Safety Eligibility Letter SS-25
b. Single 6"x8" wood with 3.0" holes
c. Single 6"x6" wood with 2.0" holes
d. Single 4"x6" wood with 1.5" holes
e. Dual W6x12 steel post on slip base
(up to 18 ppf for dual supports OK
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Regional Federal Highway Administrators
Federal Lands Highway Program Administrator
Acceptable – Dual Unmodified 89-mm x 89-mm (4- x 4-inch) Wood Posts |
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Stub Height – (No stubs were left protruding above the soil.) |
Acceptable – Drilled 89- x 140-mm (4- x 6-inch) and 140- x 140-mm (6- x 6-inch) Wood Posts |
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Unacceptable – Unmodified 89- x 140-mm (4- x 6-inch) Wood Posts |
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Acceptable – Dual Leg W6x12 and other Structural Shapes on Slip-Bases |
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Unacceptable – Dual Back-to-Back 3-kg/m (2-pound/foot) Flanged Channel "U" Posts |
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Unacceptable – Round Steel Pipe, 50-mm (2-inch) Diameter Schedule 40 |
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A summary of acceptable and not acceptable systems is attached for your convenience.
L. A. Staron, Chief
Federal-Aid and Design Division
Geometric and Roadside Design Acceptance Letter Number SS-25
"U" Post 6-kg/m (4-pound/foot) with Long Groundline Splice, Dual Posts |
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**Use of other shapes weighing up to 27 kg/m (18 pounds per foot) is also acceptable.
***Covered in June 15, 1987, memorandum. Lighter weight sections are also acceptable.
****No new information is available on "U" posts using short ground-level splices.