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Ju2Ol!392

Refer to: HNG-14

T. M. Fawley, II, P.E.

Hapco Division

P.D. Box 547

Abindgon, Virginia 24210

Dear Mr. Fawley:

Thank you for your letter of June 19 requesting the Federal Highway

Administration's (FHWA) acceptance of your company's cast aluminum anchor

(shoe) base for luminaire supports, your drawing number BJ2785. Accompanying

your letter was a report of a single pendulum test conducted at your facility

on an aluminum pole mounted on the anchor base. The report was attested to by

Jeffery A. Bloom, an independent consultant who performed the velocity

calculations. The tests were conducted to assess the breakaway performance of

thin-walled aluminum luminaire supports with this base. Requirements for

breakaway supports are found in the 1985 AASHTO Standard Specifications for

Structural Supports for Highway Signs, Luminaires and Traffic Signals. These

specifications have been adopted, with minor modifications, by the FHWA.

The test results are summarized here:

Pole Type 6063-T6 Aluminum Hapco Pole, Drawing 21-855

Pole Wall Thickness, mm (in) 4.77 (0.188)

Base Type 356-T5 Alum. Shoe Base, Dwg. BJ2785, 11” 8C

Mast Arm Mass, Kg (weight, lbs.) 5.5 (12)

Dummy Luminaire Mass, kg (wt., lbs.) 22.7

Test Article Mass, kg (wt., lbs.) 84.7

Mounting Height, m (ft) 10.7

Pendulum Mass, kg (wt., lbs.) 818

Impact Speed, km/hr (mph) 33.6

Velocity Change, m/s (fps) 4.2

Calculated High Speed

Velocity Change, m/s (fps) 2.2

Stub Height, mm (in) 75

(50)

(186.3)

(35)

(1800)

(20.9)

(14.0)

(7.1)

(3)
2 

The results of this test meet the change 5n velocity and stub height requirements 

adopted by AASHTO and the FHWA. Therefore, your company's breakaway shoe base 

described above is acceptable for use on Federal-aid highway projects, within the 

range of conditions tested, if proposed by a State. This acceptance extends ~to 

the following three applications detailed in your letter: 

1. 7" x 0.0. x .188" wall shaft, 10” - 11” bolt circle, maximum mounting 

height 35 feet, 4" x 6" nominal handhole. 

2. 7" O.D. x .156" wall shaft, 10" - 11" bolt circle, maximum mounting 

height 30 feet, 4" x 6" nominal handhole. 

3. 7" O.D. x .156" wall shaft, 10" - 11” bolt circle, maximum mounting 

height 30 feet, no handhole. 

Our acceptance is limited to breakaway characteristics of the system and ,does not 

cover its structural features. Presumably, you will supply potential users~with 

sufficient information on structural design and installation requirements to 

ensure proper performance. We 'anticipate that the States will require 

certification from HAPCO that the hardware furnished has essentially the same 

chemistry, mechanical properties, and geometry as that used in the test, and that 

it will meet the FHWA change in velocity requirements. 

The design of the HAPCO base is proprietary. For proprietary products to be used 

in a Federal-aid highway project: (a) they must be supplied through competitive 

bidding with equally suitable unpatented items; (b) the highway agency must 

certify that they are essential for synchronization with existing highway 

facilities or that no equally suitable alternate 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, a copy of which is enclosed. 

Sincerely yours, 

Enclosure 

Lawrence A. Staron 

~Chief, Federal-Aid and Design Division 

Geometric and Roadside Design Acceptance Letter g-27