Wheelchair Tiedown and Occupant Restraint Systems (WTORS)




RESNA WC18 is a revised and updated version of SAE J2249, Wheelchair Tiedown and Occupant Restraint Systems for Use in Motor Vehicles.
  WC18 requires crashworthiness evaluation of WTORS for general use in all types and sizes of motor vehicles by conducting a nominally worst-case 48 kph (30 mph) frontal sled-impact test using an 85 kg (185 lb) surrogate wheelchair (SWC) shown in the photo to the right and detailed in the engineering drawings here.  WC18 allows for, and applies to, WTORS that use different approaches to wheelchair tiedown, including four-point, strap-type tiedowns, and docking securement devices.  If it is known that a tiedown or securement system is intended only for use with a specific wheelchair model, then the WTORS and wheelchair can be tested in WC18 using performance criteria applicable to both.  

WC18 requires that every WTORS include a belt-type occupant-restraint system with both a pelvic belt and one or more shoulder belts since the evidence is clear that the combination of upper- and lower-torso belt restraints is the most effective method of reducing injuries and fatalities in a wide range of crash conditions, including frontal crashes, vehicle rollovers, and a large percentage of side impacts.  A midsize adult male anthropomorphic test device (ATD), or crash-test dummy, with a nominal mass of 78 kg (172 lb) is used to dynamically load the occupant restraint portion of the WTORS, unless testing with a specific wheelchair model. 

As of December 2015 (three years from the publication date of RENSA Volume 4), WC18 will require that WTORS that include a vehicle-anchored lap/shoulder belt occupant restraint undergo a second crash test.   This second crash test is to be performed with a surrogate wheelchair-anchored lap belt and is intended to ensure that the securement system of the WTORS are able to withstand the additional occupant restraint loads that will result from the increasing number of WC19 wheelchairs that will include a wheelchair-anchored lap belt.  Products that have passed the second test are indicated below. 

The international standard for WTORS, ISO 10542-1 (2012), also uses the same SWC.  WTORS imported from other countries may be compliant with this standard instead of, or as well as, WC18. 

More information on WC18 and ISO 10542-1 is located within the standards section of this website.


The following table is a list of WTORS products available that manufacturers have reported as being:

  • Completely compliant with the requirements of WC18: This means that the WTORS has been successfully crash tested using either the SWC or a specific wheelchair model, and that it meets all design requirements, as well as several other requirements.  A checklist of criteria for complete compliance of WC18 can be found here
  • Successfully crash tested to WC18 with a wheelchair-anchored lap belt: This means that in addition to having successfully passed a crash test using the complete WTORS, the wheelchair tiedown system portion of the WTORS has successfully met the requirements of a second crash test with using a SWC-anchored lap belt as is required by WC18 in December 2015.
Connect directly to the Google Sheet here.

  • Completely compliant with the requirements of ISO 10542-1 (2012):  This means that the WTORS has been successfully crash tested using either the SWC or a specific wheelchair model. It also meets all design requirements, as well as meeting several other requirements.  A checklist of criteria for complete compliance of ISO 10542 can be found here
Connect directly to the Google Sheet here.

  • Successfully crash tested wheelchair tiedown system only:  This means that the wheelchair tiedown system is not completely compliant with WC18 or ISO 10542 because it was successfully crash tested with a surrogate occupant restraint system (without the required commercial occupant restraint system to complete the WTORS system)
Connect directly to the Google Sheet here.

Use the links to the manufacturer websites to learn more about the listed WTORS products or to contact the person accountable for implementing the WC18 standard. 

Note:  Claims of product compliance are as reported by manufacturers and cannot always be confirmed by UMTRI personnel as these are voluntary industry standards.



Note to manufacturers: