USA Banner
  U.S. flag
              An official website of the United States government Here's how you knowOfficial US Government Icon
              **Official websites use .gov**A **.gov** website belongs to an official government organization in the United States.
            Secure Site Icon
              **Secure .gov websites use HTTPS**
                  A **lock** ( A locked padlock ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. 
 U.S. Department of Transportation Icon United States Department of Transportation
 Search DOT
            Search
                    About FHWAFHWA Organization
                Headquarters Offices
                Field Offices
                Strategic Plan
                Business Opportunities
                Staff Directories
                Careers
                Highway History
                Contact UsProgramsAcquisition Management
                Civil Rights
                Federal Lands Highway
                Infrastructure
                Innovative Program Delivery
                Operations
                Planning, Environment, and Realty
                Policy
                Research, Development, and Technology
                Safety
                Browse by TopicsResourcesCore Highway Topics
                Federal Aid Essentials
                Automation
                Complete Streets
                Laws and Regulations
                Policy & Guidance Center
                Section 508
                Publications and Statistics
                Professional Development
                National Highway Institute
                Resource Center
                Accessibility Resource Library
                FHWA Research LibraryNewsroomPress Releases
                Speeches & Testimony
                Photos
                Videos
                Media ContactsMenu FHWA Highway Safety Programs Home
                        Safety
                        Roadway Departure Safety
                        Reduce Crash Severity
                        Hardware Eligibility Letters


            
            In This Section
        Roadway Departure Safety
                Strategic Approach
                                Strategic Plan
                Crash Emphasis Brochures
                Focused Approach
                Noteworthy Practices
                Partner Resources
                Keep Vehicles on the Road
                                Pavement Friction
                Horizontal Curve Safety
                Rumble Strips and Rumble Stripes
                Nighttime Visibility
                Provide for a Safe Recovery
                                SafetyEdge
                Clear Zones
                Reduce Crash Severity
                                Overview
                Hardware Eligibility Letters
                Focus on Reducing Rural Roadway Departures (FoRRRwD)
                                Overview
                All Public Roads
                Proven Countermeasures
                Systemic Approach
                Safety Action Plans
                FoRRRwD Resources
                
                Safety Eligibility Letter SS-153
  
  **Hardware Type:**
            Sign Supports, Mailboxes, and Delineator Posts
                          **Code:**
            SS-153
                          **Date:**
            08/17/2007
                          **Testing Criteria:**
            NCHRP 350
                          **Manufacturer:**
            International FiberLok
                          **Device Description:**
            Composite Fiberglass I-beam Sign support
                          **View PDF:**
            ss153.pdf (755.07 KB)
    
    Skip to contentSkip to contentUnited States Department of Transportation - Federal Highway AdministrationDOT logo
			U.S. Department of Transportation

			**Federal Highway Administration**
			1200 New Jersey Ave. S.E.
			Washington, D.C. 20590**August 17, 2007**

**In Reply Refer To: HSSD/SS-153**

Mr. Jeff Tumlinson
International FiberLok
530 Jesse Street
Grand Prairie, Texas 75051

Dear Mr. Tumlinson :
In your letters of June 4 and June 20 2007, you requested the Federal Highway Administration (FHWA) acceptance of your company’s Fiberglass Sign Support Systems and Bolt Down Breakaway Slip Base Assembly for use on the National Highway System (NHS) under the provisions of the National Cooperative Highway Research Program (NCHRP) Report 350 “Recommended Procedures for the Safety Performance Evaluation of Highway Features.” To support your request, you provided copies of the Texas Transportation Institute’s (TTI) pendulum test reports entitled “Pendulum Testing of the International FiberLok Fiberglass Sign Support System.”

**Requirements**
Sign supports should meet the guidelines contained in the NCHRP Report 350, “Recommended Procedures for the Safety Performance Evaluation of Highway Features.” The FHWA memorandum, “ACTION: Identifying Acceptable Highway Safety Features” of July 25, 1997, provides further guidance on testing requirements of sign supports and outlines procedures for pendulum testing and estimation of high-speed breakaway performance of sign supports from low-speed pendulum test results.

**Product description**
Three International FiberLok Fiberglass Sign Support Systems were tested.

The 6 inches by 6 inches (152 mm x 152 mm) I-beam system consists of:

The stub is a 6 inches by 6 inches (152 mm x 152 mm) steel I-beam slipbase.
	The sign support is a 6 inches by 6 inches (152 mm x 152 mm) fiberglass and steel composite I-beam sign support with an International FiberLok Bolt Down Breakaway Slipbase Assembly, standard bolt keeper plate, and the four 5/8 inch (117.5 mm) diameter slipbase bolts tightened to 37 ft-lb (5.1 kg-m).
	A standard 3/8 inch (9.5 mm) fuse plate.The inclined 3 inches by 3 inches (76 mm x 76 mm) I-beam system consists of:

The stub is an inclined 3 inches by 3 inches (76 mm x 76 mm) steel I-beam slipbase.
	The sign support is a 3 inches by 3 inches (76 mm x 76 mm) fiberglass and steel composite I-beam sign support with an International FiberLok Bolt Down Breakaway Slipbase Assembly, standard bolt keeper plate, and four 1/2 inch (114.3 mm) diameter slipbase bolts tightened to 37 ft-lb (5.1 kg-m).
	A standard 1/4 inch (6.4 mm) fuse plate.The International FiberLok Bolt Down Breakaway Slipbase Assembly consists of:

The stub is an 8 inches by 5 inches (203 mm x 127 mm), 18 lb/ft (26.2 kg/m) steel I-beam slipbase.
	The sign support is an 8 inches by 5 inches (203 mm x 127 mm), 18 lb/ft (26.2 kg/m) steel I-beam with an International FiberLok Bolt Down Breakaway Slipbase Assembly, standard bolt keeper plate, and four 5/8 inch (117.5 mm) diameter slipbase bolts tightened to 37 ft-lb (5.1 kg-m).
	A standard 3/8 inch (9.5 mm) fuse plate.Sample drawings that show the design details of the International FiberLok Fiberglass Sign Support System and Bolt Down Breakaway Slipbase Assembly are enclosed. It is noted that bracing is added to the composite I-beams at the bottom of the sign support.

**Test article installations**
The 6 inches by 6 inches (152 mm x 152 mm) I-beam system was installed with 57-1/2 inches by 24 inches by 3/4 inch (1460 mm x 610 mm x 19 mm) steel plated sign panel mounted at 7.6 ft (2.3 m) to the bottom of the sign panel. The 3 inches by 3 inches (76 mm x 76 mm) system was installed with a 48 inches by 48 inches by 5/8 inch (1219 mm x 1219 mm x 16 mm) plywood sign panel mounted at 7.6 ft (2.3 m) to the bottom of the sign panel. Both systems were mounted on a steel reaction plate. The Bolt Down Breakaway Slipbase Assembly with an 8 inch by 5 inch (203 mm x 127 mm) I-beam was installed with a 57 inches by 24 inches by 3/4 inch (1460 mm x 610 mm x 19 mm) steel plated sign panel mounted at 7.6 ft (2.3 m) to the bottom of the sign panel.

**Testing**
The test article installations were tested at the TTI outdoor pendulum testing facility. The pendulum bogie was built according the specifications of the Federal Outdoor Impact Laboratory's (FOIL) pendulum, and the frontal crush of the aluminum honeycomb nose of the bogie simulated the crush of an actual vehicle. Tests with pendulums are acceptable for most breakaway supports with the exceptions of base bending or yielding supports. I agree that pendulum testing can be used on your company’s Sign Support Systems as a surrogate for a full crash testing. In addition, TTI extrapolated the high speed performance from the low speed pendulum tests. I agree that the test articles appear to perform appropriately to make such high speed extrapolations. The high speed extrapolations yield acceptable change in velocity values.

In each of the three tests the supports slipped away from the base as designed and came to rest near the impact location. No damage was noted to the support or the slipbase casting in the test with the 6 inch I-beam system. In the test with the inclined 3 inch I-beam system, no damage was noted to the slipbase stub and there was a vertical hairline fracture on the impact face of the support. Results from testing the Bolt Down Breakaway Slipbase show the support slipped away from the base as designed. For each of the three tests the entire systems could be reused after the impact. A summary of the test results are enclosed.

Based on the test results, I agree that the International FiberLok Fiberglass Sign Support Systems and the Bolt Down Breakaway Slipbase Assembly as described above meet the appropriate evaluation criteria for NCHRP 350 TL-3 devices. The I-beam sizes tested represent the minimum size acceptable for each mounting type. The maximum size acceptable is limited to the conditions and configurations stated in FHWA’s previous acceptance letters, SS-25 and SS-36, addressing standard I-beam sign support sizes utilizing generic slipbases. This FHWA acceptance applies to Fiberlok’s steel and fiberglass composite systems but is limited to bi-directional impacts on the Bolt Down Slipbase Assembly and the composite fiberglass system. Also, this FHWA acceptance limits the inclined base systems as crashworthy in one direction. These devices may be used at all appropriate locations on the NHS when selected by the contracting authority, and subject to the provisions of Title 23, Code of Federal Regulations, Section 635.411, as they pertain to proprietary products. This acceptance is based on the reported crash performance of your device and is not meant to address the limitations of testing or the systems’ installation, maintenance, or repair characteristics.

**Standard provisions**
Please note the following standard provisions that apply to the FHWA letters of acceptance:

This acceptance is limited to the crashworthiness characteristics of the devices and does not cover their structural features, nor conformity with the Manual on Uniform Traffic Control Devices.
	Any changes that may adversely influence the crashworthiness of the device will require a new acceptance letter.
	Should the FHWA discover that the qualification testing was flawed, that in-service performance reveals unacceptable safety problems, or that the device being marketed is significantly different from the version that was crash tested, it reserves the right to modify or revoke its acceptance.
	You will be expected to supply potential users with sufficient information on design and installation requirements to ensure proper performance.
	You will be expected to certify to potential users that the hardware furnished has essentially the same chemistry, mechanical properties, and geometry as that submitted for acceptance, and that they will meet the crashworthiness requirements of the FHWA and the NCHRP Report 350.
	To prevent misunderstanding by others this letter of acceptance designated as number
	SS-153 shall not be reproduced except in full. This letter and the test documentation upon which this letter is based, is public information. All such letters and documentation may be reviewed at our office upon request.
	The International FiberLok Fiberglass Sign Support System and Bolt Down Breakaway Slipbase Assembly are patented products and considered proprietary. If proprietary devices are specified by a highway agency for use on Federal-aid projects, except exempt, non-NHS projects, they: (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 the 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.
	This acceptance letter shall not be construed as authorization or consent by the FHWA to use, manufacture, or sell any patented device for which the applicant is not the patent holder. The acceptance letter is limited to the crashworthiness characteristics of the candidate device, and the FHWA is neither prepared nor required to become involved in issues concerning patent law. Patent issues, if any, are to be resolved by the applicant.Sincerely yours,

			George E. Rice

			George E. Rice, Jr.
			Acting Director, Office of Safety Design
			Office of SafetyEnclosures



Safety Home | FHWA Home | Feedback

United States Department of Transportation - **Federal Highway Administration** U.S. DEPARTMENT OF TRANSPORTATION

**Federal Highway Administration**

1200 NEW JERSEY AVENUE, SE

WASHINGTON, DC 20590

202-366-4000Subscribe to email updates
                    About
  

        
              About FHWA
                Careers
                Org Chart
                Staff Directories
                Work with UsPrograms
  

        
              Acquisition Management
                Civil Rights
                Federal Lands Highway
                Infrastructure
                Innovative Program Delivery
                Operations
                Planning, Environment, and Realty
                Policy
                Research, Development, and Technology
                SafetyPolicies, Rights, Legal
  

        
              About DOT
                Accessibility
                Budget and Performance
                Civil Rights
                FOIA
                Information Quality
                No FEAR Act
                Office of Inspector General
                Privacy Policy
                USA.gov
                Web Policies and Notices
                Web StandardsNews & Events
  

        
              Newsroom
                Press Releases
                Speeches & Testimony
                Media Contacts
                Connect with Us