L-5 -4 7 

U~SCqmtment 

of Transpartatm 

Federal Highway 

Administration May 28, 1996 

Refer to: HNG-14 

Dennis H.'O'Brien, P.E. 

Manager of Product Planning 

Industrial Products Division 

Valmont Industries, Inc. 

Valley, Nebraska 68064-0358 

Dear Mr. O'Brien: 

This is in response to your April 16 letter to Mr. Gerald L. 

Eller in which you requested Federal Highway Administration's 

(FHWA) acceptance of your company's breakaway coupling design for 

use with luminaire.supports. Your letter was accompanied by the 

Southwest Research Institute report, Pendulum Test &port of a 

v Co-, dated March 1996. I. 

During your visit on April 17, you showed us a video of the crash 

testing that was conducted to assess the breakaway performance of 

the prototype couplings. You also showed us examples of the 

prototype coupling and the coupling as you expect to produce it 

in the future. As shown in the enclosed drawings of the tested 

prototype, each of the four couplings supporting the pole is a 

miniature four-bolt slip base. 

Testing was done in accordance with the National Highway 

Cooperative Research Program Report 350, Becommended Procedm 

of wav Few. 

Requirements for breakaway supports are those in the American 

Association of State Highway and Transportation Officials* 

TO) 

*. . 

Standard for Strvts fQI . * 

av SlUnS. -and S1g~a.l~. Drawings of the 

test installation and the tested coupling are enclosed. 

A summary of the crash test is presented below: 

Test Number VAL-7 

Foundation Condition Rigid test mounting 

Luminaire & Support Mass, kg (wt.,lbs) 461 (1017) 

1 Bolt Circle Diameter, mm (in) I 381 (15) I 

Pendulum Mass, kg (wt., lbs) 816 (1800) 

Impact Speed, km/h (mph) 

Pendulum Velocity Change, m/s (fps) 

35.28 (23.4) 

3.1 (10.1) 

Calculated Change @ 100 km/h, m/s (fps) 4.8 (15.9) 

Stub Heiaht. mm (in) 32 (1.2) 
l 2 

The results of the test and the high-speed extrapolation meet the 

change-in-velocity and stub-height requirements adopted by the 

FRWA. Your company's breakaway coupling for luminaire supports 

is therefore acceptable for use on projects on the National 

Highway System (NHS) where breakaway systems are required if 

proposed by a State. 

We note that the weight of the tested pole was 1017 pounds 

(461 kg). While this is only slightly over the 1000 pounds 

(453.6 kg) we have suggested limiting luminaire pole weights to 

in the past, we believe we must comment on this overage. In the 

future we will be recommending that the mass of breakaway 

luminaire and similar supports not exceed a recommended maximum 

mass of 450 kg (992 pounds) with a maximum plus tolerance of 

1 percent, which would set the actual maximum mass at 454.5 kg 

(1002 pounds). 

You also requested our acceptance of a proposed 18productiont8 

coupling, a modified version of the tested prototype. Since this 

coupling is of different materials, finish, and size from the 

tested device, any one of which features could cause a change in 

test results; we cannot find the proposed breakaway coupling 

.acceptable for use unless qualified through testing. 

Our acceptance is limited to the breakaway characteristics of the 

tested coupling as shown in the enclosed drawings and does not 

cover its structural features. Presumably, you will supply 

potential users with sufficient information on design and 

installation requirements to ensure proper performance. We 

anticipate that the States will require certification from 

Valmont that the hardware furnished has essentially the same 

chemistry, mechanical properties, and geometry as that used in 

the crash testing and that it will meet the,FHWA change in 

velocity requirements. 

Should you seek to patent your couplings and are ultimately 

successful, they will be proprietary products. To be used in 

Federal-aid projects, except exempt, non-NH.9 projects, 

proprietary products: (a) 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 

alternative 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. 

Enclosures 

Geometric and Safety Design Group Acceptance,Letter LS-44 
a,,l!i/ 
HOLE 

k- 2.50” -1 

TOP VIEW 

MATERIAL- COLD DRAWN STEEL BAR 

SLIP BAR 

PLAN VIEW 

MATERIAL- COLD DRAWN 

STEEL TUBING 

1 .OO”-8UNC BOLT 

-18UNC X 4.25” 

SAE GRADE 8 HEX BOLT 

& HEX NUT (4 REQ’D) 

SPACER 

(4) 0.34” DIA. HOLES 

AT 90’ ON A 2.00” 

DIA. BOLT CIRCLE 

POLE CONNECTING LUG 

MATERIAL- ZINC SHEET STOCK 

1 -- KEEPER PLATE 

KEEPER PLATE 

PLAN VIEW 

ELEVATION VIEW 

0.1 I’ RADIUS AT 

90’ ON A 2.00” 

DIA. BOLT CIRCLE’ 

1.02 l”-8UNC 

TAPPED HOLE 

FINISH: 

ALL PIECE PARTS MECHANICALLY 

GALVANIZED TO ASTM: 8695 

CLASS 55. 

MATERIAL- ASTM: A36 PLATE 

POLE & ANCHOR 

CONNECTING LUG 

PLAN VIEW 

BOTTOM VIEW 
U.S. ceporImen1 

of Transportati 

FeclemlHighweF 

AdmInistratIon 

400 SWB”,h St.. s.w, 

February 24, 1997 Washington. D.C. 20590 

Refer to: HNG-14 

Armand A. Damiano, P.E. 

Product Development~Manager 

Valmont Industries, Inc. 

Nest Highway 275 

P.C. Box 358 

Valley, Nebraska 68064-0358 

Dear Mr. Damiano: 

This is in response to your December 30, 1996, letter to 

Mr. Gerald L. Eller in which you requested the Federal Highway 

Administration's (FHWA) acceptance of your company's breakaway 

coupling design for use with luminaire supports. your letter was 

accompanied by the Southwest Research Institute report, Pendulum 

Test Report of a Ereamv CoupJJ.~g. Test No. VM-3, dated 

December 1996. Our letter of May 28, $996, to Mr. Dennis O'Brien 

accepted a prototype version of this coupling which was 

fabricated from ASTM A-36 steel. The recently tested production 

model was made using powdered metal technology. The powdered 

metal parts met MPIF Standard 35 Designation Code FC-0208-50. 

A copy of this specification, which was issued by Metal Powdered 

Industry Federation, was provided to us on January 23. 

Pendulum testing was done in accordance with the National 

Cooperative Highway Research Program Report 350, v 

for the -Performance Eva- of M&gh~8y 

Features. Requirements for breakaway supports are those in the 

American Association of State Highway and Transportation 

for Stre 

Drawings of the test installation and your company's couplings 

are enclosed. 

A summary of the crash test is presented below: 

Teat Number VU-3 

Foundation Condition Rigid test mounting 

Luminaira S Support Mass Kg (wt ,lbs) 

Bolt Circle Diameter, nun (in) 

Pendulum Mass, kg (wt, lba) 

Impact Speed, km/h (mph) 

Pendulum Velocity Change, m/e (fps) 

Calc. Vel., Change @ 100 km/h, m/e (fpe) 

Stub Height, mm (in) 

461 (1017) 

381 (15) 

816 (1800) 

35.28 (23.4) 

3.2 (10.6) 

4.9 (16.0) 

38 (1.5) 
2

The results of the test and the high-speed extrapolation meet the

change-in-velocity and stub-height requirements adopted by the

FHWA. Your company's breakaway coupling for luminaire supports

as shown in the cited, enclosed drawing is therefore acceptable

for use on projects on the National Highway System (NHS) where

breakaway systems are required if proposed by a State.

Our acceptance is limited to the breakaway characteristics of the

tested coupling as shown in the enclosed drawings and does not

cover its structural features. Presumably, you will supply

potential users with sufficient information on design and

installation requirements to ensure proper performance. We

anticipate that the States will require certification from

Valmont Industries that the hardware furnished has essentially

the same chemistry, mechanical properties, and geometry as those

used in the crash testing, and that it will meet the FHWA change

in velocity requirements.

We understand that you are seeking to patent this breakaway

: coupling. If patented, it will be a proprietary product. To be

used in Federal-aid projects, except exempt, non-NHS projects,

proprietary products: (a) 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

0

alternative 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,

Dwight ‘A. Horne, Chief

Federal-Aid and Design

2 Enclosures

Federal Highway Administration

HNG-14:NArtimovich:366-1331:gm:2-10-97:DAMIANO

copies to: HNG-1 HNG-10 HNG-14

Reader, 3128 File 3128

RAs HFL-1 HHS-10 HNG-30 HNG-20 HSR-20

Division

Supplemental Geometric and Safety Design Group Acceptance

Letter LS-44A -
APR 2 1997 400 Seventh St., S.W.

Washington. D.C. 20590

Refer to: HNG-14

Armand A. Damiano, P.E.

Product Development Manager

Valmont Industries, Inc.

West Highway 275

P.O. Box 358

Valley, Nebraska 68064-0358

Dear Mr. Damiano:

This is in response to your March 3 letter to Mr. Nicholas A.

Artimovich, II, in which you requested Federal Highway

Administration's acceptance of a change in the fastener hardware

used in your company's breakaway coupling design for use with

luminaire supports. The coupling with original hardware, shown

in the enclosed drawing with the new hardware, was found

acceptable in our letter LS-44A dated February 24 and used SAE

Grade 8 fasteners. Your request is to substitute ASTM A574

fasteners for the originally accepted fasteners. These

substitute fasteners have a 20 percent higher tensile strength

than the original. You indicate that this change will increase

the load capacity and fatigue strength of the coupling.

Because of your manufacturing and quality control procedures,

this change in fasteners will have no effect on the clamping

force they exert and, thus, no effect on the breakaway

performance of the Valmont coupling, we find that such a

substitution will be acceptable. All other conditions in our

previous letter, referenced above, regarding the use of the

coupling remain in-effect.

Sincerely yours,

Enclosure

L--, .

Federal-Aid and Design Division

Supplemental Geometric and Safety Design Group

Letter LS-44B

Acceptance
BREAKAWAY COUPLING 

.025” 

I 

MATFRlAl - MPIF STANDARD 35 

DESIGNATION CODE FC-0208-50 

SLIP BAR 

PLAN VIFW 

(4) 0.34” DIA. HOLES 

. . AT 9(r ON A 2.15” ToP v’Fw 0.31”- 18UNC (hi8 METRIC) 

X 2.75” LONG ASTM A574 

ALLEN SOCKET HEAD SCREW 

W/HEX NUT (4 REQ’D) 

DIA. BOLT CIRCLE 7 

c - 2.78” 

fSLIP BAR 

CONNECTING LUG 

KEEPER PL4TE 

CONNECTING LUG 

2.78

r 

” 

SLIP BAR 

t 

I 

.Q&VATlON VIFW 

-7 , / \ \ ?- + x 

‘\ ~ ’ 

/ 

FINISH; 

ALL PIECE PARTS (EXCEPT KEEPER PLATE) 

MECHANICALLY GALVANIZED TO ASTM: 8695 

CLASS 55. 

B 

- 0.31” REGULAR HELICAL 

SPRING LOCK WASHER MATFRIAL- ZINC ALLOY 750 

0.078” MEAN THICKNESS 

ANSI 818.21.1 (4 REQ’D) 

KEEPER PIATE 

PLAN VlFI 

THREADED HOLE 

TO 1 .Oo” L’ 0.17” RADIUS AT 

OR M27 METRIC 9(r ON A 2.15” 

DIA. BULT 0RCLE 

j&TFRI&- MPIF STANDARD 35 

DESIGNATION CODE FC-0208-50 

CONNECTING LUG 

PI AN VIF\y