!aJ 3 1993 

4W Seventh St.. S.W. 

WaShinQton. D.C. 20580 

Refer to: HNG-14 

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

Engineer 

Hapco Division 

P.O. Box 547 

Abindgon, Virginia 24210 

Dear Mr. Fawley: 

Thank you for your July 26 letter requesting Federal Highway Administration's 

(FHWA) acceptance of your company's TP3405 and TP3406 aluminum poles welded 

into cast aluminum anchor (shoe) base model numbers 73407 and 73340, 

respectively. Your letter was' accompanied by the test report dated July 23, 

1993, and video documentation. Pendulum testing was conducted to assess the 

breakaway performance of the bases with various Hapco aluminum poles. The 

tests were witnessed by Mr. Jeffrey A. Bloom of Adian Engineering. 

Requirements for breakaway supports are found in the 1985 American Association 

of State Highway and Transportation Officials (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 bases are cast aluminum, as shown in the enclosed drawings, welded to 

HAPCO aluminum poles. Typical mode of failure is breaking of the welded 

connection between the pole and the base, plus some fracturing of the cast 

base. 

The test results are summarized here: 

,.?st NultmSupport Dianeter O.D., m (in) 

Yall Thickness, ma (in) 

Base Designation 

Test Article Mass, kg cut, Ibs) 

Bolt Oimeter, m (in) 

Bolt Circle Diameter, m (in) 

Uomting Height, 11111 (ft) 

PendulmRess, kg weight, Lb) 

InpactSveed.Mh(nph) 

Vetocity Change. m/s (fps) 

Calculated 60-r@ (97-Mh) 

.Velwity Change. m/s (fps) 

Stub Height, mn (in) 

1 3405 3407 34% 

152 (6.0) 152 (6.0) 2% (8.0) 

4.78 (.lsB) 3.18 (0.125) 3.% (0.156) 

73407 73407 73340 

69.1 (152.3) 52.2 (115) loo.3 (221) 

25.4 (1.0) 25.4 (1.0) 25.4 (1.0) 

229 (9.0) 229 (9.0) 304 (12.0) 

8380 (27.5) 7010 (23.0) 10 900 (35.831 

818 (1800) ala (1800) 818 (1800) 

32.2 (21.1) 32.2 (20) 32.2 (20) 

2.4 (7.8) 1.6 (5.3) 2.3 (7.5) 

1.4 (4.5) 0.91 (3.0) 1.6 (5.1) 

92 (3.625) 92 (3.625) 81 (3.1875) 
2 

The results of these tests meet the change in velocity and stub height 

requirements adopted by AASHTO and the FHWA. Therefore, the following tested 

aluminun breakaway systems are acceptable for use on National Highway System 

(NHS) projects, within the range of conditions tested, if proposed by a State: 

TP3405 (using base 73407) for 152-w (6-inch) butt diameter aluminum 

luminaire supports with wall thicknesses from 3.18 mm to 4.78 mm 

(0.125-inch to 0.188-inch) with luminaire mounting heights up to 8500 mm 

(27.5 feet). 

TP3406 (using base 73340) for 203~mm (a-inch) butt diameter aluminum 

luminaire supports with wall thickness of 3.96 mm (0.156-inch) with 

luminaire mounting heights up to 11 000 mm (36 feet). 

Our acceptance is limited to the breakaway characteristics of the systems and 

does not cover their 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 Division that the hardware 

furnished has essentially the same chemistry, mechanical properties, and 

geometry as that used in the tests, and that they will meet the FHWA change in 

velocity requirements. 

Because Hapco breakaway cast aluminum shoe bases are proprietary, to be used 

in Federal-aid projects on the NHS: (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, 

Lawreiice A. Staron 

Chief, Federal-Aid and Design Division 

2 Enclosures 

Geometric and Roadside Design Acceptance Letter LS-32 
ngure WJ 

HapcomawingNo.Tp3405 

TestIuninai~e Supports 

Pole Cap Alloy 4.3 

Alum. Pole Plate Alloy 6063-16 with l/T- l3NC Stainless St/. Hardwa~ 

,, ,, A 

Mountirig Height 

I 

+ 

/tern No. “A” “B” “c” ’ Test No. 

L 1 23’-0’ 2 1 co- .125’ 3407 _ 

25’-0’ 23’-6 .156 Not Tested_ 

r : , 21cg’ 25”6 .188= 3405 . 

6’ 0.0. 

Tapered Alum. Tube 

“C” Woll Alloy 6063-T6 

Satin Ground finish 

9’ Dia. 

Bolt Circle 

Ground Lug Opposite Handhole c 

Reinfoned Hondhole (r X 9) with 

Cover And Stainless Stl. Hex. Hd. Screws 

(73407) Alloy 356-T6 ItVh Bolt 

Stainless Stl. Hex. Hd. Scows 

.-I c-9 3/4’ squore . 

3 
r1gure (3) 

Hapco Drawing No. 73407 

6" Breakaway pase Assembly 

s" 0. D. Tube (. 125”, 

.lSs” & ,188” Wall) 

Alum. Alloy 6063-T6 

Per ASTM B221 

Nofe: Tube And Base Welded In 7he -T4 Temper With ’ 

Alloy 4043 Weld Wire And AMical~ Aged (Heat 

Base Range (47380) 

Treated) To The -T6 Temper After Werding. 

, Alum. ,qloy 356_T6 

Per ASTM 826 

IO. REVISIONS OATC TITLE 

6“ BRLilKWAY BASE ASS’Y 

CUSTOMER 

SCALE 2.66 DATE 07/l 6/93 

Oy PRS DWO. NO. 

m-mtwunmsu 

,. . . I am rJm V& YIIB CUU’D 2 A73407 

c 

i 

D: 
Iiapco Drawing No. TP3406 

TestLuninaire support 

we cop Alloy 43 

tith Stoinkss Stl. 

?trews 

\ 

7 

6’ 0.0.1 

13 o= 8’ O.D.-- 

I’-6’ 

I 

NPS Slipfitfer 

TopeM Alum. Tube (4’ 0.0.) 

.125 Wall Alloy 606.GT6 

2’ Sch 40’ Pipe Alloy 6063-T6 

\ 

\ 

‘We Hole Mth I’ LO. Rubber Grommet 

Alum. Pole Plate Alloy 6063-T6 IVth 

l/f- 13NC Stainless Stl. Hordwon 

Alum. Pole Plate Alloy 6063-T6 with 

3/g- 16NC Stainless Stl. Hordwom 

I 

35”la’ 

Mounting Height 

I 

I 

Topered Alum. Tube 

y . lS< Wall Alloy 6063-T6 

Sotin Ground FE&h 

Rigid Steel Test From 

Opposite Hondhole $ 

Reinforced Hondhole (4’ X c) WiN, 

Cover And Stainless St/. Hex. Hd. Screws 

Bose Flange (73340) Alloy 356-T6 with Bolt 

Covers And Stainless Sti. Hex. Hd. Screws 

. “CW,_ 

t 

WMNNOI k)uuu&l~Pdma-Ulrtr 

?EST POLE (EST f 3406) C-a 

ora)7_16/93 

Dwam 

1 --- cwlpo TP3406 

. 

19 
Iloy 6063- T6, 

Per ASTM 8227 

Base Flange Alloy 

356-T6 Per ASTM 

Note: Tube And Base Welded In The -74 

Temper With Alloy 4043 Weld Wire 

And Artificallv Aaed (Heat Treated) 32 

To The -T6’ Tehper’After Weldin; 

t 

3/8” 

TITLE 

8* X .156” BREAKAWAY BASE ASSEMBL’ 

CUSTOMER 

CO SCALE 2.66 DATE 06/25/93 

BY LW DWG. NO. 

cw*claAnmu c 

UIQI. VA nno CHK’D A73340