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Safety Eligibility Letter B-134D

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U.S. Department of Transportation
Federal Highway Administration

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

August 29, 2008

In Reply Refer To: HSSD/B-134D

Barry D. Stephens, P.E.
Sr. Vice President Engineering
Energy Absorption Systems, Inc.
3617 Cincinnati Avenue
Rocklin, CA 95678

Dear Mr. Stephens:

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: 12M and 4M Vulcan Barrier™
Manufacturer: Energy Absorption Systems, Inc. (EASI)
Type of system: Portable Steel Thrie Beam Longitudinal Barrier
Test Level: NCHRP Report 350 TL-4
Testing conducted by: LIER (Inrets Road Equipment Test Laboratory, France)
Date of request: June 13, 2008

You requested that we find this system 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.”

Roadside safety systems should meet the guidelines contained in the NCHRP Report 350. The FHWA Memorandum “ACTION: Identifying Acceptable Highway Safety Features” of July 25, 1997 provides further guidance on crash testing requirements of longitudinal barriers.

The system is a portable steel longitudinal barrier intended for use as a temporary barrier in highway construction zones. The EASI developed the Vulcan Barrier™ to prevent vehicle penetration at Test Level 4 (TL-4) conditions for vehicles up to 8,000 kg with impact speeds up to 80 km/h (50 mph) and impact angles up to 15 degrees. The Vulcan Barrier™ segments are available in two lengths, 4 meter (13 feet, 1 ½ inches) and 12 meter (39 feet, 4 ½ inches). It should be noted that the FHWA initially found this same Vulcan Barrier™ acceptable as a TL-3 barrier in our acceptance letter B-134 dated February 14, 2005, which included a successful crash test of a 2000p vehicle.

The test installation was 70.5 m (231.3 feet) long, consisting of six 12-meter-long Vulcan Barrier™ units pinned together with only the leading and trailing edge segments anchored. The dimensions of the 4 and 12 meter Vulcan Barrier™ units are as follows:

  4m Vulcan Barrier™ 12m Vulcan Barrier™
Height: 813 mm (32 in)813 mm (32 in)
Width: 546 mm (21.5 in)546 mm (21.5 in)
Length*: 4115 mm (162 in)11750 mm (463 in)
Weight: 395 kg (871 lbs)1017 kg (2243 lbs)

* Length measured pin to pin

The Vulcan Barrier™ consists of multiple barrier sections pinned together using a 48 mm (OD) steel connecting pin. When installed in continuous straight segments, a gap-filling steel plate is used which further reduces lateral deflection to optimize impacting vehicle redirection. The stackable steel construction allows for reductions in shipping and storage space requirements. All steel components are hot-dipped galvanized to prevent corrosion and extend product life.

Crash Testing
Full-scale crash testing was conducted on the Vulcan Barrier™. We concur that conducting two full-scale “capacity” EN 1317 (European Norm) tests (in addition to prior tests in the U.S.) was adequate to validate the performance of the system as equivalent to the NCHRP 350 TL-4.

The first test you completed was EN 1317 Test TB11 (900kg/100kph/20 deg) which is comparable to NCHRP 350 Test 4-10 (820P/100kph/20 deg). The test resulted in a maximum permanent deflection of 0.83 m (2.72 ft) and a maximum dynamic deflection of 1.1 m (3.61 ft).

The second test completed was EN 1317 Test TB51(H2) (13000kg/70kph/20 deg) which is comparable to NCHRP 350 Test 4-12 (8000S/80kph/15 deg). This test, using the heavier vehicle, utilized test conditions which require the test unit to withstand approximately 117 percent greater impact severity as compared to the NCHRP 350 Test 4-12. The test resulted in a maximum permanent deflection of 1.97 m (6.46 ft) and a maximum dynamic deflection of 2.4 m (7.87 ft).

The EASI’s use of the LS-DYNA™ simulation software to replicate the heavy vehicle test, as conducted at the LIER testing facility, provides sufficient data to show that the use of 4 meter Vulcan Barrier™ sections, in lieu of the tested 12 meter sections, yields negligible differences in maximum dynamic barrier deflection.

The test data sheet summarizing the results of the impacts is enclosed for reference. Based upon the successful completion of the aforementioned EN 1317 tests you provided, we agree that your 4 meter and 12 meter Vulcan Barrier™ systems are acceptable for use as TL-4 longitudinal barriers under NCHRP 350 TL-4 conditions. The systems, as described above, may be used on the NHS when such use is acceptable to the contracting authority.

Please note the following standard provisions that apply to the FHWA letters of acceptance:


Sincerely yours,

Signature of David A. Nicol
David A. Nicol
Director, Office of Safety Design
Office of Safety

Page last modified on August 16, 2011.
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