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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation
FHWA Highway Safety Programs

Safety Eligibility Letter B-179

Hardware Type:
Longitudinal Barriers and Bridge Rails
Code:
B-179
Date:
Testing Criteria:
NCHRP 350
Manufacturer:
Energy Absorption, Inc
Device Description:
TL-1 Triton Water Filled Barrier
View PDF:
b179.pdf (398.29 KB)

Safety Eligibility Letter B-179

Download Version
PDF [399 KB]

DOT logo
U.S. Department of Transportation
Federal Highway Administration

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

July 11, 2008

In Reply Refer To: HSSD/B-179

Mr. 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 Federal Highway Administration (FHWA) acceptance of a roadside safety system for use on the National Highway System (NHS).

  • Name of system: TRITON BARRIER® Test Level 1 (TL-1)
  • Type of system: Water Filled Barrier
  • Test Level: National Cooperative Highway Research Program (NCHRP) Report 350 TL-1
  • Testing conducted by: E-TECH Testing Services, Inc.
  • Date of request: January 11, 2008

You requested that we find this system acceptable for use on the NHS under the provisions of National Cooperative Highway Research Program 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". FHWA Memorandum “ACTION: Identifying Acceptable Highway Safety Features” of July 25, 1997 provides further guidance on crash testing requirements of longitudinal barriers.

Description
The new system is a portable, water-filled plastic longitudinal barrier intended for use as a temporary barrier in highway construction zones. Energy developed the TRITON BARRIER® TL-1 to prevent vehicle penetration at impact speeds up to 50 km/h (31 mph) and impact angles up to 25 degrees.

The test installation was 29.7 m (97.45 feet) long, consisting of 15 TRITON units. The dimensions of the individual Triton units are as follows:

Height -813 mm (32 in)
Width -533 mm (21 in)
Length* -1981 mm (78 in) [*Length measured pin to pin]
Weight (empty) -45 kg (99 lbs)
Weight (full) -595 kg (1312 lbs)
Water ballast -550 L (145 gal)
Color(s) -Orange and White

The TRITON BARRIERÒ TL-1 barrier consists of multiple barrier sections pinned together using a 48 mm (1-½ in Schedule 40) diameter steel pipe connecting pin to optimize impacting vehicle redirection. Each individual section will incorporate a 12.7 mm (1/2 in) diameter steel cable towards the top of the unit to maximize the tension capacity of the system during impacts. The plastic mold design allows for the stacking of the empty sections (up to three high) during storage and transport. The TRITON BARRIERÒ TL-1 sections are identical to the TRITON BARRIERÒ TL-2 unit previously accepted by the FHWA except the internal steel framework inherent to these existing units was removed for this TRITON BARRIERÒ TL-1 test. A decal will be affixed to the exterior of each TRITON BARRIERÒ TL-1 section to prevent these units from being mistakenly being used with the TRITON BARRIERÒ TL-2 and the TRITON BARRIERÒ TL-3 products.

Crash Testing
Full-scale crash testing was conducted on the TL-1 barrier. We concur that conducting one full-scale “capacity” NCHRP 350 test was adequate to validate the performance of this system. The test you completed was NCHRP 350 Test 1-11 (2000P/50KPH/25 deg). Your test verified that the impact performance for heavier vehicles (2000kg) was acceptable and successfully prevented vehicle penetration into the work zone behind the product. We noted that the nearly 30-meter (100-ft) long system was not anchored during the test, resulting in lateral barrier deflection of 2.7 meters (8.9 ft).

The test data sheet summarizing the results of the impact is enclosed for reference. Based upon the successful completion of the aforementioned NCHRP 350 test you provided, we agree that your TRITON BARRIER® TL-1 system is acceptable for use as a TL-1 longitudinal barrier. The system, as described above, may be used on the NHS when such use is acceptable to the contracting authority.

Findings
Therefore, the system described above and detailed in the enclosed drawing is acceptable for use on the NHS under the range of conditions tested, when acceptable to a highway agency.

Please note the following standard provisions that apply to 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-179 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.
  • Triton Barriers are patented products and considered proprietary. If proprietary systems are specified by a highway agency for use on Federal-aid projects, except exempt, non-NHS projects, they: (a) 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 David A. Nicol

David A. Nicol, P.E.
Director, Office of Safety Design
Office of Safety


Image of Triton Barrier®TL-1 Section, TRI White or Orange


Images of crash results
General Information
Test AgencyE-TECH Testing Services, Inc.
Test DesignationNCHRP 350 Test 1-11
Test No.01-4318-001
Date8/28/07
Test Article
TypeEnergy Absorption Systems. Inc.
TRITON BARRIER TL-1 System
Installation Length29.7 m - (15) sections total, pinned and freestanding
Size and/or dimension and material of key elementsPolyethylene Plastic section
Length - 1981 mm
Width - 533 mm
Height - 813 mm
Mass - 45 kg (empty)/595 kg (full)
Foundation and AnchoringPortland Cement Concrete, clean and dry, unanchored
Test Vehicle
TypeProduction Model
Designation2000P
Model1988 Chevrolet C2500 Pickup
Mass (kg)
Curb1939
Test inertial1994
DummyN/A
Gross Static1994
Impact Conditions
Speed (km/h)51.6
Angle (deg)25
Impact Severity (kJ)36.6
Exit Conditions
Speed (km/h)N/A
Angle (deg)N/A
Occupant Risk Values
Impact Velocity (m/s)
x-direction5.0
y-direction0.7
Ridedown Accelerations (g's)
x-direction-3.9
y-direction-2.6
European Committe for Normalization (CEN) Values
THIV (km/h)18.4
PHD (g's)4.5
ASI0.3
Post-Impact Vehicular Behaviour (deg - rate gyro)
Maximum Roll Angle32.4
Maximum Pitch Angle-11.8
Maximum Yaw Angle25.4
Test Article Deflection (m)
Dynamic2.7
Permanent2.7
Vehicle Damage (Primary Impatc)
Exterior
VDSLFQ-2
CDC11FLEW2
Interior
VCDIAS0000000
Maximum Deformation (mm)N/A

Figure 1. Summary of Results - TRITON BARRIER TL-1 Test -1-4318-001