1200 New Jersey Ave., SE

 Washington, D.C. 20590

January 6, 2012

FHWA:HSST:NArtimovichr:sf:x61331:1/3/12

File: s://directory folder/HSST/Artimovich/ B-227_WashHiTensionCable.docx

cc: HSSI (NArtimovich)

In Reply Refer To:

HSST/B-227

Dave Olson

Design Policy, Standards, & Research Manager

Washington State Department of Transportation

P.O. Box 47329

Olympia, Washington 98504-7329

Dear Mr. Olson:

This letter is in response to your request for the Federal Highway Administration (FHWA) to 

review a roadside safety system for eligibility for reimbursement under the Federal-aid highway 

program. 

Name of system: High Tension 3-cable median and roadside barriers

Type of system: Generic cable barrier system

Test Level: NCHRP Report 350 Test Level 3

Testing conducted by: Texas Transportation Institute

Task Force 13 Designator: SGM01b

Date of request: December 23, 2010

Date initially acknowledged: January 7, 2011

Date of completed package: January 7, 2011

Decision:

The following device is eligible, with details provided below:

• High Tension 3-cable median and roadside barriers

Based on a review of crash test results submitted by the manufacturer certifying the device 

described herein meets the crashworthiness criteria of the National Cooperative Highway 

Research Program (NCHRP) Report 350, the device is eligible for reimbursement under the 

Federal-aid highway program. Eligibility for reimbursement under the Federal-aid highway 

program does not establish approval or endorsement by the FHWA for any particular purpose or 

use. 

The FHWA, the Department of Transportation, and the United States Government do not 

endorse products or services and the issuance of a reimbursement eligibility letter is not an 

endorsement of any product or service.

Requirements

Roadside safety devices should meet the guidelines contained in the NCHRP Report 350 or the
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American Association of State Highway and Transportation Officials’ Manual for Assessing 

Safety Hardware (MASH). The FHWA Memorandum “Identifying Acceptable Highway Safety 

Features” of July 25, 1997 provides further guidance on crash testing requirements of 

longitudinal barriers. 

Description 

The purpose of this test program was to develop a generic, high-tension 3-cable roadside and 

median barrier using the same length-of-need design as the current low-tension generic cable 

systems. The 476-foot long test installation consisted of a 336 ft length modified Weak-Steel 

Post Wire Rope Guardrail System SGR01a-b with posts spaced at 16 feet. A high-tension 

terminal anchored each end. Wire rope heights are the same as detailed in the SGR01a-b 

specification. The system was terminated with Trinity terminals that utilize wire rope Controlled 

Release Posts (CRP). Standard 3x7 non-prestretched wire ropes were used to match field 

applications of the system. A splice connection was placed in the second clear span downstream 

of first contact with the test vehicle.

A Crosby 3/4-inch G-416 epoxy socket was used for termination of each wire rope. The epoxy 

socket termination performed as well as the field swage termination; however, this termination 

presented a higher risk of an unsuccessful full-scale test due to snagging at the termination site. It 

is expected that if the epoxy socket termination is successful the field swage would also be 

successful. Each epoxy socket requires 86 cc. of Crosby Wirelock W416-7 socket compound. A 

standard Crosby HG-226 1-inch x 12-inch eye and eye turnbuckle were used to connect the two 

epoxy sockets at each splice. A 1-inch x 6-inch Crosby G-291 eye bolt with double nuts was 

used to terminate the wire ropes at the CRP. Tension of the wire ropes prior to the full-scale 

crash test was 5620-5640 lb. 

You asked that field swaged fittings, previously crash tested at TTI on cable barrier systems, 

would be found eligible. Dynamic testing of the field swage fitting at Texas Transportation 

Institute (TTI) indicates that field swaged fittings performed better than the Crosby epoxy socket 

used in the full scale crash test. We concur that field swaged fittings (such as the Trinity parts 

5873 and 5874 included in the TTI evaluation) are eligible as an alternative to the Crosby epoxy 

sockets. 

Enclosed for reference is the test data summary sheet showing the crash test and results which 

were in reasonably close conformity with NCHRP Report 350. The vehicle remained upright 

and deflected the barrier 10.2 feet. A working width of 11 feet should be used for design 

purposes.

Findings

The system described above and detailed in the enclosed drawings is eligible for reimbursement 

and should be installed 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 eligibility letters:

• This letter provides a AASHTO/ARTBA/AGC Task Force 13 designator that should be 

used for the purpose of the creation of a new and/or the update of existing Task Force 13 

drawing for posting on the on-line ‘Guide to Standardized Highway Barrier Hardware’ 

currently referenced in AASHTO Roadside Design Guide. 
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• This finding of eligibility 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 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 this letter.

• 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 

review, and that it will meet the crashworthiness requirements of the FHWA and the 

NCHRP Report 350. 

• To prevent misunderstanding by others, this letter of eligibility is designated as number 

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 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 finding of eligibility 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.

• Although the barrier performed well under ideal test impact conditions with the two test 

vehicles, the likelihood of passenger car underrides of any cable system may increase as 

the post spacing increases, particularly when the barrier is installed on non-level or 

slightly irregular terrain and the cables are not restrained from lifting at each post. 

Consequently, some transportation agencies have limited post spacing to approximately 

6m (20 feet) for cable barriers. The dynamic deflection of the barrier is likely to increase 

when it is installed along the convex sides of horizontal curves, and when distances 

between anchorages exceed the 102m (336-foot) test length. 

Sincerely yours,

Michael S. Griffith

Director, Office of Safety Technologies

Office of Safety

Enclosures
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