Case Study: Hydroplane in KY Results in Firefighter Fatality

Drive to Survive: Case Studies Chris Daly

A 30-year-old firefighter was responding in his personal vehicle to a report of a high-water emergency. The firefighter was responding to the fire station on June 16, 2003, to pick up a fire apparatus when he drove over a large pool of water on the roadway.

The firefighter lost control of his personal vehicle, traveled off the road, and struck the signpost of a large billboard. During the course of the crash, the victim firefighter sustained fatal injuries.

Driver Considerations

A crash investigation by the state police revealed that no speed estimate could be made based on the lack of roadway evidence. However, a witness stated that the victim firefighter had passed her on the roadway while she was traveling at approximately 40 miles per hour (mph). This witness later discovered the crash when she continued farther down the road. Based on this witness statement, there is evidence that the victim firefighter was traveling in excess of 40 mph on a wet road.

Fire apparatus operators must understand the dangers of driving in inclement weather. Although there are many issues to consider, this case study will focus on hydroplaning. As a tire rotates on the axle, the tire tread is designed to push water and moisture out of the way so that the rubber tire face can come in contact with the road (photo 1). If the vehicle is traveling too quickly and the tire is spinning too fast, the tire tread will not have enough time to effectively move the water out of the way. As a result, a wedge of water could build up in front of the tire. Eventually, the tire may ride up on this wedge of water and lose contact with the road. This is a hydroplane.

1 The purpose of tire tread is to “push” or channel water out of the way so that the rubber tire face can come in contact with the road surface. (Photos by author.)

Driving a vehicle at a high speed on a wet roadway can lead to a hydroplane situation. The speed at which a tire will hydroplane depends on three major factors: the depth of the tire tread, the air pressure in the tire, and the depth of the water that the vehicle is driving through. A shallower tire tread will not be able to move as much water as a deeper tire tread. An underinflated tire will not be able to push the water out of the way as effectively as a properly inflated tire. And last, deeper water will be able to more easily overwhelm the tire tread.

Fire apparatus operators must understand the importance of slowing down in wet weather to give the tire enough time to properly push the water out of the way. Drivers must also understand the importance of avoiding large standing pools of water and instead try to stay in the tracks of the vehicles traveling in front of them. This is because the tracks made by the vehicles in front of the apparatus may be drier, as some of the water has already been moved out of the way. Finally, fire apparatus operators must understand the importance of keeping a close eye on the air pressure and tread depth of the emergency vehicle tires.

Driver Training Considerations

Driver training programs should stress the importance of modifying driving habits in wet or inclement weather. Although there are many reasons for modifying driving habits in inclement weather, this case study stresses the importance of avoiding a hydroplane situation. Driver training programs should also explain the need to conduct regular inspections of tires, especially the air pressure and tire tread depth.

Driver training programs should stress the importance of avoiding a hydroplane situation by slowing down when it is wet out and trying to stay in the drier tire tracks that were created by the vehicles traveling in front of the fire apparatus. If the fire apparatus operator is forced to drive through a deep standing puddle, the operator must slow to a safe speed so as to allow the tire enough time to move the water out of the way and remain in contact with the road surface (photo 2).

2 Fire apparatus operators should try to stay in the dry tracks created by the vehicles in front of them. If an operator must drive through deeper water, he should slow to a safe speed and give the tire tread enough time to move the water out of the way.

Relevant National Fire Protection Association (NFPA) Standards

NFPA 1911–8.3.3: “Tires shall be inspected for damage and shall be inflated to the tire manufacturer’s recommended pressure.”

NFPA 1911–A8.3.3: “It is important that the cold tire inflation be maintained to the emergency vehicle manufacturer’s recommended tire pressure, which is based on the weight of the completed vehicle, and not to the maximum pressure shown on the sidewall of the tire. If the information from the emergency vehicle manufacturer is not available for the tires on the vehicle, each axle should be weighed with the vehicle fully loaded and the tires inflated to the tire manufacturer’s inflation specification for the tire model, size, and axle load.”

NFPA 1911–6.3.1(3)(4): “The following deficiencies of the chassis, axles, steering and suspensions systems, driveline, wheels, and tires shall cause the vehicle to be taken out of service: 3) Tires have cuts in the sidewall that penetrate to the cord. 4) Tires have a tread depth of less than 4/32” (3.2 mm) on any steering axle or 2/32” (1.6 mm) on any non-steering axle at any two adjacent major tread grooves anywhere on the tire.”

NFPA 1451–4.3.4: “The fire and emergency service organization (FESO) shall provide members, including junior members, with hazard awareness training that includes unique hazards that can be encountered when responding to alarms in privately owned vehicles or unconventional means of transportation.”

NFPA 1451–4.3.8: “The FESO shall establish written standard operating procedures for driving and operating personally owned vehicles addressing emergency response and non-emergency activities.”

NFPA 1451–5.3.9: “FESOs shall train operators for inclement weather driving conditions, with emphasis on handling of vehicles, particularly where auxiliary braking devices are to be used.”

NFPA 1451–7.1.1: “The authority having jurisdiction shall have written policies governing speed and the limitations to be observed during inclement weather and under various road and traffic conditions.”

NFPA 1451–A7.1.1: “Each jurisdiction or FESO could have its own rules governing the speed of FESO vehicles when responding to emergencies. Some jurisdictions permit FESO vehicles to exceed posted speed limits, while others limit emergency vehicles to the posted speed limit. All drivers should have a thorough knowledge of the rules governing speed for FESO vehicles in their own jurisdictions and the jurisdictions of their mutual aid partners.”

Teaching Resources

“Avoiding Tire Related Vehicle Crashes,” Fire Engineering, February 2007.¹
“Drive to Survive: The Art of Wheeling the Rig,” Chapter 11–EVOC textbook available from Fire Engineering Books and Videos, which explains the issues related to tire safety and hydroplaning.²
“Is Your Personal Vehicle Covered in a Crash During a Response?” Fire Engineering, December 2015. ³

Endnotes

1. https://www.fireengineering.com/leadership/avoiding-tire-related-vehicle-crashes/#gref.

2. https://fireengineeringbooks.com/drive-to-survive/.

3. https://www.fireengineering.com/apparatus-equipment/is-your-personal-vehicle-covered-in-a-crash-during-a-response/#gref.

Chris Daly is a 24-year police veteran and an accredited crash reconstructionist (ACTAR #1863), having served as a lead investigator for the Chester County Serious Crash Assistance Team. In addition to his police duties, he has served in the fire service for more than 32 years including time as both a career and volunteer firefighter, holding numerous positions including assistant chief. He has a master’s degree in environmental health engineering from Johns Hopkins University and is a contributing author to numerous fire service professional publications including Fire Apparatus & Emergency Equipment and Fire Engineering. He has also developed an emergency vehicle driver training program entitled “Drive to Survive,” which has been presented to more than 24,000 firefighters and police officers at more than 565 emergency service agencies across the United States. He is the author of the EVOC textbook Drive to Survive–The Art of Wheeling the Rig (Fire Engineering). Additional resources concerning emergency vehicle crash reconstruction and seminar scheduling can be found at his Web site www.drivetosurvive.org.