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

                                  SCHEDULE 13D

                    Under the Securities Exchange Act of 1934


                           Allis-Chalmers Corporation
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                                (Name of Issuer)

                                  Common Stock
--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                    019645407
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                                 (CUSIP Number)

                              Joseph P. Bartlett, Esq.
                       Spolin Silverman Cohen & Bartlett LLP
                         1620 26th Street, Suite 2000 North
                           Santa Monica, California 90404
                                   (310) 586 - 2400
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           (Name, Address and Telephone Number of Person Authorized to
                      Receive Notices and Communications)

                                May 9, 2001
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             (Date of Event which Requires Filing of this Statement)

If the Reporting Person has previously filed a statement on Schedule 13G to
report the acquisition that is the subject of this Schedule 13D, and is filing
this schedule because of ss.ss. 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g),
check the following box |_|

NOTE: Schedules filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. See (Section) 240.13d-7(b) for
other parties to whom copies are to be sent.

* The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).



CUSIP No.  019645407                                                Page No:  3



(1)       Name of Reporting Person
          S.S. or I.R.S. Identification No. of Above Person

          Colebrooke Investments Limited

(2)       Check the Appropriate Box if a
          Member of a Group (See Instructions)             (A)  | |
                                                           (B)  |X|

(3)       SEC Use Only


(4)       Source of Funds (See Instructions)

          See Item 3.

(5)       Check if Disclosure of Legal Proceedings is Required Pursuant to Items
            2(d) or 2(e)                                                |_|


(6)       Citizenship or Place of Organization

          Guernsey

---------------------------- (7)      Sole Voting Power
                                      3,200,000 See Item 5
Number of Shares
Beneficially Owned           (8)      Shared Voting Power
by Each Reporting                     175,000   See Item 5
Person With
                             (9)      Sole Dispositive Power
                                      3,375,000 See Item 5

                             (10)     Shared Dispositive Power
                                      0
----------------------------

(11)      Aggregate Amount Beneficially Owned by Each Reporting Person
          9,992,351  See Item 5

(12)      Check if the Aggregate Amount in Row (11)
          Excludes Certain Shares (See Instructions)                      |_|

(13)      Percent of Class Represented by Amount in Row (11)
          86.2%  See Item 5

(14)      Type of Reporting Person (See Instructions)
          OO



CUSIP No.  019645407 CUSIP No.  019645407                            Page No: 4


(1)       Name of Reporting Person
          S.S. or I.R.S. Identification No. of Above Person

          Jupiter Trust

(2)       Check the Appropriate Box if a
          Member of a Group (See Instructions)             (A)  | |
                                                           (B)  |X|

(3)       SEC Use Only


(4)       Source of Funds (See Instructions)

          See Item 3.

(5)       Check if Disclosure of Legal Proceedings is Required Pursuant to Items
            2(d) or 2(e)                                                |_|


(6)       Citizenship or Place of Organization

          Guernsey

---------------------------- (7)      Sole Voting Power
                                      3,200,000 See Item 5
Number of Shares
Beneficially Owned           (8)      Shared Voting Power
by Each Reporting                     175,000   See Item 5
Person With
                             (9)      Sole Dispositive Power
                                      3,375,000 See Item 5

                             (10)     Shared Dispositive Power
                                      0
----------------------------

(11)      Aggregate Amount Beneficially Owned by Each Reporting Person
          9,992,351  See Item 5

(12)      Check if the Aggregate Amount in Row (11)
          Excludes Certain Shares (See Instructions)                      |_|

(13)      Percent of Class Represented by Amount in Row (11)
          86.2%  See Item 5

(14)      Type of Reporting Person (See Instructions)
          OO



CUSIP No. 019645407               SCHEDULE 13D                       Page No: 5



(1)       Name of Reporting Person
          S.S. or I.R.S. Identification No. of Above Person

          Ansbacher Trust Company

(2)       Check the Appropriate Box if a
          Member of a Group (See Instructions)             (A)  | |
                                                           (B)  |X|

(3)       SEC Use Only


(4)       Source of Funds (See Instructions)

          See Item 3.

(5)       Check if Disclosure of Legal Proceedings is Required Pursuant to Items
            2(d) or 2(e)                                                |_|


(6)       Citizenship or Place of Organization

          Guernsey

---------------------------- (7)      Sole Voting Power
                                      3,200,000 See Item 5
Number of Shares
Beneficially Owned           (8)      Shared Voting Power
by Each Reporting                     175,000   See Item 5
Person With
                             (9)      Sole Dispositive Power
                                      3,375,000 See Item 5

                             (10)     Shared Dispositive Power
                                      0
----------------------------

(11)      Aggregate Amount Beneficially Owned by Each Reporting Person
          9,992,351  See Item 5

(12)      Check if the Aggregate Amount in Row (11)
          Excludes Certain Shares (See Instructions)                      |_|

(13)      Percent of Class Represented by Amount in Row (11)
          86.2%  See Item 5

(14)      Type of Reporting Person (See Instructions)
          OO




CUSIP No. 019645407               SCHEDULE 13D                        Page No: 6



Item 1.  Security and Issuer


      The Schedule 13D is filed with the Securities and Exchange Commission (the
"Commission") on May 21, 2001 with respect to shares of common stock of
Allis-Chalmers Corporation ("Issuer").


         Allis-Chalmers Corporation
         4180 Cherokee Drive
         Milwaukee, Wisconsin 53045

Item 2.  Identity and Background

      The name and business address of each Reporting Person is as follows:

                  Colebrooke Investments Limited
                  P.O. Box 79, La Plaiderie House
                  St. Peter Port, Guernsey GY13DQ

                  Jupiter Trust
                  P.O. Box 79, La Plaiderie House
                  St. Peter Port, Guernsey GY13DQ

                  Ansbacher Trust Company
                  PO Box 79, La Plaiderie House
                  St. Peter Port, Guernsey GY13DQ


      The principal business of each Reporting Person is as follows:

      Colebrooke Investments Limited ("Colebrooke") is a limited company
organized under the laws of Guernsey. The principal business of Colebrooke is to
invest in securiteies. Current information regarding the identity and background
of the director of Colebrooke is set forth in Annex A hereto, which is
incorporated by reference herein in response to this Item 2. Jupiter Trust and
the Ansbacher Trust Company are trusts organized under the laws of Guernsey.

      The Reporting Persons disclaim beneficial ownership of the Securities
reported as beneficially owned by the Reporting Persons herein other than the
securities owned directly by such persons.

      None of the Reporting Persons and none of the partners, directors,
executive officers or stockholders of the Reporting Persons has, during the last
five years, (i) been convicted in a criminal proceeding (excluding traffic
violations or similar misdemeanors) or (ii) been a party to a civil proceeding
of a judicial or administrative body of competent jurisdiction and as a result
of such proceeding was or is subject to a judgment, decree or final order
enjoining future violations of, or prohibiting activities subject to, federal or
state securities laws or finding any violation of such laws.



CUSIP No. 019645407                                                  Page No: 7


Item 3.  Source and Amount of Funds or Other Consideration


           The Reporting Persons acquired their interest in the common stock of
           the Issuer (the "Common Stock") pursuant to the terms of an Agreement
           and Plan of Merger dated May 9, 2001, a copy of which is attached as
           Exhibit "1" hereto (the "Merger Agreement").


Item 4.  Purpose of Transaction


                  On May 9, 2001, OilQuip Rentals, Inc., a Delaware Corporation
           ("OilQuip"), was merged with and into Allis-Chalmers Acquisitions
           Co., a Delaware Corporation, and a wholly owned subsidiary of the
           Issuer (the "Merger"). The purpose of the Merger was to combine the
           operations of OilQuip and the Issuer. OilQuip, through its subsidiary
           Mountain Compressed Air, Inc., provides air drilling services for the
           exploration and production of natural gas in the United States. Prior
           to the Merger, the Issuer operated one active subsidiary, Houston
           Dynamic Service, Inc., an equipment repair and remanufacture facility
           located in Houston, Texas. The Issuer has publicly announced its
           intention to investigate acquisition opportunities in the natural gas
           exploration and drilling industry and its intent to use Houston
           Dynamic Service as a centralized fabrication and machining facility
           for its operations. The Reporting Persons owned 87.5% of the common
           stock of OilQuip.

                  Prior to the Merger the Issuer had outstanding 1,588,128
           shares of Common Stock. Pursuant to the Merger Agreement, the Issuer
           issued 135,000 shares of Common Stock to the Reporting Persons and
           agreed to issue an additional 3,240,000 shares on the date (the
           "Amendment Date") the Certificate of Incorporation of the Issuer is
           amended (the "Amendment") to authorize the issuance of such shares.
           The Issuer has agreed to use its best efforts to effect the Amendment
           at the earliest practical date.

                  Pursuant to the Merger Agreement, all but four of the existing
           directors of the Issuer resigned and Mr. Munawar Hidayatallah, Mr.
           Saeed M. Sheikh and Professor Philip David were appointed as
           directors of the Issuer.  In addition, Mr. Hidayatallah was appointed
           Chairman of the Board of Directors, President and Chief Executive
           Officer of the Issuer.

                  The Reporting Persons acquired the shares of Common Stock as
           an investment. Each of the Reporting Persons may seek to acquire
           additional shares of Common Stock through open market or privately
           negotiated transactions from time to time in its or his discretion.
           Any such purchases will depend upon the market prices for the shares
           of Common Stock, the number of shares which may become available for
           purchase at prices which each of the Reporting Persons regard as
           attractive and various other factors which each of the Reporting
           Persons may determine to be relevant. Alternatively, each of the
           Reporting Persons may in the future determine to dispose of all or a
           portion of the shares of Common Stock held by it or him depending
           upon, among other things, the then market price for the Common Stock.
           Such sales may be made in transactions in the open market or in
           privately negotiated transactions.


CUSIP No. 019645407                                                  Page No: 8


                  Except as set forth in this Item 4, none of the Reporting
           Persons has any current plans or proposals which relate to or would
           result in (a) an extraordinary corporate transaction, such as a
           Merger, reorganization or liquidation of The Issuer or any of its
           subsidiaries; (b) the sale or transfer of a material amount of assets
           of The Issuer or any of its subsidiaries; (c) any change in the
           Issuer's present Board of Directors or management; (d) any material
           change in the present capitalization or dividend policy of the
           Issuer; (e) any other major change in the Issuer's business or
           corporate structure; (f) any change in the Issuer's charter or
           by-laws that might impede the acquisition or control of the Issuer by
           any person; (g) the delisting of a class of the Issuer's securities
           on a national securities exchange; (h) the termination of
           registration pursuant to Section 12(g)(4) of the Exchange Act of a
           class of the Issuer's equity securities; or (i) any action similar to
           any of those enumerated above. However, as indicated above, each of
           the Reporting Persons intends continuously to review its investment
           in the Issuer. Depending upon the results of such continuing review
           and other Factors, each of the Reporting Persons reserves the right
           to propose, take or seek to cause the Issuer to take one or more of
           the transactions described in this paragraph.



Item 5.  Interest in Securities of the Issuer


                  As described in Item 4, on the effective date of the Merger,
           the Issuer issued to Colebrooke 135,000 shares of the Common Stock,
           and agreed to issue to Colebrooke an additional 3,240,000 immediately
           following the Amendment Date described in Item 4.

                  Colebrooke has the sole power to dispose of the Common Stock
           currently owned by Colebrooke, as well as the Common Stock to be
           issued to Colebrooke on the Amendment Date, subject to the
           requirements of the Share Transfer Restriction Agreement described in
           Item 6. Colebrooke shares with Mr. Hidayatallah the power to vote the
           Common Stock directly owned by Colebrooke on the date hereof,
           pursuant to the Agreement and Proxy described in Item 6. As described
           in Item 6, Colebrooke and certain other shareholders of the Issuer
           holding 1,167,351, or 58.7% of the outstanding Common Stock, have
           granted proxies to Mr. Hidayatallah to approve the Amendment. The
           Agreement and Proxy will expire upon the approval of the amendment of
           the Issuer's Certificate of Incorporation described above, and thus
           will not apply to the Common Stock issued after the Amendment Date.



CUSIP No. 019645407                                                  Page No: 9


         The group formed as a result of the agreements described in Item 6 may
be deemed to have beneficial ownership of all of the following securities:




------------------------------- ---------------------- ---------------- --------------------- ---------------
Shareholder Names               Issuer Shares          Percentage 1     Total Number of       Percentage 2
                                Currently Owned                         Shares to be Owned
                                                                        Following the
                                                                        Amendment Date
------------------------------- ---------------------- ---------------- --------------------- ---------------
                                                                                  
Mr. Hidayatallah                  175,000              8.8%             4,375,000             37.8%
------------------------------- ---------------------- ---------------- --------------------- ---------------
Colebrooke Investments Limited    135,000              6.8%             3,375,000             29.1%
------------------------------- ---------------------- ---------------- --------------------- ---------------
Saeed Sheikh                       40,000              2.0%             1,000,000             8.6%
------------------------------- ---------------------- ---------------- --------------------- ---------------
AL-CH                             417,251 3            20.1%              657,251 4           5.5%
------------------------------- ---------------------- ---------------- --------------------- ---------------
PBGC                              585,100              29.4%              585,100             5.0%
------------------------------- ---------------------- ---------------- --------------------- ---------------
       Total                    1,352,351              68.0%            9,992,351             86.2%
------------------------------- ---------------------- ---------------- --------------------- ---------------


         Ansbacher Trust Company is the trustee of the Jupitor Trust which is
the owner of 100% of the outstanding shares of Colebrooke Investments Limited
which is the direct owner of the Common Stock issued and issuable to Colebrooke
as described above.

         Mr. Hidayatallah shares voting power with respect to all Common Stock
currently held by the other shareholders listed in the above table (1,167,351),
other than 10,000 shares held by an affiliate of Al-Ch, RER Corp., as described
in footnote 3 to the table.

Item 6.  Contracts, Arrangements, Understandings or Relationships With Respect
         to Securities of the Issuer


       In connection with the Merger, Reporting Persons and the two largest
shareholders of the Issuer existing prior to the Merger, the Pension Benefit
Guarantee Corporation (the "PBGC") and AL-CH, LP, ("AL-CH") entered into an
Agreement and Proxy pursuant to which each of the parties to the agreement
granted to Munawar Hidayatallah a proxy to vote all Common Stock owned by them
in favor of the Amendment described in Item 4. The aggregate number of shares of
the Common Stock owned by Mr. Hidayatallah and subject to proxies granted to Mr.
Hidayatallah is 1,342,351 shares, which constitutes approximately 67.5% of the
outstanding Common Stock. The proxies will expire on the Amendment Date
described in Item 4.

      In connection with the Merger Agreement, the Reporting Persons entered
into a Share Transfer Restriction Agreement, pursuant to which each shareholder
agreed not to transfer more than 20% of the Common Stock received by each
shareholder pursuant to the Merger Agreement within one year following the
effective date of the Merger.


--------
1     Based on 1,988,128 shares currently outstanding.
2     Based on 11,588,128 shares to be outstanding following the issuance of the
      additional shares.
3     Includes 10,000 Shares issued to an affiliate, RER Corp., pursuant to the
      Merger Agreement.
4     Includes 250,000 Shares issued and to be issued to an affiliate, RER
      Corp., in the Merger Agreement.


CUSIP No. 019645407                                                 Page No: 10

Item 7.  Material to Be Filed as Exhibits


      1. Agreement and Plan of Merger dated May 9, 2001, by and among Allis-
Chalmers Corporation, Allis-Chalmers Acquisition, Co. and OilQuip Rentals, Inc.

      2. The Agreement and Proxy dated May 9, 2001, by and among the Pension
Benefit Guarantee Corporation, AL-CH, L.P., Saeed Sheikh, Munawar Hidayatallah,
Colebrooke Investments Limited, Jeffrey R. Freeman, RER Corp., Howard S. Lorch
and Jamie C. Lorch and John L. Palazzola, as amended by a side letter effective
May 9, 2001.

      3. Share Transfer Restriction Agreement dated May 2, 2001 by and among the
Pension Benefit Guarantee Corporation, AL-CH, L.P., Saeed Sheikh, Munawar
Hidayatallah, Colebrooke Investments Limited, Jeffrey R. Freeman, RER Corp.,
Howard S. Lorch and Jamie C. Lorch and John L. Palazzola, as amended by a side
letter effective May 9, 2001.

      4. Side letters dated May 9, 2001 amending the Agreement and Proxy dated
May 9, 2001, and the Share Transfer Restriction Agreement dated May 2, 2001.

      5. Agreement regarding Joint Filing of Schedule 13D by and among
Colebrooke Investments Limited, Jupiter Trust and Ansbacher Trust Company.



                                     ANNEX A

                   Director of Colebrooke Investments Limited

Name/Title/Citizenship          Principal Occupation            Business Address

Plaiderie Corporate             Corporate Director              P.O. Box 79, La
   Directors One                for Colebrooke                  Plaiderie House
   Limited ("Plaiderie")        Investments Limited             St. Peter Port,
   Corporate Director                                           Guernesy  GY13DQ
   (Guernesy)

      To the best of the Reporting Persons' knowledge:

      (a)   Plaiderie does not hold any shares of the Common Stock.

      (b)   Plaiderie does not have any contracts, arrangements, understandings
            or relationships with respect to the share of the Common Stock.







CUSIP No. 019645407                                                 Page No: 11




                                    SIGNATURE

         After reasonable inquiry and to the best of the undersigned's knowledge
and belief, each of the undersigned certifies that the information set forth in
this statement is true, complete and correct and agrees that this statement may
be filed jointly with the other undersigned party.




Dated:   May 30, 2001

                                       COLEBROOKE INVESTMENTS LIMITED


                                       By: /s/ Michael Wegerer
                                          ------------------------------
                                            Name: Plaiderie Corporate
                                                  Directors One Limited

                                            Title: Director



                                       JUPITER TRUST


                                       By: Ansbacher Trust Company, Trustee



                                       By: /s/ Robert Bannister
                                          -----------------------------
                                            Name: Ansbacher Trust Company
                                                  (Guernsey) Limited as Trustee

                                            Title: Directors


                                       ANSBACHER TRUST COMPANY

                                       By: /s/ Robert Bannister
                                          -----------------------------
                                            Name: Robert Bannister

                                            Title: Director




                                  EXHIBIT INDEX


     Exhibit No.                       Description

            1     Agreement and Plan of Merger dated May 9, 2001, by and among
                  Allis Chalmers Corporation, Allis Chalmers Acquisition, Co.
                  and OilQuip Rentals, Inc.

            2     The Agreement and Proxy dated May 9, 2001, by and among the
                  Pension Benefit Guarantee Corporation, AL-CH, L.P., Saeed
                  Sheikh, Munawar Hidayatallah, Colebrooke Investments, Inc.,
                  Jeffrey R. Freeman, RER Corp., Howard S. Lorch and Jamie C.
                  Lorch and John L. Palazzola.

            3     Share Transfer Restriction Agreement dated May 2, 2001 by and
                  among the Pension Benefit Guarantee Corporation, AL-CH, L.P.,
                  Saeed Sheikh, Munawar Hidayatallah, Colebrooke Investments,
                  Inc., Jeffrey R. Freeman, RER Corp., Howard S. Lorch and Jamie
                  C. Lorch and John L. Palazzola, as amended by a side letter
                  effective May 9, 2001.

            4     Letter Agreements dated as of May 9, 2001, amending the
                  Agreement and Proxy dated May 9, 2001, and the Share Transfer
                  Restriction Agreement, dated May 2, 2001.

            5     Agreement regarding Joint Filing of Schedule 13D by and
                  among Colebrooke Investments Limited, Jupiter Trust and
                  Ansbacher Trust Company.