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Interpretation ID: Ravens



    Mr. Jeff Shahan
    Engineering Manager
    Ravens, Inc.
    1400 Fairchild Avenue
    Kent, OH 44240-1818


    Dear Mr. Shahan:

    This is in response to your letter requesting an interpretation of the requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 224, "Rear Impact Protection," as applied to the Ravens Steel Dump trailer with an 18-inch deep spreader pan bolted or welded to the rear of the trailer. As explained below, the Ravens Steel Dump trailer equipped with such a spreader pan will be required to incorporate a rear impact guard that complies with FMVSS No. 223, "Rear Impact Guards."

    You provided a drawing of the Steel Dump trailer with an 18-inch deep spreader pan bolted or welded to the rear of the trailer. According to that drawing, the spreader pan extends across the full width of the rear of trailer, and the top rear edge of the spreader pan is 52 and 3/4 inches above the ground.

    FMVSS No. 224 requires most trailers and semitrailers with a gross vehicle weight rating of over 10,000 pounds to be fitted at the rear with an underride guard complying with FMVSS No. 223. The standard does not apply to pole trailers, pulpwood trailers, low chassis vehicles, special purpose vehicles, wheels back vehicles, or temporary living quarters. None of these exclusions apply to the Steel Dump trailer depicted in your drawing.

    The Steel Dump trailer clearly does not qualify as temporary living quarters or as a pole trailer, pulpwood trailer, or low chassis vehicle. As explained below, it also does not qualify as a special purpose vehicle or a wheels back vehicle.

    S4 of FMVSS No. 224 defines a "special purpose vehicle" as "a trailer or semitrailer having work-performing equipment that, while the vehicle is in transit, resides in or moves through the area that could be occupied by the horizontal member of the rear underride guard, as defined by S5.1.1 through S5.1.3." The National Highway Traffic Safety Administration (NHTSA) interprets the words "work-performing" to mean that the equipment must actively perform its function, and that the function must involve exerting force or moving something. A spreader pan does not perform work in this sense. Therefore, we do not consider the spreader pan to be work-performing equipment, and the Steel Dump trailer does not meet the definition of a "special purpose vehicle."

    Moreover, according to the drawing you provided, the spreader pan does not, while the vehicle is in transit, reside in or move through the area that could be occupied by the horizontal member of the rear underride guard. In an interpretation letter issued to the National Truck Equipment Association on September 9, 1998, NHTSA stated that the area that could be occupied by the horizontal member of the rear underride guard, or "guard zone," is the cubic area extending (1) vertically from the ground to a horizontal plane tangent to the bottom of the trailer; (2) laterally to the side extremities of the trailer as defined in S4 of FMVSS No. 224; and (3) from the rear extremity of the trailer, as defined in S4 of FMVSS No. 224, to a transverse vertical plane 12 inches forward. The spreader pan does not reside in this zone; thus the Steel Dump trailer does not meet the definition of a "special purpose vehicle."

    S4 of FMVSS No. 224 defines a wheels back vehicle as "a trailer or semitrailer whose rearmost axle is permanently fixed and is located such that the rearmost surface of tires . . . is not more than 305 mm [12 inches] forward of the transverse vertical plane tangent to the rear extremity of the vehicle." A vehicle's "rear extremity" is defined as

    the rearmost point on a vehicle that is above a horizontal plane located 560 mm [22 inches] above the ground and below a horizontal plane located 1,900 mm [75 inches] above the ground when the vehicle is configured as specified in S5.1 of this section and when the vehicle's cargo doors, tailgate, or other permanent structures are positioned as they normally are when the vehicle is in motion. Nonstructural protrusions such as taillights, rubber bumpers, hinges and latches are excluded from the determination of the rearmost point.

    Since the rearmost axle on the Steel Dump trailer is located such that the rearmost surface of the tires is only 3 and 7/8 inches forward of the rear of the tailgate, but 21 and 7/8 inches forward of the rear of the spreader pan, the question becomes whether the spreader pan is structural and, therefore, constitutes the rear extremity of the trailer.

    Merely because an object is attached to the vehicle's body does not mean that the object is a nonstructural protrusion. The attributes that the examples of nonstructural protrusions listed in the definition of "rear extremity" have in common are that they are relatively small and localized and would not have a major impact on a colliding passenger vehicle. The spreader pan is 18 inches in depth and extends the full width of the trailer. Consequently, it cannot be considered relatively small or localized. In addition, according to your drawing, the spreader pan is located 52 and 3/4 inches above the ground. At this height, and without a rear underride guard, the spreader pan could penetrate the passenger compartment of a colliding passenger vehicle. For these reasons, we do not consider the spreader pan to be nonstructural. Thus, the Steel Dump trailer equipped with a spreader pan does not meet the definition of a "wheels back vehicle."

    Since the Steel Dump trailer equipped with a spreader pan does not qualify for any of the exclusions, it must be equipped with a rear underride guard that complies with FMVSS No. 223.

    I hope this letter answers your question. If you have any further questions concerning this matter, please feel free to contact Mr. Dion Casey in the Office of the Chief Counsel at (202) 366-2992.

    Sincerely,


    John Womack
    Acting Chief Counsel

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    d.1/25/01