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                Safety Eligibility Letter B-181
  
  **Hardware Type:**
            Longitudinal Barriers and Bridge Rails
                          **Code:**
            B-181
                          **Date:**
            07/28/2008
                          **Testing Criteria:**
            NCHRP 350
                          **Manufacturer:**
            Western Federal Lands
                          **Device Description:**
            Random Rubble Cavity Wall -- Aesthetic Barrier
                          **View PDF:**
            b181.pdf (1.06 MB)
    
    Memorandum
    	

			 
			**Download Version**PDF [1.47 MB]
			
			DOT logoU.S. Department of TransportationFederal Highway Administration
1200 New Jersey Ave. S.E.Washington, D.C. 20590
            **SENT VIA ELECTRONIC MAIL**
            **Subject:** INFORMATION: FHWA Acceptance Letter B-181 Random 
Rubble  Cavit Wall
	  **Date:** July 28, 2008
	  **From:** /s/ David A. Nicol, P.E. Director, Office of Safety Design
	  **In Reply Refer To:** HSSD/B-181
	  **To:** Ms. Victoria Brinkly   Highway Safety Engineer (HFL-17)   Western Federal Lands Highway Division
            This memorandum is in response to your request for FHWA’s acceptance of a roadside  safety system for use on the NHS.
            
      Name of  system:
        Random Rubble Cavity WallType of  system:Aesthetic Stone Faced Concrete Barrier GuardwallTest Level:
        NCHRP Report 350 TL-1Testing  conducted by:SwRIDate of request:
                March 10, 2008You requested that we find this system acceptable for use on the NHS under the provisions of  the NCHRP Report 350 "Recommended Procedures for the Safety Performance Evaluation  of Highway Features."
      **Requirements**
      Roadside safety systems should meet the guidelines contained in the NCHRP Report 350,  "Recommended Procedures for the Safety Performance Evaluation of Highway Features".  The FHWA Memorandum "ACTION: Identifying Acceptable Highway Safety Features"of  July 25, 1997 provides further guidance on crash testing requirements of longitudinal  barriers
      **Description**
      The Random Rubble Cavity Wall is 460 mm wide and composed of two different height  sections. One section is 460 mm tall by 3.66 m long, and the other section is 610 mm tall by  1.68 m long as shown in the attached drawings for reference. The sections are staggered  such that there is a 610 mm tall section then a 460 mm tall section and then another 610 mm tall section. This alternating height pattern continues for the length of the installation. The  guardwall consists of a reinforced concrete footing and a reinforced concrete core.  Indigenous rock is placed on the sides and top of the concrete core. The majority of the rock  is 300 mm to 460 mm in size with smaller rocks and masonry mortar used to complete the  assembly of the guardwall.  Crash Testing  Full-scale crash testing was conducted on this barrier. The TL-2 testing at 70 km/hr  (43.5 mph) resulted in failure when the 2000P test vehicle drove over the barrier. Two TL-1  tests were conducted at 50 km/hr (31 mph), NCHRP Report 350 Test 1-10 (RW-2) and Test  1-11 (RW-1). Copies of the test data summary sheets for these tests are enclosed for  reference. In both tests the vehicles were smoothly redirected and the occupant impact  values were within the required limits. There was no deflection of the barrier in either test,  nor was there any deformation of the occupant compartment.
      **Findings**
      Therefore, Random Rubble Cavity Wall 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 the FHWA letters of acceptance:
      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 number  B-181 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.
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.   3 Attachments  Arc3 Attachments U.S. DEPARTMENT OF TRANSPORTATION

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