l-5-35-

U.S. Department

I of Transportation

Federal Highway Administration

J

400 Seventh St,, S.W

Washington, D,C 20590

February 16, 1995

Refer to: HNG-14

Ray C. Minor, P.E.

Manager of Engineering

Hapco Division

P.O. Box 547

Abingdon, Virginia 24210

Dear Mr. Minor:

Your September 15, 1994, letter to Mr. Nicholas Artimovich transmitted test

reports by the Texas Transportation Institute, dated May 1994, and video

documentation of full-scale crash testing conducted to assess the breakaway

performance of your company's aluminum extrusion breakaway bases supporting

Hapco aluminum poles. This material had been sent for our information.

By a January 12 telephone call to Mr. Artimovich you requested Federal Highway

Administration (FHWA) acceptance of the bases covered in these reports.

Requirements for breakaway supports are found in,the AASHTO Standard

Specifications'n ire and

Traffic S'analp These specifications have been adopted by'the FHWA.

testing was done in conformance with the guidelines 'in the National

The

Cooperative Highway Research Program Report Number 350 Recommended Procedures

for the Safetv Performance Evaluation of Hiahwav Features.

The breakaway bases are similar to the pendulum tested four-bolt base that w e

indicated acceptable in our letter to you dated April 26, 1993. The present

submission is for acceptance of a four-bolt base and a three-bolt base., The

bases consist of an external sleeve welded on the end of a light pole. Three

o r four pairs of ribs with flanged ends are welded to the sleeves. They mate

to u-shaped yokes that are secured by the foundation anchor bolts. The yokes

and ribs are held together by u-shaped caps that fit over the flanges on the

ends of the ribs and the legs of the yokes. These caps are held in place by

two screws in each, some of which break under impact to allow the portion of

the base welded to the pole to separate from the anchoring yokes. In

addition, friction-reducing tape is used on the "caps" to enhance breakaway

performance and a 457-mm long sleeve centered at bumper height is inserted in

the pole to minimize energy loss that might occur from collapse of the pole

under a concentrated bumper load. The test installations and breakaway base

details are shown in the enclosed drawings.
2

The test results are summarized here:

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

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

breakaway bases shown on drawings numbered 873825 (3-bolt Y base) and 873486

(4-bolt X base) for 203-mm to 229-mm (B-inch to g-inch) aluminum luminaire

supports with 4.77~mm wall thickness described above are acceptable for use on

the National Highway System, within the range of conditions tested, if

proposed by a State.

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 recommend that

installation instructions stress the need for a level base for mounting these

breakaway systems. 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 those used in the tests, and

that they will meet the FHWA change in velocity requirements.

Because the Hapco breakaway extruded aluminum bases are proprietary, to be

used in Federal-aid highway projects: (a) they must be supplied through

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

agency must certify that they are essential forsynchronization 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,

and Design Division

6 Enclosures

Geometric Roadside Design Acceptance Letter Number LS-35
. 

Pole cop Alloy 43 

With S.S. Hex. Hd. 

Topared Alum. Tube 

. ra6- won Alloy 6063-T6 

Satin Gmund Finish 

(3) I’-BNC Ful& Goiv. SU. Anchor Bolts, 

Per ASTM AU9 with b Threaded 

On Each End. &k Per ASlIt AISJ. 

(6) lo-8NC Goiv. Stl. Hex. Nuts 

(6) 1’ Gatv. St/. flotwoshers 

.2V Wail x 1 f Long Sleew 

Centered lg Abow Gmde 

Ground Lug Opposite Hondhole f 

Reinforced Hondhole (4. x 6) first CO 

With Cover And Stainless St& fili Like 

Button Hd. Socket Cap Screws 

/Extrusion Bose With Bolt Covers And St. Stl. 

Button Hd. Socket Cap Scmws 6 x 1’ x b Steel 

Fig& 1. Luminaire support and mast arm elevation. 

3 
Slotted Holes On 14’To

YS’Dio. Bolt Circle

Note: Breokowoy Bose Design

Is Potent fending

3

(4) .104’60. Ii:=:

Woming Plotc (7.3181

(73317) lnstahd By HAPCO

l/2’x 2 J/4’UHMW Tap?(73319-005)

On Clomping Surface Df Extnded Clomps

Figure 2. Plan and elevation view of break-away base.

4
(After

Right Rib0/w

?J823-00 Item No. 1 73436-004 Sleeve No. 1 8~040” I A .

7.3823- 002 7.3436-005 ) 9.040”

8

Left Rib

Weldjng Requirements

+2”& l/16’

All Portions Of The Bowing Surface Mud 1.) Weld Spotter Da/l Be Remaved. Flange Lie In The Some Phone Aod Be Perpendicular

And Bearin Sur/aces Shall Be Smoot h

2.) All Welds hali sg Be Wire Brushed Thoroughly

To The Axis Of The Sleeve

3.) he Toe Of All fillet Welds ShoN Bo

Blended Into The Parent Metol

4.) No Craters, Cracks, Lack Of Fusion.

Under-Cut, Or Overlap Are ,Not Permitted

Note:

. lpdicotes Location Of Filler Wel d
Pole cop Alloy 43

WiN, S.S. Hex. Hd.

screws \

8- o.oY

Tapemd Alum. Tube

Alum. Alloy 6063-T6

(See Table For\r,be’Size)flA”-d

___. ._

d 5/g”- 1 INC

!ch. 8&s

~o$t;ng

Heiaht

We Ho/e ln Shaft witlr

1’ 1.0. Rubber Gromme

S/6”- 1lNC Stainless

St/. Hex. Bolts

Internal Damper

, (instotkd) /

&wkawq Ease Fobnkted Fawn Alum.

Extnrrionr (Potent -ding) E4SE 0ElxlL

(4) l’-8NC Galv. St/. An&of 8ol&

Per AGMO ht314-90 Mth lb mmoded

End. &Iv. Pw ASl%i AlS3.

(8) 1’-6NC colv. Stl. Hex. Nuts

(8) 1’Gab. StL Flatwshws

.2Sr Wall x 1CT Lon Skew l.

Centemd fb Abow Ema@

Ground Lug Opposite Handhole f

Reinfonxd Hondhole (4. x 6)

It% Cow And St. Stl. Button

Hd. Socket Cap Scmvs

Extrusion &se With 8oR Covers And

_-St. St/. Button Ud. Socket Cap Scmn

Figure 1. Luminaire support and mast arm elevation.

3
Slotted Holes On 11’ To 17

Bolt C&e

14

f

Hondhole And

Woming Plate

Note: Breakaway Base Design

Is Patent Pending

Figure 2. Plan and elevation view of break-away base.

4
JFlN 31 '95WyIIam 04:tlPM HFlPCO 7036287707 ’ “em WaM. 10, P.2

(Aftvr

3

Right Rib 73440

Table )

Welding Ribs To Sleeve) *

Item No. Sleeve No. A

?3506-00 I 73436-00 1 8.048”

-1- 735O6-OO;! 734.X-00 2 9.04,0

,73506-003 73436-00 3 10.044

I.) Weld Spatter ShoM Be Removed. flange

And .._ -_-Bearina ..= --Surfaecs .____ She/f Be Smooth

2.) Ail Welds Shall Be Wire Byshed Thoroughly

3.) The foe Of Ail filet Welds Shall Be

Blended Into The Porent Metal

4.) No Cm&, Cracks, lock Of Fusion,

Unde+Cut, Or Overlap Am Not Permitted

All Porijons Of The Bean@ Surface Must

Lie In The Some Plane Ana Be Perpendicular

lo The Axis Of The Sleeve

Note:

. Indicates Location Of Filict Weld

‘I