<PAGE>

===============================================================================

                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C.  20549

                                   FORM 10-K
(Mark One)
     [ X ]  ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
            SECURITIES EXCHANGE ACT OF 1934
            For the fiscal year ended December 31, 1997

                            OR

     [   ]  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
            SECURITIES EXCHANGE ACT OF 1934
            For the transition period from      to

                         Commission file number 1-5259

                             PITT-DES MOINES, INC.
            (Exact name of registrant as specified in its charter)

               Pennsylvania                       25-0729430
     (State or other jurisdiction of            (I.R.S. Employer
     incorporation or organization)           Identification No.)

10200 Grogan's Mill Road, Suite 300, The Woodlands, Texas     77380
      (Address of principal executive offices)              (Zip Code)

                                  281-774-2200
              (Registrant's telephone number, including area code)

          Securities Registered Pursuant to Section 12(b) of the Act:

        Title of each Class            Name of each exchange on which registered
        -------------------            -----------------------------------------
     Common Stock, no par value                   American Stock Exchange

       Securities Registered Pursuant to Section 12(g) of the Act:  None

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.      Yes    X       No
                                             -----        -----

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405
of Regulation S-K is not contained herein, and will not be contained, to the
best of registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K [ X ].

The aggregate market value of the registrant's voting stock held by non-
affiliates was at least $72,538,534 on February 27, 1998, based upon the average
between the highest and lowest sales prices of the registrant's Common Stock as
reported in the consolidated transactions reporting system.

     Common Stock outstanding as of February 27, 1998 . . . . .3,515,687 shares.

Documents Incorporated by Reference:

     Certain portions of the documents of the Registrant listed below have been
incorporated by reference into the indicated parts of this Annual Report on Form
10-K:

<TABLE>
<S>                                                                                 <C>
     Proxy Statement anticipated to be dated March 31, 1998 . . . . . . . . . . . . Part III, Items 10-13

     Annual Report to Stockholders for fiscal year ended December 31, 1997 . . . . . . Part I and Part II
</TABLE>

===============================================================================
<PAGE>

                                    PART I


Item 1.  Business

General

Pitt-Des Moines, Inc. and its subsidiaries ("PDM" or the "Company") began
conducting business in 1892 and was incorporated in Pennsylvania on February 14,
1916.  The Company's principal executive offices are located at 10200 Grogan's
Mill Road, Suite 300, The Woodlands, TX  77380, telephone number (281) 774-2200.

  As a result of a refinement in the Company's strategic direction, significant
acquisitions, and the closing of the Melrose Park structural steel fabricating
facility, the Company changed its reporting in 1997 to two business segments:
Engineering and Construction, and Steel Distribution.

  A summary of the Company's products and services by business segment is set
forth below.



Engineering and Construction

In February of 1997, the Company announced plans to construct a new steel
fabricating facility in Eloy, Arizona.  This new facility is expected to be
operational in the second quarter of 1998.  Along with this plan, the Company
announced the decision to close its Melrose Park structural steel fabricating
facility in Illinois.

On March 10, 1997, the Company acquired Candraft Detailing Inc., an engineering
and drafting company, located in Vancouver, British Columbia. In June, the
Company acquired a majority ownership in Tecnologia de Almacenamiento
Industrial, TAI,S.A. (TAISA) an engineering and construction company located in
Caracas, Venezuela.   In addition, in October the Company acquired Sheffield
Steel Products, a bridge fabricator located in northeastern Florida.


  The Engineering and Construction business provides:



  a)  The capability to design, fabricate and erect oil and chemical storage
     tanks used for storing crude oil, petroleum, gasoline and other petroleum
     derivatives and chemicals.  The Company has developed and patented certain
     systems, parts and sealing devices which help to reduce the hazards of fire
     and explosion from the stored products, as well as to decrease air
     pollution and vapor loss.  Additionally, the Company fabricates and erects
     various vessels used in the processing of a variety of oil and chemical
     products.  The oil and chemical tanks, sealing devices and process vessels
     are produced principally for the petroleum, petrochemical, chemical and
     food processing industries as well as government agencies.

  b)  The capability to design, fabricate and erect elevated and flat bottom
     water storage tanks for water service and fire protection requirements and
     treatment tanks for the purification, filtration and softening of water.
     The principal purchasers of the Company's water storage tanks and
     wastewater treatment facilities are government agencies and private
     industry.

                                      -2-
<PAGE>

  Item 1.  Business (Cont'd)


  c) The capability to design, fabricate and erect many types of facilities and
     structures; services offered include research and design, material
     selection, preparation of detailed drawings, shop fabrication, field
     erection and subcontract management.

  d) The capability to fabricate and erect miscellaneous plate work which
     includes penstocks and breechings, stacks and stack liners, scrubbers,
     absorbers, flow conductors and heat exchangers for utilities and private
     industry.



  e) The capability to design, fabricate and erect high speed wind tunnels,
     altitude test chambers, hydrospace test facilities and high vacuum and
     thermal test facilities for use in connection with energy, aerospace and
     defense research.



  f) The capability to design and build supercritical fluid extraction
     facilities for the food processing industry.



  g) The capability to design and build anaerobic digesters for the wastewater
     treatment industry.



  h) The capability to fabricate and erect structural steel for commercial,
     institutional and public sector buildings for government agencies, private
     developers and general contractors.

  i) The capability to fabricate structural steel for new bridges and fabricate
     and erect structural steel for bridge rehabilitation for government
     agencies and general contractors.



Steel Distribution



The Company's Steel Distribution Segment operates seven steel service centers
and three culvert facilities located in the West and Midwest regions of the
United States.  On January 31, 1997, the Company acquired 90% of the capital
stock of General Steel Corporation, a steel service center facility, located in
Vancouver, Washington.  This acquisition will expand this segment's market area
into the Pacific Northwest.  The steel service centers process and distribute to
end users a general line of carbon steel products including plates, sheets,
structural shapes, bars, tubes, pipe and other miscellaneous metal products.
This segment also manufactures and markets to end users corrugated metal culvert
pipe and accessories.  The Steel Distribution's primary markets include steel
fabricators, original equipment manufacturers, mining, logging, agricultural and
road construction industries.


  The Company and the industry as a whole deem the maintenance of adequate
levels of inventory to be integral to the Steel Distribution business.  The
Company believes that it has adequate levels of inventory on hand to meet
current and anticipated customer demand.

                                      -3-
<PAGE>

Item 1.  Business (Cont'd)



Other


Several large companies compete nationally in some product lines with the
Company and there are several local and regional companies that compete in
certain product lines in specific geographic areas.  The majority of the
Company's business is secured through open competitive bidding or through direct
negotiations with industry or government agencies.  Competition is based
primarily on performance including the ability to provide design, engineering
and on-site field construction services in a cost-effective, timely manner.  The
Steel Distribution Segment's volume of business is based on the price, delivery,
credit terms, and first stage preprocessing of products, offered to its
customers as well as its reputation.



  The Company's earned revenue was $475 million in 1997, compared with $468
million in 1996 and $461 million in 1995.  For further financial information
refer to Consolidated Financial Statements contained in PDM's 1997 Annual Report
to Stockholders and incorporated herein by reference.



  The principal raw materials essential to the Company's business are steel,
alloys and other metal plates and structural sections.  The Company procures
these raw materials from various domestic and foreign sources including, the
mills of USX Corporation, Bethlehem Steel Corporation, Northwestern Steel and
Wire Company, Nucor Steel, British Steel and Mitsubishi International
Corporation.



  The Company has a license and technical assistance agreement with Roediger, a
German corporation, which gives the Company exclusive rights in North America
and other selected countries worldwide to use the Roediger technology, a process
which utilizes anaerobic digestion in the treatment of wastewater.  Revenues to
date from this technology have not been material to the Company.



  Some components of the other products made and erection techniques used by the
Company are covered by patents owned or licensed by the Company.  None of these
are deemed to be material to the Company from an overall financial viewpoint.



  The Company had a backlog of uncompleted contracts of $252 million on December
31, 1997 compared to $172 million on December 31, 1996.  Substantially all
backlog is expected to be completed during 1998.



  Factors such as the type and scope of operations in progress at any given
time, including weather conditions at field sites, create fluctuations in the
employment level at PDM.  On December 31, 1997, the Company employed 2,210
persons, of which 730 were salaried personnel and 1,480 were hourly personnel.



  Financial information for the Company's two business segments is included
in the Business Segment Information Section of PDM's 1997 Annual Report to
Stockholders, which section is incorporated herein by reference.

                                      -4-
<PAGE>

Item 2.  Properties



Operations of the Company are conducted at both owned and leased properties.  In
addition, certain owned properties of the Company are leased to third party
tenants.  The following table indicates each of the Company's facilities by:
segment, location, type of facility, year operations began, and square footage
of property owned or leased on December 31, 1997:

<TABLE>
<CAPTION>
                                                                               YEAR
                                                 TYPE OF                    OPERATIONS         SQUARE
  LOCATION                                       FACILITY                      BEGAN           FOOTAGE
<S>                                    <C>                                  <C>                <C>
ENGINEERING AND CONSTRUCTION
----------------------------
Harpersville, Alabama                      Warehouse and office             1996                11,500
Eloy, Arizona                               Fabrication plant               1998               108,450
Fresno, California                              Toolhouse                   1963                52,140
Stockton, California                   Fabrication plant and office         1987               143,000
Tustin, California                                Office                    1996                   185
Palatka, Florida                       Fabrication plant and office         1997               130,262
Clive, Iowa                            Fabrication plant and office         1955               176,540
Des Moines, Iowa                                Toolhouse                   1900                29,000
Pittsburgh, Pennsylvania                   Office and toolhouse             1927                98,780
Warren, Pennsylvania                        Fabrication plant               1959               125,960
Franklin, Tennessee                             Toolhouse                   1977                28,220
Conroe, Texas (1)                                 Office                    1996                 1,600
Hitchcock, Texas (2)                            Toolhouse                   1994                 5,000
The Woodlands, Texas (3)                          Office                    1996                19,300
Provo, Utah                                 Fabrication plant               1959               154,950
Eau Claire, Wisconsin                  Fabrication plant and office         1994               309,500
Wausau, Wisconsin                      Fabrication plant and office         1991               157,000
Port Coquitlam, B.C. Canada (4)                   Office                    1997                12,300
Trenton, Ontario, Canada (5)                      Office                    1997                   800

STEEL DISTRIBUTION
---------------------------------

Fresno, California                         Warehouse and office             1955               112,800
Santa Clara, California                    Warehouse and office             1947               108,530
Stockton, California                       Warehouse and office             1967               191,500
Cedar Rapids, Iowa                         Warehouse and office             1976                66,800
Sparks, Nevada                             Warehouse and office             1974                78,940
Tualatin, Oregon                           Warehouse and office             1973                31,620
Spanish Fork, Utah                         Warehouse and office             1977                74,280
Arlington, Washington (6)                  Warehouse and office             1993                13,970
Vancouver, Washington (7)                  Warehouse and office             1997               138,600

 </TABLE>


                                      -5-
<PAGE>

Item 2.  Properties (Cont'd)

<TABLE>
<CAPTION>
                                                                               YEAR
                                                 TYPE OF                    OPERATIONS         SQUARE
  LOCATION                                       FACILITY                      BEGAN           FOOTAGE
<S>                                    <C>                                  <C>                <C>
IDLE HOLDINGS, INCLUDING PLANT AND PROPERTY (8)
-----------------------------------------------
Sacramento, California                            Land                      1966                    --
Chicago, Illinois                      Fabrication plant and office         1987               520,800
Des Moines, Iowa                       Fabrication plant and office         1900               339,100
Hilliard, Ohio                         Fabrication plant and office         1971               179,000
Pittsburgh, Pennsylvania                          Office                    1927                10,234
Provo, Utah (9)                                   Office                    1959                15,731
</TABLE>
__________

(1) Company leases building from outside third party.  Lease will expire
    October 1, 1998.
(2) Company leases land and building from outside third party.  Lease will
    expire July 1, 1999.
(3) Company leases building from outside third party.  Lease will expire
    August 31, 2006.
(4) Company leases building from outside third party.  Lease will expire
    November 30, 2002.
(5) Company leases building from outside third party.  Lease is month-to
    month.
(6) Company leases land from outside third party.  Lease will expire January
    31, 2003.
(7) Company leases land and building from outside third party.  Lease will
    expire September 1, 1999.
(8) Company pursues the sale or development of all idle facilities and
    regularly evaluates similar opportunities for facilities not fully utilized.
(9) Company is leasing facility to outside third party.



  The properties listed above are utilized by the Company's business segments as
indicated.  The Company's production capacity is adequate for its present needs.
The Company believes that its properties have been adequately maintained, are
generally in good condition and are suitable for the Company's business as now
conducted.




Item 3.  Legal Proceedings

See Contingencies note accompanying the consolidated financial statements
contained in PDM's 1997 Annual Report to Stockholders, which note is
incorporated herein by reference, except that the fourth paragraph of such note
is amended as follows:


  In an order dated October 28, 1997 the District Court denied the Company's
post-trial motions in the OSHA Criminal Proceeding. A sentencing hearing was
held on March 20, 1998 and the Company was fined $1,000,250. Such fine was paid
on March 27, 1998. The Company has filed an appeal with the United States Court
of Appeals for the Seventh Circuit.

                                      -6-
<PAGE>

  On May 14, 1996 the Company filed an action in the United States District
Court for the Northern District of Illinois (Eastern Division) captioned PITT-
DES MOINES, INC. V. METROPOLITAN PIER & EXPOSITION AUTHORITY ET AL. seeking
reimbursement in excess of $15.0 million for additional work and making other
claims in connection with this matter.  On June 4, 1996, certain of the
defendants in said action made counterclaims against the Company in amounts
approximating $3.5 million.  While counsel believes that the Company has a basis
for the claim, neither management nor counsel is able to predict with certainty
the ultimate resolution of this matter.  As additional information becomes
available, the Company may revise its estimate of potential recovery, which
could result in a material adjustment to the results of operations in future
periods.



Item 4.  Submission of Matters to a Vote of Security Holders


  Not applicable


Executive Officers of the Registrant


  Information regarding executive officers of the Registrant is presented in
Part III of this report and is incorporated herein by reference.

                                      -7-
<PAGE>

                                  PART II



Information for Items 5, 6 and 7 is included in PDM's 1997 Annual Report to
Stockholders and is incorporated herein by reference (and except for these
sections, and sections incorporated herein by reference in Items 1 and 8 of this
report, PDM's Annual Report to Stockholders is not deemed to be filed as part of
this report):

                                                       ANNUAL REPORT
                                                       TO STOCKHOLDERS
ITEM NO.    TITLE                                      SECTION/TITLE
-------------------------------------------------------------------------------
Item 5.     Market for Registrant's Common Equity      Common Stock Information
            and Related Stockholder Matters            included in Stockholders'
                                                       Reference section

Item 6.     Selected Financial Data                    Five-Year Selected
                                                       Financial Data

Item 7.     Management's Discussion and Analysis       Management's Discussion
            of Financial Condition and Results of      and Analysis
            Operations

Item 8.     Financial Statements and Supplemental Data

The financial statements consisting of Consolidated Statements of Income,
Consolidated Statements of Financial Condition, Consolidated Statements of Cash
Flows, Consolidated Statements of Stockholders' Equity, Notes to Consolidated
Financial Statements, and Business Segment Information are included in the
Consolidated Financial Statements section of PDM's 1997 Annual Report to
Stockholders, which is incorporated herein by reference.  The report of
independent auditors on PDM's consolidated financial statements is contained in
the Report of Independent Auditors and Management section of PDM's 1997 Annual
Report to Stockholders, which is incorporated herein by reference.

  The unaudited Two Year Quarterly Results of Operations contained in PDM's 1997
Annual Report to Stockholders is incorporated herein by reference.


Item 9. Changes in and Disagreements With Accountants on Accounting and
        Financial Disclosure



  Not applicable

                                      -8-
<PAGE>

                                 PART III


Item 10.  Directors and Executive Officers of the Registrant (1)


  Regarding the directors of the Registrant, reference is made to the
information set forth under the caption "Election of Directors" in the Company's
definitive Proxy Statement anticipated to be dated March 31, 1998 (the "Proxy
Statement") which information is incorporated herein by reference.



  The principal executive officers of the Company and their recent business
experience are as follows:


W. R. Jackson, age 89


  Director since 1940;

  Chairman Emeritus since 1988; formerly Chairman of the Board since 1971.
  Mr. Jackson has been with the Company since 1936 and is the father of Mr.
Jackson, Jr. and   Mrs. Townsend.


P. O. Elbert, age 67


  Director since 1988;

  Chairman of the Board of the Company since 1990; formerly President of the
  Company since 1988 and President, PDM Structural Group since 1987.  Mr. Elbert
  joined the Company in 1987.  Prior to 1987, Mr. Elbert was Vice Chairman of
  Chicago Steel Corporation since 1986; formerly a partner of Elbert and McKee
  Company since 1984; formerly President and Chief Executive Officer of Flint
  Steel Corporation since 1979; and formerly Group Vice President of Inryco,
  Inc., a subsidiary of Inland Steel Company since 1969.


Wm. W. McKee, age 59 (2)


  Director since 1988;

  President and Chief Executive Officer of the Company since 1990; formerly
  President, PDM Plate Group since May 1987 and formerly Executive Vice
  President, PDM Structural Group since April 1987.  Mr. McKee joined the
  Company in 1987.  Prior to 1987, Mr. McKee was Secretary of Chicago Steel
  Corporation since 1986; formerly a partner of Elbert and McKee Company since
  1984; formerly a consultant with McKee and Associates since 1983; formerly
  President of Hogan Manufacturing since 1980; and formerly President of Herrick
  Corporation since 1973.



R. A. Byers, age 50 (2)


  Treasurer since 1988 and Vice President, Finance and Administration since
  1987; formerly Vice President, Finance since 1984; formerly Controller since
  1982; formerly Assistant Controller since 1981; formerly Manager of Financial
  Reporting since 1979; and formerly with Ernst & Young LLP for ten years.

                                      -9-
<PAGE>

Item 10.  Directors and Executive Officers of the Registrant (Cont'd)

T. R. Lloyd, age 49 (2)


  Secretary and General Counsel since 1990; formerly Senior Attorney of Buchanan
  Ingersoll Professional Corporation, since 1989; formerly Vice President,
  Secretary and General Counsel for Arch Mineral Corporation since 1984; and
  formerly Director and Secretary of U.S. Steel Mining Co., Inc. since 1979.

____________________
(1)   Except where otherwise indicated, all references are to positions held
      with Pitt-Des Moines, Inc.  Each executive officer of the Company is
      elected annually by the Board of Directors until his successor is elected
      and qualified, and each has served continually as an officer since first
      elected.

(2)   The Company has agreements with each of Messrs. McKee, Byers and Lloyd
      covering, among other things, their positions as executive officers of the
      Company after a change of control.


Item 11.  Executive Compensation


  Reference is made to the information set forth under the captions "Board of
Directors and Committees of the Board," "Executive Compensation and Other
Information," and "Compensation Committee Interlocks and Insider Participation"
appearing in the Company's Proxy Statement, which information is incorporated
herein by reference; provided, however, that the information set forth under the
captions "Compensation Committee Report on Executive Compensation" and
"Performance Graph" in the Proxy Statement shall not be deemed to be soliciting
material or to be "filed" with the Commission or subject to Regulation 14A or
14C (other than as provided in Item 402 of Regulation S-K) or to the liabilities
of Section 18 of the Securities Exchange Act of 1934, as amended.


Item 12.  Security Ownership of Certain Beneficial Owners and Management


  Reference is made to the information contained under the captions
"Stockholdings of Management" and "Principal Holders of Common Stock" in the
Company's Proxy Statement, which information is incorporated herein by
reference.


Item 13.  Certain Relationships and Related Transactions


  Reference is made to the information contained under the caption "Compensation
Committee Interlocks and Insider Participation" in the Company's Proxy Statement
which information is incorporated herein by reference.

                                      -10-
<PAGE>

                                    PART IV


Item 14. Exhibits, Financial Statement Schedules and Reports on Form 8-K


(a) 1.   Financial Statements


         The following consolidated financial statements and Report of
         Independent Auditors previously incorporated by reference in Part II,
         Item 8 of this report are incorporated herein by reference:



         Report of Independent Auditors



         Consolidated Statements of Income -- Years Ended December 31, 1997,
         1996 and 1995



         Consolidated Statements of Financial Condition as of December 31, 1997
         and 1996



         Consolidated Statements of Cash Flows -- Years Ended December 31, 1997,
         1996 and 1995



         Consolidated Statements of Stockholders' Equity -- Years Ended December
         31, 1997, 1996 and 1995



         Notes To Consolidated Financial Statements


  2.     Financial Statement Schedules


         The following consolidated financial statement schedule of Pitt-Des
         Moines, Inc. and subsidiaries is included in Item 14(d):



         Schedule II. Valuation and Qualifying Accounts for years ended December
         31, 1997, 1996 and 1995



         All other schedules are omitted because they are not applicable or the
         required information is shown in the consolidated financial statements
         or notes thereto.


  3.     Exhibits:


  3.1    Articles of Incorporation, as amended to date (filed as Exhibit 3.1 to
         the Company's quarterly report on Form 10-Q for the quarter ended
         September 30, 1989 and incorporated herein by reference)



  3.2    Bylaws, as amended to date (filed as Exhibit 3.2 to the Company's
         quarterly report on Form 10-Q for the quarter ended September 30, 1989
         and incorporated herein by reference)

                                      -11-
<PAGE>

Item 14.  Exhibits, Financial Statement Schedules and Reports on Form 8-K
(Cont'd)


  4.1    Amended and Restated Credit Agreement dated as of June 30, 1992 by and
         among Pitt-Des Moines, Inc. and Pittsburgh National Bank, Wells Fargo
         Bank, N.A. and American National Bank (filed as Exhibit 4.1 to the
         Company's annual report on Form 10-K for the year ended December 31,
         1992 and incorporated herein by reference)



  4.2    First Amendment dated November 23, 1992 to Credit Agreement filed as
         Exhibit 4.1 hereto (filed as Exhibit 4.2 to the Company's annual report
         on Form 10-K for the year ended December 31, 1992 and incorporated
         herein by reference)



  4.3    Second Amendment dated June 10, 1993 to Credit Agreement filed as
         Exhibit 4.1 hereto (filed as Exhibit 4.1 to the Company's quarterly
         report on Form 10-Q for the quarter ended June 30, 1992 and
         incorporated herein by reference)



  4.4    Third Amendment dated December 16, 1993 to Credit Agreement filed as
         Exhibit 4.1 hereto (filed as Exhibit 4.2 to the Company's annual report
         on Form 10-K for the year ended December 31, 1993 and incorporated
         herein by reference)



  4.5    Fourth Amendment dated June 14, 1994 to Credit Agreement filed as
         Exhibit 4.1 hereto (filed as Exhibit 4.1 to the Company's quarterly
         report on Form 10-Q for the quarter ended June 30, 1994 and
         incorporated herein by reference)



  4.6    Fifth Amendment dated December 8, 1994 to Credit Agreement filed as
         Exhibit 4.1 hereto (filed as Exhibit 4.6 to the Company's annual report
         on Form 10-K for the year ended December 31, 1994 and incorporated
         herein by reference)



  4.7    Sixth Amendment dated May 31, 1995 to Credit Agreement filed as Exhibit
         4.1 hereto (filed as Exhibit 4.1 to the Company's quarterly report on
         Form 10-Q for the quarter ended June 30, 1995 and incorporated herein
         by reference)



  4.8    Seventh Amendment dated June 30, 1996 to Credit Agreement filed as
         Exhibit 4.1 hereto (filed as Exhibit 4.1 to the Company's quarterly
         report on Form 10-Q for the quarter ended June 30, 1996 and
         incorporated herein by reference)


  4.9    Eighth Amendment dated June 30, 1997 to Credit Agreement filed as
         Exhibit 4.1 hereto (filed as Exhibit 4.1 to the Company's quarterly
         report on Form 10-Q for the quarter ended June 30, 1997 and
         incorporated herein by reference)


  10.1*  Agreement executed by and between the Company and Wm. W. McKee (filed
         as Exhibit 10.1 to the Company's annual report on Form 10-K for the
         year ended December 31, 1990 and incorporated herein by reference)


  10.2*  Amendment to agreement executed by and between the Company and Wm. W.
         McKee filed as Exhibit 10.1 hereto (filed herewith)

                                      -12-
<PAGE>

Item 14.  Exhibits, Financial Statement Schedules and Reports on Form 8-K
(Cont'd)


  10.3*  Agreement executed by and between the Company and R. A. Byers (filed as
         Exhibit 10.1 to the Company's quarterly report on Form 10-Q for the
         quarter ended June 30, 1991 and incorporated herein by reference)



  10.4*  Amendment to agreement executed by and between the Company and R. A.
         Byers filed as Exhibit 10.3 hereto (filed herewith)


  10.5*  Agreement executed by and between the Company and T. R. Lloyd (filed as
         Exhibit 10.2 to the Company's quarterly report on Form 10-Q for the
         quarter ended June 30, 1991 and incorporated herein by reference)



  10.6*  Amendment to agreement executed by and between the Company and T. R.
         Lloyd filed as Exhibit 10.5 hereto (field herewith)



  10.7*  Management Incentive Plan (filed as Exhibit 10.5 to the Company's
         annual report on Form 10-K for the year ended December 31, 1992 and
         incorporated herein by reference)



  10.8*  Summary of Company 1997 Management Incentive Plan (MIP) (filed
         herewith)



  10.9*  Retirement Plan for PDM Outside Directors as amended, effective May 26,
         1994 (filed as Exhibit 10.7 to the Company's annual report on Form 10-K
         for the year ended December 31, 1994 and incorporated herein by
         reference)



  10.10* Retirement Plan for PDM Outside Directors, effective May 26, 1994,
         as amended on September 14, 1995 (filed as Exhibit 10.7 to the
         Company's annual report on Form 10-K for the year ended December 31,
         1995 and incorporated herein by reference)



  10.11* Stock Option Plan of 1990 (filed as Exhibit 4.01 to the Company's
         Registration Statement No. 33-34787 on Form S-8 filed May 7, 1990 and
         incorporated herein by reference)



  10.12* Investment Letter and Registration Rights Agreement dated September 21,
         1993 by and between Pitt-Des Moines, Inc. and William W. McKee, Jr.
         (filed as Exhibit 10.1 to the Company's quarterly report on Form 10-Q
         for the quarter ended September 30, 1993 and incorporated herein by
         reference)



  10.13* Amendment to Investment Letter and Registration Rights Agreement dated
         September 21, 1993 by and between Pitt-Des Moines, Inc. and William W.
         McKee, Jr. filed as Exhibit 10.12 hereto (filed herewith)

                                      -13-
<PAGE>

Item 14.  Exhibits, Financial Statement Schedules and Reports on Form 8-K
(Cont'd)

  10.14* Investment Letter and Registration Rights Agreement dated September 21,
         1993 by and between Pitt-Des Moines, Inc. and Phillip O. Elbert (filed
         as Exhibit 10.2 to the Company's quarterly report on Form 10-Q for the
         quarter ended September 30, 1993 and incorporated herein by reference)


  10.15* Amendment to Investment Letter and Registration Rights Agreement dated
         September 21, 1993 by and between Pitt-Des Moines, Inc. and P. O.
         Elbert filed as Exhibit 10.14 hereto (filed herewith)


  10.16* Directors Stock Plan (filed under the Company's Registration Statement
         No. 333-13043 on Form S-8 dated September 30, 1996 and incorporated
         herein by reference)



  10.17* Stock Option Agreement executed by and between the Company and P. O.
         Elbert (filed as Exhibit 10.12 to the Company's annual report on Form
         10-K for the year ended December 31, 1996 and incorporated herein by
         reference)

  10.18* Amendment to Stock Option Agreement executed by and between the Company
         and P. O. Elbert filed as Exhibit 10.17 hereto (filed herewith)


  10.19* Supplemental Benefit and Supplemental Salaried Retirement Plan (filed
         herewith)


  13     Those portions of the Annual Report to Stockholders for fiscal year
         ended December 31, 1997, which are incorporated herein by reference
         (filed herewith)


  21     Subsidiaries of Pitt-Des Moines, Inc. (filed herewith)


  23     Consent of Independent Auditors, Ernst & Young LLP (filed herewith)


  27.1   Current FDS for year ended December 31, 997


  27.2   Restated FDS including columns for the prior three periods ended (March
         31, 1997, June 30, 1997, September 30, 1997) and prior year end
         (December 31, 1996)


  27.3   Restated FDS including columns for the prior three periods ended (March
         31, 1996, June 30, 1996, September 30, 1996) and prior year end
         (December 31, 1995)

(b)   Reports on Form 8-K:

      A Form 8-K dated October 7, 1997 (Item 5 Other Events), was filed to
      report the acquisition of Sheffield Steel Products, a bridge fabricator
      located in Palatka, Florida.


------------------------
* Denotes management contract or compensatory plan or arrangement.

                                      -14-
<PAGE>

                                   Signatures



  Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange
Act of 1934, the registrant has duly caused this report to be signed on its
behalf by the undersigned, thereunto duly authorized.



                             PITT-DES MOINES, INC.



March 27, 1998                                   By:    /s/  Wm. W. McKee
                                                    ----------------------------
                                                          Wm. W. McKee
                                                          President and
                                                      Chief Executive Officer


   Pursuant to the requirements of the Securities Exchange Act of 1934, this
report has been signed below by the following persons on behalf of the
Registrant and in the capacities and on the dates indicated.


  Signatures                             Title                       Date

Principal Executive Officer:

 /s/ Wm. W. McKee                     President, Chief            March 27, 1998
------------------------------------  Executive Officer and
     Wm. W. McKee                     Director


Principal Financial and Accounting Officer:


 /s/ R. A. Byers                      Chief Financial Officer     March 27, 1998
------------------------------------  and Chief Accounting
     R. A. Byers                      Officer


Other Directors:

 /s/ J. C. Bates                      Director                    March 27, 1998
------------------------------------
     J. C. Bates


/s/  V. G. Beghini                    Director                    March 27, 1998
------------------------------------
     V. G. Beghini

                                      -15-
<PAGE>

                                 Signatures (Cont'd)


  Signatures                             Title                       Date

/s/ R. W. Dean                        Director                    March 27, 1998
------------------------------------
    R. W. Dean


/s/ P. O. Elbert                      Director                    March 27, 1998
------------------------------------
    P. O. Elbert


/s/ W. R. Jackson                     Director                    March 27, 1998
------------------------------------
    W. R. Jackson


/s/ W. R. Jackson, Jr.                Director                    March 27, 1998
------------------------------------
    W. R. Jackson, Jr.


/s/ W. E. Lewellen                    Director                    March 27, 1998
------------------------------------
    W. E. Lewellen


/s/ A. J. Paddock                     Director                    March 27, 1998
------------------------------------
    A. J. Paddock


/s/ J. W. Robinson                    Director                    March 27, 1998
------------------------------------
    J. W. Robinson


/s/ P. J. Townsend                    Director                    March 27, 1998
------------------------------------
    P. J. Townsend

                                      -16-
<PAGE>

                SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS
                             Pitt-Des Moines, Inc.



<TABLE>
<CAPTION>
                                                          Additions  Deductions(1)
                                                          ---------  -------------
                                             Balance at   Charged to
                                            Beginning of  Costs and   Credited    Balance at End
   Description                                 Period      Expenses   to Asset      of Period
-----------------------------------         ------------  ----------  --------    --------------
<S>                                         <C>           <C>         <C>         <C>
Deducted from accounts receivable
as allowance for doubtful accounts:

Year ended December 31, 1997                $868,000      $363,233    $172,509    $1,058,724


Year ended December 31, 1996                $868,000      $ 90,000    $ 90,000    $  868,000


Year ended December 31, 1995                $923,000      $220,000    $275,000    $  868,000
</TABLE>


---------------------
(1)  Write-off of accounts deemed to be uncollectible
<PAGE>

                                 EXHIBIT INDEX




  3.1    Articles of Incorporation, as amended to date (filed as Exhibit 3.1 to
         the Company's quarterly report on Form 10-Q for the quarter ended
         September 30, 1989 and incorporated herein by reference)



  3.2    Bylaws, as amended to date (filed as Exhibit 3.2 to the Company's
         quarterly report on Form 10-Q for the quarter ended September 30, 1989
         and incorporated herein by reference)



  4.1    Amended and Restated Credit Agreement dated as of June 30, 1992 by and
         among Pitt-Des Moines, Inc. and Pittsburgh National Bank, Wells Fargo
         Bank, N.A. and American National Bank (filed as Exhibit 4.1 to the
         Company's annual report on Form 10-K for the year ended December 31,
         1992 and incorporated herein by reference)



  4.2    First Amendment dated November 23, 1992 to Credit Agreement filed as
         Exhibit 4.1 hereto (filed as Exhibit 4.2 to the Company's annual report
         on Form 10-K for the year ended December 31, 1992 and incorporated
         herein by reference)



  4.3    Second Amendment dated June 10, 1993 to Credit Agreement filed as
         Exhibit 4.1 hereto (filed as Exhibit 4.1 to the Company's quarterly
         report on Form 10-Q for the quarter ended June 30, 1992 and
         incorporated herein by reference)



  4.4    Third Amendment dated December 16, 1993 to Credit Agreement filed as
         Exhibit 4.1 hereto (filed as Exhibit 4.2 to the Company's annual report
         on Form 10-K for the year ended December 31, 1993 and incorporated
         herein by reference)



  4.5    Fourth Amendment dated June 14, 1994 to Credit Agreement filed as
         Exhibit 4.1 hereto (filed as Exhibit 4.1 to the Company's quarterly
         report on Form 10-Q for the quarter ended June 30, 1994 and
         incorporated herein by reference)



  4.6    Fifth Amendment dated December 8, 1994 to Credit Agreement filed as
         Exhibit 4.1 hereto (filed as Exhibit 4.6 to the Company's annual report
         on Form 10-K for the year ended December 31, 1994 and incorporated
         herein by reference)



  4.7    Sixth Amendment dated May 31, 1995 to Credit Agreement filed as Exhibit
         4.1 hereto (filed as Exhibit 4.1 to the Company's quarterly report on
         Form 10-Q for the quarter ended June 30, 1995 and incorporated herein
         by reference)



  4.8    Seventh Amendment dated June 30, 1996 to Credit Agreement filed as
         Exhibit 4.1 hereto (filed as Exhibit 4.1 to the Company's quarterly
         report on Form 10-Q for the quarter ended June 30, 1996 and
         incorporated herein by reference)



<PAGE>

                            EXHIBIT INDEX  (Cont'd)



  4.9    Eighth Amendment dated June 30, 1997 to Credit Agreement filed as
         Exhibit 4.1 hereto (filed as Exhibit 4.1 to the Company's quarterly
         report on Form 10-Q for the quarter ended June 30, 1997 and
         incorporated herein by reference)

  10.1   Agreement executed by and between the Company and Wm. W. McKee (filed
         as Exhibit 10.1 to the Company's annual report on Form 10-K for the
         year ended December 31, 1990 and incorporated herein by reference)



  10.2   Amendment to agreement executed by and between the Company and Wm. W.
         McKee filed as Exhibit 10.1 hereto (filed herewith)



  10.3   Agreement executed by and between the Company and R. A. Byers (filed as
         Exhibit 10.1 to the Company's quarterly report on Form 10-Q for the
         quarter ended June 30, 1991 and incorporated herein by reference)



  10.4   Amendment to agreement executed by and between the Company and R. A.
         Byers filed as Exhibit 10.3 hereto (filed herewith)


  10.5   Agreement executed by and between the Company and T. R. Lloyd (filed as
         Exhibit 10.2 to the Company's quarterly report on Form 10-Q for the
         quarter ended June 30, 1991 and incorporated herein by reference)



  10.6   Amendment to agreement executed by and between the Company and T. R.
         Lloyd filed as Exhibit 10.5 hereto (field herewith)


  10.7   Management Incentive Plan (filed as Exhibit 10.5 to the Company's
         annual report on Form 10-K for the year ended December 31, 1992 and
         incorporated herein by reference)



  10.8   Summary of Company 1997 Management Incentive Plan (MIP) (filed
         herewith)



  10.9   Retirement Plan for PDM Outside Directors as amended, effective May 26,
         1994 (filed as Exhibit 10.7 to the Company's annual report on Form 10-K
         for the year ended December 31, 1994 and incorporated herein by
         reference)



  10.10  Retirement Plan for PDM Outside Directors, effective May 26, 1994,
         as amended on September 14, 1995 (filed as Exhibit 10.7 to the
         Company's annual report on Form 10-K for the year ended December 31,
         1995 and incorporated herein by reference)



  10.11  Stock Option Plan of 1990 (filed as Exhibit 4.01 to the Company's
         Registration Statement No. 33-34787 on Form S-8 filed May 7, 1990 and
         incorporated herein by reference)
<PAGE>

                             EXHIBIT INDEX (Cont'd)



  10.12  Investment Letter and Registration Rights Agreement dated September 21,
         1993 by and between Pitt-Des Moines, Inc. and William W. McKee, Jr.
         (filed as Exhibit 10.1 to the Company's quarterly report on Form 10-Q
         for the quarter ended September 30, 1993 and incorporated herein by
         reference)



  10.13  Amendment to Investment Letter and Registration Rights Agreement dated
         September 21, 1993 by and between Pitt-Des Moines, Inc. and William W.
         McKee, Jr. filed as Exhibit 10.12 hereto (filed herewith)



  10.14  Investment Letter and Registration Rights Agreement dated September 21,
         1993 by and between Pitt-Des Moines, Inc. and Phillip O. Elbert (filed
         as Exhibit 10.2 to the Company's quarterly report on Form 10-Q for the
         quarter ended September 30, 1993 and incorporated herein by reference)


  10.15  Amendment to Investment Letter and Registration Rights Agreement dated
         September 21, 1993 by and between Pitt-Des Moines, Inc. and P. O.
         Elbert filed as Exhibit 10.14 hereto (filed herewith)


  10.16  Directors Stock Plan (filed under the Company's Registration Statement
         No. 333-13043 on Form S-8 dated September 30, 1996 and incorporated
         herein by reference)



  10.17  Stock Option Agreement executed by and between the Company and P. O.
         Elbert (filed as Exhibit 10.12 to the Company's annual report on Form
         10-K for the year
         ended December 31, 1996 and incorporated herein by reference)

  10.18  Amendment to Stock Option Agreement executed by and between the Company
         and P. O. Elbert filed as Exhibit 10.17 hereto (filed herewith)


  10.19  Supplemental Benefit and Supplemental Salaried Retirement Plan (filed
         herewith)


  13     Those portions of the Annual Report to Stockholders for fiscal year
         ended December 31, 1997, which are incorporated herein by reference
         (filed herewith)


  21     Subsidiaries of Pitt-Des Moines, Inc. (filed herewith)



  23     Consent of Independent Auditors, Ernst & Young LLP (filed herewith)



  27.1   Current FDS for year ended December 31, 1997



  27.2   Restated FDS including columns for the prior three periods ended
         (March 31, 1997, June 30, 1997, September 30, 1997) and prior year end
         (December 31, 1996)



  27.3   Restated FDS including columns for the prior three periods ended
         (March 31, 1996, June 30, 1996, September 30, 1996) and prior year end
         (December 31, 1995)