and certainly vesting in, such successor Trustee all such rights,
powers and trusts.

     No successor Trustee shall accept its appointment unless at the time of
such acceptance such successor Trustee shall be qualified and eligible under
this Article.

     Section 8.11  Merger, Conversion, Consolidation or Succession to Business.
                   -----------------------------------------------------------
Any Person into which the Trustee may be merged or converted or with which it
may be consolidated, or any Person resulting from any merger, conversion or
consolidation to which the Trustee shall be a party, or any Person succeeding to
all or substantially all of the corporate trust business of the Trustee, shall
be the successor of the Trustee hereunder, provided such Person shall be
otherwise qualified and eligible under this Article, without the execution or
filing of any paper or any further act on the part of any of the parties hereto.
In case any Notes shall have been authenticated, but not delivered, by the
Trustee then in office, any successor by merger, conversion or consolidation to
such authenticating Trustee may adopt such authentication and deliver the Notes
so authenticated with the same effect as if such successor Trustee had itself
authenticated such Notes.

     Section 8.12  Maintenance of Agencies.
                   -----------------------

          (a)  There shall at all times be maintained in the Borough of
     Manhattan, The City of New York, an office or agency where Notes may be
     presented or surrendered for registration of transfer or for exchange, and
     for payment thereof and where notices and demands to or upon the Trustee in
     respect of the Notes or of this Indenture may be served. Such office or
     agency shall be initially at the Trustee's office located at 14 Wall

                                      -47-
<PAGE>

     Street, 8/th/ Floor, Window #2, New York, New York  10005.  Written notice
     of the location of each such other office or agency and of any change of
     location thereof shall be given by the Trustee to the Company and the
     Noteholders. In the event that no such office or agency shall be maintained
     or no such notice of location or of change of location shall be given,
     presentations and demands may be made and notices may be served at the
     Corporate Trust Office of the Trustee.

          (b)  There shall at all times be a Registrar and a paying agent (each
     an "Authorized Agent") hereunder.  Each such Authorized Agent shall be a
         ----------------
     bank or trust company, shall be a corporation organized and doing business
     under the laws of the United States of America or any state or territory
     thereof or of the District of Columbia, with a combined capital and surplus
     of at least $100,000,000, or, if the Trustee shall be acting as the
     Registrar or paying agent hereunder, a corporation the obligations of which
     are guaranteed by a corporation organized and doing business under the laws
     of the United States of America or any State or Territory thereof or of the
     District of Columbia, with a combined capital and surplus of at least
     $100,000,000, and shall be authorized under such laws to exercise corporate
     trust powers, subject to supervision by federal or state authorities.  The
     Trustee shall initially be the paying agent and Registrar hereunder.  Each
     Registrar shall furnish to the Trustee, at stated intervals of not more
     than six months, and at such other times as the Trustee may request in
     writing, a copy of the Register.

          (c)  Any corporation into which any Authorized Agent may be merged or
     converted or with which it may be consolidated, or any corporation
     resulting from any merger, consolidation or conversion to which any
     Authorized Agent shall be a party, or any corporation succeeding to the
     corporate trust business of any Authorized Agent, shall be the successor of
     such Authorized Agent hereunder, if such successor corporation is otherwise
     eligible under this Section, without the execution or filing of any paper
     or any further act on the part of the parties hereto or such Authorized
     Agent or such successor corporation.

          (d)  Any Authorized Agent may at any time resign by giving written
     notice of resignation to the Trustee and the Company.  The Company may, and
     at the request of the Trustee shall, at any time terminate the agency of
     any Authorized Agent by giving written notice of termination to such
     Authorized Agent and to the Trustee.  Upon the resignation or termination
     of an Authorized Agent or in case at any time any such Authorized Agent
     shall cease to be eligible under this Section (when, in either case, no
     other Authorized Agent performing the functions of such Authorized Agent
     shall have been appointed), the Company shall promptly appoint a qualified
     successor Authorized Agent, reasonably satisfactory to the Trustee, to
     perform the functions of the Authorized Agent which has resigned or whose
     agency has been terminated or who shall have ceased to be eligible under
     this Section.  The Company shall give written notice of any such
     appointment made by them to the Trustee; and in each case the Trustee shall
     mail notice of such appointment to all Noteholders as their names and
     addresses appear on the Register.

                                      -48-
<PAGE>

          (e)  The Company and the Guarantor agree to pay, or cause to be paid,
     pursuant to separate agreements from time to time to each Authorized Agent
     reasonable compensation for its services and to reimburse it for its
     reasonable expenses.

     Section 8.13  Money for Note Payments to Be Held by Trustee.  All moneys
                   ---------------------------------------------
deposited with any paying agent for the purpose of any payment on Notes shall be
deposited and held in trust for the benefit of the Noteholders entitled to such
payment, subject to the provisions of this Section.

     The Trustee will cause each paying agent other than the Trustee to execute
and deliver to it an instrument in which such paying agent shall agree with the
Trustee, subject to the provisions of this Section, that such paying agent will:

          (a)  hold all sums held by it for payments on Notes in trust for the
     benefit of the Persons entitled thereto until such sums shall be paid to
     such Persons or otherwise disposed of as herein provided;

          (b)  give the Trustee notice of any default by any obligor upon the
     Notes in the making of any such payment; and

          (c)  at any time during the continuance of any such default, upon the
     written request of the Trustee, forthwith pay to the Trustee all sums so
     held in trust by such paying agent.

     The Trustee may at any time, for the purpose of obtaining the satisfaction
and discharge of this Indenture or for any other purpose, direct any paying
agent to pay to the Trustee all sums held in trust by such paying agent, such
sums to be held by the Trustee upon the same trusts as those upon which such
sums were held by such paying agent; and, upon such payment by any paying agent
to the Trustee, such paying agent shall be released from all further liability
with respect to such money.

                                  ARTICLE IX

                           Supplements to Indenture
                           ------------------------

     Section 9.01  Supplements to Indenture Without Consent of Noteholders.
                   -------------------------------------------------------
Without the consent of the Noteholders, the Company and the Guarantor may, and
the Trustee (subject to Section 9.03) shall, at any time and from time to time
enter into one or more agreements supplemental hereto, in form satisfactory to
the Trustee, for any of the following purposes:

          (a)  to evidence the succession of another Person to the Company or
     the Guarantor and the assumption by any such successor Person of the
     covenants of the Company or the Guarantor, as applicable, contained herein
     in accordance with this Indenture;

                                      -49-
<PAGE>

          (b)  to add to the covenants of the Company or the Guarantor for the
     benefit of the Noteholders, or to surrender any right or power herein
     conferred upon the Company or the Guarantor, as applicable;

          (c)  to cure any ambiguity, to correct any manifest error or to
     correct or supplement any provision herein which may be defective or
     inconsistent with any other provision herein or to make any other
     provisions with respect to matters or questions arising under this
     Indenture, provided that any such action shall not adversely affect the
     interests of the Noteholders; or

          (d)  to add or substitute Collateral or to release Collateral in
     accordance with Article III.

     Section 9.02  Supplements to Indenture with Consent of Noteholders.  With
                   ----------------------------------------------------
the consent of the Noteholders representing more than 66 2/3% of the aggregate
unpaid principal of the Notes then outstanding, by Act of such Noteholders
delivered to the Company, the Guarantor and the Trustee, the Company and the
Guarantor may, and the Trustee (subject to Section 9.03) shall, enter into an
agreement or agreements supplemental hereto for the purpose of adding any
provisions to or changing in any manner or eliminating any of the provisions of
this Indenture or of modifying in any manner the rights and obligations of the
Noteholders under this Indenture; provided, however, that no such supplemental
                                  --------  -------
agreement shall, without the consent of each registered holder of an outstanding
Note affected thereby:

          (a)  reduce in any manner the amount of, or change the date of, any
     payments on the Notes, or change the place of payment where, or the coin or
     currency in which, any Note is payable, or impair the right to institute
     suit for the enforcement of any such payment or distribution on or after
     the Scheduled Payment Date applicable thereto;

          (b)  reduce the percentage of the aggregate unpaid principal amount of
     Notes then outstanding required for any such supplemental agreement, or
     reduce such percentage required for any waiver (of compliance with certain
     provisions of this Indenture or certain defaults hereunder and their
     consequences) provided or in this Indenture;

          (c)  modify any of the provisions of this Section or Section 4.05,
     except to increase any such percentage or to provide that certain other
     provisions of this Indenture cannot be modified or waived without the
     consent of the registered holder of each Note affected thereby; or

          (d)  eliminate the guarantee of the Guarantor or modify such guarantee
     in a manner adverse to the Noteholders.

     Section 9.03  Documents Affecting Immunity or Indemnity.  If in the opinion
                   -----------------------------------------
of the Trustee any document required to be executed by it pursuant to the terms
of Section 9.01 or 9.02 affects any interest, right, duty, obligation, immunity
or indemnity in favor of the Trustee under this Indenture, the Trustee may in
its discretion decline to execute such document.

                                      -50-
<PAGE>

     Section 9.04  Execution of Supplements to Indentures.  In executing, or
                   --------------------------------------
accepting the additional trusts created by, any supplemental agreement permitted
by this Article or the modifications thereby of the trusts created by this
Indenture, the Trustee shall be provided, and shall be fully protected in
relying upon, an Opinion of Counsel and an Officers' Certificate, each stating
that the execution of such supplemental agreement is authorized or permitted by
this Indenture.

     Section 9.05  Effect of Supplements to Indenture.  Upon the execution of
                   ----------------------------------
any supplemental agreement under this Article, this Indenture shall be modified
in accordance therewith, and such supplemental agreement shall form a part of
this Indenture for all purposes; and every Noteholder theretofore or thereafter
authenticated and delivered hereunder shall be bound thereby.

     Section 9.06  Reference in Notes to Supplements to Indentures.  Notes
                   -----------------------------------------------
authenticated and delivered after the execution of any supplemental agreement
pursuant to this Article may bear a notation in form approved by the Trustee as
to any matter provided for in such supplemental agreement, and, in such case,
suitable notation may be made upon outstanding Notes after proper presentation
and demand.

                                   ARTICLE X

                                 Miscellaneous
                                 -------------

     Section 10.01 Rights Confined to Parties and Holders.  Nothing expressed
                   --------------------------------------
or implied herein shall be construed to confer upon any Person other than the
parties hereto and the holders of the Notes, any right, remedy or claim under or
by reason of this Indenture or of any term, agreement or condition herein, and
all the terms, covenants and conditions herein shall be for the sole and
exclusive benefit of the parties hereto and their successors and of the holders
of the Notes.

     Section 10.02 No Recourse.  No recourse under this Indenture shall be had
                   -----------
against any Person, solely by reason of the fact that he is a stockholder,
officer or director of the Company or the Guarantor, as such, by the enforcement
of any assessment or by any legal or equitable proceeding, by virtue of any
statute or otherwise; it being expressly agreed that this Indenture is solely a
corporate obligation, and that no personal liability whatever shall attach to or
be incurred by any Person, solely by reason of the fact that he is a
stockholder, officer or director of the Company or the Guarantor, under or by
reason of any of the terms, agreements or conditions contained in this
Indenture, or implied therefrom, and that any and all such personal liability,
either at common law or in equity, or by statute or constitution, is hereby
expressly waived as a condition of and consideration for the execution of this
Indenture.

     Section 10.03 Binding Upon Assigns.  Except as otherwise provided herein,
                   --------------------
the provisions of this Indenture shall be binding upon and shall inure to the
benefit of the parties hereto and their respective successors and assigns.

                                      -51-
<PAGE>

     Section 10.04  Notices.  All demands, notices and communications hereunder
                    -------
shall be in writing and shall be deemed to have been received by the addressee
on the date of actual receipt (if such date is a Business Day, otherwise on the
next Business Day), if transmitted by mail, telex, telecopy (confirmed by hard
copy) or similar transmission, or by hand, addressed as follows:  (a) in the
case of the Company or the Guarantor, 225 West Washington Street, 19/th/ Floor,
Chicago, Illinois 60606, marked to the attention of its Treasurer, or such other
address as may hereafter be furnished to the Trustee in writing by the Company
or the Guarantor, (b) in the case of the Trustee, the address set forth in the
definition of Corporate Trust Office in Section 1.01 or such other address as
may hereafter be furnished to the Company in writing by the Trustee, and (c) in
the case of any holder of Notes, at its address shown on the registry books
maintained by the Trustee or at such other address as such holder may from time
to time furnish to the Trustee for such purpose.  An affidavit by any Person
representing or acting on behalf of the Company, the Guarantor or the Trustee,
as to such mailing, having the registry receipt attached, shall be conclusive
evidence of the giving of such demand, notice or communication.

     Section 10.05  Effect of Headings; Date Executed; and Governing Law.
                    ----------------------------------------------------

          (a)  The Article and Section headings herein are for convenience only
     and shall not affect the construction hereof.

          (b)  This Indenture shall be deemed to have been executed on the date
     of the acknowledgment thereof by the officer of the Trustee who signed it
     on behalf of the Trustee.

          (c)  This Indenture shall be governed by the laws of the State of New
     York.

     Section 10.06  Legal Holidays.  In any case where any date for payment of
                    --------------
interest, date for payment of rental or date of maturity of any installment of
principal on the Notes shall not be a Business Day, then, notwithstanding any
other provision of this Indenture or the Notes, payment need not be made on such
date, but may be made on the next succeeding Business Day with the same force
and effect as if made on such date for payment of interest, date for payment of
rental or date of maturity of any installment of principal on the Notes, and if
payment is made on such next succeeding Business Day no interest shall accrue on
the amount of such payment for the period from and after such date for payment
of interest, or for payment of rental or date of maturity of any installment of
principal on the Notes, as the case may be, to and including such next
succeeding Business Day.

     Section 10.07  Counterparts.  For the purpose of facilitating the execution
                    ------------
of this Indenture and for other purposes, this Indenture may be executed
simultaneously in any number of counterparts, each of which counterparts shall
be deemed to be an original, and all of which counterparts shall constitute but
one and the same instrument.

                                      -52-
<PAGE>

     IN WITNESS WHEREOF, the Trustee, the Company and the Guarantor have caused
their names to be signed hereto by their respective officers thereunto duly
authorized and their respective corporate seals, duly attested, to be hereunto
affixed as of the day and year first above written.

                              BANK ONE, N.A., as Trustee

                              By: /s/ Janice Ott Rotunno
                                 ------------------------------------------
                              Name:  Janice Ott Rotunno
                              Title: Vice President and Assistant Secretary
Attest:

   /s/ Benita Pointer
---------------------

                              EXSIF WORLDWIDE, INC.

                              By: /s/ M.J. Garrette
                                 ------------------------------------------
                              Name:  M.J. Garrette
                              Title: Vice President

Attest:

   /s/ R.W. Webb
---------------------
Secretary

                              UNION TANK CAR COMPANY

                              By: /s/ M.J. Garrette
                                 ------------------------------------------
                              Name:  M.J. Garrette
                              Title: Vice President

Attest:

   /s/ R.W. Webb
---------------------
Secretary

                                      -53-
<PAGE>

                                                                      Schedule 1

                           Description of Equipment
                           ------------------------

                                 See Attached
<PAGE>

                                                                      Schedule 2

                             Insurance Provisions
                             --------------------

1.   The Company will carry general liability insurance with respect to the
     Equipment with a minimum coverage level of $100,000,000 per occurrence and
     an annual aggregate of $100,000,000.  There may be deductibles or self-
     insured retentions on such general liability insurance of up to $25,000,000
     per occurrence.

2.   Property damage or physical damage insurance on the Equipment will not be
     required unless the Company is in default.  If property damage insurance is
     required, there will be a limit of $10,000,000 per occurrence, and such
     coverage may provide for a deductible or self-insured retention of up to
     $1,000,000 per occurrence.

3.   The insurance listed above may be a part of an insurance program that also
     covers companies that are affiliated with Company.

4.   The general liability insurance referred in item 1 above will contain these
     provisions:

     a.   The Trustee will be an additional insured on such insurance
          policy(ies).

     b.   The Company will have the insurer(s) waive any right to subrogation
          against the Trustee.

     c.   The Trustee shall have no responsibility for any insurance premiums.

     d.   In substance, all of the terms, conditions, insuring agreements, and
          endorsements, with the exception of limits of liability and liability
          for premiums, commissions, assessments or calls (which shall solely be
          a liability of the Company) shall operate in the same manner as if
          there were a separate policy covering each insured.

     e.   The Trustee will receive 30 days' notice before cancellation or
          termination of the policy(ies) other than for normal expiration or
          non-payment of premiums and 10 days' notice before cancellation for
          non-payment of premiums.

     f.   The Company will use its reasonable best efforts to obtain a provision
          providing that the coverage will not be invalidated as to the Trustee
          due to any action or inaction of the Company, provided that the
          Company shall be under no obligation to obtain such a provision if it
          is not available to Company in policies available to the Company at
          commercially reasonable rates in the markets in which the Company has
          placed its insurance program.

     g.   The Company's insurance will be primary without contribution by any
          similar insurance maintained by the Trustee.

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