Motorcoach Side Glazing Retention Research

In 2003, National Highway Traffic Safety Administration (NHTSA) and Transport Canada entered into a joint research program conducted by Martec Limited that focused on preventing unrestrained occupant ejections during motorcoach rollovers by improving standard window glazing and retention. Through computer simulation the Martec study (MS) determined that the impact velocity of an occupant striking the glazing was as much as 21.6 km/h (13.4 mph). Results from this research aided in the development of a dynamic test device of 26 kg (57 lb) mass that represents the torso of the 50th percentile adult male side impact dummy (US-SID). A section of a Motor Coach Industries (MCI) 1993 102D motorcoach was used by the Vehicle Research and Test Center (VRTC) to conduct impact tests at the center of the window and near the latch at different impact speeds. In center impacts, no windows with tempered glass broke and no windows opened under the MS impact conditions (26 kg at 21.6 km/h). In near-latch impacts, all latches opened when struck at the MS conditions. Testing was expanded to other motorcoach manufacturers and coach series to establish fleet baseline performance. Market share studies indicated that the fleet was well represented by conducting tests on a Prevost model H3-45, Van Hool model C2045, and MCI E/J-series, in addition to the MCI D-series line. Testing was conducted on glazing mounted to test frames that represented the side passenger window frames for each of the three manufacturers. Windows from all three manufacturers exhibited latch openings in near-latch tests on production latches at MS conditions. An attempt was made to modify the latch systems with simple designs to see if the impactor could be contained when tested at the MS conditions. In near-latch tests on countermeasure latches at MS conditions, the MCI E/J-series latches required the simplest modification to improve its performance. The MCI E/J-series countermeasure latch and glass remained intact. However, no simple countermeasures were identified for the Van Hool and Prevost latches. A study was conducted and a test procedure developed to address the glazing strength in the event the window is broken in a rollover crash prior to occupant loading. A series of tests was performed on fixed windows from the MCI E/J-series to determine their performance under MS conditions. Tests near the retaining clips on unbroken glazing produced partial window openings. For tests conducted at the center of the daylight opening, the unbroken single-glazed window opened, but neither the unbroken or pre-broken double-glazed windows opened. Finally, a series of tests was conducted to compare the setups of the MCI D-series bus section tests and window frame tests. Determining the relative stringency of the two test methods was inconclusive. In five comparison tests, the event of window opening or remaining closed was similar. Also, the peak forces from the frame tests were higher than those from the bus section tests, but there was no clear trend for the peak excursion measurements.


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Photos; Tables;
  • Pagination: 102p

Subject/Index Terms

Filing Info

  • Accession Number: 01518977
  • Record Type: Publication
  • Report/Paper Numbers: DOT HS 811 862
  • Created Date: Feb 26 2014 4:43PM