October 12, 2004
Refer to: HSA-10/WZ-158
Mr. Peter Speer
Bunzl Extrusion Tacoma Incorporated
3110 70th Avenue East
Tacoma, Washington 98424
Dear Mr. Speer:
This is in response to your email request of April 16, 2003, requesting Federal Highway Administration (FHWA) acceptance of your company's T3B Type III Barricades using 14 Gage perforated square steel tube framing material and 12-foot long extruded plastic panels as crashworthy traffic control devices for use in work zones on the National Highway System (NHS). You requested that we find these devices acceptable for use on the NHS under the provisions of National Cooperative Highway Research Program (NCHRP) Report 350 "Recommended Procedures for the Safety Performance Evaluation of Highway Features" based on testing of other generic Type III barricades.
The FHWA guidance on crash testing of work zone traffic control devices is contained in two memoranda. The first, dated July 25, 1997, titled "INFORMATION: Identifying Acceptable Highway Safety Features," established four categories of work zone devices: Category I devices were those lightweight devices which could be self-certified by the vendor, Category II devices were other lightweight devices which needed individual crash testing, Category III devices were barriers and other fixed or massive devices also needing crash testing, and Category IV devices were trailer mounted lighted signs, arrow panels, etc. The second guidance memorandum was issued on August 28, 1998, and is titled "INFORMATION: Crash Tested Work Zone Traffic Control Devices." This later memorandum lists devices that are acceptable under Categories I, II, and III.
The T3B Barricade is a plastic, lightweight, portable Type III barricade. The T3B 25.4mm x 210 mm (1 inch x 8 inch) hollow plastic barricade panels are made from a specially formulated polyolefin plastic, and the vertical uprights are 44.5-mm (2 inch) square thermoplastic tubing extrusions. The support legs are 14 ga, 50.8-mm (2 inch) square perforated galvanized mild steel tubing. One 150-mm (6 inch) tall PSST stub is welded to each support leg, and the vertical uprights are inserted into them. The T3B is acceptable in widths between 1219 mm (4 feet) and 2440 mm (8 feet) and heights between 1524 mm (5 feet) and 1829 mm (6 feet) Testing of your 2438-mm (8 foot) wide version of this barricade is discussed below. The fasteners are 7.94 mm (5/16") or 9.52-mm (3/8") bolts with Nylock nuts and steel washers to attach panels to the uprights.
Your present request is to allow the substitution of perforated square steel tube uprights (44.5 mm/1-¾ inch square, 14 gage, 1524 mm/60 inches long ) in lieu of the tested 44.5-mm (2 inch) square thermoplastic tubing extrusions. In all cases the specification and grade of the steel will be ASTM A570 grade 50 steel. In addition, you are requesting acceptance of 12-foot wide barricades.
|Barricade foot||2-inch 14 ga PSST or Qwik-punch||2 x 2 x 60 inch w/ PSST Stub||12 lb|
|Upright||1 ¾ inch 12 ga PSST||1 ¾ x 1 ¾ x 60 inch||9 lb|
|T3B 8-inch panels||Thermoplastic||¾ x 8 ¾ x 96 inch||5.25 lb|
Full-scale automobile testing was conducted on your company' devices and found acceptable per the NCHRP Report 350. The FHWA acknowledged TB3 barricades in our acceptance letters to you: WZ-39, dated June 29, 2000, and WZ-63, dated January 29, 2001. The use of one or two lightweight warning lights was also found acceptable. Crash testing of other Type III barricades using 1-¾ inch, 14-gage perforated square steel tube frame was conducted by Korman Signs using your company's 12 foot long extruded plastic rail elements. This testing, documented in WZ-100, Amendment #3, showed acceptable performance as long as the rails and uprights remain attached to each other and function as a unit when impacted.
Because of the successful history of crash testing of your original T3B and the Korman 12 foot wide Type III barricades using perforated square steel tube frame uprights, the Bunzl T3B barricade described in the request above and detailed in the enclosed drawings is acceptable for use on the NHS under the range of conditions that the original T3B was tested, when proposed by a State.
Please note the following standard provisions that apply to the FHWA letters of acceptance:
/Original Signed by/
John R. Baxter, P.E.
Director, Office of Safety Design
Office of Safety