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                Safety Eligibility Letter CC-109B
  
  **Hardware Type:**
            Barrier Terminals and Crash Cushions
                          **Code:**
            CC-109B
                          **Date:**
            08/17/2011
                          **Testing Criteria:**
            NCHRP 350
                          **Manufacturer:**
            Barrier Systems
                          **Device Description:**
            TL-3 X-Ten Backstop Extension
                          **View PDF:**
            cc109b.pdf (87.54 KB)
    
    Safety Eligibility Letter CC-109B


			 

			**Download Version**PDF [88 KB]

			

			DOT logoU.S. Department of Transportation**Federal Highway Administration**

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

			August 17, 2011

			In Reply Refer To: HSSD/CC-109B

			

	 Mr.  Gerrit A. Dyke, P.E.
	   Barrier  Systems, Inc.
	   3333  Vaca Valley Parkway, Suite 800
	   Vacaville,  CA 95688
	 Dear Mr. Dyke:

   This  letter is in response to your request for the Federal Highway Administration  (FHWA) acceptance of a roadside safety system for use on the National Highway  System (NHS).
Name of system:

					X-TENuator and X-TENuator Wide Backstop ExtensionType of system:

					Backstop Extension for X-TEN and X-TEN Wide Crash CushionsTest Level:

					NCHRP Report 350 Test Level 3 (TL-3)Testing conducted by:

					Safe Technologies Inc.Date of request:

					December 29, 2010Request Initially acknowledged:

					January 7, 2011Task Force 13 designator:

					SCI23c X-TENuator Backstop Extension; and,
 	  X-TENuator Wide Backstop ExtensionYou  requested that we find a backstop extension design used in conjunction with  your X-TEN and X-TEN Wide crash cushions acceptable for use on the NHS under  the provisions of the National Cooperative Highway Research Program (NCHRP)  Report 350 “Recommended Procedures for the Safety Performance Evaluation of  Highway Features.” The original design width described in FHWA Acceptance  letter CC-109 for your parallel-sided attenuator was 36-inches (926-millimeters)  and the maximum width for your X-TEN Wide described in Acceptance letter  CC-109A was 60-inches (1525-millimeters) wide.
    **Requirements**
      Roadside  safety devices should meet the guidelines contained in the NCHRP Report 350 if  tested prior to December 31, 2010 or the American Association of State Highway  and Transportation Officials’ Manual for Assessing Safety Hardware (MASH) if  tested after that date.  The FHWA  Memorandum “Identifying Acceptable Highway Safety Features” of July 25, 1997  provides further guidance on crash testing requirements of longitudinal  barriers.
    **Decision**
      The  following system design was found acceptable, with details provided below:
    X-TENuator  and X-TENuator Wide Backstop Extension********
    ****
    **Description**
      The  X-TEN and X-TEN Wide systems are both redirective, non-gating crash cushion  designed to decelerate an errant vehicle to a safe stop when struck end-on or  redirect an errant vehicle away from roadside or median hazards when impacted  along either side.  The systems are  comprised of an energy absorbing nose bracket and cover, dual X-Tension impact  heads and cables, front cable anchors, and W-Beam side panels.  The narrow X-TEN uses single posts or double  support posts with braces, whereas the X-TEN Wide uses only the double row of  specially designed posts and post braces.   Standard W-Beam offset blocks are used to attach the side panels to the  posts.
    The  X-TEN Backstop Extension is intended for use with the X-TEN when hazards wider  than 36 inches (926 millimeters) are encountered or with the X-TEN Wide for  hazards greater than 60 inches (1525 millimeters) in width.  By separate correspondence, you indicated  that the Backstop Extension would be marketed to shield hazards 48 inches, 60  inches, and 72 inches ( 1.2 meters, 1.5 meters, and1.9 meters ) wide when used  behind the narrow, parallel-sided X-TEN, and 86 inches, 98 inches and 110  inches (2.2 meters, 2.5 meters, and 2.8 meters ) wide hazards when used with  the X-TEN Wide unit.  The Backstop  Extension (Enclosure 1) uses fabricated steel posts (Enclosure 2),  variable-sized cross braces (Enclosure 3), and attachment brackets (Enclosure  4) in addition to standardized hardware items.
    **Crash  Testing**
      Since  both the X-TEN and the X-TEN Wide designs were fully crash-tested and accepted  for use on the NHS by FHWA, only two tests were considered necessary to verify  the crashworthiness of the X-TEN Backstop Extension.  Tests 3-36 and 3-38 were conducted with the  Backstop Extension installed at its maximum 10-degree angle and connected to  the narrow X-TEN design.  For both tests,  the  system was attached to a  75-millimeter (3-inch) thick Asphalt Concrete (AC) pad over 300 millimeters (12  inches) of a dense graded aggregate with eighty-six (86) 20-millimeter  (3/4-inch) long all thread studs embedded 400 millimeters(16 inches) and  epoxied in place. Enclosures 5 and 6 summarize the results of these tests.
    **Findings**
      The  FHWA concurs that the tests you ran were sufficient to verify acceptable crash  performance under NCHRP Report 350 and that each test met the appropriate  evaluation criteria.  In your letter, you  have requested FHWA acceptance of the following:
    The X-TEN Backstop       Extension may be considered an NCHRP Report 350 TL-3 design
      The Backstop Extension may       be used with the narrow X-TEN to shield hazards up to 72-inches       (1830-millimeters) wide, or with the X-TEN Wide to shield hazards up to       110-inches (2800-millimeters) wide.
      As with the crash       cushions, the Backstop Extension can be installed on an AC pad as       described above or on a 10-inch (250-millimeter) PCC pad.
      The  X-TEN Backstop Extension can be further extended using Thrie-beam barrier  and/or attached to concrete barrier by using standard transitions that have  been accepted for attaching “W” profile guardrails to rigid barrier systems.Based  on our review of the submitted information, including test reports, the X-TEN  Backstop Extension described above and detailed in the enclosed drawings is  acceptable for use on the NHS under the range of conditions tested, when such  use is acceptable to a highway agency.
    Please  note the following standard provisions that apply to FHWA letters of  acceptance:
    This  letter includes a Task Force 13 designator to be used when drafting new of  revised Task Force 13 drawings.
      This  acceptance is limited to the crashworthiness characteristics of the systems and  does not cover their structural features, nor conformity with the Manual on  Uniform Traffic Control  Devices.
      Any  changes that may adversely influence the crashworthiness of the system will  require a new acceptance letter.
      Should  the FHWA discover that the qualification testing was flawed, that in-service  performance reveals unacceptable safety problems, or that the system being  marketed is significantly different from the version that was crash tested, we  reserve the right to modify or revoke our acceptance.
      You  will be expected to supply potential users with sufficient information on  design and installation requirements to ensure proper performance.
      You  will be expected to certify to potential users that the hardware furnished has  essentially the same chemistry, mechanical properties, and geometry as that  submitted for acceptance, and that it will meet the crashworthiness  requirements of the FHWA and the NCHRP Report 350.
      To  prevent misunderstanding by others, this letter of acceptance is designated as  numberCC-109B  and shall not be reproduced except in full. This letter and the test  documentation upon which it is based are public information. All such letters  and documentation may be reviewed at our office upon request.
    The  X-TEN Backup Extension is a patented product and considered proprietary.  If proprietary systems are specified by a  highway agency for use on Federal-aid projects, except exempt, non-NHS  projects, (a) they must be supplied through competitive bidding with equally  suitable unpatented items; (b) the highway agency must certify that they are  essential for synchronization with the existing highway facilities or that no  equally suitable alternative exists; or (c) they must be used for research or  for a distinctive type of construction on relatively short sections of road for  experimental purposes.  Our regulations  concerning proprietary products are contained in Title 23, Code of Federal  Regulations, Section 635.411.
      This acceptance letter shall not be construed as  authorization or consent by the FHWA to use, manufacture, or sell any patented  system for which the applicant is not the patent holder.  The acceptance letter is limited to the  crashworthiness characteristics of the candidate system, and the FHWA is  neither prepared nor required to become involved in issues concerning patent  law.  Patent issues, if any, are to be  resolved by the applicant.Sincerely yours,
			      
			      */* Signature of Michael S. Griffith */*
			      
			      Michael S. GriffithDirector, Office of Safety TechnologiesOffice of SafetyEnclosures U.S. DEPARTMENT OF TRANSPORTATION

**Federal Highway Administration**

1200 NEW JERSEY AVENUE, SE

WASHINGTON, DC 20590

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