[EXECUTION COPY]
     
     
     
                                                                        
     
     
     
     
               AMENDMENT AND RESTATEMENT OF
                  ARTICLES IV, V AND VI 
                 OF THE OVERRIDE AGREEMENT
                            and
               AMENDMENT AND RESTATEMENT OF
                  APPENDIX A, DEFINITIONS
                             
               dated as of February 15, 1996
                             
                             
                             
                       by and among
                             
                             
                     DRAVO CORPORATION
                    DRAVO LIME COMPANY
            DRAVO BASIC MATERIALS COMPANY, INC.
                             
                    FIRST ALABAMA BANK
                             
              PNC BANK, NATIONAL ASSOCIATION
                             
                 BANK OF AMERICA ILLINOIS
                             
        THE PRUDENTIAL INSURANCE COMPANY OF AMERICA
                             
                             
                             
                                                                     
          <PAGE>
               AMENDMENT AND RESTATEMENT
     
     
          THIS AMENDMENT AND RESTATEMENT, dated as of February 15, 1996
     is entered into by and among FIRST ALABAMA BANK ("FAB"), PNC BANK,
     NATIONAL ASSOCIATION (f/k/a Pittsburgh National Bank) ("PNC"), BANK
     OF AMERICA ILLINOIS ("BAI"), THE PRUDENTIAL INSURANCE COMPANY OF
     AMERICA ("Prudential"); FAB, PNC, BAI and Prudential herein
     collectively referred to as "Lenders" and each a "Lender") and DRAVO
     CORPORATION, a Pennsylvania corporation ("Dravo"), DRAVO LIME
     COMPANY, a Delaware corporation ("Lime") and DRAVO BASIC MATERIALS
     COMPANY, INC., an Alabama corporation ("Basic"; Lime and Basic are
     sometimes hereinafter collectively referred to as the "Companies").
     
     
                 PRELIMINARY STATEMENTS
     
          (1)  The Companies, Dravo and the Lenders have entered into
     an Override Agreement, dated as of January 21, 1992, as amended by
     the First Amendment to Override Agreement, dated March 10, 1993, the
     Second Amendment to Override Agreement, dated as of March 7, 1994,
     the Amendment Agreement, dated as of August 1, 1994, the Amendment
     Agreement, dated as of January 3, 1995 and the Amendment Agreement
     dated as of December 31, 1995 (as so amended and amended, modified
     or supplemented from time to time, the "Override Agreement").  In
     addition, the Companies, the Agent and the Lenders have entered into
     an Amended and Restated Revolving Credit Agreement, dated as of
     January 21, 1992, as amended by the First Amendment to Amended and
     Restated Revolving Credit Agreement, dated as of March 7, 1994, by
     the Amendment Agreement dated as of August 1, 1994, the Amendment
     Agreement dated as of January 3, 1995 and the Amendment Agreement
     dated as of December 31, 1995 (as so amended and amended, modified
     or supplemented from time to time, the "Revolving Credit
     Agreement").  Capitalized terms used but not defined herein shall
     have the meanings assigned to such terms in the Override Agreement,
     as amended hereby.
     
          (2)  The parties hereto desire to amend and restate Articles
     IV, V and VI of the Override Agreement and Appendix A.
     
          In consideration of the mutual agreements herein contained and
     other good and valuable consideration, the receipt and adequacy of
     which are hereby acknowledged, the parties hereto hereby agree to
     amend and restate Articles IV, V and VI of the Override Agreement as
     follows and Appendix A as attached hereto.
     
     
                       ARTICLE I
     
               AMENDMENT AND RESTATEMENT
     
          SECTION 1.01.  Amendment and Restatement of Articles IV, V and
     VI.  Each of the following Articles IV, V and VI of the Override
     Agreement shall be amended and restated in full as follows:
     
     
                       ARTICLE IV
             UNIFORM AFFIRMATIVE COVENANTS
     
          SECTION 4.01.  Dravo Parties Affirmative Covenants.  So long
     as a Lender shall hold any Note or Notes or any Secured Obligation
     remains outstanding, the Dravo Parties shall comply with the
     following:
     
               (a)  Financial Statements.  Each of the Dravo Parties
               will deliver in triplicate to each Lender (or any other holder
               of any Note or Notes) so long as such Lender (or holder) shall
               hold any Note or Notes:
     
                    (i)  as soon as practicable and in any event
                    within 45 days after the end of each quarterly period in
                    each fiscal year, consolidating and consolidated
                    statements of income and cash flows, of such corporation
                    and its Subsidiaries for the period from the beginning
                    of the current fiscal year to the end of such quarterly
                    period, and a consolidating and consolidated balance
                    sheet of such corporation and its Subsidiaries as at the
                    end of such quarterly period, setting forth in each case
                    in comparative form figures for the corresponding period
                    in the preceding fiscal year, all in reasonable detail
                    and certified by an authorized financial officer of such
                    corporation, subject to changes resulting from normal
                    year-end adjustments;
     
                    (ii) as soon as practicable and in any event
                    within 90 days after the end of each fiscal year,
                    consolidating and consolidated statements of income and
                    cash flows and a consolidated statement of stockholders'
                    equity of such corporation and its Subsidiaries for such
                    year, and a consolidating and consolidated balance sheet
                    of such corporation and its Subsidiaries as at the end
                    of such year, setting forth in each case in comparative
                    form corresponding consolidated figures from the
                    preceding annual audit, all in reasonable detail and
                    satisfactory in form to each of the Lenders and, as to
                    the consolidated statements, reported on by independent
                    public accountants of recognized national standing
                    selected by such Dravo Party whose report shall be
                    without limitation as to the scope of the audit and
                    satisfactory in substance to the Majority Lenders and,
                    as to the consolidating statements, certified by an
                    authorized financial officer of such Dravo Party;
     
                    (iii)     promptly upon transmission thereof,
                    copies of all such financial statements, proxy
                    statements, notices and reports as it shall send to its
                    stockholders and copies of all registration statements
                    (without exhibits) and all reports which it files with
                    the Securities and Exchange Commission (or any
                    governmental body or agency succeeding to the functions
                    of the Securities and Exchange Commission);
     
                    (iv) as soon as is practicable and in any event
                    prior to the end of each fiscal year, a projected income
                    statement, balance sheet and cash flow statement for
                    each of the Dravo Parties for the ensuing fiscal year,
                    setting forth in each case figures on an annual basis in
                    reasonable detail and certified by an authorized
                    financial officer of each such corporation;
     
                    (v)  promptly upon receipt thereof, a copy of
                    each other report submitted to such corporation or any
                    Subsidiary by independent accountants in connection with
                    any annual, interim or special audit made by them of the
                    books of such corporation or any Subsidiary;
     
                    (vi) upon the request of a holder of any Note,
                    provide such holder, and any qualified institutional
                    buyer designated by such holder, such financial and
                    other information as such holder may reasonably
                    determine to be necessary in order to permit compliance
                    with the information requirements of Rule 144A under the
                    Securities Act in connection with the resale of Notes,
                    except at such times as Dravo is subject to the
                    reporting requirements of section 13 or 15(d) of the
                    Exchange Act.  For the purpose of this clause (vi), the
                    term "qualified institutional buyer" shall have the
                    meaning specified in Rule 144A under the Securities Act;
     
                    (vii)     with reasonable promptness, such other
                    financial data as any Lender may reasonably request; and
     
                    (viii)     a report, delivered not less
                    frequently than once during each period of four
                    consecutive months, of the General Counsel of Dravo that
                    describes and evaluates all pending litigation against
                    any Dravo Party where the amount of potential loss could
                    exceed $5,000,000.  Each such report should include a
                    brief description of the events that have occurred in
                    such litigation since the date of the last report,
                    including, without limitation, the occurrence and/or
                    outcome of any motions for summary judgment, discovery
                    motions, substantive discovery responses, or motions for
                    final adjudication.  In addition, at the request of any
                    Lender, each Dravo Party shall, at its expense, provide
                    each Lender, and its outside counsel, an opportunity to
                    receive copies of all documentation received or prepared
                    in connection with any such litigation, and to discuss
                    the status thereof with the General Counsel of Dravo and
                    the outside counsel of any such Dravo Party handling
                    such matter.  Notwithstanding the foregoing, at no time
                    shall any Dravo Party or its counsel be required to make
                    any disclosure or provide any access to information
                    pursuant to this paragraph which would result in the
                    loss to such Dravo Party of any privilege against
                    disclosure generally recognized under law.
     
          Together with each delivery of financial statements required
     by clauses (i) and (ii) above, each of the Dravo Parties will
     deliver to each Lender (addressed to it) a Compliance Certificate,
     in the form of Exhibit O hereto, demonstrating (with computations in
     reasonable detail except to the extent specifically set forth in
     such financial statements) compliance by the Dravo Parties with
     Section 4.02(b), 5.01(a), (b), (c)(i), (c)(ii) and (d), and stating
     that there exists no Default or Event of Default, or, if any such
     Default or Event of Default exists, specifying the nature thereof,
     the period of existence thereof and what action such corporation
     proposes to take with respect thereto.
     
          Together with each delivery of financial statements required
     by clause (ii) above, each of the Dravo Parties will deliver to each
     Lender a certificate of said accountants stating that, in making the
     audit necessary to the certification of such financial statements
     they have obtained no knowledge of any Default or Event of Default,
     or, if any such Default or Event of Default exists, specifying the
     nature and period of existence thereof.  Such accountants, however,
     shall not be liable to anyone by reason of their failure to obtain
     knowledge of any Default or Event of Default which would not be
     disclosed in the course of an audit conducted in accordance with
     generally accepted auditing standards.  Each Lender is hereby
     authorized to deliver a copy of any financial statement delivered to
     such Lender pursuant to this Section 4.01(a) to any regulatory body
     having jurisdiction over such Lender.
     
          Each of the Dravo Parties also covenants that forthwith upon
     the chief executive officer, principal financial officer or
     principal accounting officer of such Dravo Party obtaining knowledge
     of:
     
               (i)  a Default or an Event of Default;
     
               (ii) a material adverse change in the financial
               condition, business or operations of such Dravo Party and its
               Subsidiaries, taken as a whole;
     
               (iii)     the institution of legal proceedings against such
               Dravo Party and/or any Subsidiary, which has a reasonable
               possibility of materially adversely affecting the financial
               condition, business or operations of such Dravo Party and its
               Subsidiaries, taken as a whole or which in any manner draws
               into question the validity of or has a reasonable possibility
               of impairing the ability of such Dravo Party to perform its
               obligations under this Agreement or any of the other Operative
               Documents to which it is a party;
     
               (iv) the occurrence of any default under any agreement
               or note evidencing borrowed money;
     
               (v)  the occurrence of any other event that reasonably
               could impair the ability of such Dravo Party to meet its
               obligations hereunder or under any other Operative Document;
               or
     
               (vi) any (A) Environmental Liabilities, (B) pending,
               threatened or anticipated Environmental Proceedings, (C)
               Environmental Notices, (D) Environmental Judgments and Orders,
               or (E) Environmental Releases at, on, in, under or in any way
               materially affecting the Properties;
     
     such Dravo Party will deliver to the Lenders an Officer's
     Certificate specifying the nature and period of existence thereof
     and what action such Dravo Party has taken, is taking or proposes to
     take with respect thereto.
     
          (b)  Inspection of Property.  Each of the Dravo Parties
     covenants that, so long as a Lender shall hold any Note or Notes,
     any of them will permit any person designated by such Lender in
     writing, at the expense of such Dravo Party, to visit and inspect
     any of the properties of any such Dravo Party and its Subsidiaries,
     to examine the corporate books and financial records of any such
     Dravo Party and its Subsidiaries and make copies thereof or extracts
     therefrom and to discuss the affairs, finances and accounts of any
     such corporation with the principal officers and independent public
     accountants of such corporation, all at such reasonable times and
     upon such reasonable notice and as often as such Lender may
     reasonably request.
     
          (c)  Secure Notes Equally.  Each of the Dravo Parties
     covenants that, if any of the Dravo Parties creates or assumes any
     Lien upon any of its property or assets, whether now owned or
     hereafter acquired, other than Liens excepted by the provisions of
     Section 5.03(a)(i) (unless prior written consent to the creation or
     assumption thereof shall have been obtained pursuant to Section
     8.02), it will make or cause to be made effective provisions whereby
     the Notes then outstanding will be further secured by such Lien
     equally and ratably with any and all other debt thereby secured as
     long as such other debt shall be so secured.
     
          (d)  Guaranteed Obligations.  Each of the Dravo Parties
     covenants that if, at any time after the date hereof, it or any of
     its Subsidiaries incurs or permits to exist any Debt or other
     obligation guaranteed or collateralized in any other manner by any
     Person, it will simultaneously cause such Person to execute and
     deliver to each holder of any Note a guaranty agreement in form and
     substance satisfactory to such holder guaranteeing payment of the
     principal amount of the Notes and any premium and interest thereon,
     which bears the same ratio to the total unpaid principal amount of
     the Notes as the amount of such other obligation which is guaranteed
     bears to the total unpaid principal amount of such other obligation,
     or if such other obligation is collateralized, to collateralize the
     Notes equally and ratably with such other obligation.
     
          (e)  Maintenance of Insurance.  Each of the Dravo Parties
     will maintain, and will cause each of its Subsidiaries to maintain,
     with responsible insurers, insurance with respect to its properties
     and business against such casualties and contingencies (including
     public liability, larceny, embezzlement or other criminal
     misappropriation) and in such amounts as is customary in the case of
     similarly situated corporations engaged in the same or similar
     businesses, and, if requested in writing by a Lender, together with
     each delivery of financial statements under clause (ii) of Section
     4.01(a) each of the Dravo Parties will deliver an Officer's
     Certificate specifying the details of such insurance in effect.
     
          (f)  Taxes.  Neither Dravo nor either of the Companies nor
     any Subsidiary thereof will file, or cause to be filed, any federal
     income tax return inconsistent with the representation contained in
     Section 7.01(e).
     
          (g)  Maintenance of Corporate Existence/Compliance with
     Law/Preservation of Property.  Except as allowed under Section
     5.03(a)(iii) or 5.03(a)(iv), each of the Dravo Parties covenants
     that it and each Subsidiary (other than Discontinued Subsidiaries)
     will do or cause to be done all things necessary to preserve, renew
     and keep in full force and effect the corporate existence of such
     Dravo Party and its Subsidiaries (other than Discontinued
     Subsidiaries) and comply in all material respects with all laws and
     regulations (including, without limitation, laws and regulations
     relating to equal employment opportunity and employee safety)
     applicable to it and its Subsidiaries (other than Discontinued
     Subsidiaries), the failure with which to comply would have a
     reasonable possibility of materially adversely affecting the
     business, operations or financial condition of such Dravo Party and
     its Subsidiaries (other than Discontinued Subsidiaries), taken as a
     whole; at all times maintain, preserve and protect all material
     intellectual property of such Dravo Party and its Subsidiaries
     (other than Discontinued Subsidiaries), and preserve all the
     remainder of its material property used or useful in the conduct of
     its business and keep the same in good repair, working order and
     condition.
     
          (h)  Compliance with Environmental Laws.  Each of the Dravo
     Parties will, and will cause each of its Subsidiaries to, comply in
     a timely fashion with, or operate pursuant to valid waivers of the
     provisions of, all Environmental Requirements including, without
     limitation, the emission of wastewater effluent, solid and hazardous
     waste and air pollution, and establishing general environmental
     conditions, together with any other applicable requirements for
     conducting, on a timely basis, periodic tests and monitoring for
     contamination of ground water, surface water, air and land and for
     biological toxicity of the aforesaid, and diligently comply with the
     regulations (except to the extent such regulations are waived by
     appropriate governmental authorities) of the Environmental
     Protection Agency or other relevant federal, state or local
     governmental authority, except where the failure to do so would not
     have a reasonable possibility of materially adversely affecting the
     business, operations or financial condition of such Dravo Party and
     its Subsidiaries, taken as a whole.
     
          (i)  Appraisals.  From time to time, a Lender or Lenders may
     commission or obtain an appraisal of the property covered by the
     Lime Mortgages by an appraiser satisfactory to such Lender or
     Lenders and in compliance with the standards of the Member Appraisal
     Institute and may commission or obtain such other valuations as a
     Lender or Lenders may reasonably require from time to time.
     
          (j)  Additional Mortgage Conveyances.  Upon the acquisition
     by any Dravo Party of any additional properties located adjacent to,
     or used or usable in connection with the operations of the Dravo
     Parties on, the property covered by the Lime Mortgages or the
     commencement of any such operations thereon by the Dravo Parties,
     then, upon the request of a Lender or Lenders, the Dravo Parties
     shall convey or cause to be conveyed duly authorized, executed and
     delivered mortgages on such properties (or, at the option of
     Lenders, modifications to the existing mortgages) in order to cause
     such additional properties to be subjected to the lien and
     encumbrance of the applicable Lime Mortgages.  In connection with
     any such conveyance, the Dravo Parties shall also deliver the items
     described in Section 3.01(e), "Real Estate Documents", hereof with
     respect to such additional property and the mortgage conveyance of
     such additional property.
     
          (k)  Consents.  The Dravo Parties will obtain on or prior to
     March 31, 1996 the consent of (1) Ohio Power Company to the
     assignment by Dravo Black River Limited Partnership to Lime of the
     Lime Supply Agreement dated June 21, 1993 between Lime and Ohio
     Power Company and (2) Svedala Industries, Inc. to the assignment by
     Dravo Black River Limited Partnership to Lime of the Agreement,
     dated as of August 27, 1993, as amended, by and between Svedala 
     Industries, Inc., through its Kennedy Van Saun division, and Lime.
     
          SECTION 4.02  Dravo Additional Covenants.  So long as a Lender
     shall hold any Note or Notes or any Secured Obligation remains
     outstanding, Dravo shall comply with the following.
     
          (a)  Ancillary Reports.  Dravo shall deliver to each Lender
     the following reports in triplicate:
     
               (i)  a monthly balance sheet, income statement and cash
               flow statement for Dravo and its Subsidiaries prepared by
               Dravo, within thirty days after the close of each calendar
               month; provided, however, that delivery of the Directors
               Report shall be deemed to satisfy the requirements of this
               clause; and
     
               (ii) for each of Dravo's fiscal quarters commencing
               with the fiscal quarter ending March 31, 1996, a report
               listing all letters of credit then issued and outstanding on
               behalf of Dravo and its Subsidiaries, as well as the amount of
               and issuing institution for each such letter of credit, within
               thirty days after the close of each such quarter. 
     
          (b)  Fixed Charge Test.  Dravo shall cause the Fixed Charge
     Coverage Ratio of Dravo and its Subsidiaries as at the end of each
     of Dravo's fiscal quarters to equal or exceed 1.25 from the
     Effective Date to and including December 31, 1996 and 1.5
     thereafter.
     
          (c)  Mandatory Payments of Note Receivable.  Dravo shall make
     the repayments required under the Note Receivable.
     
     
                       ARTICLE V
               UNIFORM NEGATIVE COVENANTS
     
          SECTION 5.01.  Dravo Negative Covenants.  So long as a Lender
     shall hold any Note or Notes or any Secured Obligation remains
     outstanding, Dravo shall comply with each of the following.
     
          (a)  Net Worth Requirements. Dravo will not permit its
     Consolidated Net Worth at any time to be less than $90,784,000 (the
     "Base Amount") as of the Effective Date hereof and as of each
     quarter ending thereafter to be less than a sum equal to the Base
     Amount plus 50% of Consolidated Net Earnings available to common
     shareholders (to the extent this is a positive number) for each
     quarter ending after the Effective Date.
     
          (b)  Dividend Restrictions.  Dravo shall not: (x) pay or
     declare any dividend on any class of its stock or make any other
     distribution on account of any class of its stock (referred to
     herein collectively as "Dividends") or (y) make, directly or
     indirectly (including by a Subsidiary of Dravo), any Excess
     Redemption  (all Dividends and Excess Redemptions collectively
     referred to herein as "Dravo Restricted Payments") if such Dravo
     Restricted Payments, taken together with all other Dravo Restricted
     Payments made on or after September 30, 1995, would exceed 25% of
     Consolidated Net Earnings from Continuing Operations after
     September 30, 1995.  There shall not be included in Dravo Restricted
     Payments (x) Dividends paid, or distributions made, in stock of
     Dravo; or (y) exchanges of stock of one or more classes of Dravo for
     common stock of Dravo or for stock of Dravo of the same class,
     except to the extent that cash or other value is involved in such
     exchange; or (z) the payment of regularly scheduled dividends on the
     Shares or the Preferred Stock Series B originally issued to the
     Mechling estate ("Mechling Shares").  The term "stock" as used in
     this Section 5.01(b) shall include warrants or options to purchase
     stock.  Notwithstanding the foregoing, Dravo shall not make  a Dravo
     Restricted Payment if a Default or Event of Default has occurred or
     would occur as a result of such Dravo Restricted Payment.  As used
     herein, the term "Excess Redemption" means any redemption, purchase
     or other acquisition of any shares of the capital stock of Dravo in
     an amount exceeding the cash proceeds received by Dravo in
     connection with any issuance or sale of any capital stock (including
     without limitation any preferred stock) of Dravo in an amount
     exceeding cash proceeds received by Dravo (net of all reasonable
     costs and expenses incurred by Dravo in connection with such
     issuance of capital stock) occurring after September 30, 1995.
     
          (c)  Debt.  Dravo shall not, and shall not permit any of its
     Subsidiaries to, create, incur, assume or suffer to exist;
     
               (i)  any Debt in excess of 50% of Dravo Consolidated
               Net Tangible Assets from the Effective Date hereof to and
               including December 31, 1996 and 45% of Dravo Consolidated Net
               Tangible Assets thereafter; or
     
               (ii) any Debt so that the ratio of Debt to EBDIAT would
               exceed 3.25 to 1.0 from the Effective Date hereof to and
               including December 31, 1996 and 3.0 to 1.0 thereafter.
     
          (d)  Secured Debt.  Dravo shall not, and shall not permit any
     of its Subsidiaries to, create, incur, assume or suffer to exist at
     any time the aggregate of (i) any secured Debt (other than the
     Secured Obligations) plus (ii) an amount equal to the greater of the
     fair market value or acquisition cost of any additional real estate
     (plus improvements) acquired by a Person (other than a Dravo Party)
     for the benefit of any Dravo Party or any affiliate thereof located
     adjacent to, or used or usable in connection with the operations of
     the Dravo Parties on, the property covered by the Lime Mortgages, in
     excess of 7% of Dravo Consolidated Net Tangible Assets.
     
          SECTION 5.02.  Companies Negative Covenants.  So long as a
     Lender shall hold any Note or Notes or any Secured Obligation
     remains outstanding, neither of the Companies shall make any payment
     to Dravo with respect to or on account of the Dravo affiliated
     group's consolidated federal income tax liability ("Dravo
     Consolidated Tax Liability") in excess of the amount of such tax
     liability that would have been apportioned to such Company had
     Section 1552(a)(1) of the Code and Treasury Regulation
     31.155201(a)(1) been used to determine each such Company's tax
     liability.  In addition, no payment shall be made by any Other
     Subsidiary or any Subsidiary of the Companies to Dravo with respect
     to or on account of the Dravo Consolidated Tax Liability.  No
     intercompany account or indebtedness owing from the Companies or
     their Subsidiaries shall be created in connection with any tax
     sharing agreement or arrangement with respect to or on account of
     the Dravo Consolidated Tax Liability and any such intercompany
     account or indebtedness that may have been created prior to the date
     hereof shall be, and hereby is, contributed to the capital of the
     Companies and each such Company is thereby released from any further
     liability arising in connection with such intercompany account or
     indebtedness.
     
          SECTION 5.03.  Dravo Parties Negative Covenants.  So long as
     a Lender shall hold any Note or Notes or any Secured Obligation
     remains outstanding, each of the Dravo Parties shall comply with
     each of the following:
     
               (a)  Liens and Other Restrictions.  None of the Dravo
               Parties will, nor will any of them permit any Subsidiary to:
     
                    (i)  Liens.  Create, assume or suffer to exist
                    any Lien upon any of its property or assets, whether now
                    owned or hereafter acquired (whether or not provision is
                    made for the equal and ratable securing of the Notes in
                    accordance with the provisions of Section 4.01(c)),
                    except
     
                         (A)  Liens for taxes not yet due or that
                         (a) are being actively contested in good faith by
                         appropriate proceedings diligently contesting
                         such obligations, and (b) would not have a
                         material and adverse effect on the business,
                         conditions, operations or prospects of such
                         corporation in the event that the underlying
                         obligations for such Liens were not paid,
     
                         (B)  other Liens incidental to the conduct
                         of its business or the ownership of its property
                         and assets which were not incurred in connection
                         with the borrowing of money or the obtaining of
                         advances or credit, and which do not in the
                         aggregate materially detract from the value of
                         its property or assets or materially impair the
                         use thereof in the operation of its business,
     
                         (C)  Liens on property or assets of a
                         Subsidiary to secure its obligations to the Dravo
                         Party (other than Dravo) of which it is a
                         Subsidiary or another Subsidiary of such Dravo
                         Party (other than Dravo),
     
                         (D)  any Lien existing on any property of
                         any corporation at the time it becomes a
                         Subsidiary of such Dravo Party, or existing prior
                         to the time of acquisition upon any property
                         acquired by such Dravo Party or any Subsidiary of
                         such Dravo Party through purchase, merger or
                         consolidation or otherwise, whether or not
                         assumed by such Dravo Party or such Subsidiary,
                         or placed upon property at the time of
                         acquisition by such Dravo Party or any Subsidiary
                         of such property to secure all or a portion of
                         (or to secure Debt incurred to pay all or a
                         portion of) the purchase price thereof, provided
                         that (a) any such Lien shall not encumber any
                         other property of such Dravo Party or such
                         Subsidiary, and (b) the amount secured by each
                         such Lien shall not exceed, at the time such
                         corporation becomes a Subsidiary of such Dravo
                         Party or at the time of acquisition of such
                         property by such Dravo Party or a Subsidiary of
                         such Dravo Party or at the time of any renewal,
                         extension or refunding of such Lien, 75% of the
                         lower of either the cost or market value of the
                         property being acquired,
     
                         (E)  any liens securing Debt of such Dravo
                         Party or a Subsidiary of such Dravo Party
                         incurred in connection with an industrial revenue
                         bond or pollution control revenue bond financing
                         of the facilities or equipment to be occupied or
                         operated by such Dravo Party or such Subsidiary,
     
                         (F)  any Lien renewing, extending or
                         refunding any Lien permitted by clauses (D) and
                         (E) of this Section 5.03(a)(i), provided that the
                         amount secured shall not be increased, and the
                         Lien shall not be extended to other property,
     
                         (G)  Liens created or permitted by any
                         Operative Document entered into in connection
                         with this Agreement , and
     
                         (H)  Liens set forth in Schedule
                         5.03(a)(i) hereto;
     
                    (ii) Loans, Advances, Investments and Contingent
                    Liabilities.  Make or permit to remain outstanding any
                    loan or advance to, or Guarantee, endorse or otherwise
                    be or become contingently liable, directly or
                    indirectly, in connection with the obligations, stock or
                    dividends of, or own, purchase or acquire any stock,
                    obligations or securities of, or any other interest in,
                    or make any capital contribution to, any Person, except
                    that such Dravo Party or any Subsidiary of such Dravo
                    Party may
     
                         (A)  own, purchase or acquire stock,
                         obligations or securities of a Subsidiary of such
                         Dravo Party or of a corporation which immediately
                         after such purchase or acquisition will be a
                         Subsidiary of such Dravo Party,
     
                         (B)  acquire and own stock, obligations or
                         securities received in settlement of debts
                         (created in the ordinary course of business)
                         owing to such Dravo Party or any Subsidiary of
                         such Dravo Party,
     
                         (C)  own, purchase or acquire prime
                         commercial paper and certificates of deposit in
                         United States commercial banks (having capital
                         surplus in excess of $100,000,000), in each case
                         due within one year from the date of purchase and
                         payable in the United States in Dollars,
                         obligations of the United States Government or
                         any agency thereof, and obligations guaranteed by
                         the United States Government, and repurchase
                         agreements of such banks for terms of less than
                         one year in respect to the foregoing certificates
                         and obligations,
     
                         (D)  endorse negotiable instruments for
                         collection in the ordinary course of business,
     
                         (E)  guarantee Debt of a Subsidiary of
                         such Dravo Party which is permitted by Section
                         5.01(d),
     
                         (F)  make or permit to remain outstanding
                         travel and other like advances to officers and
                         employees in the ordinary course of business,
     
                         (G)  make or permit to remain outstanding
                         loans or advances to, or Guarantee, endorse or
                         otherwise be or become contingently liable in
                         connection with the obligations, stock or
                         dividends of, or own, purchase or acquire stock,
                         obligations or securities of, any other Person,
                         provided that the aggregate principal amount of
                         such loans and advances, excluding the aggregate
                         amount of all loans made pursuant to clause (H)
                         of this Section 5.03(a)(ii), plus the aggregate
                         amount of such contingent liabilities, plus
                         (without duplication) the aggregate amount of
                         liabilities permitted by clauses (A) and (E) of
                         Section 5.03(a)(viii), plus the aggregate amount
                         of the investment (at original cost) in such
                         stock, obligations and securities shall not
                         exceed $5,000,000 for the Dravo Parties and their
                         Subsidiaries on a combined basis (excluding from
                         such amount those letters of credit for which the
                         Dravo Parties are liable on the Closing Date as
                         set forth in Schedule 5.03(a)(ii)(G) hereto as
                         well as any term obligation or obligations into
                         which such letters of credit may be converted) at
                         any time outstanding, and further provided that
                         no Subsidiary of such Dravo Party shall make any
                         loan or advance to, or acquire any stock,
                         obligations or securities of, such Dravo Party,
     
                         (H)  with respect to the Companies, make
                         loans to Dravo from time to time to the extent
                         permitted under Section 5.02(a)(iv) hereof;
                         provided, however, that notwithstanding anything
                         to the contrary provided in this Section, all
                         such loans made by the Companies, and Dravo's
                         obligations to the Companies resulting from such
                         loans, shall be evidenced at all times by a note
                         or notes which (i) shall be in form and substance
                         satisfactory to the Majority Lenders, and
                         (ii) shall be pledged to the Collateral Agent on
                         behalf of the Lenders pursuant to the Companies
                         Pledge Agreement,
     
                         (I)  allow to exist loans, guarantees,
                         investments or contingent liabilities outstanding
                         on the Closing Date and set forth on Schedule
                         5.03(a)(ii)(I);
     
                    (iii)      Sale of Stock and Debt of Subsidiaries. 
                    Sell or otherwise dispose of, or part with control of,
                    any shares of stock or Debt of any Subsidiary of such
                    Dravo Party, except to such Dravo Party or another
                    Subsidiary of such Dravo Party, and except that all
                    shares of stock and Debt of any Subsidiary of such Dravo
                    Party at the time owned by or owed to such Dravo Party
                    and its Subsidiaries may be sold as an entirety for a
                    cash consideration which represents the fair value (as
                    determined in good faith by the Board of Directors of
                    such Dravo Party) at the time of sale of the shares of
                    stock and Debt so sold, provided that the assets of such
                    Subsidiary do not constitute more than 10% of the
                    consolidated assets of Dravo and all of its Subsidiaries
                    and that the earnings of such Subsidiary shall not have
                    contributed more than 10% of the Consolidated Net
                    Earnings of Dravo and its Subsidiaries for any of the
                    three fiscal years then most recently ended, and further
                    provided that, at the time of such sale, such Subsidiary
                    shall not own, directly or indirectly, any shares of
                    stock or Debt of any other Subsidiary of such Dravo
                    Party (unless all of the shares of stock and Debt of
                    such other Subsidiary owned, directly or indirectly, by
                    such Dravo Party and all of its Subsidiaries are
                    simultaneously being sold in a transaction permitted by
                    this Section 5.03(a)(iii)); provided, however, that the
                    foregoing provisions of this Section 5.03(a)(iii) shall
                    not apply to any Discontinued Subsidiary.
     
                    (iv) Merger and Sale of Assets.  Merge or
                    consolidate with any other corporation or sell, lease or
                    transfer or otherwise dispose of assets constituting
                    more than 10% of the consolidated assets of the Dravo
                    Parties and their Subsidiaries on a combined basis, or
                    assets which shall have contributed more than 10% of the
                    Dravo Consolidated Net Earnings for any of the three
                    fiscal years then most recently ended, to any Person,
                    except that so long as no Default or Event of Default
                    shall have occurred and be continuing;
     
                         (A)  any Subsidiary of Basic or Lime may
                         merge with that Company of which it is a
                         Subsidiary (provided that such Company shall be
                         the continuing or surviving corporation) or with
                         any one or more other Subsidiaries of such
                         Company,
     
                         (B)  any Subsidiary of Basic or Lime may
                         sell, lease, transfer or otherwise dispose of any
                         of its assets to that Company of which it is a
                         Subsidiary or another Subsidiary of such Company,
     
                         (C)  any Subsidiary may sell or otherwise
                         dispose of all or substantially all of its assets
                         to any Person other than Dravo subject to the
                         conditions specified in Section 5.03(a)(iii) with
                         respect to a sale of the stock of such
                         Subsidiary, and
     
                         (D)  a Dravo Party may merge or
                         consolidate with any other corporation, provided
                         that (i) such Dravo Party shall be the continuing
                         or surviving corporation or the continuing or
                         surviving corporation shall assume all
                         obligations of such Dravo Party under the
                         Operative Documents (pursuant to documents
                         acceptable to the Lenders) and, in any case, the
                         merged or consolidated corporation is at the time
                         of such merger or consolidation in a line of
                         business related to that of such Dravo Party or
                         any Subsidiary thereof, and (ii) such corporation
                         as the continuing or surviving corporation shall
                         not, immediately after such merger or
                         consolidation, be in default under this Agreement
                         or the other Operative Documents, including all
                         covenants herein and therein contained;
     
                    (v)       Sale and Lease-Back.  Enter into or
                    permit to remain in effect any arrangement with any
                    lender or investor or to which such lender or investor
                    is a party providing for the leasing by a Dravo Party or
                    any Subsidiary thereof of real or personal property
                    which has been or is to be sold or transferred by such
                    Dravo Party or any Subsidiary thereof to such lender or
                    investor or to any Person to whom funds have been or are
                    to be advanced by such lender or investor on the
                    security of such property or rental obligations of such
                    Company or any Subsidiary thereof;
     
                    (vi)      Sale or Discount of Receivables.  Sell
                    with recourse, or discount or otherwise sell for less
                    than the face value thereof, any of its notes or
                    accounts receivable except for those notes or accounts
                    receivable which have been past due for 90 days or more
                    and transferred in the ordinary course for collection
                    purposes;
     
                    (vii)     Certain Contracts.  Enter into or be a party
                    to
     
                         (A)  any contract providing for the making
                         of loans, advances or capital contributions to
                         any Person other than a Subsidiary of such Dravo
                         Party (except where the obligation is limited to
                         a fixed maximum amount which is within the
                         limitations of clause (H) of Section 5.03(a)(ii),
                         or the obligation is one incurred in connection
                         with the making of any loan or loans pursuant to
                         clause (I) of Section 5.03(a)(ii)), or for the
                         purchase of any property from any Person, in each
                         case in order to enable such Person to maintain
                         working capital, net worth or any other balance
                         sheet condition or to pay debts, dividends or
                         expenses, or
     
                         (B)  any contract for the purchase of
                         materials, supplies or other property or services
                         if such contract (or any related document)
                         requires that payment for such materials,
                         supplies or other property or services shall be
                         made regardless of whether or not delivery of
                         such materials, supplies or other property or
                         services is ever made or tendered, or
     
                         (C)  any contract to rent or lease (as
                         lessee) any real or personal property if such
                         contract (or any related document) provides that
                         the obligation to make payments thereunder is
                         absolute and unconditional under conditions not
                         customarily found in commercial leases then in
                         general use or requires that the lessee purchase
                         or otherwise acquire securities or obligations of
                         the lessor, or
     
                         (D)  any contract for the sale or use of
                         materials, supplies or other property, or the
                         rendering of services, if such contract (or any
                         related document) requires that payment for such
                         materials, supplies or other property, or the use
                         thereof, or payment for such services, shall be
                         subordinated to any indebtedness (of the
                         purchaser or user of such materials, supplies or
                         other property or the Person entitled to the
                         benefit of such services) owed or to be owed to
                         any Person, or
     
                         (E)  any other contract which, in economic
                         effect, is substantially equivalent to a
                         Guarantee, except as permitted by clause (D) of
                         Section 5.03(a)(ii) or where the obligation is
                         limited to a fixed maximum amount which is within
                         the limitations of clause (H) of Section
                         5.03(a)(ii);
     
                    (viii)    Transactions With Stockholders. 
                    Directly or indirectly purchase, acquire or lease any
                    property from, or sell, transfer or lease any property
                    to, or otherwise deal with, in the ordinary course of
                    business or otherwise (i) any Affiliate, or (ii) any
                    Substantial Stockholder, provided that (a) such acts and
                    transactions prohibited by this Section 5.03(a)(viii))
                    may be performed or engaged in if made upon terms not
                    less favorable to a Company than if no such relationship
                    described in clauses (i) and (ii) above existed, (b) a
                    Company may sell to, or purchase (within the limitations
                    of Section 5.03(b)) from any such Person shares of such
                    Company stock, and (c) such Company may pay management
                    fees (within the limitations of Section 5.03(b)) to any
                    such Person;
     
               (b)  Issuance of Stock.  Neither of the Companies
               (either directly, or indirectly by the issuance of rights or
               options for, or securities convertible into, such shares) will
               issue, sell or otherwise dispose of any shares of any class of
               its stock, except to Dravo or the other Company, and Dravo and
               the Companies will at all such times own l00% of the issued
               and outstanding stock of all classes of each of the Companies,
               and neither of the Companies will permit any of its
               Subsidiaries (either directly, or indirectly by the issuance
               of rights or options for, or securities convertible into, such
               shares) to issue, sell or otherwise dispose of any shares of
               any class of its stock except to such Company or another
               Subsidiary of such Company.
     
               (c)  Environmental Matters.  Each of the Dravo Parties
               covenants that it will not, and will not permit any Third
               Party to, use, produce, manufacture, process, generate, store,
               dispose of, manage at, or ship or transport to or from the
               Properties any Hazardous Materials except for Hazardous
               Materials used, produced, manufactured, processed, generated,
               stored, disposed of, released or managed in the ordinary
               course of business in compliance in all material respects with
               all applicable Environmental Requirements and except for
               Hazardous Materials released in amounts which do not require
               investigation or remediation pursuant to applicable
               Environmental Requirements.
     
               (d)  Liabilities of DNRC.  Each of the Dravo Parties
               covenants that it will not allow DNRC to incur liabilities for
               any purpose other than as set forth in Section 1 of the DNRC
               Agency Agreement or allow any Person other than DNRC to
               perform the duties set forth in Section 1 of the DNRC Agency
               Agreement or amend the DNRC Agency Agreement without the prior
               written consent of the Lenders.
     
     
                       ARTICLE VI
               UNIFORM EVENTS OF DEFAULT
     
          SECTION 6.01.  Uniform Events of Default.  If any of the
     following events shall occur and be continuing for any reason
     whatsoever (and whether such occurrence shall be voluntary or
     involuntary or come about or be effected by operation of law or
     otherwise):
     
               (a)  either of the Companies defaults in the payment of
               any principal of any Note when the same shall become due,
               either by the terms thereof or otherwise as herein provided;
               or
     
               (b)  either of the Companies defaults in the payment of
               any interest or premium, if any, on any Note or any other
               amount due under any Operative Document for more than 10 days
               after the date due; or
     
               (c)  any of the Dravo Parties or any Subsidiary of any
               of the Dravo Parties defaults in payment of principal of or
               interest on any other obligation for money borrowed of
               $100,000 or more, including, without limitation, on any
               obligation arising under the Convertible Notes (or any
               Capitalized Lease Obligation, any obligation under a
               conditional sale or other title retention agreement, any
               obligation issued or assumed as full or partial payment for
               property whether or not secured by a purchase money mortgage
               or any obligation under notes payable or drafts accepted
               representing extensions of credit) beyond any period of grace
               provided with respect thereto, or defaults in the performance
               or observance of any other agreement, term or condition
               contained in any agreement under which any such obligation is
               created (or if any other default under any such agreement
               shall occur and be continuing) and the effect of such default
               is to cause, or to permit the holder or holders of such
               obligation (or a trustee on behalf of such holder or holders)
               to cause, such obligation to become due (or to be defeased or
               repurchased by a Dravo Party or any Subsidiary) prior to its
               stated maturity; or
     
               (d)  any representation or warranty made by any of the
               Dravo Parties herein or in any other Operative Document or in
               connection with this Agreement or any other Operative Document
               shall be false in any material respect on the date as of which
               made; or
     
               (e)  any Dravo Party defaults in the performance or
               observance of any of the covenants contained in Section
               4.01(c), 4.01(d), 4.02(b) or Article V; or
     
               (f)  any Dravo Party defaults in the performance or
               observance of any other agreement, term or condition contained
               herein, and such default shall not have been remedied within
               30 days after any officer of such Dravo Party obtains actual
               knowledge thereof; or
     
               (g)  any of the Dravo Parties or any Subsidiary thereof
               makes an assignment for the benefit of creditors or is
               generally not paying its debts as such debts become due; or
     
               (h)  any order, judgment or decree is entered under any
               bankruptcy, reorganization, compromise, arrangement,
               insolvency, readjustment of debt, dissolution or liquidation
               or similar law whether now or hereafter in effect (herein
               called the "Bankruptcy Law") of any jurisdiction adjudicating
               any of the Dravo Parties or any Subsidiary thereof bankrupt or
               insolvent or that is an order for relief; or
     
               (i)  any of the Dravo Parties or any Subsidiary thereof
               petitions or applies to any tribunal for, or consents to, the
               appointment of, or taking possession by, a trustee, receiver,
               custodian, liquidator or similar official, of such Dravo Party
               or any Subsidiary thereof, or of any substantial part of the
               assets of such Dravo Party or any Subsidiary thereof, or
               commences a voluntary case under the Bankruptcy Law of the
               United States or any proceedings (other than proceedings for
               the voluntary liquidation or dissolution of a Subsidiary of
               such Dravo Party) relating to such Dravo Party or any
               Subsidiary thereof under the Bankruptcy Law of any other
               jurisdiction, whether now or hereafter in effect, or shall
               take any corporate action in furtherance of any of the
               foregoing; or
     
               (j)  any such petition or application is filed, or any
               such proceedings are commenced, against any of the Dravo
               Parties or any Subsidiary thereof or any of the Dravo Parties
               or any Subsidiary thereof by any act indicates its approval
               thereof, consent thereto or acquiescence therein, or an order
               for relief is entered in an involuntary case under the
               Bankruptcy Law of the United States, as now or hereafter
               constituted, or an order, judgment or decree is entered
               appointing any such trustee, receiver, custodian, liquidator
               or similar official, or approving the petition in any such
               proceedings, and such order, judgment or decree remains
               unstayed and in effect for more than 30 days; or
     
               (k)  any order, judgment or decree is entered in any
               proceedings against any of the Dravo Parties decreeing the
               dissolution of any of the Dravo Parties and such order,
               judgment or decree remains unstayed and in effect for more
               than 60 days; or
     
               (l)  any order, judgment or decree is entered in any
               proceedings against any of the Dravo Parties or any Subsidiary
               thereof decreeing a split-up of such Dravo Party or such
               Subsidiary which requires the divestiture of 10%, or the
               divestiture of the stock of a Subsidiary whose assets
               constitute 10% of the consolidated assets of Dravo and its
               Subsidiaries determined in accordance with GAAP or which
               requires the divestiture of assets, or stock of a Subsidiary
               of such Dravo Party, which shall have contributed l0% of the
               Consolidated Net Earnings of Dravo and its Subsidiaries
               determined in accordance with GAAP for any of the three fiscal
               years then most recently ended, and such order, judgment or
               decree remains unstayed and in effect for more than 60 days;
               or
     
               (m)  a judgment in an amount in excess of $5,000,000 is
               rendered against any of the Dravo Parties or any Subsidiary
               thereof and within 60 days after entry thereof, such judgment
               is not discharged or execution thereof stayed pending appeal,
               or within 60 days after the expiration of any such stay, such
               judgment is not discharged; or
     
               (n)  any of the Dravo Parties shall fail to comply with
               the terms of any of the Operative Documents or any Hedging
               Arrangement to which it is a party beyond applicable grace
               periods, if any, specified in such Operative Documents or any
               such Hedging Arrangement; or
     
               (o)   at any time, the aggregate commitment for
               advances (excluding any sublimit or commitment for the
               issuance of letters of credit) under all revolving credit
               facilities of the Companies having a revolving term with an
               expiration date later than six calendar months after such time
               shall be less than $40,000,000; or
     
               (p)       the DNRC Agency Agreement shall cease to be in
               full force and effect or DNRC shall fail to comply with the
               DNRC Agency Agreement;
     
     then (i) if such event is an Event of Default specified in clause
     (g), (h), (i), or (j) of this Section 6.01, all of the Notes at the
     time outstanding shall automatically become immediately due and
     payable at par together with interest accrued thereon, without
     presentment, demand, protest or notice of any kind, all of which are
     hereby waived by the Companies, and (ii) if such event is an Event
     of Default specified in clause (a) or (b) of this Section 6.01, any
     holder of any Note may at its option during the continuance of such
     Event of Default, by notice in writing to the Companies, declare all
     of the Notes held by such holder to be, and all of the Notes held by
     such holder shall thereupon be and become, immediately due and
     payable together with interest accrued thereon and together with the
     Yield-Maintenance Premium, if any, with respect to each such Term
     Note, without presentment, demand, protest or notice of any kind,
     all of which are hereby waived by each of the Companies and (iii) if
     such event is any other Event of Default, the Requisite Lenders may,
     at their option, by notice in writing to the Companies, declare the
     Notes or any of them, as the case may be, to be, and the Notes or
     any of them, as the case may be, shall thereupon be and become,
     immediately due and payable together with the Yield-Maintenance
     Premium, if any, with respect to each Term Note, without
     presentment, demand, protest or other notice of any kind, all of
     which are hereby waived by the Companies, provided that the
     Yield-Maintenance Premium, if any, with respect to each Term Note
     shall be due and payable upon such declaration only if (x) such
     event is an Event of Default specified in any of clauses (a) through
     (f), inclusive, or (k) through (p), inclusive, of this Section 6.01,
     (y) Prudential shall have given to the Companies at least ten
     Business Days' written notice before such declaration stating its
     intention so to declare the Term Notes to be immediately due and
     payable and identifying one or more such Events of Default whose
     occurrence on or before the date of such notice permits such
     declaration and (z) one or more of the Events of Default so
     identified shall be continuing at the time of such declaration.  If
     any Note shall have been declared to be due and payable pursuant to
     clause (ii) or (iii) above, any holder of any other Note may at
     anytime thereafter, regardless of whether any Event of Default shall
     at such time be continuing, by notice in writing to the Companies,
     declare all of the Notes held by such holder to be, and all of the
     Notes held by such holder shall thereupon be and become, immediately
     due and payable together with interest accrued thereon and together
     with the Yield-Maintenance Premium, if any, with respect to each
     such Term Note, without presentment, demand, protest or notice of
     any kind, all of which are hereby waived by the Companies, provided
     that the Yield-Maintenance Premium, if any, with respect to each
     Term Note shall be due and payable upon any declaration pursuant to
     this Section 6.01 as provided in the foregoing.
     
          SECTION 6.02.  Rescission of Defaults.  If, at any time after
     the outstanding principal amount of the Notes shall have become due
     and payable pursuant to Section 6.01, and no judgment or decree for
     any amounts so becoming due and payable shall have been entered, (a)
     all amounts of principal and interest which shall have become due
     and payable in respect of all of the Notes otherwise than pursuant
     to Section 6.01 shall have been paid in full, together with interest
     on all such overdue principal and (to the extent permitted by
     applicable law) interest at the rate specified in such Note or
     Notes, and an amount sufficient to cover all costs and expenses of
     collection incurred by or on behalf of the Lenders (including
     counsel fees and expenses) and (b) every other Default (whether or
     not constituting an Event of Default) shall have been remedied or
     waived, then the Majority Lenders may, by written notice to the
     Companies, rescind and annul such acceleration and its consequences,
     but no such rescission and annulment shall extend to or affect any
     subsequent Default or Event of Default or impair any right
     consequent thereon, and no such rescission and annulment shall
     require Lenders to repay any interest, principal or premium actually
     received as a result of such acceleration.
     
          SECTION 6.03.  Other Remedies.  If any Event of Default or
     Default shall occur and be continuing, each Lender may proceed to
     protect and enforce its rights under this Agreement and the
     Operative Documents, as the case may be, by exercising such remedies
     as are available to them in respect thereof under applicable law,
     either by suit in equity or by action at law, or both, whether for
     specific performance of any covenant or other agreement contained in
     this Agreement or in aid of the exercise of any power granted in
     this Agreement or the Operative Documents.  No remedy conferred in
     this Agreement upon a Lender is intended to be exclusive of any
     other remedy, and each and every such remedy shall be cumulative and
     shall be in addition to every other remedy conferred herein or now
     hereafter existing at law or in equity or by statute or otherwise.
     
          SECTION 1.02. Amendment and Restatement of Appendix A. 
     Appendix A shall be amended and restated in full to read as the
     Appendix A attached hereto.
     
     
                       ARTICLE II
     
                  CONDITIONS PRECEDENT
     
          SECTION 2.01.  Conditions of Effectiveness.  This Amendment
     and Restatement shall become effective when, and only when, (a) King
     & Spalding shall have received counterparts of this Amendment and
     Restatement executed by each of the Dravo Parties and the Lenders
     and all of the following documents, each (unless otherwise
     indicated) being dated the date of receipt thereof by King &
     Spalding (which date shall be the same for all such documents), in
     form and substance satisfactory to the Lenders:
     
               (i)  Copies of (A) all documents evidencing all
               requisite corporate action of each Dravo Party (including any
               and all resolutions of the Board of Directors of each Dravo
               Party) authorizing the execution, delivery and performance of
               this Amendment and Restatement and the matters contemplated
               hereby and thereby, (B) all documents evidencing all
               Governmental Approvals, if any, with respect to this Amendment
               and Restatement and the matters contemplated hereby and
               thereby, and (C) the certificate or articles of incorporation
               and by-laws of each Dravo Party.
     
               (ii) A good standing certificate issued by the
               Secretary of State of its incorporation for each Dravo Party,
               each dated as of a date not more than five days prior to the
               date hereof.
     
               (iii)     A certificate of the Secretary or an Assistant
               Secretary of each Dravo Party certifying the names and true
               signatures of the officers authorized to sign this Amendment
               and Restatement on behalf of such Dravo Party and any other
               documents to be delivered by such Dravo Party hereunder.
     
               (iv) Amendment to the First Mortgage and Security
               Agreement, dated as of January 21, 1992, by Lime in favor of
               the Collateral Agent, recorded in Pendleton County, Kentucky,
               duly executed by Lime and the Collateral Agent.
     
               (v)  A signed copy of a commitment for title insurance
               providing for a date-down endorsement to the title insurance
               policy issued by Commonwealth Land Title Insurance Company,
               Loan Policy Number E0835807, covering the land utilized by the
               Project in Pendleton County, Kentucky, containing such
               exceptions as the Lenders may determine to be acceptable.
     
               (vi) A Warranty Bill of Sale and Assignment, pursuant
               to which all of the personal property conveyed by Lime to
               Dravo Black River Limited Partnership (the "SPV") under the
               Warranty Bill of Sale and Assignment, dated as of August 1,
               1994, by Lime to the SPV, is conveyed back to Lime, duly
               executed by Lime and the SPV.
     
               (vii)     An Improvements Deed, pursuant to which all of the
               Improvements conveyed by Lime to the SPV under the
               Improvements Deed, dated as of August 1, 1994, by Lime to the
               SPV, are conveyed back to Lime, duly executed by Lime and the
               SPV.
     
               (viii)    Financing Statements on Form UCC-1 covering
               the personal property conveyed under the Warranty Bill of Sale
               and Assignment delivered pursuant to clause (vi) above, to be
               filed in all jurisdictions as may be necessary or, in the
               opinion of the Collateral Agent, desirable to perfect the
               security interests of the Collateral Agent therein.
     
               (ix) A Termination of Ground Lease, pursuant to which
               the Ground Lease, dated as of August 1, 1994, between Lime and
               the SPV will be terminated of record, duly executed by Lime
               and the SPV.  
     
               (x)  A Termination of Easement Agreement, pursuant to
               which the Easement Agreement, dated as of August 1, 1994,
               between Lime and the SPV will be terminated of record, duly
               executed by Lime and the SPV. 
     
               (xi) A Termination of Mortgage Subordination Agreement,
               pursuant to which the Mortgage Subordination Agreement, dated
               as of August 1, 1994, by the Collateral Agent in favor of the
               SPV will be terminated of record, duly executed by the
               Collateral Agent and the SPV.
     
               (xii)     A favorable opinion of Buchanan Ingersoll,
               Professional Corporation, special counsel for the Dravo
               Parties, in form and substance satisfactory to the Lenders.
     
               (xiii)    Such other documents, instruments, approvals
               (and, if required by the Agent, certified duplicates of
               executed copies thereof) or opinions as the Agent or any
               Lender may reasonably request.
     
          (b)  The representations and warranties contained herein
     shall be true on and as of the date hereof; there shall exist on the
     date hereof, no Event of Default or Default; there shall exist no
     material adverse change in the financial condition, business
     operation or prospects of any Dravo Party or its Subsidiaries since
     December 31, 1994; and each Dravo Party shall have delivered to the
     Lenders an Officer's Certificate, dated the date hereof, to such
     effect.
     
     
                      ARTICLE III
     
             REPRESENTATIONS AND WARRANTIES
     
          SECTION 3.01.  Representations and Warranties of the Dravo
     Parties.  (a)  Each of the Dravo Parties hereby repeats and confirms
     each of the representations and warranties made by it in Article VII
     of the Override Agreement as though made on and as of the date
     hereof, with each reference therein to "this Agreement", the
     "Operative Documents", "hereof", "hereunder", "thereof",
     "thereunder" and words of like import being deemed to be a reference
     to the Override Agreement, as amended hereby.
     
          (b)  Each of the Dravo Parties further represents and
     warrants as follows:
     
               (i)  Such Dravo Party and each of its Subsidiaries is
               a corporation duly organized, validly existing and in good
               standing under the laws of the state of its incorporation and
               is duly qualified to do business in, and is in good standing
               in, all other jurisdictions where the nature of its business
               or the nature of property owned or used by it makes such
               qualification necessary.
     
               (ii)      The execution, delivery and performance by
               such Dravo Party of this Amendment and Restatement are within
               its corporate powers, have been duly authorized by all
               necessary corporate action and do not contravene (A) such
               Dravo Party's charter or by-laws, (B) law or (C) any legal or
               contractual restriction binding on or affecting such Dravo
               Party; and such execution, delivery and performance do not or
               will not result in or require the creation of any Lien upon or
               with respect to any of its properties.
     
               (iii)     No Governmental Approval is required for the due
               execution, delivery and performance by such Dravo Party of
               this Amendment, except for such Governmental Approvals as have
               been duly obtained or made and which are in full force and
               effect on the date hereof and not subject to appeal.
     
               (iv)      This Amendment and Restatement constitutes
               the legal, valid and binding obligations of such Dravo Party
               enforceable against such Dravo Party in accordance with its
               terms; subject to the qualifications, however, that the
               enforcement of the rights and remedies herein is subject to
               bankruptcy and other similar laws of general application
               affecting rights and remedies of creditors and that the remedy
               of specific performance or of injunctive relief is subject to
               the discretion of the court before which any proceedings
               therefor may be brought.
     
               (v)       Except as set forth in the Form 10-Q dated
               September 30, 1995, there are no pending or threatened
               actions, suits or proceedings affecting such Dravo Party or
               any of its Subsidiaries or the properties of such Dravo Party
               or any of its Subsidiaries before any court, governmental
               agency or arbitrator, that may, if adversely determined,
               materially adversely affect the financial condition,
               properties, business, operations or prospects of such Dravo
               Party and it Subsidiaries, considered as a whole, or affect
               the legality, validity or enforceability of the Override
               Agreement or any other Operative Document, as amended hereby.
     
            [Signatures Begin on Next Page.]
          <PAGE>
     IN WITNESS WHEREOF, each of the parties hereto have caused
     this Amendment and Restatement to be duly executed and delivered by
     their respective officers thereunto duly authorized as of the date
     first above written.
     
     
                              FIRST ALABAMA BANK
     
     
     
                              By: /s/ PETER P. GAILLARD
                              Name: Peter P. Gaillard
                              Title: Senior Vice President
     
     
                              PNC BANK, NATIONAL
                                ASSOCIATION (f/k/a Pittsburgh
                                National Bank)
     
     
     
                              By:/s/ DALE A. STEIN
                              Name: Dale A. Stein
                              Title: Vice President
     
     
                              BANK OF AMERICA ILLINOIS
     
     
     
                              By:/s/ MICHAEL J. MCKENNEY
                              Name: Michale J. McKenney
                              Title: Vice President
     
     
          <PAGE>
                         THE PRUDENTIAL INSURANCE
                                COMPANY OF AMERICA
     
     
     
                              By:/s/ KEVIN J. KRASKA
                              Name: Kevin J. Kraska
                              Title: Vice President
     
     
                              DRAVO CORPORATION
     
     
     
                              By:/s/ ERNEST F. LADD III
                              Name: Ernest F. Ladd III
                              Title: Executive Vice President
     
     
                              DRAVO LIME COMPANY
     
     
     
                              By:/s/ ERNEST F. LADD III
                              Name: Ernest F. Ladd III
                              Title: Executive Vice President
     
     
                              DRAVO BASIC MATERIALS
                              COMPANY, INC.
     
     
     
                              By:/s/ ERNEST F. LADD III
                              Name: Ernest F. Ladd III
                              Title: Executive Vice President
          <PAGE>