Federal Highway Administration
1200 New Jersey Ave., S.E.
May 5, 2008
Mr. Greg Mercier
Director of Design Engineering
26252 Hillman Highway
Abingdon, VA 24210
Dear Mr. Mercier:
This letter is in response to your request for Federal Highway Administration (FHWA) acceptance of a roadside safety device for use on the National Highway System (NHS).
You requested that we find this device acceptable for use on the NHS under the provisions of National Cooperative Highway Research Program (NCHRP) Report 350 “Recommended Procedures for the Safety Performance Evaluation of Highway Features.”
Roadside safety devices 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 luminaire supports.
The following two 20 ft (6.1 m) HAPCO decorative luminaire supports were tested at the TTI outdoor pendulum testing facility:
HAPCO 72133 Cast Base Assembly Georgetown (B13163). The base of the lighting pole was cast aluminum (alloy 356-T6) with a 10-1/8 inch (257.18 mm) round base tapering to a fluted shape for a base height of 42-5/8 inches (1082.68 mm). A 6 inch (152.4 mm) outside diameter tapering to a 3 inch (76.2 mm) outside diameter aluminum tube (alloy 6063-T6) with 1/4 inch (6.35 mm) wall thickness and 16 foot 7 inch (5.05 m) long was welded to the base, giving a total height of 20 feet (6.1 m). A cast aluminum adapter ring was placed on top of the pole to accommodate the round light. The weight of the pole with base was 134 pounds and the round light was 17 pounds, totaling a weight of 151 pounds. The 1/2 inch (12.7 mm) base plate was bolted to a steel reaction plate using 3/4 inch (19.05 mm) anchor bolts on a 7 inch (177.8 mm) diameter bolt circle. Drawings of the HAPCO Georgetown (B13163) decorative luminaire support with cast base assembly 72531 are enclosed.
HAPCO 72133 Cast Base Assembly GeorgetownEmbedded Pedestal (B13164). The base of the lighting pole was cast aluminum (alloy 356-T6) with a 10-1/8 inch (257.18 mm) round base (72133) tapering to a fluted shape for base height of 42-5/8 inches (1082.68 mm). A 6 inch (152.4 mm) outside diameter tapering to a 3 inch (76.2 mm) outside diameter aluminum tube (alloy 6063-T6) with 1/4 inch (6.35 mm) wall thickness and 16 foot 7 inch (5.05 m) long was welded to the base, giving a total height 20 feet (6.1 m). A cast aluminum adapter ring was placed on top the pole to accommodate the round light. Weight of the pole with base was 156 pounds and the round light was 14.6 pounds, totaling a weight 170.6 pounds. The base was welded to a 6 inch (152.4 mm) diameter aluminum tube (12315) with 1/4 inch (6.35 mm) wall thickness, 4 feet (1.22 m) long and flattened the lower 1 foot (0.305 m) to close the opening at the bottom to 2 1/2 inches (63.5 mm), and embedded in NCHRP Report 350 standard soil. Two slotted holes were positioned at 180 degrees to each other in the aluminum ground tube with centerline at 2 feet (0.61 m) below the base. Drawings of the HAPCO Embedded Pedestal (B13164) decorative luminaire support are enclosed.
Your company’s decorative lighting poles were tested at TTI’s outdoor pendulum testing facility, as a surrogate for full-scale crash testing. The pendulum bogie was built according the specifications of the Federal Outdoor Impact Laboratory's (FOIL) pendulum, and the frontal crush of the aluminum honeycomb nose of the bogie simulated the crush of an actual vehicle. Tests with pendulums are acceptable for most breakaway supports, exceptions being base bending or yielding supports.
Two low speed pendulum tests were conducted on your company’s decorative lighting supports, one test on each of the poles. Summaries of test results are enclosed. All Decorative Lighting Poles met the NCHRP Report 350 occupant risk criteria. In addition, TTI extrapolated the high-speed performance of these four lighting poles installation from the low speed pendulum tests. I agree that the test articles appear to perform appropriately to make such high-speed extrapolations. All high speed extrapolations yield lower change in velocity values than the paired low speed pendulum test.
In tests with HAPCO B13163 and HAPCO B13164 decorative lighting poles the base separated from the ground and the lighting pole separated from the decorative base section. The base fractured at ground line and this performance satisfies the FHWA limit of maximum 3.9 inch (100 mm) stub height remaining after a support breaks away.
In summary, the HAPCO 72133 Cast Base Assembly Georgetown (B13163) and HAPCO Embedded Pedestal (B13164) 20 ft (6.1 m) decorative lighting poles as described above, meet the appropriate evaluation criteria for a NCHRP 350 TL-3 device and may be used at all appropriate locations on the NHS when selected by the contracting authority, subject to the provisions of Title 23, Code of Federal Regulations, Section 635.411 as they pertain to proprietary products. The HAPCO Georgetown (B13163) is accepted with luminaire mounting heights up to 20 feet (6.1 m) with shafts up to 1/4 inch (6.35 mm) wall thickness with diameters up to 6 inches (152.4 mm). The HAPCO Embedded Pedestal (B13164) is accepted with luminaire heights up to 20 feet (6.1 m), shafts up to 1/4 inch (6.35 mm) wall thickness with diameters up to 6 inches (152.4 mm), and embedment lengths not less than 4 feet (1.22 m). Furthermore, the embedment tube wall thickness must be equal to the shaft wall thickness.
Please note the following standard provisions that apply to FHWA letters of acceptance:
David A. Nicol, P.E.
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