Concerns regarding rollover protection surfaced in 1991 when the National Transportation Safety Board investigated seven highway accidents involving cargo tanks that had overturned and released hazardous materials. All of the tanks met federal design requirements. NTSB found that, in all cases, the rollover protection devices failed to protect the cargo tank manholes and fittings. It recommended further study by RSPA and the Federal Highway Administration.
The UMTRI study, released late in 1998, investigated the dynamics of mild, moderate and severe rollover crash events involving cargo tanks. Crash situations and vehicle characteristics were influenced by the rollover accidents in the NTSB report. All of the tanks met federal standards and, in each incident, the top damage protection structures were impacted.
RSPA has asked for comments on the study, possible changes for new tanks and retrofits of older tanks. Comments are due in writing May 15, 2000. The request for comments, including several specific questions, was published in the Nov. 16 Federal Register and can be accessed on the Internet at http://www.access.gpo.gov/su_docs/aces/aces140.html. Copies of the UMTRI study, “The Dynamics of Tank-Vehicle Rollover and the Implications for Rollover-Protection Devices, ” can be obtained by calling the RSPA Records Center at (202) 366-5046 or can be downloaded from the document management center (http://dms.dot.gov).