A full-scale vehicle testing program was undertaken to analyze the rollover stability of double-bottom tankers (associated with a high incidence of rollover accidents in Michigan). The testing was part of a total research program which included yaw plane and roll plane analytical studies. Test vehicle loading, anti-rollover outriggers, instrumentation, and modification hardware are discussed. The baseline Michigan tanker was found to have an exceptionally low dynamic rollover stability, particularly in accident-evasion maneuvers. This instability probably accounted for most of the accidents in which the pup trailer alone rolled over. An improvement to the baseline double can be attained by installing, between the dolly and the semitrailer, a hitch which is rigid in both the steer and roll directions and by installing devices in the suspensions to eliminate excessive clearance in the left spring constraints. This modified tanker exhibits a rollover stability level comparable to that of the short Michigan single tanker. The pup trailer of the baseline vehicle has a lightly damped mode of yaw oscillation; it can become unstable if only the rear compartment is loaded and the speed exceeds 50 mph. Virtually all current double and single trailer combinations, and perhaps many straight trucks, incorporate a suspension feature which can reduce the dynamic rollover threshold by as much as 15%. This feature, involving free play in the vertical location of suspension leaf springs, can be almost eliminated with a minor modification. The findings on vehicle stability were combined with exposure to produce estimates of the comparative rollover rating of tanker fleets. It was concluded that fuel delivery using short Michigan single tankers yields the highest exposure to fire hazard of all known fleet options (excluding the unmodified double-bottom tanker), and fuel delivery using conventional 9000 gal. single tankers may yield an exposure to fire hazzrd equal to or greater than that of modified double-bottom tankers and large single tankers.

  • Availability:
  • Supplemental Notes:
    • Presented at SAE Truck Meeting, Dearborn, Michigan, 11-14 December 1978. See also HS-023 240 and HS-025 618U--HS-025 619U.
  • Corporate Authors:

    Society of Automotive Engineers (SAE)

    400 Commonwealth Drive
    Warrendale, PA  United States  15096
  • Authors:
    • Winkler, C B
    • Ervin, R D
  • Publication Date: 1978

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00399202
  • Record Type: Publication
  • Source Agency: National Highway Traffic Safety Administration
  • Report/Paper Numbers: SAE 781066, HS-025 620U
  • Contract Numbers: MPA-78-002A
  • Files: HSL, ATRI, USDOT
  • Created Date: Oct 31 1985 12:00AM