llmeportment 

of liunsportaticm 

Federal W-Y 

AdmlnistmHon 

JUL 27 I992 

Refer to: HNG-14 

Jeffrey A. Bloom, P.E. 

Vice President 

Adian Engineering Corporation 

900 Orchard Way 

Silver Spring, Maryland 20904 

Oear Mr. Bloom: 

Thank you for your letter of July 6 to Mr. James H. Hatton requesting Federal 

Highway Administration's (FHWA) acceptance of the Adian Breakaway Base for 

Luminaire Supports, Model TB-01. Your letter reported on static and pendulum 

testing conducted to assess the breakaway performance of the 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 base consists of five components - a flanged upper base section, a mating 

flanged lower base section, a horizontally oriented, torsion resisting shear 

pin centered at the interface between the upper and lower flanges, a retaining 

ring consisting of three equal segments that hold the flanges of the upper and 

lower base sections together, and a breakaway strap around the retaining ring 

segments. The flanged upper and lower base sections and the retaining ring 

are shown in the enclosed drawing. Upon impact, the upper base section moves, 

breaking the stainless steel strap (banding) holding the three retaining ring 

pieces in place, thus, releasing the retaining ring segments and allowing the 

upper base section to slide off the lower base section. In addition, except 

for impacts aligned with the axis of the shear pin, the shear pin will be 

partially or fully sheared when the upper section of the base moves. 

The test results are summarized below: 

m Preliminarv Test Uualification Test 

Support Type Aluminum Aluminum 

Test Article Mass, kg 196 (431) 241.5 (531.4) 

(weight, lbs.) 

Test Article Mass, kg 

(weight, lbs.) 

196 (431) 241.5 (531.4) 
2 

Mounting Height, m (ft) Unreported 15.2 (50) 

Pendulum Mass, kg 818 (1800) 818 (1800) 

(weight, lbs.) 

Impact Speed, km/h (mph) 31.9 (19.8) 30.6 (19.0) 

Velocity Change, m/s (fps) 1.8 (5.9) 1.6 (5.4) 

Calculated High Speed Not Calculated 3.7 (12.1) 

Velocity Change, m/s 

Stub Height, mm (in) 

The results of these 

requirements adopted 

(fps) 

75 (3) 75 (3) 

tests meet the change in velocity and stub height 

by AASHTO and the FHWA. Therefore, the Adian Breakaway 

Base for Luminaire supports described above is acceptable for use on Federalaid highway projects, within the range of conditions tested, if proposed by a 

State. 

Our acceptance is limited to the 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 Adian Engineering or the manufacturer or supplier 

that the hardware furnished has essentially the same chemistry, mechanical 

properties, and geometry as that used in the tests, and that it will meet the 

FHWA change in velocity requirements. 

It is our understanding that the Adian Breakaway Base is proprietary. For 

proprietary products 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 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 projects are contained in 

Title 23, Code of Federal Regulations, Section 635.411, a copy of which is 

enclosed. 

Sincerely yours, 

Lawrence A. Staron 

Chief, Federal-Aid and Design Division 

Enclosures 

Geometric and Roadside Design Acceptance Letter LS-28 
t------18,00----------_-1 

UPPER BASE 356 Aluninun 

LOllHR BASE 356 Ahminun 

-T CA. 

80.54 

-I_ 

I 133 

0.33 IA I 

0.83 

0.93 

RETAlWlNG Rlffi 6061-T6 Aluninun 

ADlAN BREAKAWAY BASE FOR LLMINAIRE SWPORTS 

MODEL l-B-01 

UPPER BOLT CIRCLE DIAMETER RANGE - 12 TO 13 INCHES 

LWER BOLT CIRCLE DIIUW-ER W - 16 TO 17 INCHES 
23 CFR Ch. I (4-l-90 Edlti#l)

.

I g35.411 Material or product s&ctlon.

(a) Federal funds shall not particl- pate, directly or indirectly, in payment for any premium or royalty on any

patented or proprietary material, sDec_ ification. or process specifically set forth in the plans and specifications

for a luoject, unless:

:I: f&ck, . . PL=~ ..&s..Ca~ ..-..-ls*aru - Oi )11vy*8cuor,

item ls purchased or obtained through competitive bidding with equally suitsble unpatented items: or

(2) The State highway agency certifies either that such patented or PI’@

prietary item ls essential for synchm nisatlon with existing highway facilities. or that no equally suitable alternate exists; or

(3) Such patented or proprietur item is used for research or for a db-

_-a

_- _

Hlghwoy Admlnlstmtion, DOT

tinctive type of construction on rela- ’ tlvely short sections of road for experimental Purposes.

(b) When there is available for pur- chase more than one nonpatented.

I &proprietary material. semifinished

or finlshed article or product that will

fulfill the requirements for an item of

work of a project and these available

materials or products are judged to be

of satisfactory quality and equally acceptable on the basis of engineering

analysis and the anticipated prices for the related item(s) of work are estimated to be approximately the same.

the PS&E for the project shall elther contain or include by reference the

specifications for each such material

or product that is considered acceptable for incorporation in the work. If

the State highway agency wishes to

substitute some other acceptable material or product for the material or

product designated by the successful

bidder or bid ss the lowest alternate.

snd such substitution results in an lncrease in costs, there will not be Federal-aid particlpatlon in any increase In

costs.

(c) A State highway agency may re- quire a specific material or product

when there are other acceptable materials and products, when such specific

choice is approved by the Division Administratdr as being in the public interest. When the Division Administrator’s approval is not obtained, the item will be nonparticipating unless bidding

procedures are used that establish the

unit price of each acceptable altemative. In this case Federal-aid participation will be based on the lowest price

so established.

(d) Appendix A sets forth the

FHWA requirements regarding f 1 I the . . . snecuication oi alternative types of culvert pipes, and (2) the number and

types of such alternatives which must

be set forth in the specifications for

various types of drainage installations.

te) Reference in specifications and on plans to single trade name materirls will not be approved on Federal-aid cmeacts.