Document:

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                                                                     Exhibit 4.2

               FIRST SUPPLEMENTAL INDENTURE (this "Supplemental Indenture"),
dated as of December 22, 2005, between D-R Steam LLC (the "New Guarantor"), a
subsidiary of Dresser-Rand Group Inc., a Delaware corporation (the "Company"),
the existing Guarantors listed on the signature page to the Indenture (as
defined below) (the "Existing Guarantors") and Citibank, N.A., as trustee under
the Indenture referred to below (the "Trustee").

                              W I T N E S S E T H :

               WHEREAS, the Company and the Existing Guarantors have heretofore
executed and delivered to the Trustee an indenture (as amended, supplemented or
otherwise modified, the "Indenture"), dated as of October 29, 2004, providing
for the issuance of 7?% Senior Subordinated Notes due 2014 (the "Notes");

               WHEREAS, Section 4.17 of the Indenture provides that under
certain circumstances the New Guarantor shall execute and deliver to the Trustee
a supplemental indenture pursuant to which the New Guarantor shall
unconditionally guarantee all of the Company's Obligations under the Notes and
the Indenture on the terms and conditions set forth herein (the "Note
Guarantee"); and

               WHEREAS, pursuant to Section 9.01 of the Indenture, the Trustee,
the Company and the Existing Guarantors are authorized to execute and deliver
this Supplemental Indenture.

               NOW THEREFORE, in consideration of the foregoing and for other
good and valuable consideration, the receipt of which is hereby acknowledged,
the New Guarantor, the Company and the Trustee mutually covenant and agree for
the equal and ratable benefit of the Holders of the Notes as follows:

               1. DEFINED TERMS. Defined terms used herein without definition
shall have the meanings assigned to them in the Indenture.

               2. AGREEMENT TO INDENTURE. The New Guarantor hereby agrees,
jointly and severally with all Existing Guarantors, to provide an unconditional
guarantee on the terms and subject to the conditions set forth in Article 11 of
the Indenture and to be bound by all other applicable provisions of the
Indenture, including the provisions relating to the subordination of such
guarantee set forth in Article 11, and the Notes and to perform all of the
obligations and agreements of a Guarantor under the Indenture.

               3. NO RECOURSE AGAINST OTHERS. No past, present or future
director, manager, officer, employee, incorporator, stockholder or member of the
Company, any parent entity of the Company or any Subsidiary, as such, will have
any liability for any obligations of the Company or the Guarantors under the
Notes, this Indenture, the Note Guarantees or for any claim based on, in respect
of, or by reason of, such obligations or their creation. Each Holder by
accepting a Note waives and releases all such liability. The waiver and release
are part of the consideration for issuance of the Notes. The waiver may not be
effective to waive liabilities under the federal securities laws.

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               4. NOTICES. All notices or other communications to the New
Guarantor shall be given as provided in Section 13.02 of the Indenture.

               5. RATIFICATION OF INDENTURE; SUPPLEMENTAL INDENTURES PART OF
INDENTURE. Except as expressly amended hereby, the Indenture is in all respects
ratified and confirmed and all the terms, conditions and provisions thereof
shall remain in full force and effect. This Supplemental Indenture shall form a
part of the Indenture for all purposes, and every holder of Notes heretofore or
hereafter authenticated and delivered shall be bound hereby.

               6. GOVERNING LAW. THIS INDENTURE, THE NOTES AND THE NOTE
GUARANTEE SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF
THE STATE OF NEW YORK.

               7. COUNTERPARTS. The parties may sign any number of copies of
this Supplemental Indenture. Each signed copy shall be an original, but all of
them together represent the same agreement.

               8. EFFECT OF HEADINGS. The Section headings herein are for
convenience only and shall not effect the construction thereof.

               9. TRUSTEE MAKES NO REPRESENTATION. The Trustee makes no
representation as to the validity or sufficiency of this Supplemental Indenture.

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               IN WITNESS WHEREOF, the parties hereto have caused this
Supplemental Indenture to be duly executed and attested, all as of the date
first above written.

Dated: December 22, 2005

DRESSER-RAND GROUP LLC                  D-R STEAM LLC

By: /s/ Elizabeth C. Powers             By: /s/ Elizabeth C. Powers
    ---------------------------------      ---------------------------------
Name:   Elizabeth C. Powers             Name:   Elizabeth C. Powers
Title:  Vice President and Chief        Title:  Vice President -- Treasurer
          Administrative Officer

                                        CITIBANK, N.A.
DRESSER-RAND LLC                              as Trustee

By: /s/ Elizabeth C. Powers             By: /s/ Louis Piscitelli
    ---------------------------------       --------------------------------
Name:   Elizabeth C. Powers             Name:   Louis Piscitelli
Title:  Secretary                       Title:  Vice President

DRESSER-RAND POWER LLC

By: /s/ B.W. Dickson
    ---------------------------------
Name:   B.W. Dickson
Title:  President

DRESSER-RAND COMPANY

By: /s/ Elizabeth C. Powers
    ---------------------------------
Name:   Elizabeth C. Powers
Title:  Secretary

DRESSER-RAND GLOBAL SERVICES, LLC

By: /s/ Talbot A. Lancaster
    ---------------------------------
Name:   Talbot A. Lancaster
Title:  Vice President Treasurer<PAGE>

                                                                    Exhibit 10.7

                     SUPPLEMENT NO. 1 TO DOMESTIC GUARANTEE
                            AND COLLATERAL AGREEMENT

               SUPPLEMENT NO. 1 dated as of December 22, 2005 (this
"Supplement"), to the Domestic Guarantee and Collateral Agreement dated as of
October 29, 2004 (the "Domestic Guarantee and Collateral Agreement"), among D-R
INTERHOLDING, LLC, a Delaware limited liability company ("Holdings"),
DRESSER-RAND GROUP INC., a Delaware corporation ("Acquisition Corp." or the
"Domestic Borrower"), each Domestic Subsidiary Loan Party identified therein
(each, a "Domestic Subsidiary Loan Party") and CITICORP NORTH AMERICA, INC.
("CNAI"), as collateral agent (in such capacity, the "Collateral Agent") for the
Secured Parties.

               A. Reference is made to the Credit Agreement dated as of October
29, 2004 (as amended, supplemented, waived or otherwise modified from time to
time, the "Credit Agreement"), among Holdings, the Domestic Borrower, the
Foreign Borrowers party thereto from time to time, the lenders party thereto
from time to time (the "Lenders"), CNAI as Administrative Agent and as
Collateral Agent for the Lenders, MORGAN STANLEY SENIOR FUNDING, INC. ("MS") and
UBS SECURITIES LLC ("UBS"), as Co-Syndication Agents, CITIGROUP GLOBAL MARKETS
INC., MS and UBS, as Joint Lead Arrangers and Joint Book Managers and NATEXIS
BANQUES POPULAIRES and BEAR STEARNS CORPORATE LENDING INC, as Co-Documentation
Agents.

               B. Capitalized terms used herein and not otherwise defined herein
shall have the meanings assigned to such terms in the Credit Agreement and the
Domestic Guarantee and Collateral Agreement.

               C. The Guarantors have entered into the Domestic Guarantee and
Collateral Agreement in order to induce the Lenders to make Loans and each
Issuing Bank to issue Letters of Credit. Section 7.15 of the Domestic Guarantee
and Collateral Agreement provides that additional Subsidiaries may become
Domestic Subsidiary Loan Parties under the Domestic Guarantee and Collateral
Agreement by execution and delivery of an instrument in the form of this
Supplement. The undersigned Subsidiary (the "New Subsidiary") is executing this
Supplement in accordance with the requirements of the Credit Agreement to become
a Domestic Subsidiary Loan Party under the Domestic Guarantee and Collateral
Agreement in order to induce the Lenders to make additional Loans and each
Issuing Bank to issue additional Letters of Credit and as consideration for
Loans previously made and Letters of Credit previously issued.

               Accordingly, the Collateral Agent and the New Subsidiary agree as
follows:

               SECTION 1. In accordance with Section 7.15 of the Domestic
Guarantee and Collateral Agreement, the New Subsidiary by its signature below
becomes a Domestic Subsidiary Loan Party and a Guarantor under the Domestic
Guarantee and Collateral Agreement with the same force and effect as if
originally named therein as a Domestic Subsidiary Loan Party and a Guarantor,
and the New Subsidiary hereby (a) agrees to all the terms and provisions of the
Domestic Guarantee and Collateral Agreement applicable to it as a Domestic
Subsidiary Loan Party and Guarantor thereunder and (b) represents and warrants
that the representations and

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warranties made by it as a Guarantor thereunder (as supplemented by the attached
supplemental Schedules to the Perfection Certificate) are true and correct, in
all material respects, on and as of the date hereof. In furtherance of the
foregoing, the New Subsidiary, as security for the payment and performance in
full of the Guaranteed Obligations, does hereby create and grant to the
Collateral Agent, its successors and assigns, for the ratable benefit of the
Secured Parties, their successors and assigns, a security interest in and Lien
on all the New Subsidiary's right, title and interest in and to the Collateral
(as defined in the Domestic Guarantee and Collateral Agreement) of the New
Subsidiary. Each reference to a "Domestic Subsidiary Loan Party" or a
"Guarantor" in the Domestic Guarantee and Collateral Agreement shall be deemed
to include the New Subsidiary. The Domestic Guarantee and Collateral Agreement
is hereby incorporated herein by reference.

               SECTION 2. The New Subsidiary represents and warrants to the
Collateral Agent and the other Secured Parties that this Supplement has been
duly authorized, executed and delivered by it and constitutes its legal, valid
and binding obligation, enforceable against it in accordance with its terms,
subject to (i) the effects of bankruptcy, insolvency, moratorium,
reorganization, fraudulent conveyance or other similar laws affecting creditors'
rights generally, (ii) general principles of equity (regardless of whether such
enforceability is considered in a proceeding in equity or at law) and (iii)
implied covenants of good faith and fair dealing.

               SECTION 3. This Agreement may be executed in two or more
counterparts, each of which shall constitute an original but all of which when
taken together shall constitute but one contract. This Supplement shall become
effective when (a) the Collateral Agent shall have received a counterpart of
this Supplement that bears the signature of the New Subsidiary and (b) the
Collateral Agent has executed a counterpart hereof.

               SECTION 4. The New Subsidiary has attached hereto supplemental
Schedules 1(a) through 17 to the Perfection Certificate in substantially the
same form as the equivalent Schedules to the Perfection Certificate, and the New
Subsidiary hereby represents and warrants that the attached Schedules are
complete and correct with respect to the New Subsidiary.

               SECTION 5. Except as expressly supplemented hereby, the Domestic
Guarantee and Collateral Agreement shall remain in full force and effect.

               SECTION 6. THIS SUPPLEMENT AND THE RIGHTS AND OBLIGATIONS OF THE
PARTIES UNDER THIS SUPPLEMENT SHALL BE CONSTRUED IN ACCORDANCE WITH AND GOVERNED
BY THE LAWS OF THE STATE OF NEW YORK.

               SECTION 7. In the event any one or more of the provisions
contained in this Supplement should be held invalid, illegal or unenforceable in
any respect, the validity, legality and enforceability of the remaining
provisions contained herein and in the Domestic Guarantee and Collateral
Agreement shall not in any way be affected or impaired thereby. The parties
shall endeavor in good-faith negotiations to replace the invalid, illegal or
unenforceable provisions with valid provisions the economic effect of which
comes as close as possible to that of the invalid, illegal or unenforceable
provisions.

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               SECTION 8. All communications and notices hereunder shall be in
writing and given as provided in Section 7.01 of the Domestic Guarantee and
Collateral Agreement.

               SECTION 9. The New Subsidiary agrees to reimburse the Collateral
Agent for its reasonable out-of-pocket expenses in connection with this
Supplement, including the reasonable fees, disbursements and other charges of
counsel for the Collateral Agent.

                 (Remainder of paged intentionally left blank.)

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               IN WITNESS WHEREOF, the New Subsidiary and the Collateral Agent
have duly executed this Supplement to the Domestic Guarantee and Collateral
Agreement as of the day and year first above written.

                                    D-R STEAM LLC

                                    By: /s/ Randy D. Rinicella
                                        ---------------------------------------
                                        Name:  Randy D. Rinicella
                                        Title:  Secretary

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                                     CITICORP NORTH AMERICA, INC., as
                                         Collateral Agent

                                     By: /s/ William G. Martens III
                                         --------------------------------------
                                         Name:  William G. Martens III
                                         Title:  Vice President

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