Exhibit
      10.6

    


    COMPLIANCE
      ESCROW AGREEMENT

    


    THIS
      COMPLIANCE ESCROW AGREEMENT (this “Escrow
      Agreement”)
      made
      as of October 31, 2008, by and among Hyde Park Acquisition Corp., a Delaware
      corporation (the “Purchaser”), KCP
      Services, LLC, a Delaware limited liability company (the “Seller
      Representative”),
      and
      KeyBank National Association, as escrow agent (the “Escrow
      Agent”).
      

    


    WITNESSETH

    


    WHEREAS,
      Essex Crane Rental Corporation, a Delaware corporation (“Essex”),
      the
      Purchaser, Seller Representative, Essex Holdings LLC, a Delaware limited
      liability company (“Holdings”)
      and
      the members of Holdings (the “Members”)
      have
      entered into a certain Purchase Agreement dated as of March 6, 2008, as amended
      May 9, 2008 and August 14, 2008 (the “Purchase
      Agreement”)
      with
      respect to the sale to Purchaser of a majority of the equity securities of
      Holdings; 

    


    WHEREAS,
      pursuant to the Purchase Agreement, Essex, Holdings, Seller Representative,
      the
      Members and Purchaser have entered into a certain Compliance Agreement dated
      as
      of March 6, 2008 (the “Compliance
      Agreement”)
      (capitalized terms used but not otherwise defined herein shall have the meanings
      attributed to them in the Compliance Agreement); and

    


    WHEREAS,
      pursuant to the Purchase Agreement and Compliance Agreement a portion of the
      Total Purchase Price (as defined in the Purchase Agreement) shall be delivered
      to the Escrow Agent to be held in escrow in accordance with the provisions
      hereof.

    


    NOW,
      THEREFORE, in consideration of the premises set forth herein and for other
      good
      and valuable consideration, the receipt and sufficiency of which are hereby
      acknowledged, the parties agree as follows:

    


    1. Appointment
      of Escrow Agent.
      The
      Escrow Agent is hereby appointed to act as Escrow Agent hereunder in accordance
      with the terms set forth herein, and the Escrow Agent hereby agrees to accept
      such
      appointment.

    


    2. Deposit
      of Escrow Funds.
      

    


    (a) At
      the
      Closing (as defined in the Purchase Agreement), the Purchaser shall deliver
      to
      the Escrow Agent an aggregate amount of $492,225 (the “Escrow
      Funds”)
      by
      wire transfer of immediately available funds. The Escrow Funds are to be held
      and disbursed by the Escrow Agent in accordance with the terms set forth herein.
      

    
      


      
        
          
          

        

        
          
          

          
            

          

        

        
          
          



      

    

    (b) During
      the term of this Escrow Agreement, the Escrow Funds shall be held in a trust
      account at KeyBank National Association (“Trust
      Account”),
      together with the Cash Escrow Funds subject to that certain Escrow Agreement,
      dated October 31, 2008, among Purchaser, Seller Representative and Escrow Agent
      (the “General
      Escrow Agreement”),
      segregated apart from the general funds of KeyBank National Association, pending
      disbursement pursuant to this Escrow Agreement. The Escrow Agent shall cause
      the
      Escrow Funds to be invested, to the maximum practical extent, in United States
      Treasury bills having a maturity of thirty-one (31) days or less or other
      similar short-term instruments, including, without limitation, the Victory
      Institutional Money Market Fund, payment of the principal and interest on which
      is backed by the full faith and credit of the United States. Any interest earned
      on the Escrow Funds shall be for the account of the Seller Representative.
      Accordingly, the Escrow Agent shall distribute to Seller Representative within
      five days following the end of each calendar quarter an amount equal to any
      interest or other earnings on such Escrow Funds. The Escrow Agent shall not
      have
      any liability for any loss sustained as a result of any investment in an
      investment made pursuant to the terms of this Escrow Agreement. The Escrow
      Agent
      shall have the right to liquidate any investments held in order to provide
      funds
      necessary to make required payments under this Escrow Agreement.

     

    3. Release
      of
      Escrow Funds.
      The
      Escrow Funds shall be distributed by the Escrow Agent as follows:

    


    (a) If
      the
      Seller Representative and the Purchaser shall at any time jointly direct Escrow
      Agent in writing to distribute some or all of the Escrow Funds, or if Escrow
      Agent shall have received an order, decree or judgment of a court or arbitrator
      of competent jurisdiction and directing Escrow Agent to distribute some or
      all
      of the Escrow Funds, Escrow Agent shall on the fifth (5th) Business Day
      thereafter distribute the amount of the Escrow Funds as directed in such joint
      written direction, order, decree or judgment. 

    


    (b) At
      any
      time during the term of this Agreement, Purchaser may give to Seller
      Representative and the Escrow Agent written notice (a “Payment
      Notice”)
      describing in reasonable detail any costs incurred by Purchaser or the Company
      following the Closing with respect to completion of the work items listed on
      Schedule A hereto (“Costs”).
      In
      the event that Seller Representative disputes that the amount of the Costs
      specified in a Payment Notice, or any portion thereof, is due and payable to
      Purchaser, Seller Representative shall deliver to Purchaser and Escrow Agent
      a
      notice (an “Objection
      Notice”)
      indicating the amount of such dispute (a “Disputed
      Amount”)
      and
      describing in reasonable detail the grounds for such dispute. If the Escrow
      Agent does not receive a copy of an Objection Notice on or prior to the tenth
      (10th)
      Business Day (the “Objection
      Date”)
      immediately following receipt by the Escrow Agent of a copy of a Payment Notice
      delivered pursuant to the this Agreement, then the Escrow Agent shall, on the
      fifth (5th)
      Business Day after the Objection Date, distribute to, or as directed by, the
      Purchaser the amount claimed by the Purchaser in the Payment
      Notice.

    


    (c) If
      the
      Escrow Agent receives a copy of an Objection Notice on or prior to the Objection
      Date, then the Escrow Agent shall (i) on the fifth (5th)
      Business Day after the Objection Date distribute to, or as directed by, the
      Purchaser the amount claimed by the Purchaser in the Payment Notice which is
      not
      disputed by the Seller Representative in such Objection Notice and (ii) retain
      as part of the Escrow Funds the Disputed Amount, and continue to hold and
      disburse such amount in accordance with the provisions of this Escrow
      Agreement.

    


    
      
        
        

      

      
        -2-

        
          

        

      

      
        
        

      

       

    

    (d) Promptly,
      but in no event longer than five (5) Business Days, following the date on which
      Purchaser and Seller agree that the work items listed on Schedule A have been
      fully completed, the Purchaser and the Seller Representative shall deliver
      joint
      written notice to the Escrow Agent directing the Escrow Agent to distribute
      to,
      or as directed by, the Seller Representative the then-remaining amount of the
      Escrow Funds less
      (A) the
      aggregate of any Disputed Amounts and (B) the amount claimed by the Purchaser
      in
      any Payment Notices received as of such date by the Escrow Agent in respect
      of
      which an Objection Notice had not yet been received, or required to be received,
      by the Escrow Agent (“Pending
      Claim Amounts”).
      The
      Escrow Agent shall continue to hold and disburse such Disputed Amounts and
      Pending Claim Amounts in accordance with the provisions of this Escrow
      Agreement.

    


    4. Escrow
      Agent.

    


    (a) The
      Escrow Agent undertakes to perform only such duties as are expressly set forth
      herein and no duties shall be implied. The Escrow Agent shall have no liability
      under and no duty to inquire as to the provisions of any agreement other than
      this Escrow Agreement. The Escrow Agent shall neither be responsible for, nor
      chargeable with, knowledge of, nor have any requirements to comply with, the
      terms and conditions of any other agreement, instrument or document between
      any
      of the parties hereto, in connection herewith, if any, including without
      limitation the Compliance Agreement, nor shall the Escrow Agent be required
      to
      determine if any person or entity has complied with any such agreements, nor
      shall any additional obligations of the Escrow Agent be inferred from the terms
      of such agreements, even though reference thereto may be made in this Escrow
      Agreement.

    


    (b) The
      Escrow Agent may rely upon and shall not be liable for acting or refraining
      from
      acting upon any written notice, instruction or request furnished to it hereunder
      and reasonably believed by it to be genuine and to have been signed or presented
      by the proper party or parties. The Escrow Agent shall be under no duty to
      inquire into or investigate the validity, accuracy or content of any such
      document. The Escrow Agent shall have no duty to solicit any payments which
      may
      be due it or the Escrow Funds. The Escrow Agent shall have no duty or obligation
      to make any calculations of any kind hereunder.

    


    (c) The
      Escrow Agent shall not be liable for any action taken or omitted by it in good
      faith except to the extent that a court of competent jurisdiction determines
      that the Escrow Agent's gross negligence or willful misconduct was the primary
      cause of any loss to the Purchaser or the Seller Representative. The Escrow
      Agent may execute any of its powers and perform any of its duties hereunder
      directly or through agents or attorneys (and shall be liable only for the
      careful selection of any such agent or attorney) and may consult with counsel,
      accountants and other skilled persons to be selected and retained by it. The
      Escrow Agent shall not be liable for anything done, suffered or omitted in
      good
      faith by it in accordance with the advice or opinion of any such counsel,
      accountants or other skilled persons. In the event that the Escrow Agent shall
      be uncertain as to its duties or rights hereunder or shall receive instructions,
      claims or demands from any party hereto which, in its opinion, conflict with
      any
      of the provisions of this Escrow Agreement, it shall be entitled to refrain
      from
      taking any action and its sole obligation shall be to hold safely all the Escrow
      Funds until it shall be directed otherwise in writing by the Purchaser and
      the
      Seller Representative jointly or by a final order or judgment of a court of
      competent jurisdiction. The parties to this Escrow Agreement agree to pursue
      any
      redress or recourse in connection with any dispute without making the Escrow
      Agent a party to the same, except where the Escrow Agent is a necessary party
      or
      is otherwise required by law to be a party to such dispute.

    


    
      
        
        

      

      
        -3-

        
          

        

      

      
        
        

      

    

    


    (d) Anything
      in this Escrow Agreement to the contrary notwithstanding, in no event shall
      the
      Escrow Agent be liable for special, indirect or consequential loss or damage
      of
      any kind whatsoever (including but not limited to lost profits), even if the
      Escrow Agent has been advised of the likelihood of such loss or damage and
      regardless of the form of action.

    


    5. Succession.
      The
      Escrow Agent may resign and be discharged from its duties or obligations
      hereunder by giving 30 days advance notice in writing of such resignation to
      the
      Purchaser and the Seller Representative specifying a date when such resignation
      shall take effect. The Purchaser and the Seller Representative shall use their
      best efforts to mutually agree on a successor escrow agent within thirty (30)
      days after receiving such notice The successor escrow agent shall execute and
      deliver an instrument accepting such appointment and it shall, without further
      acts, be vested with all the estates, properties, rights, powers and duties
      of
      the predecessor escrow agent as if originally named escrow agent. If the
      Purchaser and the Seller Representative have failed to appoint a successor
      escrow agent prior to the expiration of thirty
      (30) days following receipt of the notice of resignation, the Escrow Agent
      may
      petition any court of competent jurisdiction for the appointment of a successor
      escrow agent or for other appropriate relief, and any such resulting appointment
      shall be binding upon all of the parties hereto. Escrow Agent’s sole
      responsibility after such thirty (30) day notice period expires shall be to
      hold
      the Escrow Funds (without any obligation to reinvest the same) and to deliver
      the same to a designated substitute escrow agent, if any, or in accordance
      with
      the directions of a final order or judgment of a court of competent
      jurisdiction, at which time of delivery Escrow Agent’s obligations hereunder
      shall cease and terminate. The Escrow Agent shall have the right to withhold
      an
      amount equal to any amount due and owing to the Escrow Agent, plus any costs
      and
      expenses the Escrow Agent shall reasonably believe may be incurred by the Escrow
      Agent in connection with the termination of this Escrow Agreement. Any
      corporation or association into which the Escrow Agent may be merged or
      converted or with which it may be consolidated, or any corporation or
      association to which all or substantially all the escrow business of the Escrow
      Agent’s line of business may be transferred, shall be the Escrow Agent under
      this Escrow Agreement without further act.

    


    6. Fees.
      The
      Purchaser and the Seller Representative agree jointly and severally to (i)
      pay
      the Escrow Agent upon execution of this Escrow Agreement and from time to time
      thereafter reasonable compensation for the services to be rendered hereunder,
      pursuant to the fee schedule set forth in the General Escrow Agreement, and
      (ii)
      pay or reimburse the Escrow Agent upon request for all expenses, disbursements
      and advances, including reasonable attorney's fees and expenses, incurred or
      made by it in connection with the preparation, execution, performance, delivery,
      modification and termination of this Escrow Agreement. 

    


    7. Indemnity.
      The
      Purchaser and the Seller Representative shall jointly and severally indemnify,
      defend and save harmless the Escrow Agent
      and its
      directors, officers, agents and employees from all loss, liability or expense
      (including the fees and expenses of in house or outside counsel) arising out
      of
      or in connection with (i) the Escrow Agent's execution and performance of this
      Escrow Agreement, except in the case of any indemnitee to the extent that such
      loss, liability or expense is finally adjudicated by a court of competent
      jurisdiction to have been primarily caused by the gross negligence or willful
      misconduct of such indemnitee, or (ii) its following any instructions or other
      directions from the Purchaser or the Seller Representative, except to the extent
      that its following any such instruction or direction is expressly forbidden
      by
      the terms hereof. The parties hereto acknowledge that the foregoing indemnities
      shall survive the resignation or removal of the Escrow Agent or the termination
      of this Escrow Agreement. The Purchaser and the Seller Representative hereby
      grant the Escrow Agent a lien on, right of set-off against and security interest
      in the Escrow Funds for the payment of any claim for indemnification,
      compensation, expenses and amounts due hereunder.

    


    
      
        
        

      

      
        -4-

        
          

        

      

      
        
        

      

       

    

    8. Termination.
      This
      Escrow Agreement shall automatically, without any action by the Purchaser or
      the
      Seller Representative, be terminated upon the disbursement by the Escrow Agent
      of all the Escrow Funds pursuant to the terms herein.

    


    9. Notices.
      

    


    (a) All
      communications hereunder shall be in writing and shall be deemed to be duly
      given and received:

    


    (i)
      upon
      delivery if delivered personally or upon confirmed transmittal if by
      facsimile;

    


    (ii)
      on
      the next Business Day (as hereinafter defined) if sent by overnight courier;
      or

    


    (iii)
      four (4) Business Days after mailing if mailed by prepaid registered mail,
      return receipt requested, to the appropriate notice address set forth below
      or
      at such other address as any party hereto may have furnished to the other
      parties in writing by registered mail, return receipt requested.

    


    (b) Notwithstanding
      the above, in the case of communications delivered to the Escrow Agent pursuant
      to (ii) and (iii) of this Section 9, such communications shall be deemed to
      have
      been given on the date received by the Escrow Agent. In the event that the
      Escrow Agent, in its sole discretion, shall determine that an emergency exists,
      the Escrow Agent may use such other means of communication as the Escrow Agent
      reasonably deems appropriate.

    


    (c) "Business
      Day" shall mean any day other than a Saturday, Sunday or any other day on which
      the Escrow Agent located at the notice address set forth below is authorized
      or
      required by law or executive order to remain closed.

    


    (d) All
      communications under this Escrow Agreement shall be delivered to the following
      address:

    


    
      
        
        

      

      
        -5-

        
          

        

      

      
        
        

      

    

    


    
      	
              If
                to the Purchaser:

            	
              Hyde
                Park Acquisition Corp.

              461
                Fifth Avenue, 25 Floor

              New
                York, NY 10017 

              Attn:
                Laurence S. Levy and Edward Levy 

              Fax:
                (212) 644-6262

            
	 	 
	
              with
                a copy to:

            	
              Katten
                Muchin Rosenman LLP

              575
                Madison Avenue

              New
                York, NY 10022

              Attention:
                Todd J. Emmerman, Esq.

              Fax:
                (212) 940-8776

            


    

     

    
      	
              If
                to Seller Representative:

            	
              KCP
                Services LLC

              3201
                Enterprise Parkway, Suite 200

              Beachwood,
                OH 44122

              Attention:
                Michael DeGrandis

              Fax
                (216) 593-0240

               

            
	
              with
                a copy to:

            	
              Jones
                Day

              North
                Point

              901
                Lakeside Avenue

              Cleveland,
                OH 44114

              Attention:
                Charles W. Hardin Jr.

              Fax
                (216) 579-0212

            


    

    


    
      	
              If
                to the Escrow Agent:

            	
              KeyBank
                National Association

              127
                Public Square

              Corporate
                Escrow Dept., 14th
                Floor

              Cleveland,
                Ohio 44114

              Attn:
                Joyce A. Apostolec

              Fax
                (216) 689-3777

            


    

    


    10. Amendments
      and Waivers.
      This
      Escrow Agreement may only be amended with the written consent of the parties
      or
      their respective successors and assigns. Any amendment or waiver effected in
      accordance with this Section 10 shall be binding upon the parties and their
      respective successors and assigns.

    


    11. Successors
      and Assigns.
      The
      terms and conditions of this Escrow Agreement shall inure to the benefit of
      and
      be binding upon the parties and their successors and assigns. Except as
      otherwise set forth herein, no party to this Escrow Agreement may assign its
      rights or delegate its duties under this Escrow Agreement without the consent
      of
      the other parties hereto. The
      term
“Escrow Agent” as used herein shall also refer to the successors and assigns of
      Escrow Agent, including, without limitation, a receiver, trustee, custodian
      or
      debtor-in-possession.

    


    
      
        
        

      

      
        -6-

        
          

        

      

      
        
        

      

       

    

    12. Titles
      and Subtitles.
      The
      titles and subtitles used in this Escrow Agreement are used for convenience
      only
and are not to be considered in construing or interpreting this Escrow
      Agreement.

    


    13. Severability.
      If one
      or more provisions of this Escrow Agreement are held to be unenforceable under
      applicable law, the parties agree to renegotiate such provision in good faith.
      In the event that the parties cannot reach a mutually agreeable and enforceable
      replacement for such provision, then (i) such provision shall be excluded
      from this Escrow Agreement, (ii) the balance of this Escrow Agreement shall
      be interpreted as if such provision were so excluded and (iii) the balance
      of this Escrow Agreement shall be enforceable in accordance with its
      terms.

    


    14. Entire
      Agreement.
      This
      Escrow Agreement constitutes the entire agreement among the parties hereto
      pertaining to the subject matter hereof, and merges all prior negotiations
      and
      drafts of the parties with regard to the transactions contemplated
      herein.

    


    15. Counterparts.
      This
      Escrow Agreement may be executed in a number of identical counterparts but
      all
      counterparts shall constitute one agreement. All signatures of the parties
      to
      this Escrow Agreement may be transmitted by facsimile, and such facsimile will,
      for all purposes, be deemed to be the original signature of such party whose
      signature it reproduces and will be binding upon such party.

    


    16. Governing
      Law.
      This
      Escrow Agreement and all acts and transactions pursuant hereto and the rights
      and obligations of the parties hereto shall be governed, construed and
      interpreted in accordance with the laws of the State of New York, without giving
      effect to principles of conflicts of law.

    


    17. Consent
      to Jurisdiction; Waiver of Jury Trial.
      Each of
      the parties hereto hereby irrevocably consents to the exclusive jurisdiction
      of
      the courts of the State of New York and the United States District Court for
      the
      Southern District of New York and waives trial by jury in any action or
      proceeding with respect to this Escrow Agreement.

    


    18. Compliance
      with Court Orders.
      In the
      event that any escrow property shall be attached, garnished or levied upon
      by
      any court order, or the delivery thereof shall be stayed or enjoined by an
      order
      of a court, or any order, judgment or decree shall be made or entered by any
      court order affecting the property deposited under this Escrow Agreement, the
      Escrow Agent is hereby expressly authorized to obey and comply with all writs,
      orders or decrees so entered or issued, which it is advised by legal counsel
      is
      binding upon it, and in the event that the Escrow Agent obeys or complies with
      any such writ, order or decree it shall not be liable to any of the parties
      hereto or to any other person, firm or corporation, by reason of such compliance
      notwithstanding such writ, order or decree be subsequently reversed, modified,
      annulled, set aside or vacated.

    


    19. Tax
      Reporting.
      Prior
      to execution of this Escrow Agreement, the Seller Representative shall provide
      the Escrow Agent with a fully executed W-8 or W-9 Internal Revenue Service
      form,
      which shall include its Tax Identification Number (TIN) as assigned by the
      Internal Revenue Service. 


    
      
        
           

        

        
        

      

      
        -7-

        
          

        

      

      
        
        

        
        

      

    


    IN
      WITNESS WHEREOF, the parties have duly executed this Escrow Agreement as of
      the
      date first hereinabove stated.

    


    
      	
              KEYBANK
                NATIONAL ASSOCIATION

            	 
	 	 
	 	 
	
              /s/
                Joyce A. Apostolec

            	 
	
              Name:
                Joyce A. Apostolec

            	 
	
              Title:
                Assistant Vice President

            	 
	 	 
	
              HYDE
                PARK ACQUISITION CORP.

            	 
	 	 
	 	 
	
              /s/
                Laurence Levy

            	 
	
              Name:
                Laurence Levy

            	 
	
              Title:
                Chief Executive Officer

            	 
	 	 
	 	 
	
              KCP
                SERVICES LLC

            	 
	 	 
	
              By:
                Kirtland Capital Corporation, its managing member

            	 
	 	 
	 	 
	
              /s/
                Michael T. DeGrandis

            	 
	
              Name:
                Michael T. DeGrandis

            	 
	
              Title:
                Vice President

            	 
	
              Title:

            	 


    

    


    [Signature
      page to Compliance Agreement Escrow]


    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    


    Schedule
      A

    


    
      	
              Facility

            	 	
              Item#

            	 	
              Description
                of Work Item

            
	 	 	 	 	 
	
              Alabaster,
                AL

            	 	
              1

            	 	
              Construct
                three buildings (wash pad and containment)

            
	 	 	
              2

            	 	
              Finalize
                SPCC plan

            
	 	 	
              3

            	 	
              Compliance
                with applicable area source requirements

            
	 	 	 	 	 
	
              Arcola,
                TX

            	 	
              1

            	 	
              Wash
                pad reconstruction

            
	 	 	
              2

            	 	
              Contaminated
                soil testing, loading, transport and disposal

            
	 	 	
              3

            	 	
              Confirmatory
                soil sampling and analysis

            
	 	 	
              4

            	 	
              Contingency
                contaminated soil excavation, testing, loading, transport and
                disposal

            
	 	 	
              5

            	 	
              Contingency
                backfill

            
	 	 	
              6

            	 	
              Concrete
                pad for secondary containment area

            
	 	 	
              7

            	 	
              Waste
                oil transfer system (portable containers)

            
	 	 	
              8

            	 	
              Waste
                oil transfer system pump

            
	 	 	
              9

            	 	
              Waste
                oil transfer system hoses, fittings, compressed air
                line

            
	 	 	
              10

            	 	
              Fuel
                dispenser drip tray

            
	 	 	
              11

            	 	
              Clarifier
                / oil water separator system

            
	 	 	
              12

            	 	
              Installation,
                supervision and training for above

            
	 	 	
              13

            	 	
              Finalize
                SPCC Plan

            
	 	 	
              14

            	 	
              Compliance
                with applicable area source requirements

            
	 	 	 	 	 
	
              Carlisle,
                PA

            	 	 	 	
              None

            
	 	 	 	 	 
	
              Fontana,
                CA

            	 	 	 	
              None

            
	 	 	 	 	 
	
              Longmont,
                CO

            	 	 	 	
              None

            
	 	 	 	 	 
	
              Rochester,
                WA

            	 	 	 	
              None

            
	 	 	 	 	 
	
              Tampa,
                FL

            	 	
              1

            	 	
              Pre-engineered
                steel roof, containment building, concrete curb

            
	 	 	 	 	
              behind
                maintenance building

            
	 	 	
              2

            	 	
              Compliance
                with applicable area source requirements

            
	 	 	 	 	 
	
              General

            	 	
              1

            	 	
              Engineering
                oversight

            


    

    


    [End
      of
      Exhibit A]