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                Safety Eligibility Letter WZ-99
  
  **Hardware Type:**
            Work Zone Devices
                          **Code:**
            WZ-99
                          **Date:**
            11/21/2001
                          **Testing Criteria:**
            NCHRP 350
                          **Manufacturer:**
            Dicke Tool Co
                          **Device Description:**
            8-27-01
                          **View PDF:**
            wz99.pdf (438.74 KB)
    
    Safety Eligibility Letter

            
            			
            DOT logoU.S. Departmentof Transportation**Federal Highway Administration**
                   	400 Seventh St., S.W.Washington, D.C.  20590

       	    Refer To: HSA-10/WZ-99Mr. Grant Dicke
Dicke Tool Company
1201 Warren Avenue
P.O. Box 518
Downers Grove, IL  60515
            Dear Mr. Dicke:
            Thank you for your letter of  August 27 requesting Federal Highway Administration (FHWA) acceptance of your  company’s DF-4503 and SLIP-60 portable sign systems as crashworthy  traffic control devices for use in work zones on the National Highway System  (NHS). Accompanying your letter was a  preliminary report of crash testing  conducted by Midwest Roadside Safety Facility and a video of the tests. 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.”
            **Introduction**
              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.
            A brief description of the  devices follows:
            (Systems 56 and 57, Test No.  D-29) DF-4503 Stand - A heavy duty, double torsion spring mounted portable sign  support with a 1219 x 1219 mm sign mounted at a height of 1518 mm from the  ground and with three wood-staffed flags at a height of 3778 mm. This stand  supported a RUR48 reflective vinyl roll up sign. Tested at both 90 degrees and head-on.
            	(Systems 60 and 61, Test No.  D-31) SLIP-60 Stand. A rigid mounted  portable sign support with a 1219 x 1219 mm sign mounted at a height of 1613 mm  from the ground. This stand features a  three-bolt slip base mechanism to enhance performance. It supported a 2.00 mm thick aluminum  sign. Tested at both 90 degrees and  head-on with an EMPCO type “B” light mounted to the type of the vertical  mast. Height to top of light 3473 mm.
          		(Systems 62 and 63, Test No.  D-32) SLIP-60 Stand. A rigid mounted  portable sign support with a 1219 x 1219 mm sign mounted at a height of 1638 mm  from the ground. This stand is the same  as the SLIP- 60 tested as systems 60 and 61 except that no warning light was  attached to the top supported a 2.00 mm thick aluminum sign. Tested at both 90 degrees and head-on.**Testing**Full-scale automobile testing was  conducted on your company’s devices. Two  stand-alone examples of the device were tested in tandem, one turned 90 degrees  and the next placed six meters downstream struck  head-on, as called for in our guidance memoranda. The complete device as tested is shown in  Enclosure 1. The crash test is  summarized in the table below:
              Test Number
                  D-29
                  D-31
                  D-32Test Article
                  DF-4503
                  SLIP-60
                  SLIP-60Sign
                  1219 x 1219 mm
                  roll up
                  1219 x 1219 mm
                  2 mm aluminum
                  1219 x 1219 mm
                  2 mm aluminumHeight to Sign Bottom
                  1518 mm (60 in)
                  1613 mm (60 in)
                  1651 mm (65 in)Height to Sign Top
                  3239 mm
                  3277 mm
                  3300 mm (130 in)Flags or lights
                  With flags
                  Empco Light
                  NoneTest Article Mass
                  20.5 kg
                  32 kg
                  30.6 kgTotal Mass of Ballast
                  none
                  250 kg
                  250 kgVehicle Inertial Mass
                  897 kg
                  897 kg
                  883 kgImpact Speed, Head-on
                  104.5 km/hr
                  88.9 km/hr
                  97.8 km/hrImpact Speed, 90 Deg.
                  107.7 km/hr
                  107.8 km/hr
                  101.5 km/hrVelocity Change*
                  0.89 m/sec
                  5.25 m/sec
                  1.02 m/secVehicle crush
                  Minor cracks, scrapes on bumper    and roof
                  Minor damage to bumper and    lights
                  Minor roof deformationOccupant Compart. 
                      Intrusion
                  None
                  None
                  NoneWindshield Damage
                  None
                  None
                  None* Velocity change of vehicle was  measured after striking both test articles.  In test D-30 the brakes malfunctioned between impacts so the “velocity  change” shown above does not reflect the action of the test article.
              **Findings** 
                Damage was limited to dents on  the bumper, grill, hood, and roof. There  was no windshield damage nor passenger compartment intrusion due to the test  articles. The results of the testing met  the FHWA requirements and, therefore, the devices described above and shown in  the enclosed drawings for reference are acceptable for use on the NHS under the  range of conditions tested, when proposed by a State.

            Please note the following  standard provisions which apply to FHWA letters of acceptance:
            Our  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 FHWA and NCHRP Report 350.
                To  prevent misunderstanding by others, this letter of acceptance, designated as  number WZ-99 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.Dicke Tool sign stands may  include patented components and if so are considered  "proprietary." The use of  proprietary work zone traffic control devices in Federal-aid projects is  generally of a temporary nature. They  are selected by the contractor for use as needed and removed upon completion of  the project. Under such conditions they  can be presumed to meet requirement "a" given below for the use of  proprietary products on Federal-aid projects.  On the other hand, if proprietary devices are specified 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 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.
			  
            Sincerely yours,
                   	  
                        Michael L. HalladayActing Program Manager, SafetyEnclosure U.S. DEPARTMENT OF TRANSPORTATION

**Federal Highway Administration**

1200 NEW JERSEY AVENUE, SE

WASHINGTON, DC 20590

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