Exhibit 5.1




                                  [Letterhead]







                                            September [24], 2004



Bucyrus International, Inc.
P.O. Box 500
1100 Milwaukee Avenue
South Milwaukee, Wisconsin  53172


Ladies and Gentlemen:

         We have acted as special counsel to Bucyrus International, Inc., a
Delaware corporation (the "Company"), and are delivering this opinion in
connection with the Registration Statement on Form S-8 of the Company (the
"Registration Statement") being filed with the Securities and Exchange
Commission (the "Commission") on the date hereof, relating to the registration
by the Company of 2,026,400 shares (the "Plan Shares") of Class A common
stock, par value $0.01 per share (the "Common Stock"), of the Company
authorized for issuance pursuant to the Company's 2004 Equity Incentive Plan
(the "2004 Equity Incentive Plan") and the Company's 1998 Management Stock
Option Plan (the "Stock Option Plan" and, together with the 2004 Equity
Incentive Plan, the "Plans").

         This opinion is being delivered in accordance with the requirements
of Item 601(b)(5) of Regulation S-K under the Securities Act of 1933, as
amended (the "Securities Act").

         In connection with this opinion, we have examined originals or
copies, certified or otherwise identified to our satisfaction, of (i) the
Registration Statement; (ii) the Plans; (iii) certain resolutions of the Board
of Directors of the Company relating to the Plans, dated March 17, 1998,
December 16, 1998, June 30, 2004 and July 26, 2004, as certified by Craig R.
Mackus, Chief Financial Officer, Controller and Secretary of the Company; (v)
the Company's Amended and Restated Certificate of Incorporation, as certified
by the Secretary of State of the State of Delaware; (vi) the Company's Amended
and Restated Bylaws, as certified by Craig R. Mackus, Chief Financial Officer,
Controller and Secretary of the Company; and (vii) specimen certificates
representing the Common Stock. We have also examined originals or copies,
certified or otherwise identified to our satisfaction, of such records of the
Company and such agreements, certificates and receipts of public officials,
certificates of officers or other representatives of the Company and others,
and such other documents, certificates and records as we have deemed necessary
or appropriate as a basis for the opinions set forth herein.

         In our examination, we have assumed the legal capacity of all natural
persons, the genuineness of all signatures, the authenticity of all documents
submitted to us as originals, the conformity to original documents of all
documents submitted to us as facsimile, electronic, certified, or photostatic
copies and the authenticity of the originals of such copies. In making our
examination of executed documents or documents to be executed, we have assumed
that the parties thereto other than the Company, had or will have the power,
corporate or other, to enter into and perform all obligations thereunder and
have also assumed the due authorization by all requisite action, corporate or
other, and execution and delivery by such parties of such documents and the
validity and binding effect thereof on such parties. As to any facts material
to the opinions expressed herein that we did not independently establish or
verify, we have relied upon statements and representations of officers and
other representatives of the Company and others and of public officials.

         In rendering the opinion set forth below, we have assumed that the
certificates evidencing the Plan Shares in the form examined by us will be
manually signed by an authorized officer of the transfer agent and registrar
for the Common Stock and registered by such transfer agent and registrar and
that prior to the issuance of any Plan Shares issuable upon the exercise of
options, the Company and the relevant option holder will have duly entered into
stock option agreements (the "Option Agreements") in accordance with the
resolutions of the Board of Directors. We have also assumed that prior to the
issuance of any Plan Shares, the Company will have received the consideration
contemplated by the applicable resolutions of the Board of Directors
authorizing the issuance of such shares pursuant to the terms of the respective
Plans and, with respect to Plan Shares issuable upon the exercise of options,
the consideration provided for in the applicable Option Agreements.

         Members of our firm are admitted to the bar in the State of New York
and we do not express any opinion as to laws of any other jurisdiction other
than the General Corporation Law of the State of Delaware, and we do not
express any opinion as to the effect of any other laws on the opinion stated
herein.

         Based on and subject to the foregoing, we are of the opinion that the
Plan Shares have been duly authorized by the Company and, when awarded by the
board of directors or the compensation committee of the board of directors of
the Company and issued and paid for in accordance with the terms of the
respective Plans, and, with respect to Plan Shares issuable upon exercise of
options, the Option Agreements, will be validly issued, fully paid and
non-assessable.


         We hereby consent to the filing of this opinion with the Commission
as an exhibit to the Registration Statement. In giving such consent, we do not
thereby admit that we are in the category of persons whose consent is required
under Section 7 of the Securities Act or the rules and regulations of the
Commission promulgated thereunder.


                                  Respectfully submitted,


                                  /s/ SKADDEN, ARPS, SLATE, MEAGHER & FLOM LLP