1
                                                                EXHIBIT 10.22(a)

                                                                  EXECUTION COPY

                                 AMENDMENT NO. 1
                                       TO
                                CREDIT AGREEMENT

          THIS AMENDMENT No. 1 TO CREDIT AGREEMENT (the "Amendment") is made as
of February 6, 2001 by and among CHICAGO BRIDGE & IRON COMPANY N.V. (the
"Company"), CB&I CONSTRUCTORS, INC., CBI SERVICES, INC., CHICAGO BRIDGE & IRON
COMPANY (DELAWARE) and CB&I TYLER COMPANY (collectively, the "SUBSIDIARY
BORROWERS," and, together with the Company, the "BORROWERS"), the financial
institutions listed on the signature pages hereof (the "Lenders"), BANK ONE, NA
(having its principal office in Chicago, Illinois), in its individual capacity
as a Lender and in its capacity as contractual representative (the
"Administrative Agent"), BANK OF AMERICA, N.A., as Syndication Agent, and HARRIS
TRUST AND SAVINGS BANK, as Documentation Agent, under that certain Credit
Agreement dated as of December 1, 2000 by and among the Borrowers, the financial
institutions party thereto, the Administrative Agent, the Syndication Agent, the
Documentation Agent and BANC ONE CAPITAL MARKETS, INC., as Lead Arranger and
Sole Book Runner (the "Credit Agreement") Defined terms used herein and not
otherwise defined herein shall have the meaning given to them in the Credit
Agreement.

                                   WITNESSETH

          WHEREAS, the Borrowers, the Lenders, the Administrative Agent, the
Syndication Agent and the Documentation Agent are parties to the Credit
Agreement; and

          WHEREAS, the Borrowers have requested that the Administrative Agent,
the Syndication Agent, the Documentation Agent and the requisite number of
Lenders under Section 9.2 of the Credit Agreement amend the Credit Agreement on
the terms and conditions set forth herein; and

          WHEREAS, the Borrowers, the requisite number of Lenders under Section
9.2 of the Credit Agreement, the Administrative Agent, the Syndication Agent and
the Documentation Agent have agreed to amend the Credit Agreement on the terms
and conditions set forth herein;

          NOW, THEREFORE, in consideration of the premises set forth above, the
terms and conditions contained herein, and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties hereto have agreed to the following amendments to the Credit Agreement:

          1. Amendments to the Credit Agreement. Effective as of February 6,
2001 and subject to the satisfaction of conditions precedent set forth in
Section 2 below, the Credit Agreement is hereby amended as follows:

   2
     1.1. Section 1.1 of the Credit Agreement is amended to insert immediately
          after the phrase "the H-B Acquisition" now appearing in clause (i) of
          the definition of "CHANGE OF CONTROL", the following: "and the PDM
          Acquisition".

     1.2. Section 1.1 of the Credit Agreement is amended to insert immediately
          prior to the period (".") at the end of the definition Of "TRANSACTION
          DOCUMENTS", the following: ", and, from and after the consummation of
          the PDM Acquisition, the documents executed and delivered by the
          Company or any of its Subsidiaries in connection with the PDM
          Acquisition, including, without limitation, the PDM Acquisition
          Agreement".

     1.3. Section 1.1 of the Credit Agreement is amended to add the following
          definitions thereto in the applicable alphabetical locations:

               "PDM ACQUISITION" means the acquisition by the Company of
          substantially all of the assets comprising the water and engineered
          construction divisions of Pitt-Des Moines, Inc, for consideration
          including (i) a cash purchase price of up to $40,000,000 and (ii) the
          issuance of 2,848,172 shares of Capital Stock of the Company, and
          otherwise on terms consistent in all material respects with the terms
          disclosed to the Administrative Agent and set forth in the PDM
          Acquisition Agreement.

               "PDM ACQUISITION AGREEMENT" means that certain Asset Purchase
          Agreement, dated as of February __, 2001, by and between Pitt-Des
          Moines, Inc., a Pennsylvania corporation, as the seller, and the
          Company and CB&I Constructors, Inc., as the buyers, as delivered to
          the Administrative Agent on February 5, 2001.

     1.4. Section 2.3 of the Credit Agreement is amended to delete the reference
          to "six (6) Interest Periods" and to substitute therefor: "seven (7)
          Interest Periods."

     1.5. Section 2.14(D)(iii) of the Credit Agreement is amended to delete the
          language now contained therein and to substitute the following
          therefor:

               "(iii) Notwithstanding anything herein to the contrary, (x) from
          the Closing Date to but not including the date the PDM Acquisition is
          closed and the "Purchase Price" as defined in Section 3.1(a) of the
          PDM Acquisition Agreement is paid as provided therein (the "PDM
          Effective Date"), the Applicable Floating Rate Margin, Applicable
          Eurodollar Margin, Applicable Commitment Fee Percentage and Applicable
          L/C Fee Percentages shall be determined based on a Leverage Ratio of
          greater than or equal to 1.50 to 1.00 and less than 2.00 to 1.00 and
          (y) from and after the PDM Effective Date to but not including the
          fifth (5th) Business Day following receipt of the Company's audited
          financial statements delivered pursuant to Section 7.1(A)(i) (and
          accompanying officer's certificate) for the fiscal quarter ended March
          31, 2001, the Applicable Floating Rate Margin, Applicable Eurodollar
          Margin, Applicable L/C Fee Percentages and Applicable Commitment Fee
          Percentage shall be determined based upon a Leverage Ratio of


                                      -2-
   3
          greater than or equal to 2.00 to 1.00 at which time the Applicable
          Floating Rate Margin, Applicable Eurodollar Margin, Applicable L/C Fee
          Percentages and Applicable Commitment Fee Percentage shall be
          determined based on such financial statements and officer's
          certificate delivered therewith."

     1.6. Article VI of the Credit Agreement is amended to insert the following
          new Section 6.22 and Section 6.23 at the end thereof:

               6.22. PDM Financial Statements.

               (A) Pro Forma Financials. The combined pro forma balance sheet,
          income statements and statements of cash flow of the Company and its
          Subsidiaries (after giving effect to the PDM Acquisition), copies of
          which are attached hereto as Schedule 6.22 to this Agreement, present
          on a pro forma basis the financial condition of the Company and such
          Subsidiaries as of such date, and demonstrate that the Company and its
          Subsidiaries can repay their debts and satisfy their other obligations
          as and when due, and can comply with the requirements of this
          Agreement. The projections and assumptions expressed in the pro forma
          financials referenced in this Section 6.22 were prepared in good faith
          and represent management's opinion based on the information available
          to the Company at the time so furnished and, since the preparation
          thereof and up to the effective date of Amendment No. 1 to this
          Agreement, there has occurred no change in the business, financial
          condition, operations, or prospects of the Company or any of its
          Subsidiaries, or the Company and its Subsidiaries taken as a whole, or
          the water and engineered construction divisions of Pitt-Des Moines,
          Inc. taken as a whole, which has had or could reasonably be expected
          to have a Material Adverse Effect.

               (B) Combined Financial Statements. Complete and accurate copies
          of the audited, combined statements of income, equity and cash flows
          (and the audit reports related thereto) of the water and engineered
          construction divisions of Pitt-Des Moines, Inc. for the fiscal years
          ended December 31, 1997, December 31, 1998 and December 31, 1999 have
          been delivered to the Administrative Agent and such financial
          statements were prepared in accordance with generally accepted
          accounting principles in effect on the date such statements were
          prepared and fairly present the combined financial condition and
          operations of the water and engineered construction divisions of
          Pitt-Des Moines, Inc. at such date and the combined results of their
          operations for the period then ended.

               (C) Interim Financial Statements for PDM. Complete and accurate
          copies of the unaudited, combined statements of income, equity and
          cash flows of the water and engineered construction divisions of
          Pitt-Des Moines, Inc. for the nine-month period ended September 30,
          2000, have been delivered to the Administrative Agent and such
          financial statements were prepared in accordance with generally
          accepted accounting principles in effect on the date such statements
          were prepared and fairly present the combined financial condition and
          operations of the water and engineered construction divisions of
          Pitt-Des Moines,



                                      -3-
   4
          Inc. at such date and the combined results of their operations for the
          period then ended, subject to normal year-end audit adjustments.

               6.23. PDM Acquisition Transactions. As of the closing date for
          the PDM Acquisition and immediately prior to the making of any Loans
          for the purpose of financing the PDM Acquisition:

               (i) the PDM Acquisition Agreement is in full force and effect, no
          material breach, default or waiver of any term or provision thereof by
          the Company or any of its Subsidiaries or, to the best of the
          Company's knowledge, the other parties thereto, has occurred (except
          for such breaches, defaults and waivers, if any, consented to in
          writing by the Administrative Agent) and no action has been taken by
          any competent authority which restrains, prevents or imposes any
          material adverse condition upon, or seeks to restrain, prevent or
          impose any material adverse condition upon, the PDM Acquisition;

               (ii) the representations and warranties of the Company and its
          Subsidiaries contained in the PDM Acquisition Agreement, if any, are
          true and correct in all material respects, and

               (iii) all conditions precedent to, and all consents necessary to
          permit, the funding of the PDM Acquisition have been satisfied or
          waived with the approval of the Administrative Agent (such approval
          not to be unreasonably withheld).

     1.7. Section 7.3(A)(viii) of the Credit Agreement is amended to delete the
          reference to "$30,000,000" and to substitute therefor: "$35,000,000."

     1.8. Section 7.3(F) of the Credit Agreement is amended (i) to insert the
          phrase "and the PDM Acquisition" after the first occurrence of the
          phrase "the H-B Acquisition", and to insert, "the PDM Acquisition"
          after the second occurrence of the phrase "the H-B Acquisition", in
          each case now appearing in clause (a) thereof; (ii) to insert the
          phrase "(other than the PDM Acquisition)" immediately after the phrase
          "since the Closing Date" now appearing in clause (a)(6) thereof; (iii)
          to re-letter clause (ii) thereof as "clause (b)"; and (iv) to insert
          the following new clause (c) at the end thereof:

               (c) On or prior to the date of the PDM Acquisition, the Company
          shall furnish to the Administrative Agent each of the following, with
          sufficient copies for the Lenders, all in form and substance
          satisfactory to the Administrative Agent and the Lenders:

          (1)  Evidence satisfactory to the Administrative Agent that (i)
               all conditions precedent to the consummation of the PDM
               Acquisition have been satisfied or waived with the approval of
               the Administrative Agent, (ii) the PDM Acquisition Agreement has
               been approved by all necessary corporate action of the Board of
               Directors of the Loan Parties party thereto, and have not been
               amended, waived or modified without the




                                      -4-
   5
               approval of the Administrative Agent and (iii) the
               representations and warranties in the PDM Acquisition Agreement
               shall be accurate as of the date of the PDM Acquisition; and the
               Administrative Agent and the Lenders shall have received an
               opinion of counsel satisfactory to them as to (a) the
               enforceability of the PDM Acquisition Agreement and (b) the Loan
               Parties' compliance with law in respect thereof;

          (2)  Evidence satisfactory to the Administrative Agent that all
               required governmental approvals related to the PDM Acquisition
               have been obtained and all related filings made and any
               applicable waiting periods shall have expired or been terminated;

          (3)  Evidence satisfactory to the Administrative Agent that there
               exists no injunction or temporary restraining order which, in the
               judgment of the Administrative Agent, would prohibit the
               consummation of the PDM Acquisition, or any litigation seeking
               such an injunction or restraining order or which could reasonably
               be expected to have material adverse effect on the business or
               financial condition of the water and engineered construction
               divisions of Pitt-Des Moines, Inc.;

          (4)  Copies of any fairness opinion issued to the Company in respect
               of the PDM Acquisition, and opinions of value, solvency and
               other appropriate factual information and advice in form and
               substance reasonably satisfactory to the Administrative Agent
               from the Chief Financial Officer of the Company supporting the
               conclusions that after giving effect to the PDM Acquisition, the
               Company and its Subsidiaries on a consolidated basis are Solvent
               and will be Solvent subsequent to incurring the indebtedness
               contemplated under the Transaction Documents (after giving effect
               to the PDM Acquisition), will be able to pay its debts and
               liabilities as they become due and will not be left with
               unreasonably small working capital for general corporate
               purposes; and

          (5)  Such other documents as the Administrative Agent may have
               reasonably requested, including, without limitation, a copy of
               the final, executed PDM Acquisition Agreement, and all
               instruments, agreements and other documents related thereto,
               including, without limitation, any shareholder agreement.

     1.9. Section 7.4(B) of the Credit Agreement is amended to insert
          immediately after the reference to "("Fixed Charge Coverage Ratio")"
          the following:

          "without duplication"

          and is further amended to insert immediately after the reference to
          "Restricted Payments" in clause (ii)(d) the following:





                                      -5-
   6
           "other than Restricted Payments made to purchase Capital Stock of the
           Company from Pitt-Des Moines, Inc. acquired by Pitt-Des Moines, Inc.
           in connection with the PDM Acquisition"

           and is further amended to insert immediately after the reference to
           "Rentals for such period" in clause (ii)(e) the following:

           "plus (f) amounts paid during such period with respect to Capitalized
           Lease Obligations".

     1.10. Section 7.4(D) of the Credit Agreement is amended to add at the end
           of clause (c) immediately after the reference to "Equity Interests"
           the following:

           "except for the adjustment made to reflect the issuance of Equity
           Interests in connection with the PDM Acquisition plus (d) seventy
           percent (70%) of the amount by which stockholders' equity of the
           Company is, in accordance with Agreement Accounting Principles,
           adjusted as a result of the issuance of Equity Interests by the
           Company in connection with the PDM Acquisition."

     1.11. The Schedules to the Credit Agreement are amended to add a new
           Schedule 6.22 in the form attached to this Amendment and to
           substitute the attached Schedules 1.1.5 and 6.8 for those now part
           of the Credit Agreement.

          2. Conditions of Effectiveness. The effectiveness of this Amendment
is subject to the conditions precedent that the Administrative Agent shall have
received the following:

     (a)  duly executed originals of this Amendment from each of the Borrowers,
          the requisite number of Lenders under Section 9.2 of the Credit
          Agreement, the Administrative Agent, the Syndication Agent and the
          Documentation Agent;

     (b)  duly executed originals of a Reaffirmation in the form of Attachment A
          attached hereto from each of the Subsidiary Guarantors identified
          thereon;

     (c)  payment of an amendment fee of 5 basis points (0.05%) on the
          Commitment of each Lender that approves this Amendment and returns a
          signature page signed by such Lender to James E. Clark of Sidley &
          Austin by telecopy (312-853-7036) by 5:00 p.m. (Chicago time) on
          Friday, January 12, 2001; and

     (d)  such other documents, instruments and agreements as the Administrative
          Agent may reasonably request.

          3. Representations and Warranties of the Borrowers.

     (a)  The Borrowers hereby represent and warrant that this Amendment, the
          attached Reaffirmations and the Credit Agreement, as previously
          executed and as amended hereby, constitute legal, valid and binding
          obligations of the Borrowers and the Subsidiary Guarantors parties
          thereto and are enforceable against the Borrowers and the Subsidiary
          Guarantors parties thereto in accordance with their terms



                                      -6-
   7
          (except as enforceability may be limited by bankruptcy, insolvency, or
          similar laws affecting the enforcement of creditors' rights
          generally).

     (b)  Upon the effectiveness of this Amendment and after giving effect
          hereto, (i) the Borrowers hereby reaffirm all covenants,
          representations and warranties made in the Credit Agreement as amended
          hereby, and agrees that all such covenants, representations and
          warranties shall be true and correct as of the effective date of this
          Amendment (unless such representation and warranty is made as of a
          specific date, in which case such representation and warranty shall be
          true and correct as of such date) and (ii) no Default or Unmatured
          Default has occurred and is continuing.

          4. References to the Credit Agreement.

     (a)  Upon the effectiveness of Section 1 hereof, on and after the date
          hereof each reference in the Credit Agreement (including any reference
          therein to "this Credit Agreement," "hereunder," "hereof," "herein" or
          words of like import referring thereto) or in any other Loan Document
          shall mean and be a reference to the Credit Agreement as amended
          hereby.

     (b)  Except as specifically amended above, the Credit Agreement and all
          other documents, instruments and agreements executed and/or delivered
          in connection therewith, shall remain in full force and effect, and
          are hereby ratified and confirmed.

     (c)  The execution, delivery and effectiveness of this Amendment shall not,
          except as expressly provided herein, operate as a waiver of any
          right, power or remedy of the Administrative Agent or the Lenders, nor
          constitute a waiver of any provision of the Credit Agreement or any
          other documents, instruments and agreements executed and/or delivered
          in connection therewith.

          5. GOVERNING LAW. THIS AMENDMENT SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE INTERNAL LAWS (INCLUDING 735 ILCS 105/5-1 ET SEQ., BUT
OTHERWISE WITHOUT REGARD TO THE CONFLICT OF LAW PROVISIONS) OF THE STATE OF
ILLINOIS.

          6. Headings. Section headings in this Amendment are included herein
for convenience of reference only and shall not constitute a part of this
Amendment for any other purpose.

          7. Counterparts. This Amendment may be executed by one or more of the
parties to this Amendment on any number of separate counterparts and all of said
counterparts taken together shall be deemed to constitute one and the same
instrument.

                     [REMAINDER OF PAGE INTENTIONALLY BLANK]



                                       -7-


   8
          IN WITNESS WHEREOF, this Amendment has been duly executed as of the
day and year first above written.


                                     CHICAGO BRIDGE & IRON COMPANY
                                     N.V., as the Company
                                     By:  Chicago Bridge & Iron Company B.V.
                                     Its: Managing Director

                                     By: /s/ Gerald M. Glenn
                                         --------------------------
                                      Name:  Gerald M. Glenn
                                      Title: Managing Director

                                     CB&I CONSTRUCTORS, INC., as a
                                     Subsidiary Borrower

                                     By: /s/ Timothy J.P. Moran
                                         --------------------------
                                      Name:  Timothy J.P. Moran
                                      Title: Treasurer

                                     CBI SERVICES, INC., as a Subsidiary
                                     Borrower

                                     By: /s/ Dennis C. Planic
                                         --------------------------
                                      Name:  Dennis C. Planic
                                      Title: Treasurer

                                     CHICAGO BRIDGE & IRON COMPANY
                                     (DELAWARE), as a Subsidiary Borrower

                                     By: /s/ Timothy J.P. Moran
                                         --------------------------
                                      Name:  Timothy J.P. Moran
                                      Title: Treasurer

   9


                                          CB&I TYLER COMPANY, as a Subsidiary
                                          Borrower

                                          By: /s/ Timothy J.P. Moran
                                              -------------------------------
                                              Name: Timothy J.P. Moran
                                              Title: Treasurer

AGENTS AND LENDERS:                       BANK ONE, NA (having its principal
                                          office in Chicago, Illinois), as
                                          Administrative Agent and as a Lender


                                          By: /s/ Richard T. Bedell
                                              -------------------------------
                                              Name: Richard T. Bedell
                                              Title: Vice President

                                          BANK OF AMERICA, N.A., as Syndication
                                          Agent and as a Lender

                                          By: /s/ Charles F. Lilygren
                                              -------------------------------
                                              Name: Charles F. Lilygren
                                              Title: Managing Director

                                          HARRIS TRUST AND SAVING BANK, as
                                          Documentation Agent and as a Lender

                                          By: /s/ David M. Rubin
                                              -------------------------------
                                              Name: David M. Rubin
                                              Title: Managing Director

                                          ABN AMRO BANK N.V., as a Lender

                                          By: /s/ Thomas K. Peterson
                                              -------------------------------
                                              Name: Thomas K. Peterson
                                              Title: Senior Vice President

                                          By: /s/ Mary L. Honda
                                              -------------------------------
                                              Name: Mary L. Honda
                                              Title: Group Vice President







   10
                                     THE CHASE MANHATTAN BANK, as a
                                     Lender

                                     By: /s/ C.J. Droogan
                                        ---------------------------
                                      Name: C.J. Droogan
                                      Title: Vice President
   11

                                                                    ATTACHMENT A

                                  REAFFIRMATION

     Each of the undersigned hereby acknowledges receipt of a copy of the
foregoing Amendment No. 1 to the Credit Agreement dated as of December 1, 2000
by and among CHICAGO BRIDGE & IRON COMPANY N.V. (the "Company"), CB&I
CONSTRUCTORS, INC., CBI SERVICES, INC., CHICAGO BRIDGE & IRON COMPANY (DELAWARE)
and CB&I TYLER COMPANY (collectively, the "Subsidiary Borrowers", and, together
with the Company, the "Borrowers"), the financial institutions from time to time
party thereto (the "Lenders"), BANK ONE, NA (having its principal office in
Chicago, Illinois), in its individual capacity as a Lender and in its capacity
as contractual representative (the "Administrative Agent") BANK OF AMERICA,
N.A., as Syndication Agent, and HARRIS TRUST AND SAVINGS BANK, as Documentation
Agent, and BANC ONE CAPITAL MARKETS, INC., as Lead Arranger and Sole Book Runner
(as amended and as the same may be amended, restated, supplemented or otherwise
modified from time to time, the "Credit Agreement"), which Amendment No. 1 is
dated as of February __, 2001 (the "Amendment"). Capitalized terms used in this
Reaffirmation and not defined herein shall have the meanings given to them in
the Credit Agreement. Without in any way establishing a course of dealing by the
Administrative Agent or any Leader, each of the undersigned reaffirms the terms
and conditions of the Guaranty, the Subsidiary Security Agreement, the
Subsidiary Pledge Agreement and any other Loan Document executed by it and
acknowledges and agrees that such agreement and each and every such Loan
Document executed by the undersigned in connection with the Credit Agreement
remains in full force and effect and is hereby reaffirmed, ratified and
confirmed. All references to the Credit Agreement contained in the
above-referenced documents shall be a reference to the Credit Agreement as so
modified by the Amendment and as the same may from time to time hereafter be
amended, modified or restated.

Dated: February ___, 2001




CHICAGO BRIDGE & IRON COMPANY              CHICAGO BRIDGE & IRON COMPANY
                                           (DELAWARE)


By /s/ TIMOTHY J.P. MORAN                  By  /s/ TIMOTHY J.P. MORAN
- -------------------------------------      ------------------------------------
Name:  Timothy J.P. Moran                  Name:  Timothy J.P. Moran
Title: Treasurer                           Title: Treasurer





   12

CB&I TYLER COMPANY                          CBI CONSTRUCTORS PTY, LTD.

By /s/ Timothy J.P. Moran                   By /s/ David J. Cochrane
   ----------------------------                ------------------------------
Name:  Timothy J.P. Moran                   Name:  David J. Cochrane
Title: Treasurer                            Title: Director

CB&I CONSTRUCTORS, INC.                     LEALAND FINANCE COMPANY B.V.

By /s/ Timothy J.P. Moran                   By /s/ Timothy J.P. Moran
   ----------------------------                ------------------------------
Name:  Timothy J.P. Moran                   Name:  Timothy J.P. Moran
Title: Treasurer                            Title: Managing Director

CBI SERVICES, INC.                          CB&I (EUROPE) B.V.

By /s/ Dennis C. Planic                     By /s/ J.H. Schurink
   ----------------------------                ------------------------------
Name:  Dennis C. Planic                     Name:  J.H. Schurink
Title: Treasurer                            Title: Director

HORTON CBI, LIMITED                         ARABIAN GULF MATERIAL SUPPLY
                                            COMPANY, LIMITED

By /s/ James W. House                       By /s/ Alan R. Black
   ----------------------------                ------------------------------
Name:  James W. House                       Name:  Alan R. Black
Title: Treasurer                            Title: Vice President

CBI VENEZOLANA, S.A.                        ASIA PACIFIC MATERIAL SUPPLY
                                            COMPANY LTD.

By /s/ Mario Marquez                        By /s/ Timothy J.P. Moran
   ----------------------------                ------------------------------
Name:  Mario Marquez                        Name:  Timothy J.P. Moran
Title: Vice President                       Title: Treasurer

CBI EASTERN ANSTALT                         CBI COMPANY LIMITED

By /s/ Timothy J.P. Moran                   By /s/ Timothy J.P. Moran
   ----------------------------                ------------------------------
Name:  Timothy J.P. Moran                   Name:  Timothy J.P. Moran
Title: Administrator                        Title: Treasurer







   13
CBI CONSTRUCCIONES S.A.                         CHICAGO BRIDGE & IRON (ANTILLES)
                                                N.V.

By: /s/ William P. Hare                         By: /s/ Gerald M. Glenn
    ----------------------------                    ----------------------------
Name:  William P. Hare                          Name:  Gerald M. Glenn
Title: Vice President                           Title: Managing Director


CBI CONSTRUCTORS LIMITED                        CHICAGO BRIDGE & IRON COMPANY
                                                B.V.

By: /s/ J.H. Schurink                           By: /s/ Gerald M. Glenn
    ----------------------------                    ----------------------------
Name:  J.H. Schurink                            Name:  Gerald M. Glenn
Title: Director                                 Title: Managing Director


CBI HOLDINGS (U.K.) LIMITED                     CMP HOLDINGS B.V.


By: /s/ J.H. Schurink                           By: /s/ J.H. Schurink
    ----------------------------                    ----------------------------
Name:  J.H. Schurink                            Name:  J.H. Schurink
Title: Director                                 Title: Director


CBI OVERSEAS, LLC                               PACIFIC RIM MATERIAL SUPPLY
                                                COMPANY, LTD.

By: /s/                                         By: /s/ Alan R. Black
    ----------------------------                    ----------------------------
Name:                                           Name:  Alan R. Black
Title:                                          Title: Vice President


CENTRAL TRADING COMPANY, LTD.


By: /s/ Timothy J.P. Moran
    ----------------------------
Name:  Timothy J.P. Moran
Title: Treasurer
   14
HOWE-BAKER INTERNATIONAL, L.L.C.


By: /s/ Ronald D. Brazzel
    --------------------------
Name:  Ronald D. Brazzel
Title: President and Chief Executive Officer


HOWE-BAKER ENGINEERS, LTD.
By and through its General Partner
Howe-Baker Management, L.L.C.

By: /s/ Ronald D. Brazzel
    --------------------------
Name:  Ronald D. Brazzel
Title: President


HOWE-BAKER HOLDINGS, L.L.C.


By: /s/ Ronald D. Brazzel
    --------------------------
Name:  Ronald D. Brazzel
Title: President and Chief Executive Officer


HOWER-BAKER MANAGEMENT, L.L.C.


By: /s/ Ronald D. Brazzel
    --------------------------
Name:  Ronald D. Brazzel
Title: President


HOWE-BAKER, L.P.
By and through its General Partner
Howe-Baker Management, L.L.C.


By: /s/ Ronald D. Brazzel
    --------------------------
Name:  Ronald D. Brazzel
Title: President
   15
MATRIX ENGINEERING, LTD.
By and through its General Partner
Howe-Baker International Management, L.L.C.


By: /s/ Ronald D. Brazzel
    --------------------------
Name:  Ronald D. Brazzel
Title: Chairman of the Board and Chief Executive Officer


HBI HOLDINGS, L.L.C.


By: /s/ Ronald D. Brazzel
    --------------------------
Name:  Ronald D. Brazzel
Title: President and Chief Executive Officer


HOWE-BAKER INTERNATIONAL MANAGEMENT, L.L.C.


By: /s/ Ronald D. Brazzel
    --------------------------
Name:  Ronald D. Brazzel
Title: Chairman of the Board and Chief Executive Officer


A & B BUILDERS, LTD.
By and through its General Partner
Matrix Management Services, L.L.C.


By: /s/ Ronald D. Brazzel
    --------------------------
Name:  Ronald D. Brazzel
Title: Chairman of the Board and Chief Executive Officer


MATRIX MANAGEMENT SERVICES, L.L.C.

By: /s/ Ronald D. Brazzel
    --------------------------
Name:  Ronald D. Brazzel
Title: Chairman of the Board and Chief Executive Officer
   16
CALLIDUS TECHNOLOGIES INTERNATIONAL, L.L.C.


By: /s/ Ronald D. Brazzel
    --------------------------
Name:  Ronald D. Brazzel
Title: Chairman of the Board


CALLIDUS TECHNOLOGIES, L.L.C.


By: /s/ Ronald D. Brazzel
    --------------------------
Name:  Ronald D. Brazzel
Title: Chairman of the Board


CONSTRUCTORS INTERNATIONAL, L.L.C.


By: /s/ Ronald D. Brazzel
    --------------------------
Name:  Ronald D. Brazzel
Title: President and Chief Executive Officer


PROCESS MANAGEMENT, L.L.C.


By: /s/ Ronald D. Brazzel
    --------------------------
Name:  Ronald D. Brazzel
Title: President Chief Executive Officer