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                                                                    EXHIBIT 2.11

                         REGISTRATION RIGHTS AGREEMENT

               This REGISTRATION RIGHTS AGREEMENT (this "Agreement"), dated as
of February 1, 2002, is made by and between Allis-Chalmers Corporation, a
Delaware corporation (the "Company"), and Energy Spectrum Partners, LP, a
Delaware limited partnership ("Energy Spectrum").

                                   WITNESSETH:

               WHEREAS, the Company, Energy Spectrum and Strata Directional
Technology, Inc. (the "Corporation") are parties to that certain Stock Purchase
Agreement, dated as of February 1, 2002 (the "Securities Purchase Agreement"),
pursuant to which, among other things, Energy Spectrum is exchanging shares of
capital stock of the Corporation for shares of capital stock of the Company; and

               WHEREAS, in connection with the consummation of the transactions
contemplated by the Securities Purchase Agreement, the Company has agreed to
grant to Energy Spectrum certain registration rights with respect to shares of
Common Stock owned or to be acquired by Energy Spectrum;

               NOW, THEREFORE, in consideration of the foregoing and the mutual
covenants and agreements set forth herein, the mutual benefits to be gained by
the performance thereof and other good and valuable consideration, the receipt
and sufficiency of which are hereby acknowledged and accepted, the parties
hereto hereby agree as follows:

               SECTION 1. Definitions. For purposes of this Agreement, the terms
set forth below shall have the following respective meanings:

               "Commission" means the Securities and Exchange Commission.

               "Common Stock" means the common stock, par value $0.15 per share,
of the Company.

               "Common Stock Equivalents" means securities convertible into, or
exchangeable or exercisable for, shares of Common Stock, including without
limitation the Company Preferred Stock and all rights, warrants and options
granted by the Company to third parties or shareholders or employees of the
Company.

               "Company" has the meaning set forth in the preamble hereto.

               "Company Preferred Stock" means the Series A 10% Cumulative
Convertible Preferred Stock, $0.01 par value, issued by the Company and
convertible into Common Stock.

               "Corporation" has the meaning set forth in the recitals hereto.

               "Demand Registration" has the meaning set forth in Section 2(a)
hereto.


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               "Demand Registration Request" has the meaning set forth in
Section 2(a) hereto.

               "Energy Spectrum" has the meaning set forth in the preamble
hereto.

               "Holdback Agreements" has the meaning set forth in Section 4
hereto.

               "Indemnified Party" has the meaning set forth in Section 7(c)
hereto.

               "Issuer Indemnified Party" has the meaning set forth in Section
7(c) hereto.

               "Person" means an individual, partnership, corporation, limited
liability company, association, joint stock company, trust, joint venture,
unincorporated organization or governmental entity or any department, agency or
political subdivision thereof.

               "Piggyback Registration" has the meaning set forth in Section 3
hereto.

               "Registrable Shares" means at any time any shares of Common Stock
owned by Energy Spectrum, whether acquired on the date hereof or hereafter
acquired, including without limitation, any shares of Common Stock issuable upon
the conversion, exchange or exercise of Common Stock Equivalents owned by Energy
Spectrum; provided, however, that Registrable Shares shall not include any
shares the sale of which has been registered pursuant to a registration
statement filed under the Securities Act which has been declared effective or
which may be otherwise transferred without restriction (including volume
restrictions) under Rule 144 or any similar successor rule or provision then in
force.

               "Registration Expenses" has the meaning set forth in Section 6
hereto.

               "Securities Act" means the Securities Act of 1933, as amended, or
any successor federal statute, and the rules and regulations promulgated
thereunder, all as the same may be in effect from time to time.

               "Securities Exchange Act" means the Securities Exchange Act of
1934, as amended, or any successor federal statute, and the rules and
regulations promulgated thereunder, all as the same may be in effect from time
to time.

               "Selling Indemnified Party" has the meaning set forth in Section
7(a) hereto.

               SECTION 2. Demand Registration.

                      (a) Requests for Registration. Subject to the limitations
        set forth in this Section 2 at any time, but no more than twice, Energy
        Spectrum may request the Company to register under the Securities Act
        all or any part of the Registrable Shares (a "Demand Registration
        Request").

                      (b) Registration by the Company. Unless the Company has
        the right to refuse registration pursuant to Section 2(c) hereof, the
        Company shall file a registration statement under the Securities Act
        covering the Registrable Shares which are the subject of


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        any Demand Registration Request as soon as practicable after receipt by
        the Company of any such Demand Registration Request (each, a "Demand
        Registration"); provided, however, that if (i) in the good faith
        judgment of the Board of Directors of the Company, such registration
        would be seriously detrimental to the Company (or any proposed
        acquisition or disposition of assets or properties) and the Board of
        Directors of the Company concludes, as a result, that it is essential to
        defer the filing of such registration statement at such time, and (ii)
        the Company shall furnish Energy Spectrum a certificate signed by the
        Chief Executive Officer of the Company stating that, in the good faith
        judgment of the Board of Directors of the Company, it would be seriously
        detrimental to the Company for such registration statement to be filed
        in the near future and that it is, therefore, essential to defer the
        filing of such registration statement, then the Company shall have the
        right to defer such filing for the period during which the disclosure
        contained in such filings would be seriously detrimental to the Company,
        provided, however, that the Company may not defer the filing of a
        registration statement for a period of more than 120 days after receipt
        of the Demand Registration Request of Energy Spectrum, and, provided
        further, that the Company shall not defer its obligation in this manner
        more than once in any twelve-month period and shall give written notice
        to Energy Spectrum immediately after the reason for deferring the filing
        of the registration statement has ceased to exist. The Company shall not
        be required to register any shares of Registrable Securities during any
        period in which it has exercised its deferral right as aforesaid.

                      (c) Demand Registration Limitations. The Company shall not
        be required to make any Demand Registration pursuant to this Section 2
        during the period ending 90 days after the effective date of any
        registration statement filed pursuant to the Securities Act for an
        underwritten public offering by the Company of shares of Common Stock
        other than in connection with an employee benefit plan, dividend
        reinvestment plan or merger, consolidation or other business
        combination.

                      (d) Priority on Demand Registrations. The registration
        statement filed pursuant to the Demand Registration Request of Energy
        Spectrum may, subject to the limitations set forth below, include other
        securities of the Company, with respect to which registration rights
        have been granted, and may include securities of the Company being sold
        for the account of the Company. If a Demand Registration is an
        underwritten public offering and the managing underwriters advise the
        Company in writing that in their opinion the number of Registrable
        Shares and other securities requested to be included exceeds the number
        of Registrable Shares and other securities which can be sold in such
        offering, the Company shall include in such registration, first the
        number of Registrable Shares requested to be included by Energy Spectrum
        and then any securities to be sold by the Company or any other
        securities which are not Registrable Shares.

                      (e) Underwriters. The parties agree that Jeffries &
        Company, Inc. shall be the managing underwriter for any Demand
        Registration, provided that they agree to serve as such and further
        provided that they have entered into an agreement with the Company to
        serve generally as managing underwriter for the Company. If Jeffries &
        Company, Inc. will not be the managing underwriter of a Demand
        Registration, then any managing underwriter


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        or underwriters for any Demand Registration shall be selected by Energy
        Spectrum, which managing underwriter or underwriters shall be reasonably
        acceptable to the Company.

               SECTION 3. Piggyback Registration.

                      (a) Right to Piggyback. If at any time the Company
        proposes to file a registration statement under the Securities Act with
        respect to any underwritten offering of any securities of the Company,
        other than a registration statement on Form S-4 or S-8 (or any
        substitute form for comparable purposes that may be adopted by the
        Commission) or a registration statement filed in connection with an
        exchange offer or an offering of securities solely to the Company's
        existing security holders (a "Piggyback Registration"), the Company
        shall in each case give written notice of such proposed filing to Energy
        Spectrum as soon as practicable, but in no event less than 30 days
        before the anticipated filing date, and shall, subject to Section 3(h)
        hereof, include in such registration statement all Registrable Shares
        with respect to which the Company has received a written request for
        inclusion therein within 15 days after the Company's notice is received
        by Energy Spectrum.

                      (b) Priority in Piggyback Registrations. If the managing
        underwriters advise the Company in writing that in their opinion the
        number of securities requested to be included in a Piggyback
        Registration exceeds the number which can be sold in such offering, the
        Company shall include in such registration (i) first, the securities the
        Company proposes to sell, if any, and (ii) second, the Registrable
        Shares requested to be included in such registration, pro rata among
        Energy Spectrum and the holders of other securities requested to be
        included on the basis of the then number of Registrable Shares and other
        securities requested to be included by each holder of such securities.

                      (c) Right to Withdraw. Notwithstanding anything to the
        contrary, neither the delivery of the notice by the Company nor of the
        request by Energy Spectrum shall in any way obligate the Company to
        file, or Energy Spectrum to have included in, a registration statement
        under this Section 3 and notwithstanding such filing, the Company may,
        at any time prior to the effective date thereof, in its sole discretion,
        determine not to offer the securities to which the registration
        statement relates without liability to Energy Spectrum, and Energy
        Spectrum may determine not to include its Registrable Shares therein
        without liability.

                      (d) Selection of Underwriters. The managing underwriter or
        underwriters for any Piggyback Registration shall be selected by the
        Company, by action of the Board of Directors.

               SECTION 4. Holdback Agreements. In the event that Registrable
Shares are registered by the Company pursuant to Section 2 or 3 hereof, Energy
Spectrum shall enter into such agreements, including underwriting agreements and
lock-up agreements, as the managing underwriter of any offering registered under
the Securities Act shall reasonably request (collectively, "Holdback
Agreements"); provided, however, that with respect to any registrations, such
Holdback Agreements shall not exceed a period of 14 calendar days prior to, and
120 calendar days after, the effective date of such registration.


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               SECTION 5. Registration Procedures. Whenever Energy Spectrum has
requested that any Registrable Shares be registered pursuant to this Agreement,
the Company shall use its best efforts to effect the registration and the sale
of such Registrable Shares in accordance with the intended method of disposition
thereof, and pursuant thereto the Company shall as expeditiously as possible:

                      (a) prepare and file with the Commission a registration
        statement with respect to such Registrable Shares and use its best
        efforts to cause such registration statement to become and remain
        effective until such securities are sold, in any case not to exceed six
        months;

                      (b) prepare and file with the Commission such amendments
        and supplements to such registration statement and the prospectus used
        in connection therewith as may be necessary to keep such registration
        statement effective for a period of not more than six months and comply
        with the provisions of the Securities Act with respect to the
        disposition of all securities covered by such registration statement
        during such period in accordance with the intended methods of
        disposition by the sellers thereof set forth in such registration
        statement;

                      (c) furnish, without charge, to Energy Spectrum and the
        underwriters of the securities being registered such number of copies of
        such registration statement, each amendment and supplement thereto, in
        each case including all exhibits, the prospectus included in such
        registration statement, including each preliminary prospectus, and such
        other documents as Energy Spectrum or the underwriters may reasonably
        request in order to facilitate the disposition of the Registrable Shares
        owned by Energy Spectrum or the sale of such securities by such
        underwriters;

                      (d) use its best efforts to register or qualify such
        Registrable Shares under such other securities or blue sky laws of such
        jurisdictions as Energy Spectrum shall reasonably request and do any and
        all other acts and things which may be reasonably necessary or advisable
        to enable Energy Spectrum to consummate the disposition in such
        jurisdictions of the Registrable Shares owned by Energy Spectrum,
        provided, however, that the Company shall not be required to (1) qualify
        generally to do business in any jurisdiction where it would not
        otherwise be required to qualify but for this Section 5(d), (ii) subject
        itself to taxation in any such jurisdiction or (iii) consent to general
        service of process in any such jurisdiction;

                      (e) cause all such Registrable Shares covered by such
        registration statement to be listed on the principal securities exchange
        on which similar securities issued by the Company are then listed, if
        any, if the listing of such Registrable Shares is then permitted under
        the rules of such exchange;

                      (f) provide and cause to be maintained a transfer agent
        and registrar for all such Registrable Shares not later than the
        effective date of such registration statement;


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                      (g) enter into such customary agreements, including
        underwriting agreements in customary form, and take all such other
        actions as the underwriters, if any, reasonably request in order to
        expedite or facilitate the disposition of such Registrable Shares;

                      (h) upon receipt of such confidentiality agreements as the
        Company may reasonably request, make reasonably available for inspection
        by Energy Spectrum, any underwriter participating in any disposition
        pursuant to such registration statement, and any attorney, accountant or
        other agent retained by Energy Spectrum or any such underwriter, all
        financial and other records, pertinent corporate documents and
        properties of the Company, and cause the Company's officers, directors,
        employees and independent accountants to supply all information
        reasonably requested by Energy Spectrum or any such underwriter,
        attorney, accountant or agent in connection with such registration
        statement;

                      (i) promptly notify Energy Spectrum, (i) of the time when
        the registration statement, any pre-effective amendment, the prospectus
        or any prospectus supplement related thereto or post-effective amendment
        to the registration statement has been filed and, with respect to the
        registration statement or any post-effective amendment, when the same
        has become effective and (ii) of the receipt by the Company of any
        notification with respect to the suspension of the qualification of any
        Registrable Shares for sale under the securities or blue sky laws of any
        jurisdiction or the initiation of any proceeding for such purpose;

                      (j) notify Energy Spectrum of any requests by the
        Commission for the amending or supplementing of such registration
        statement or prospectus or for additional information;

                      (k) prepare and file with the Commission, promptly upon
        the request of Energy Spectrum, any amendments or supplements to such
        registration statement or prospectus which, in the written opinion of
        counsel selected by Energy Spectrum, is required under the Securities
        Act or the rules and regulations thereunder in connection with the
        distribution of Registrable Shares by Energy Spectrum;

                      (l) prepare and promptly file with the Commission and
        promptly notify Energy Spectrum of the filing of such amendment or
        supplement to such registration statement or prospectus as may be
        necessary to correct any statements or omissions if, at the time when a
        prospectus relating to such securities is required to be delivered under
        the Securities Act, any event shall have occurred as the result of which
        any such prospectus as then in effect would include an untrue statement
        of a material fact or omit to state any material fact necessary to make
        the statements therein, in the light of the circumstances in which they
        were made, not misleading;

                      (m) advise Energy Spectrum, promptly after the Company
        shall receive notice or obtain knowledge thereof, of the issuance of any
        stop order by the Commission suspending the effectiveness of such
        registration statement or the initiation or threatening of


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        any proceeding for such purpose and promptly use all reasonable efforts
        to prevent the issuance of any stop order or to obtain its withdrawal if
        such stop order should be issued;

                      (n) provide notice within a reasonable amount of time
        prior to the filing of any registration statement or prospectus of any
        amendment or supplement to such registration statement or prospectus,
        furnish a copy thereof to Energy Spectrum and refrain from filing any
        such registration statement, prospectus, amendment or supplement to
        which counsel selected by Energy Spectrum shall have reasonably objected
        on the grounds that such amendment or supplement does not comply in all
        material respects with the requirements of the Securities Act or the
        rules and regulations thereunder, unless, in the case of an amendment or
        supplement, the Company reasonably believes the filing of such amendment
        or supplement is reasonably necessary to protect the Company from any
        liabilities under any applicable federal or state law;

                      (o) at the request of Energy Spectrum in connection with
        an underwritten offering, furnish on the date or dates provided for in
        the underwriting agreement: (i) an opinion of counsel, addressed to the
        underwriters and Energy Spectrum, covering such matters as such
        underwriters may reasonably request including, without limiting the
        generality of the foregoing, opinions to the effect that (A) such
        registration statement has become effective under the Securities Act;
        (B) to the best of such counsel's knowledge no stop order suspending the
        effectiveness thereof has been issued and no proceedings for that
        purpose have been instituted or are pending or contemplated under the
        Securities Act; (C) the registration statement, the prospectus, and each
        amendment or supplement thereto comply as to form in all material
        respects with the requirements of the Securities Act and the applicable
        rules and regulations of the Commission thereunder except that such
        counsel need express no opinion as to financial statements or other
        financial or statistical data contained therein; and (ii) a "cold
        comfort" letter or letters from the independent certified public
        accountants of the Company addressed to the underwriters and Energy
        Spectrum, covering such matters as such underwriters may reasonably
        request, in which letters such accountants shall state, without limiting
        the generality of the foregoing, that they are independent certified
        public accountants within the meaning of the Securities Act and that in
        the opinion of such accountants the financial statements and other
        financial data of the Company included in the registration statement,
        the prospectus, or any amendment or supplement thereto comply in all
        material respects with the applicable accounting requirements of the
        Securities Act;

                      (p) subject to any confidentiality agreements, deliver,
        promptly after the receipt thereof, to Energy Spectrum and each
        underwriter, if any, copies of all correspondence between the Commission
        and the Company, its counsel or auditors and all memoranda relating to
        discussions with the Commission or its staff with respect to the
        registration statement, other than those portions of any such
        correspondence and memoranda which contain information subject to
        attorney-client privilege with respect to the Company;

                      (q) provide a CUSIP number for all Registrable Shares, not
        later than the effective date of the registration statement;


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                      (r) make reasonably available its employees and personnel
        and otherwise provide reasonable assistance to the underwriters, taking
        into account the needs of the Company's business and the requirements of
        the marketing process, in the marketing of Registrable Shares in any
        underwritten offering;

                      (s) prior to the filing of any document which is to be
        incorporated by reference into the registration statement or the
        prospectus, after the initial filing of such registration statement,
        provide copies of such document to counsel to Energy Spectrum and to the
        managing underwriter, if any, and make the Company's representatives
        reasonably available for discussion of such document and make such
        changes in such document prior to the filing thereof as counsel for
        Energy Spectrum or such underwriters may reasonably request;

                      (t) furnish, promptly after the filing thereof, to Energy
        Spectrum and the managing underwriter, without charge, at least one
        signed copy of the registration statement and any post-effective
        amendments thereto, including financial statements and schedules, all
        documents incorporated therein by reference and all exhibits, including
        those incorporated by reference;

                      (u) comply with all applicable rules and regulations of
        the Commission, and make generally available to its security holders, as
        soon as reasonably practicable after the effective date of the
        registration statement, and in any event within 16 months thereafter, an
        earnings statement (which need not be audited) covering the period of at
        least twelve consecutive months beginning with the first day of the
        Company's first calendar quarter after the effective date of the
        registration statement, which earnings statement shall satisfy the
        provisions of Section 11 (a) of the Securities Act and Rule 158
        thereunder; and

                      (v) take all such other commercially reasonable actions as
        are necessary or advisable in order to expedite or facilitate the
        disposition of such Registrable Shares.

               SECTION 6. Registration Expenses. Except as otherwise provided
herein, all expenses incident to the Company's performance of or compliance with
this Agreement, including without limitation, all registration and filing fees,
fees and expenses of compliance with securities or blue sky laws, including a
blue sky survey and the related fees and expenses of counsel; printing expenses,
messenger and delivery expenses; fees and disbursements of counsel for the
Company and its independent certified public accountants; fees and disbursements
of one counsel selected by Energy Spectrum; fees and disbursements of any other
Persons (including experts) retained by the Company; and all other fees and
disbursements of underwriters customarily paid by issuers or sellers of
securities (all such expenses being herein called "Registration Expenses"),
shall be borne by the Company. In addition, the Company shall pay its internal
expenses, including without limitation, all salaries and expenses of its
officers and employees performing legal or accounting duties, the expense of any
annual audit or quarterly review, the expense of any liability insurance
obtained by the Company and the expenses; fees for listing the securities so
registered on each securities exchange on which any shares of common stock are
then listed or on the Nasdaq Stock Market. Registration Expenses shall not
include (a) the fees and expenses of more than one counsel for


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Energy Spectrum, or (b) any underwriting discounts, commissions or similar
charges attributable to the sale of Registrable Shares included in such
registration.

               SECTION 7. Indemnification and Contribution.

                      (a) Indemnification by the Company. The Company shall
        indemnify and hold harmless to the fullest extent permitted by law
        Energy Spectrum, its officers, directors, fiduciaries, stockholders,
        partners (and the directors, officers, employees and stockholders
        thereof) and agents and each Person, if any, who controls Energy
        Spectrum within the meaning of Section 15 of the Act or Section 20 of
        the Securities Exchange Act (collectively, the "Selling Indemnified
        Parties" and, individually, a "Selling Indemnified Party"), from and
        against, on a current basis, any and all losses, claims, damages,
        whether in contract, tort or otherwise, liabilities, expenses, actions
        and proceedings, whether commenced or threatened, in respect thereof,
        including reasonable costs of investigation, counsel fees and amounts
        paid in settlement, whatsoever (as incurred or suffered) arising out of
        or based upon any untrue statement or alleged untrue statement of a
        material fact contained in any registration statement or preliminary,
        final or summary prospectus relating to the Registrable Shares or in any
        amendment or supplement thereto, or arising out of or based upon any
        omission or alleged omission to state therein a material fact required
        to be stated therein or necessary to make the statements therein not
        misleading, except insofar as such losses, claims, damages, liabilities
        or expenses arise out of, or are based upon, any such untrue statement
        or omission or allegation thereof based upon information furnished in
        writing to the Company by Energy Spectrum or on Energy Spectrum's behalf
        expressly for use therein. The Company shall also indemnify any
        underwriters of the Registrable Shares, their officers, partners and
        directors and each Person who controls such underwriters on
        substantially the same basis as that of the indemnification of the
        Selling Indemnified Parties provided in this Section 7 or to provide
        such other indemnification customarily obtained by underwriters at the
        time of offering.

                      (b) Conduct of Indemnification Proceedings. If any action
        or proceeding, including any governmental investigation, shall be
        brought or asserted against any Selling Indemnified Party in respect of
        which indemnity may be sought from the Company, the Company shall, at
        its expense, assume the defense thereof, including the employment of
        counsel reasonably satisfactory to such Selling Indemnified Party. Such
        Selling Indemnified Party shall have the right to employ separate
        counsel in any such action and to participate in the defense thereof,
        but the fees and expenses of such counsel shall be at the expense of
        such Selling Indemnified Party unless (i) the Company has agreed to pay
        such fees and expenses, (ii) the Company fails to diligently defend the
        action or proceeding within 20 days after receiving notice from the
        Selling Indemnified Party that the Selling Indemnified Party believes
        the Company has so failed or (iii) the named parties to any such action
        or proceeding, including any impleaded parties, include both such
        Selling Indemnified Party and the Company, and such Selling Indemnified
        Party shall have been advised by counsel that there may be a conflict of
        interest between any of the parties, or that representation of the
        Selling Indemnified Party and the Company is otherwise inappropriate
        under applicable standards of professional conduct, or one or more legal
        defenses are available to such Selling


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        indemnified Party which are different from or additional to those
        available to the Company; in which case, if such Selling Indemnified
        Party notifies the Company in writing that it elects to employ separate
        counsel at the expense of the Company, the Company shall not have the
        right to assume the defense of such action or proceeding on behalf of
        such Selling Indemnified Party; it being understood, however, that the
        Company shall not, in connection with any one such action or proceeding
        or separate but substantially similar or related actions or proceedings
        in the same jurisdiction arising out of the same general allegations or
        circumstances, be liable for the fees and expenses of more than one
        separate firm of attorneys (together with appropriate local counsel) at
        any time for all such Selling Indemnified Parties, which firm shall be
        designated in writing by a majority of the Selling Indemnified Parties.
        The Company shall not be liable for any settlement of any such action or
        proceeding effected without the Company's written consent, but if
        settled with its written consent, which consent shall not be
        unreasonably withheld or delayed, or if there be a final judgment no
        longer subject to appeal for the plaintiff in any such action or
        proceeding, the Company agrees to indemnify and hold harmless such
        Selling Indemnified Parties from and against any loss or liability (to
        the extent stated above) by reason of such settlement or judgment.

                      (c) Indemnification by Energy Spectrum. Energy Spectrum
        shall indemnify and hold harmless the Company, its directors, officers,
        fiduciaries, stockholders and agents and each Person, if any, who
        controls the Company within the meaning of either Section 15 of the Act
        or Section 20 of the Securities Exchange Act (collectively, the "Issuer
        Indemnified Parties" and, individually, a "Issuer Indemnified Party"
        and, together with a Selling Indemnified Party an "Indemnified Party"),
        to the same extent as the foregoing indemnity from the Company to Energy
        Spectrum, but only with respect to information furnished in writing by
        Energy Spectrum or on Energy Spectrum's behalf expressly for use in any
        registration statement or prospectus relating to the Registrable Shares,
        or any amendment or supplement thereto, or any preliminary prospectus.
        In case any action or proceeding shall be brought against an Issuer
        Indemnified Party, in respect of which indemnity may be sought against
        Energy Spectrum, Energy Spectrum shall have the rights and duties given
        to the Company, and the Issuer Indemnified Parties shall have the rights
        and duties given to Energy Spectrum, by the preceding Section 7(b)
        hereof. Energy Spectrum shall also indemnify and hold harmless
        underwriters of the Registrable Shares, their officers, directors,
        fiduciaries, stockholders and agents and each Person who controls such
        underwriters on substantially the same basis as that of the
        indemnification of the Company provided in this Section 7.

                      (d) Contribution. If the indemnification provided for in
        this Section 7 is unavailable to any Indemnified Party in respect of any
        losses, claims, damages, liabilities, expenses, actions or proceedings
        referred to herein, then each such indemnifying party, in lieu of
        indemnifying such Indemnified Party, shall contribute to the amount paid
        or payable by such Indemnified Party as a result of such losses, claims,
        damages, liabilities, expenses, actions and proceedings (i) as between
        the Issuer Indemnified Parties and the Selling Indemnified Parties on
        the one hand and the underwriters on the other, in such proportion as is
        appropriate to reflect the relative benefits received by the Issuer
        Indemnified Parties and


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        the Selling Indemnified Parties on the one hand and the underwriters on
        the other from the offering of the Registrable Shares, or if such
        allocation is not permitted by applicable law, in such proportion as is
        appropriate to reflect not only such relative benefits but also the
        relative fault of the Issuer Indemnified Parties and the Selling
        Indemnified Parties on the one hand and of the underwriters on the other
        in connection with the statements or omissions which resulted in such
        losses, claims, damages, liabilities, expenses actions or proceedings,
        as well as any other relevant equitable considerations and (ii) as
        between the Issuer Indemnified Parties, on the one hand, and each
        Selling Indemnified Party on the other, in such proportion as is
        appropriate to reflect the relative fault of the Issuer Indemnified
        Parties and of each Selling Indemnified Party in connection with such
        statements or omissions, as well as any other relevant equitable
        considerations. The relative benefits received by the Issuer Indemnified
        Parties and the Selling Indemnified Parties on the one hand and the
        underwriters on the other shall be deemed to be in the same proportion
        as the total proceeds from the offering, net of underwriting discounts
        and commissions but before deducting expenses, received by the Issuer
        Indemnified Parties and the Selling Indemnified Parties bear to the
        total underwriting discounts and commissions received by the
        underwriters, in each case as set forth in the table on the cover page
        of the prospectus. The relative fault of the Issuer Indemnified Parties
        and the Selling Indemnified Parties on the one hand and of the
        underwriters on the other shall be determined by reference to, among
        other things, whether the untrue or alleged untrue statement of a
        material fact or the omission or alleged omission to state a material
        fact relates to information supplied by the Issuer Indemnified Parties
        and the Selling Indemnified Parties or by the underwriters. The relative
        fault of the Issuer Indemnified Parties on the one hand and of each
        Selling Indemnified Party on the other shall be determined by reference
        to, among other things, whether the untrue or alleged untrue statement
        of a material fact or the omission or alleged omission to state a
        material fact relates to information supplied by such party, and the
        parties' relative intent, knowledge, access to information and
        opportunity to correct or prevent such statement or omission.

                      The Company and Energy Spectrum hereby agree that it would
        not be just and equitable if contribution pursuant to this Section 7(d)
        were determined by pro rata allocation, even if the underwriters were
        treated as one entity for such purpose, or by any other method of
        allocation which does not take account of the equitable considerations
        referred to in the immediately preceding paragraph. The amount paid or
        payable by an Indemnified Party as a result of the losses, claims,
        damages, liabilities, expenses, actions or proceedings referred to in
        the immediately preceding paragraph shall be deemed to include, subject
        to the limitations set forth above, any legal or other expenses
        reasonably incurred by such indemnified party in connection with
        investigating or defending any such action or claim. Notwithstanding the
        provisions of this Section 7(d), no underwriter shall be required to
        contribute any amount in excess of the amount by which the total price
        at which the Registrable Shares underwritten by it and distributed to
        the public were offered to the public exceeds the amount of any damages
        which such underwriter has otherwise been required to pay by reason of
        such untrue or alleged untrue statement or omission or alleged omission,
        and Energy Spectrum shall not be required to contribute any amount in
        excess of the amount by which the total price at which the Registrable
        Shares of Energy Spectrum were offered to the public exceeds the amount
        of any damages which Energy Spectrum has otherwise


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<PAGE>

        been required to pay by reason of such untrue or alleged untrue
        statement or omission or alleged omission. No Person guilty of
        fraudulent misrepresentation, within the meaning of Section 11(f) of the
        Securities Act, shall be entitled to contribution from any Person who
        was not guilty of such fraudulent misrepresentation.

                      (e) Settlement or Compromise. No indemnifying party shall
        without the written consent of the Indemnified Party, effect the
        settlement or compromise of, or consent to the entry of any judgment
        with respect to, any pending or threatened action or claim in respect of
        which indemnification or contribution may be sought hereunder, whether
        or not the Indemnified Party is an actual or potential party to such
        action or claim, unless such settlement, compromise or judgment (A)
        includes an unconditional release of the Indemnified Party from all
        liability arising out of such action or claim and (B) does not include a
        statement as to or an admission of fault, culpability or a failure to
        act, by or on behalf of any Indemnified Party.

                      (f) Rights not Exclusive. The indemnity agreements
        contained in this Section 7 shall be in addition to any other rights to
        indemnification or contribution which any Indemnified Party may have
        pursuant to law or contract and shall remain operative and in full force
        and effect regardless of any investigation made or omitted by or on
        behalf of any indemnified party and shall survive the transfer of the
        Registrable Shares by any such party.

               SECTION 8. Compliance with Rule 144. At the request of Energy
Spectrum proposing to sell securities in compliance with Rule 144 promulgated by
the Commission under the Securities Act, the Company shall (i) forthwith furnish
to Energy Spectrum a written statement of compliance with the filing
requirements of the Commission as set forth in Rule 144 as such rule may be
amended from time to time and (ii) timely file and make available to the public
and Energy Spectrum such reports and other information as will enable Energy
Spectrum to make sales pursuant to Rule 144.

               SECTION 9. Participation in Underwritten Registrations. No Person
may participate in any registration hereunder which is underwritten unless such
Person (a) agrees to sell such Person's securities on the basis provided in any
underwriting arrangements approved by the Person or Persons entitled hereunder
to approve such arrangements, (b) provides all such information as is reasonably
required to effect such registration and completes and executes all
undertakings, questionnaires, powers of attorney, indemnities, underwriting
agreements and other documents reasonably required under the terms of such
underwriting arrangements or applicable laws, and (c) complies with all other
reasonable requests of the managing underwriter and with the Company and
complies with all other reasonable requests related to such registration.

               SECTION 10. Additional Grants of Registration Rights. Subsequent
to the date of this Agreement, the Company may not, without the prior written
consent of Energy Spectrum, not to be unreasonably withheld, (i) offer other
registration rights other than (a) piggyback registration rights and one demand
registration right (at his expense) granted to Jens H. Mortensen, Jr. in
connection with the Shareholder Agreement between the Company and him and (b)
those granted to Wells Fargo Energy Capital, Inc. or (ii) extend the
registration rights provided for in this


                                       12

<PAGE>

Agreement to other Persons who are or become holders of Common Stock or Common
Stock Equivalents.

               SECTION 11. Remedies. Any Person having rights under any
provision of this Agreement will be entitled to enforce such rights
specifically, to recover damages caused by reason of any breach of any provision
of this Agreement and to exercise all other rights granted by law.

               SECTION 12. Amendments and Waivers. Except as otherwise expressly
provided herein, the provisions of this Agreement including, but not limited to,
notice provisions may be amended or waived at any time only by the written
agreement of the Company and Energy Spectrum. Any waiver, permit, consent or
approval of any kind or character on the part of Energy Spectrum of any
provision or condition of this Agreement must be made in writing and shall be
effective only to the extent specifically set forth in writing.

               SECTION 13. Successors and Assigns. Except as otherwise expressly
provided herein, all covenants and agreements contained in this Agreement by or
on behalf of any of the parties hereto will bind and inure to the benefit of the
respective successors and assigns of the parties hereto, whether so expressed or
not.

               SECTION 14. Final Agreement. This Agreement constitutes the final
agreement of the parties hereto concerning the matters referred to herein, and
supersedes all prior agreements and understandings with respect to the subject
matter hereof.

               SECTION 15. Severability. Whenever possible, each provision of
this Agreement shall be interpreted in such manner as to be effective and valid
under Applicable law, but if any provision of this Agreement is held to be
prohibited by or invalid under applicable law, such provision will be
ineffective only to the extent of such prohibition or invalidity, without
invalidating the remainder of this Agreement.

               SECTION 16. Descriptive Headings. The descriptive headings of
this Agreement are inserted for convenience of reference only and do not
constitute a part of and shall not be utilized in interpreting this Agreement.

               SECTION 17. Notices. Any notice or other communication required
or permitted hereunder shall be in writing and shall be delivered by hand, by
telex or telecopier, by overnight courier service or by certified or registered
mail, postage prepaid and return receipt requested. Notices shall be deemed to
have been given upon delivery, if delivered by hand, three days after mailing,
if mailed, one business day after delivery to the courier, if delivered by
overnight courier service, and upon receipt of an appropriate electronic
confirmation, if by telex or telecopier. Notices shall be delivered to the
Company and Energy Spectrum at the addresses set forth below.

                      If to the Company:

                      Allis-Chalmers Corporation
                      7660 Woodway, Suite 200
                      Houston, Texas 77063


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<PAGE>

                      Attention:  Chief Executive Officer
                      Telephone:  713-369-0550
                      Telecopy:  713-369-0555




                      If to Energy Spectrum:

                      Energy Spectrum Partners, LP
                      5956 Sherry Lane, Suite 900
                      Dallas, Texas 75225
                      Attention: Thomas O. Whitener, Jr.
                      Telephone: (214) 987-6100
                      Telecopy: (214) 987-6110

               SECTION 18. GOVERNING LAW. THE VALIDITY, MEANING AND EFFECT OF
THIS AGREEMENT SHALL BE DETERMINED IN ACCORDANCE WITH THE LAWS OF THE STATE OF
TEXAS APPLICABLE TO CONTRACTS MADE AND TO BE PERFORMED IN THAT STATE.

               SECTION 19. Counterparts. This Agreement may be executed in any
number of counterparts, each of which when so executed and delivered shall be
deemed an original, and such counterparts together shall constitute one
instrument. Each party shall receive a duplicate original of the counterpart
copy or copies executed by it and the Company.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]



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               IN WITNESS WHEREOF, the undersigned have executed this Agreement
as of the date first above written.

                          ALLIS-CHALMERS CORPORATION


                          By:     /s/ Munawar H. Hidayatallah
                                  --------------------------------------
                                  Munawar H. Hidayatallah
                                  Chairman and Chief Executive Officer


                          ENERGY SPECTRUM PARTNERS, LP

                          By:     Energy Spectrum Capital LP, General Partner
                                  By:    Energy Spectrum LLC, General Partner


                                         By:    /s/ Thomas O. Whitener, Jr.
                                                -------------------------------
                                                Thomas O. Whitener, Jr.
                                                Chief Operating Officer