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                Safety Eligibility Letter WZ-107
  
  **Hardware Type:**
            Work Zone Devices
                          **Code:**
            WZ-107
                          **Date:**
            02/07/2002
                          **Testing Criteria:**
            NCHRP 350
                          **Manufacturer:**
            Yodock Wall Co., Inc.
                          **Device Description:**
            Energy Dispersement Cell Barricade
                          **View PDF:**
            wz107.pdf (193.97 KB)
    
    
Refer to: HSA-10/WZ-107
  Mr. Leo J. Yodock, III
    Yodock Wall Co., Inc.Ft. Lauderdale, FL  33315
  Dear Mr. Yodock:
  Thank you for your letters of September 4, 2001, requesting Federal Highway 
    Administration (FHWA) acceptance of your company's Energy Dispersement 
    Cell Barricade (EDCB) as a crashworthy traffic control device for use 
    in work zones on the National Highway System (NHS).  Accompanying your letter 
    was a report of crash testing conducted by the Texas Transportation Institute 
    and videos of the tests. You requested that we find this device acceptable 
    as a Test Level 3 (TL-3) devices, respectively, 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.”
  On December 13, 2001, you met with members of the Office of Safety Design 
    staff to discuss the crash-testing program, the results, and the proposed 
    uses associated with these devices.  On January 9, 2002, you submitted additional 
    information as discussed at our meeting.
  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 device follows:
  Energy Dispersement Cell Barricade - TL-3
  The Yodock Barrier Model 2001 EDCB units are rotomolded, low-density polyethylene, 
    water-filled containers.  Overall dimensions on these units are 1830 mm long, 
    1170 mm tall, 610 mm width at the base, and 280 mm wide at the top.  There 
    are two forklift holes at 530 mm above ground level that nominally measure 
    150 mm x 280 mm. The bottom vertical face of the device is 230 mm in height.  
    For this test, water ballast was placed in the units to the maximum capacity.  
    The approximate full mass of each unit is 1025 kg (1650 pounds.)  A total 
    of three units were placed adjacent to each other and coupled with Polyethylene 
    couplers.  The total length of the installation was 5.5 m (18 ft.)
  The Type III barricade atop each water filled unit was fabricated with two 
    50 mm (2 inch) schedule 80 PVC pipes, 2.59 m long (102 inch) supports.  The 
    center of the support pipes are placed 330 mm (13 in) from each end of the 
    units.  Hollow plastic lumber measuring 20 mm (3/4 inch) thick, 195 mm (7.7 
    inches) tall, by 1840 mm (72.4 inches) long was attached to the PVC pipe with 
    6 mm (1/4 inch) “U” bolts.  The top of the middle horizontal panel was 1940 
    mm (76.4 inches) above the ground.  The top of the upper horizontal panel 
    was mounted 2440 mm (96 inches) above grade. In addition, a 1220 mm x 1220 
    mm x 12 mm (4 foot x 4 foot x 7/6 inch) plywood sign panel was bolted to the 
    middle Type III barricade.  The top of the sign panel was 3250 mm (128 inches) 
    above grade.  Four battery powered warning lights were attached to the top 
    of the pipe supports.
  This device was evaluated as a road-closure system to be placed perpendicular 
    to the centerline of the roadway.  A similar Yodock system was successfully 
    crash tested earlier and accepted by FHWA Acceptance Letter WZ-34 dated March 
    23, 2000.  It consisted of a single unit with type III apparatus with no water 
    ballast added.  Because the vehicle velocity change for that device was 3.9 
    m/s it was known that an impact into a similar barricade system filled with 
    water would cause unacceptable decelerations.  It was decided to run such 
    a test anyway to determine the worst possible performance of this system.  
    One reason for this ultimate test was the proposed use for such a system: 
    it is intended to be placed at right angles to the roadway to deter vehicles 
    from proceeding beyond that point.  It was expected that the water-filled 
    barricade would keep vehicles from filtering through, be very difficult for 
    unauthorized persons to move, yet still be somewhat forgiving in the event 
    of a crash.  Please note that, as a result of this testing, it has been determined 
    that these units may not be completely filled with water when deployed.
  For this device, a single Report 350 test 3-71 was conducted with an 820 
    kg passenger car impacting the center barricade of the array head-on at a 
    speed of 100 km/hr.
  Testing
  Full-scale automobile testing was conducted on your company's devices.  The 
    test results are summarized in the following table.
  
Test Number
    400001-YWC2NCHRP Report 350 Test 
        #
    3-71Test Article
    Type 
        III BarricadeHeight to Bottom of 
        Sign
    1535 
        mmHeight to Top of Sign
    3260 
        mmFlags or lights
    4 Type 
        A/C BeaconsTest Article Mass 
        (one cell)
    1056 
        kgVehicle Inertial Mass
    820 kgImpact Speed
    96.3 
        km/hrOccupant Risk Values:Occupant Impact 
        Velocity
    8.5 m/sRidedown x-direction
    -2.0 
        g'sRidedown y-direction
    2.0 g'sMax 0.050-s accel 
        x-dir
    -16.2 
        g'sMax 0.050-s accel 
        y-dir
    -1.4 
        g'sMax 0.050-s accel 
        z-dir
    -3.2 
        g'sVehicle crush
    280 mm 
        maxOccupant 
        Compartment Intrusion
    95 mm 
        (crush)Windshield Damage
    Hole 
        caused by hoodThe mass of the middle cell was 60 kg (cell unit) +  965 kg (water) + 20 
    kg (barricade posts and panels) + 11 kg (sign on middle cell only)
  In the EDCB test, the vehicle broke through the middle barricade, 
    pulling those to the right and to the left along with it for a short distance.  
    The impact forced the hood back into the windshield, causing a hole in the 
    glass.  Even though the test resulted in a hole in the windshield, parts of 
    the device itself did not show potential for penetrating the occupant compartment. 
    Because of the mass of the water in the filled cells, Occupant Impact Velocity 
    exceeded that for a breakaway work zone traffic control device.  However, 
    it was within the desirable limit for a crash cushion impact and is considered 
    survivable.
  Findings
  The Model 2001 Type III EDCB tested full of water, exceeded the velocity 
    change requirements for a work zone traffic control device.  However, its 
    intended use is to hinder access to an area and be difficult to move.  The 
    researchers calculated that the occupant impact velocity of 5 meters per second 
    would not be exceeded if the volume of water was reduced by half in these 
    units.  Therefore, we conclude that the Model 2001 Type III barricade will 
    be acceptable for road closures in if the cell units are used half filled 
    with water (482 kg of water).   The fill mark or other method of regulating 
    the maximum water line must be permanently incorporated into the EDCB units.  
    An additional condition is that they not be placed in a location where traffic 
    running perpendicular to the closed road cannot impact the end of a EDCB installation 
    as they have not been crash tested at the 90 degree orientation.
  Because this device has been tested and met the unique requirements that 
    had been set for them, the device described above and shown in the enclosed 
    drawings for reference is acceptable for use on the NHS under the range of 
    conditions tested and the additional conditions discussed above, when proposed 
    by a State.  In addition, the Model 2001m EDCB, the base unit of which is 
    812 mm tall, will also be acceptable subject to the same conditions and restrictions 
    as the crash-tested Model 2001 EDCB.
  Please note the following standard provisions that 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 MUTCD.
  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 the will meet the crashworthiness 
      requirements of FHWA and NCHRP Report 350.
  To prevent misunderstanding by others, this letter of acceptance, designated 
      as number WZ-107 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 Yodock Wall plastic safety shape units are patented and 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 the 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 types 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. Halladay
  Acting Program Manager, Safety
  Enclosure U.S. DEPARTMENT OF TRANSPORTATION

**Federal Highway Administration**

1200 NEW JERSEY AVENUE, SE

WASHINGTON, DC 20590

202-366-4000Subscribe to email updates
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