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                Safety Eligibility Letter LS-71
  
  **Hardware Type:**
            Luminaire Supports
                          **Code:**
            LS-71
                          **Date:**
            01/31/2011
                          **Testing Criteria:**
            NCHRP 350
                          **Manufacturer:**
            Akron Foundry Company
                          **Device Description:**
            Cast Aluminum Transformer Bases
                          **View PDF:**
            ls71.pdf (65.46 KB)
    
    "FHWA Logo"

1200 New Jersey Ave. S.E.
Washington, D.C. 20590

January 31, 2011

In Reply Refer To: HSST/LS-71

Mr. Robert Sik
Akron Foundry Company
P.O. Box 27028
Akron, Ohio 44314

Dear Mr. Sik:

This is in response to your letter of December 13, 2010 requesting the Federal Highway Administration’s (FHWA) acceptance of a common modification to a number of your cast aluminum transformer bases. You wish to modify the top bolt circle of your crashworthy transformer bases to a pattern other than what was originally tested. You accomplish this by welding a 3/4 thick plate with the revised bolt pattern to the tops of these bases.

Because all of the breakaway features are in the lower portion of these transformer bases, we concur that modifying the top will have no significant affect on crash performance. As long as the new plate is securely welded to the top, and the bottoms are identical to bases tested and accepted, they will still be considered acceptable for use on the National Highway System. The following chart summarizes the FHWA acceptance letters that address these bases.

LS-14
			May 30, 1990
			Valmont Industries
			Cast Al transformer base No. 0283093 15 inch bolt circle
			Transformer BaseLS-17
			August 6, 1990
			Akron Foundry
			CS-300 and CS-370 Al Transformer Bases (tests of Feralux bases)
			Transformer BaseLS-18
			August 6, 1990
			Akron Foundry
			F-1300 and F-1302 Al Transformer Bases (tests of Pole Lite bases)
			Transformer BaseLS-19
			August 6, 1990
			Akron Foundry
			TB-3-17, TB-5-9, TB-6-9 Transformer Bases, 11.5 to 15.5" BC
			Transformer BaseLS-22
			September 19, 1990
			Akron Foundry
			Chart summarizing approval letters LS-2, LS-4, LS-9, LS-15, LS-19
			Transformer BaseLS-58
			February 8, 2005
			Akron Foundry
			Addition of Stack Pack washers to TB1-17
			Transformer BaseLS-61
			December 15, 2006
			Akron Foundry
			Revised bolt circle on Akron Foundry TB-6-9
			Transformer BaseLS-62
			December 15, 2006
			Akron Foundry
			Revised bolt circle on Feralux CS-300
			Transformer BaseLS-63
			December 15, 2006
			Akron Foundry
			Revised bolt circle on Pole-lite F-1300
			Transformer BaseEnclosed for reference please find a set of drawings representing this condition which would be true for your complete line of bases. All previous conditions contained in the acceptance letters remain in effect.

Sincerely

			*/* Signature of Michael S. Griffith */*

			Michael S. Griffith
			Director, Office of Safety Technologies
			Office of SafetyEnclosures U.S. DEPARTMENT OF TRANSPORTATION

**Federal Highway Administration**

1200 NEW JERSEY AVENUE, SE

WASHINGTON, DC 20590

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