August 18, 2000
Refer to: HSA-I/SS-90
Mr. Larry M. Mims
Director of Marketing
K&K Systems, Inc.
699 Plametto Road
Tupelo, Mississippi 38801
Dear Mr. Mims:
Thank you for your June 29 letter requesting acceptance of your company's solar powered warning light/sign support systems as a breakaway supports for use on the National Highway System (NHS). Accompanying your letter was a report of crash testing done at Southwest Research Institute (SWRI) dated June 2000, and videos of the crash tests. On July 18 you provided additional information regarding a heavier configuration of warning system than the one that was tested.
Introduction
Testing of the supports was in compliance with the guidelines contained in the National Cooperative Highway Research Program (NCHRP) Report 350, Recommended Procedures for the Safety Performance Evaluation of Highway Features. Requirements for breakaway supports are those in the American Association of State Highway and Transportation Officials' (AASHTO) Standard Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals.
Two crash tests were conducted, one at 35km/hr and another at 100 km/hr. The test articles were Model 112 K&K Systems Solar Panel Sign Supports as shown in Enclosure 1. They were mounted on Marion Steel "SLIP-SAFE'" breakaway slip bases. The two-bolt slip-bases for u-channel supports were previously accepted by the Federal Highway Administration (FHWA) (See acceptance letter SS- 69 dated 9-1 8-1996). The posts are 6 kg/m (4 pound-per-foot) u-channel sign supports of steel conforming to re-rolled rail steel specifications. Each test article consisted of the breakaway post, aluminum warning sign, aluminum battery cabinet/battery/controller, double head flasher, and 80 watt solar panel. The height to the top of the signpost was 4775-mm. The angled solar panel extended slightly above that height.
A summary of the crash tests of the single square tube posts is presented in the following table.
Test No. |
K&K 1 |
K&K 2 |
NCHRP 350 Designation |
3-60 |
3-6 1 |
Vehicle Mass |
798 kg |
|
Vehicle Impact Speed |
36.4 km/hr |
101.3 km/hr |
Soil Type |
Standard, or “Strong” soil |
|
Impact Angle |
0 degrees |
|
Test Article Mass |
87.1 kg |
|
Occupant Impact Speed |
0.9 m / s |
0.5 m/s |
Vehicle Velocity Change |
0.9 m / s |
0.6 m/s |
Windshield Damage |
No contact |
No contact |
Vehicle Deformation |
Shallow dent in bumper |
Dents in bumper and hood |
Stub Height |
100 mm |
100 mm |
The tested supports met the change in velocity and stub height requirements of the AASHTO Standard Specifications and NCHRP Report 350. There were no deformations of the passenger compartment and no damage to the windshield. Therefore, this K&K Systems Model 112 Solar Panel Sign Support on Marion Steel slip-base supports are acceptable for use on the NHS within the range of conditions tested, when requested by a State. Because the supports were tested in standard soil and there was little or no motion of the stubs in the soil as a result of the test, this breakaway support will also be acceptable when placed in a concrete foundation in standard soil.
You also requested that we find other combinations of solar panel, lights, battery box, splices, and timers acceptable according to the chart shown as Enclosure 2. All K&K Models are lighter in weight except for systems CT 117 and CT 118. These heaviest systems are approximately 50 percent heavier than the tested model. Calculations supplied by Joe Maya of SWRI show that the projected occupant impact velocity for the worst-case 100 km/hr impact would only be 1.97 m / s. This is still under the "desirable" limit of 3 m/s in NCHRP Report 350. Based upon this calculation and the successful crash tests we will consider any configuration of your company's Solar Panel Sign Supports on Marion Steel slip-base supports using 6 kg/m u-channel posts acceptable provided the total mass is 135 kg or less and the center of gravity of the assembly is no lower than the tested system.
Please note the following standard provisions which apply to FHWA letters of acceptance:
Sincerely yours,
[original signed
by Frederick G. Wright, Jr.]
Frederick G. Wright, Jr.
Program Manager, Safety
Enclosure 2
K & K SYSTEMS, INC.
TUPELO, MISSISSIPPI 38801
NCHRP 350 TESTED...
ACCEPTED… CERTIFIED
MODEL |
SOLAR |
LED’S |
BATTERY |
SPLICERS |
BREAK |
TIMER |
SYSTEM |
CT112 |
80 WATT |
2-12” |
SINGLE |
2 |
1 |
1 |
192 lbs. Tested |
CT103 & CT104 |
32 WATT |
8” |
SINGLE |
2 |
1 |
NA |
169 lbs. – 23 |
CT105 & CT106 |
50 WATT |
8” |
SINGLE |
2 |
1 |
NA |
176 lbs. – 16 |
CT110 |
50 WATT |
2-8” |
SINGLE |
2 |
1 |
1 |
182 lbs. – 10 |
CT113 & CT114 |
80 WATT |
2-8” |
SINGLE |
2 |
1 |
NA |
187 lbs. – 5 |
CT115 & CT116 |
80 WATT |
12” |
SINGLE |
2 |
1 |
NA |
184 lbs. – 8 |
CT117 & CT118 |
2-80 WATT |
2-12” |
DOUBLE |
3 |
1 |
NA |
290 lbs. + 98 |
CT120 |
32 WATT |
2-8” |
SINGLE |
2 |
1 |
1 |
174 lbs. – 18 |
CT122 |
50 WATT |
2-12” |
SINGLE |
2 |
1 |
1 |
185 lbs. – 7 |
CT124 |
50 WATT |
2-8” |
SINGLE |
2 |
1 |
1 |
181 lbs. – 11 |
K & K Systems, Inc.
SUMMARY
All above systems use identical breakaways located 4" above ground level, lap splices, solar mounting configuration welded to 4 lb/ft steel "U" channel poles, battery cabinets and wiring. The signage or bottom LED is always mounted 7 foot above ground level, which puts majority of weight of system above the oncoming vehicle. Respectfully submit that all above systems be certified NCHRP 350 approved.
Enclosure 3
Sec. 635.411 Material or product selection.
(a) Federal funds
shall not participate, directly or indirectly, in payment for any premium
or royalty on any patented or proprietary material, specification, or process
specifically set forth in the plans and specifications for a project, unless:
(1) Such patented or proprietary item is purchased or obtained through competitive bidding with equally suitable unpatented items; or
(2) The State highway agency certifies either that such patented or proprietary
item is essential for synchronization with existing highway facilities, or
that no equally suitable alternate exists; or
(3) Such patented or proprietary item is used for research or for a distinctive type of construction on relatively short sections of road for experimental purposes.
(b) When there is available for purchase more than one nonpatented, nonproprietary
material, semifinished or finished 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 either 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 as the lowest alternate, and such substitution results in an
increase in costs, there will not be Federal-aid participation in any increase
in costs.
(c) A State highway
agency may require a specific material or product when there are other acceptable
materials and products, when such specific choice is approved by the Division
Administrator 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 alternative.
In this case Federal-aid participation will be based on the lowest price so
established.
(d) Appendix
A sets forth the FHWA requirements regarding (1) the specification of 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.
(e) Reference in specifications and on plans to single trade name materials will not be approved on Federal-aid contracts.