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Interpretation ID: medcoaches3277.cmc

    Mr. Dick Mattice
    Vice President Engineering
    Medical Coaches
    399 Co Hwy 58
    PO Box 129
    Oneonta, NY 13820-0129


    Dear Mr. Mattice:

    This responds to your letter in which you asked about the requirements of Federal Motor Vehicle Safety Standard (FMVSS) Nos. 403, Platform lift systems for motor vehicles, and 404, Platform lift installations in motor vehicles, as they apply to platform lifts and mobile medical units manufactured by your company. I have addressed your questions below.

    By way of background, the National Highway Traffic Safety Administration (NHTSA) has authority to prescribe safety standards applicable to new motor vehicles and new items of motor vehicle equipment (49 U.S.C. Chapter 301). Under this authority, NHTSA adopted FMVSS Nos. 403 and 404, which establish minimum performance standards for platform lifts designed for installation on motor vehicles and motor vehicles installed with platform lifts, respectively. The purpose of the standards is to protect individuals that are aided by canes, walkers, wheelchairs, scooters, and other mobility devices and rely on platform lifts to enter/exit a motor vehicle. The standards are effective December 27, 2004.

    In your letter, you stated that your company manufactures trailers equipped with mobile medical units (e.g., MRI, PET, PET/CT units). You explained that all of these units have patient lifts that "fold and store in an under-floor skirt compartment during transit." You further explained that although the lift design "is primarily used for non-ambulatory patients on gurneys, it could just as easily be used for wheelchair-bound patients."You stated that the lifts are designed so that a gurney would be parallel to the trailer when on the platform, and therefore a wheelchair would also be oriented parallel to the trailer when on the platform. You then asked several questions regarding the application of FMVSS Nos. 403 and 404 to the lifts and vehicles manufactured by your company.

    1) Platform Dimensions

      Your letter explained that:

        [The] lifts are designed so that a gurney will be parallel to the trailer when entering or leaving the trailer. The platform itself is 84" wide x 38" deep (inner roll stop to ramp). As a result, a wheelchair would also be parallel to the trailer and not perpendicular.

    You then asked if the lift orientation and dimensions would be permitted under the new standards.

    Before discussing lift dimension requirements, it is important to note that FMVSS Nos. 403 and 404 differentiate between public use lifts and private use lifts, and that different requirements apply based on a lifts designation. Under FMVSS No. 404, lift-equipped buses, school buses and multipurpose passenger vehicles other than motor homes with a GVWR greater than 4,536 kg (10,000 pounds) must be equipped with a lift certified to all requirements applicable to a public use lift (see S4.1.1). All other lift-equipped motor vehicles must be equipped with a platform lift certified as complying with either the public use or private use lift requirements (see S4.1.2). FMVSS No. 404 does not include trailers as a vehicle type that must be equipped with a public use lift. Therefore, the trailers manufactured by your company may be equipped with lifts certified to the public or private lift requirements.

    FMVSS No. 403 does not establish requirements specifying the orientation of a wheelchair during lift operation. For public use lifts, S6.4.2.1 of FMVSS No. 403 does establish a minimum operating platform volume, which is based on the sum of an upper and lower part (see Figure 3; copy enclosed). The lower part must accommodate a rectangular solid that has a minimum width of 725 mm (28.5 in) along the platform surface and a minimum height of 50 mm (2 in). The upper part must accommodate a rectangular solid that has a base with a minimum dimension of 760 mm (30 in) wide by 1,220 mm (48 in) long and a minimum height of 711 mm (28 in). While the standard specifies that the base of the upper part must be tangent to the top surface of the lower rectangular volume and the centroids of both parts must coincide with the vertical centroidal axis of the platform, the standard does not specify the orientation of the upper part to the lower part. There is nothing preventing the upper part from being rotated in relation to the lower part.

    Based on the information provided in your letter, your platform would conform to the minimum operating platform volume requirement for public use lifts. Your platform is 84 inches by 38 inches and would be able to accommodate an upper and a lower rectangular solid of the minimum size required. Further, if you were to certify the lift to the private use lift requirements, you would be required to specify the unobstructed platform operating volume and include it in the lift insert to the vehicle owners manual.

    2) Wheelchair retention device impact test

    Again, you stated that upon loading, a wheelchair is intended to be oriented parallel to the trailer. You ask if S7.7, Wheelchair retention device impact test, must be performed in this orientation, with the wheelchair accelerated in a direction parallel to the trailer.

    The wheelchair retention device impact test verifies the integrity of the inner roll stop and the wheelchair retention device or outer barrier. The test simulates uncontrolled acceleration of a wheelchair or mobility aid when loading a platform. When loading the platform at the vehicle floor level, a mobility aid may accelerate forward and strike the wheelchair retention device. When loading the platform at ground level, a mobility aid may accelerate forward and strike the inner roll stop. In both instances, the mobility aid has the opportunity to achieve a measure of speed and momentum in a direction perpendicular to the trailer before striking a barrier.

    In FMVSS No. 403, S7.7.2.3 requires a test device to be positioned with its plane of symmetry coincident with the lift reference plane. This results in the test device oriented perpendicular to the vehicle. The reference to the orientation of the test device in S7.7 refers to whether a wheelchair is loaded onto the platform in the forward or reverse direction.

    On your vehicles, a mobility aid is loaded in a perpendicular direction to the trailer, even though once loaded it is positioned parallel to the trailer. Once the mobility aid is positioned on the platform parallel to the vehicle body, it is stationary. Even if it were to move forward or rearward, because of limited space on the platform, it could not achieve the level of momentum that is possible when rolling onto a platform from the vehicle or ground. However, during loading, an unimpeded mobility aid could heavily impact either a wheelchair retention device or outer barrier. Accordingly, the wheelchair retention device impact test would be performed on the wheelchair retention device/outer barrier and the inner roll stop.

    3) Public use verses private use lift

    Your letter asked if the lifts installed on the mobile medical units manufactured by your company would be required to be certified as public use lifts. As explained in response #1, because the vehicles manufactured by your company are trailers, the lifts could be certified as complying with either the public use or private use lift requirements.

    4) Platform freefall limits

    Under S6.6 of FMVSS No. 403, no portion of a platform may fall vertically faster than 305 mm (12 in) per second in the event of any single-point failure of systems for raising, lowering, or supporting the platform. Your letter asked if a failure of a hydraulic line by rupture constitutes a single-point failure.

    If a system for raising, lowering, or supporting a platform were to include a hydraulic line, then the rupture of that line would constitute a single-point failure under S6.6. Therefore, if the hydraulic line were to rupture, the platform must not fall vertically faster than permitted by the standard. Additionally, you may need to evaluate other failures, as S6.6 applies to any single-point failure.

    I hope that you find our responses helpful. If you have any additional questions, please contact Mr. Chris Calamita of my staff at (202) 366-2992.

    Sincerely,

    Jacqueline Glassman
    Chief Counsel

    Enclosure
    ref:403#404
    d.6/25/04