Exhibit
      10.11

    LOCK-UP
      AGREEMENT

    


    October
      31, 2008

    


    Hyde
      Park
      Acquisition Corp.

    461
      Fifth
      Avenue, 25th Floor

    New
      York,
      NY 10017

    


    The
      undersigned is executing and delivering this Lock-Up Agreement to the Company
      (as defined below) in connection with the Purchase Agreement (the “Agreement”)
      made and entered into as of March 6, 2008, as amended, by and among Essex Crane
      Rental Corp., a Delaware corporation (“Essex Crane”), Essex Holdings LLC, a
      Delaware limited liability company (“Holdings”), the members of Holdings as
      listed on the signature page to the Agreement (the “Members”), KCP Services,
      LLC, as Seller Representative (the “Seller Representative”), and Hyde Park
      Acquisition Corp., a Delaware corporation (the “Company”).

    


    The
      undersigned is a record and beneficial owner of units in Holdings which are
      exchangeable for shares of common stock of the Company (such units in Holdings,
      the shares of common stock or other securities into which such units are
      exchangeable, and any securities issued as a dividend or other distribution
      with
      respect to, or in exchange for or in replacement of, any of the foregoing being
      hereinafter referred to as the “Common Shares”). 

    


    In
      order
      to induce the Company to enter into the Agreement and the transactions ancillary
      thereto, and for other good and valuable consideration, the receipt and
      sufficiency of which are hereby acknowledged, the undersigned agrees that during
      the period beginning on and including the date hereof and ending on the second
      anniversary of the date hereof (the “Termination Date”), the undersigned will
      not, without the prior written consent of the Company (acting through its board
      of directors), directly or indirectly (a) sell, transfer, pledge or otherwise
      hypothecate or dispose of any Common Shares, including by way of the grant
      of
      any option, entering into of any short sale position, establishment of an open
      “put equivalent position” (within the meaning of Rule 16a-1(h) under the
      Securities Exchange Act of 1934, as amended) or entering into of any other
      arrangement with respect to the Common Shares by which the economic risk of
      ownership of the Common Shares is transferred by the undersigned or (b) agree
      to
      do, or publicly announce an intention to do, any of the foregoing.

    


    The
      foregoing shall not apply to the transfer of Common Shares, either during the
      undersigned’s lifetime or on death, by gift, will or intestate succession to the
      immediate family of the undersigned or to a trust the beneficiaries of which
      are
      exclusively the undersigned and/or a member or members of his immediate family;
      provided, however, that in any such case it shall be a condition to such
      transfer that the transferee executes and delivers to the Company an agreement
      stating that the transferee is receiving and holding the Common Shares subject
      to the provisions of this Lock-Up Agreement. For purposes of this paragraph,
      the
      term “immediate family” shall have the same meaning as set forth in Rule
      16a-1(e) promulgated under the Securities Exchange Act of 1934, as
      amended.

    


    
      
         

      

      
         

        
          

        

      

      
         

      

       

    

    Notwithstanding
      the foregoing, in the event that prior to the Termination Date, Laurence Levy
      and/or Edward Levy (or their respective affiliates) transfer to any third party
      (other than by gift, will or intestate succession to their respective immediate
      families or to a trust the beneficiaries of which are exclusively either
      themselves and/or a member or members of their respective immediate families)
      any shares of common stock of the Company, or warrants exercisable for such
      shares of common stock, obtained by them directly or indirectly prior to or
      in
      connection with the Company’s initial public offering (“Founder Shares”), then
      the Termination Date shall be automatically changed to the date of the earliest
      such transfer. In the event that Laurence Levy and/or Edward Levy (or their
      respective affiliates) decide to effect any such transfer prior to the
      Termination Date, Laurence Levy and/or Edward Levy (as applicable) shall provide
      prior written notice thereof to the undersigned specifying the date and time
      of
      such transfer, which notice shall be sent (a) at least 48 hours prior to such
      transfer, in the event such Founder Shares have been registered under the
      Securities Act of 1993, as amended (the “Securities Act”), prior to such
      transfer or (b) at least 20 days prior to such transfer, in the event that
      such
      Founder Shares have not been so registered prior to such transfer. For the
      avoidance of doubt, (x) the registration for resale under the Securities Act
      of
      1933, as amended, of any Founder Shares shall not result in any change of the
      Termination Date until and unless such Founder Shares are actually sold to
      a
      third party, and (y) nothing in this Lock-Up Agreement shall limit the
      undersigned’s right to register the sale of the Common Shares pursuant to the
      registration rights provided for in the Registration Rights Agreement relating
      to the Common Shares of even date herewith to which the undersigned is a party
      if Laurence Levy and/or Edward Levy (as applicable) shall offer Founder Shares
      in a registered offering under the Securities Act. Notwithstanding the
      foregoing, in the event such notice of the transfer of Founder Shares has been
      given, but the transfer shall not have occurred at the time of the transfer
      specified therein, the Termination Date shall occur at the time specified in
      such notice, unless not less than 24 hours prior to such time, Laurence Levy
      and/or Edward Levy (as applicable) shall have given written notice to the
      undersigned, with evidence of actual receipt thereof by the undersigned, that
      such transfer has been cancelled, in which case such transfer of Founder Shares
      shall not occur until a subsequent notice thereof has been given in accordance
      with the terms hereof or waived by the undersigned.

    


    This
      Lock-Up Agreement is irrevocable and will be binding on the undersigned and
      the
      successors, heirs, personal representatives and assigns of the undersigned.
      The
      undersigned hereby represents and warrants that the undersigned has full power
      and authority to enter into this Lock-Up Agreement and executed and delivered
      by
      the undersigned and is a valid and binding agreement of the undersigned. This
      Lock-Up Agreement shall be governed by and construed in accordance with the
      laws
      of the State of New York.

    


    [Signature
      Page Immediately Follows]

     

    
      
         

      

      
        2

        
          

        

      

      
         

      

    


    In
      witness whereof, the undersigned has executed and delivered this agreement
      as of
      the date first set forth above.

    

      
        	
                /s/
                  William L. Erwin

              	 
	
                William
                  L. Erwin

              	 


      

    

    


    [Signature
      page to W. Erwin Lock-Up Agreement]