Determining critical wind speeds for overturning two types of ambulances and a large city bus

Thomas W. Schmidlin, PhD; Barbara O. Hammer, MA; Paul S. King, BS; L. Scott Miller, PhD; Gregory Thumann, MS; Helene Wetherington, MA

doi:10.5055/jem.2005.0016

Authors

Thomas W. Schmidlin, PhD
Barbara O. Hammer, MA
Paul S. King, BS
L. Scott Miller, PhD
Gregory Thumann, MS
Helene Wetherington, MA

DOI:

https://doi.org/10.5055/jem.2005.0016

Keywords:

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Abstract

Two types of ambulances and a city bus were modeled in a wind tunnel for the minimum wind speed required to upset the stationary vehicles. The Type I ambulance was vulnerable to upset with wind speeds of 135 to 150 mph on the vehicle over wind angles of 40° to 145°. The Type II ambulance was vulnerable to upset with wind speeds of 140 to 170 mph over wind angles of 30° to 145°. The 40-passenger city bus was vulnerable to upset with wind speeds of 60 to 75 mph over wind angles of 35° to 145°. These results showed ambulances were more stable in high winds than common passenger vehicles, but the city bus was very vulnerable in high winds. Testing showed that moving ambulances can be driven at low speeds in minimal hurricane-force winds without exceeding the upset wind speeds on the vehicles. This information provides guidance for safe operation of these vehicles during high winds including hurricanes, thunderstorms, and extra-tropical cyclones.

Author Biographies

Thomas W. Schmidlin, PhD

Department of Geography, Kent State University, Kent, Ohio.

Barbara O. Hammer, MA

Department of Geography, Kent State University, Kent, Ohio.

Paul S. King, BS

Boyce Thompson Institute, Cornell University, Ithaca, New York.

L. Scott Miller, PhD

Department of Aerospace Engineering, Wichita State University, Wichita Kansas.

Gregory Thumann, MS

Department of Aerospace Engineering, Wichita, Kansas.

Helene Wetherington, MA

Division of Emergency Management, West Palm Beach, Florida.

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