REFER TO: 

HNG-14 

Mr. Robert A. Sik 

Vice President, Permanent Mold Division 

Akron Foundry Company 

2728 Wingate Avenue 

P.O. 80x 27028 

Akron, Ohio 44319-0009 

.I,.‘ ! 

Dear Mr. Sik: 

This is in response to your April 1 request for acceptance by the Federal 

Highway Administration (FHWA) of your company's T81 series transformer bases 

for use on Federal-aid highway projects. Tests were conducted to assess the 

compliance of these bases with Section 7 of the 1985 AASHTO specifications. 

You enclosed ~for our review seven Southwest Research Institute reports 

(Project No. 06-2128-103) dated March 1988, containing pendulum tests on the 

bases. 

The tests used an instrumented 1,800-pound pendulum fitted with a 10 stage 

crushable nose which simulates a 1979 Volkswagen Rabbit. The measured and 

extrapolated results from the tests were as follows: 

Test Date Stub -- 

Measured change Extrapolated change 

No. in velocity at 20 m.p.h in velocity at 60 m.p.h. Height 

1. 2-21-88~~~ :: ~-6.19 fps 8.24 fps * 

G: 2-21-88 -7~;17 6.44 fps fps 10.23444 fps fps * 

ii: 2-22-88 10.1 11.18 fps 

fps 

15.76612 fps 

fps 

3.06" * 

5A. 2-22-88 9.33 fps 15.43 fps 5.75” 

58. 2-22-88 9.92 fps 15.61 fps * 

(Tests 4B and 5B are retests of tests 4A and 5A.) 

* Base broke away completely. No remains other than mounting bolts. 

Table 1, copy enclosed, lists the various tests and the pole types that were 

tested using bases TBl-AF 1315-17, TBl-AF 131%17IW, and TBl-AF Modified-17. 

The above information shows that the actual tests and calculated changes in 

velocity of the pole-base combinations shown in Table 1 meet the change in 

velocity and stub height provisions of Section 7 of the 1985 American 

Association of State Highway and Transportation Officials (AASHTO) "Standard 

Specifications for Structural Supports for Highway Signs, Luminaires and 

Traffic Signals" with the exception of tests 4A through 5B. The FHWA will 

accept the results of tests 4A through 58 per the following discussion: 
2 

The calculated changes in velocity at 60 m.p.h. for the four ~tests exceed the 

15.0 fps specified in AASHTO. The extrapolation formula used to make these 

estimates is known to usually be conservative. The FHWA is currently 

undergoing a rulemaking process to adopt Section 7 of the 1985 AASHTO 

specification% for breakaway devices for use on Federal-aid highway projects. 

The FHWA anticipates accepting breakaway devices which causea: change in 

velocity up to 16 feet per second. The extrapolated changes in velocity for 

tests 4A, 48, 5A, and 5B are below, or round to meet the 16 foot per second 

velocity change requirement. The non-conforming stub height of test 5A 

resulted in a retest. Test 5B showed compliance to the stub height 

requirement. 

The bases shown in Table 1 and the enclosed drawings (2) are acceptable for use 

on Federal-aid projects, within the range of conditions tested, if proposed by 

a State. The acceptance is limited to breakaway characteristics of the bases 

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 base performance. 

The FHWA is currently in the process of formally adopting Section 7 of the 1985 

AASHTO specification. A change of velocity criterion of 16.0 fps instead of 

15.0 fps, and a transition period for full implementation of approximate 

18 months are being considered. Because these actions are not yet finalized, 

this acceptance must be somewhat limited. Should the lower acceptance level be 

adopted, our acceptance of those supports not meeting the adopted level will 

expire at the end of the transition period. On the other hand, if the FHWA's 

final rule on breakaway sets the acceptance level at 16 fps or higher our ', 

limitation on this acceptance will not be applicable. 

We anticipate that the States will require certification from Akron Foundry 

Company that castings furnished have essentially the same chemistry, mechanical 

properties, and geometry as the castings used in the tests and that the 

castings will meet the FHWA change in velocity requirements. 

Sincerely yours, 

L. A. Staron 

Chief, Federal-Aid and Design Division 

Enclosures 
~Test BSSS TOP Bottom Pole Pole Nominal 

Number Number Bolt Bolt Height 

Weight TOP 

Type 

TOP 

Circle c1rc1e 

W/Arm 4 Luminaire Washers, Washers 

Diameter Dlameter 

Dummy Nountlng Outside Inside 

Height Diameter Diameter 

**t***~******tt*tttt*.*****************************************************.**********.****************************** 

1 TBl-RF 1315-17 13” 15” ALUMINUM 35’ 

2 TEl-RF 1315-17 IY 13” 15” ALUMINUM AD. 5’ 

j TBl-AF 1315-17 i+ I+ STEEL 

4A TM-AF 1315-17 IW 

:;: 

” 

::n 

STEEL Z.5’ 

48 TBl-AF 1315-17 II STEEL 44.5’ 

:: 

TM-AF MODIFIED-17 

:;: 

10.5” STEEL 35’ 

TEL-AF MODIFIED-17 10.5” STEEL 35' 

437 I 42.0' : 2 l/2" 1 l/16" 

511 I 51iz G 2 l/Z" 1 l/16' 

832 C 42.0" 2 112" 

: 778 i 50.0" 2 l/2" : :::z:: 

778 I 50.0" i 2 l/2" 

: 832 t 

a32 4 42.0' > 2 l/2" 1 l/16" 

“II” refers to an internal weld inside the base l ; assembly also requires rectangular 

TABLE 

‘t/i i 

NUMBER 1 !,j 1 1 

: ,,I, 
. - 

* ALA WA@HIR8 TO BE 2lWC YSCHANICAL COATLD l tS A#TY E OEE -SE CLAIE ED 

‘CHIYICAL 8 MY. C@RtE TO Et 

. 

\ 1o.m / EUIPLIED WITH SACH EHIPYtKT 

..; 

: 

33/i DIA. X E/E THK. ., : 

u/l. LD. ET22L WAEHM . . 

‘FOCI 1. DlA ANCHOR COKNCCTUIQ BOLTS 

OS 

2 E/4 DIA. X l/2 TMK. WITH CITKLS 1 l/l-i’Oll 

1 E/l8 LD. ETXEL WAEKSRE fOS SITHKR 1 l OR 

I 1, l/4 DIA. CONWECTINQ BOLT8 

<.)KSTRUCTlON LA?ILE APPW UlEtDL WAL 

.OPPOElTS DOOR OPENIll 

. 

11.11 

.. 

BSOUND ECMW HOLS l/2-18 TAP TKSU 

. - 

._ I 1;; i- 

+ 

* 

I 

/ 

IE~4_DI&. x l/2 TnlG 

.)_1LlE_bD. STE2L WAEWSS FOR 1‘ DIA. BOLT8 

OR 2 E/4 DM. X l/2 TM. 

1 E/lE LD. ETKSL WAEKKS tOS 

‘1 l/4 DIA. BOLT8 

_y++D42 WISL WITH AAPmOX 8. OF WEU ow 

ZAcn OF THE (41 lsTuKAL Con*228 

.Oym PAICI NO. wlm EUm2 LW. FOS 

StTMKAL WELDED COSS2SE 

.E.E. WItlUAERATtD flNlEH 

OS.-TE 

1 AKRON FOUNDRY CO. 

I .-. AL. ESLAKAWAY TRAWE~OSYtS EAEE 
I 

* ALL WASHERS TO SE ZINC YECHAMICAL COATED PER ASTM B .SS-SS CLASS SO 

I 

. . 

. 

. 

‘CHEYICAi &.HY. CERTS TO BE 

8UPPLIED WITH. EACH 8HIPYEWT.. 

. .k I 

, .‘ ‘, 

. . . . 

l/g DIA. X S/S TIiK. 1 l/l6 LD. 

ELYMH2fLkO~I~CONNECIJMQ BOLT1 

OR 

. 

._ ____. _ 

a $14 DIA. X l/2 THK. WITN LITNEll 1 l/l@ OR 

1 s/l6 I.D. 8TEXL WASHER POR EITHER 1 - OR \ 

1 l/4 DIA. CONNECTlNQ BOLTS 

yu4-20 Ii EILJlD._U2!_LQ_8.2.. 8.CRXW . 

. 

INSTRUCTION LABELS tm lHSIDE.WALL . 

PP_lmirurooRPPurlNao~~un 

11.75 -2PECIAL YOUNTINQ INSTRUCTION LABEL 

.lt.DO NlQn 

.QROUND_8CREYILHDLC l/4 .t_tO IAP.THRU 

. 

aRO@ND SCREW HOLE l/2 - iS TAP THRU 

J 

. 1,4 v <Mla _404S_WRL 

.? 

2 1/2.DlA. X.2/. TNK. 1 1110 LD. . . 

,tTEEL.WiSHER AND 2 S/4 X 4 l/4 X 6/I THK. 

. RECTANQULAR WASHER, 

. . 

IPE WITH APPROX S- OF WELD ON 

ZNE (4) INTERNAL CORNER8 

. 

.b8.. WHEELAERATED FINISH 

16 6/O APPROX. 1. AKRONFOUNDRYCO. 

AL. BREAKAWAY TRAN8PORYER l A8E 

': TEST #&&B :;;:;;a' ~l+bDiFED-17 

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