Safety Eligibility Letter B-118
Hardware Type:
Longitudinal Barriers and Bridge Rails
Code:
B-118
Date:
Testing Criteria:
NCHRP 350
Manufacturer:
Oregon DOT
Device Description:
3-Tube Bridge Rail @TL-4
View PDF:
b118.pdf (354.56 KB)
HSA-10/B-118 - Acceptance of Oregon 3-Tube Bridge Rail
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Memorandum |
| U.S. Department of Transportation | |
| Federal Highway Administration |
| INFORMATION: Acceptance of Oregon 3-Tube Bridge Rail | April 22, 2003 | ||
| Michael S. Griffith/original
signed by Charles A. Aiken/ for
Acting Director, Office of Safety Design |
HSA-10/B-118 | ||
| Mr. Bruce Johnson FHWA Division Bridge Engineer Salem, OR |
In your April 18 memorandum to Mr. Richard Powers of my staff, you requested formal acceptance of the Oregon Department of Transportation 3-Tube Bridge Rail for use on the National Highway System (NHS). This design was tested by the Texas Transportation Institute to the National Cooperative Highway Research Program (NCHRP) Report 350 test level 4 (TL-4) and documented in three separate reports, all dated May 2000, entitled "NCHRP Report 350 Test 4-10 of the Oregon 3-Tube Bridge Rail", "NCHRP Report 350 Test 4-11 of the Oregon 3-Tube Bridge Rail", and "NCHRP Report 350 Test 4-12 of the Oregon 3-Tube Bridge Rail", respectively.
The Oregon 3-Tube Bridge Rail consists of three TS 178 x 102 x 6.4 tubes supported by W200 x 36 steel posts on 3-meter centers. The top rail is 1068 mm above the deck surface, the middle rail is 820 mm above the deck and the lower rail is 496-mm high. The lower two rails are blocked out from the support posts with TS 178 x 76 x 6.4 steel tubes, each 165-mm long. The top tube is installed with the narrow side against the post so the traffic sides of the rail elements lie in the same plane. The posts are mounted on a 178-mm high curb with four 22.2-mm diameter A325 steel bolts. These and additional details are shown in the attachment to this memorandum.
Based on staff review of the three tests that were conducted and their recommendations, I agree that the Oregon 3-Tube Bridge Rail meets all the evaluation criteria for an NCHRP Report 350 bridge rail at TL-4 and that it can be used on the NHS when such use is selected by the contracting authority. Although its crash performance was exceptionally good, I did note that in test 4-11, there was localized bridge deck damage when the two post bolts on the impact side of the rail sheared off. The use of larger or higher strength bolts would most likely minimize repair costs.
Attachment
