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Federal Highway Administration |
400 Seventh St., S.W. |
January 7, 1994
Refer to HNG-14
J. M. Essex, P.E.
Vice President, Sales
Energy Absorption Systems, Inc.
One East Wacker Drive
Chicago, Illinois 60601
Dear Mr. Essex:
Your December 14, 1993, letter requested the Federal Highway Administration's (FHWA) acceptance of the TRITON Barrier as the barrier's own end treatment. Details of the design and crash tests results were included in your "TRITON Barrier End Treatment Crash Test Report" dated December 1993.
Our review of the crash test data indicated that you successfully completed the tests required for a non-redirective crash cushion for Test Level 2 conditions. These tests are summarized as follows:
| NCHRP 350 Test Number | Vehicle Mass (kg) | Impact Speed (km/h) | Impact Angle (degree) | Occ. Imp. Velocity (m/s) | Ridedown Acceleration (g's) |
|---|---|---|---|---|---|
| 2-40 | 820 | 70 | 0 | 9.4 | -5.9 |
| 2-41 | 2000 | 70 | 0 | 6.3 | -7.8 |
| 2-42 | 820 | 70 | 15 | 8.3 | -3.6 |
| 2-43 | 2000 | 70 | 15 | 5.7 | -6.6 |
| 2-44 | 2000 | 70 | 20 | 6.6 | -7.1 |
Based on the above results, we consider the TRITON barrier end treatment to be an acceptable terminal for the TRITON barrier itself, provided the end, or first section, contains no water and the retaining pin is left out of the exposed end. Under the stated Test Level 2 conditions, the barrier length of need begins at the sixth segment from the end.
This acceptance is given with the understanding that the TRITON end treatment is applicable for use only on the end of a TRITON longitudinal barrier installation and is not appropriate to shield fixed object hazards. It is further understood that, like the barrier itself, it is not acceptable for use where impact speeds in excess of 70 km/h are likely. Users of this system must be further cautioned that significant vehicular penetration is possible for impacts at or near the end, and that a clear unobstructed runout area is needed behind the terminal sections for optimal performance.
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Sincerely yours,
Lawrence A. Staron |
