Next, Moore said, rescue workers need to disable the vehicle's 12-volt battery, similar to those found in a conventional vehicle. "At a normal crash we would raise the hood and cut or disconnect the 12-volt battery cables. It's a little bit more challenging on a hybrid."
One of the problems is that a hybrid can turn off its gasoline engine and "go to sleep," to save fuel when the car stops. "Now, if you are sitting at an intersection and are crashed into, when a firefighter or paramedic or police officer gets to your car, it will be totally silent," Moore said. "They could go around to the front to raise the hood, but it could be in sleep mode and drive forward on electricity, not using gas at all."
The hybrid Ford Escape can go 25 mph on electricity alone, Moore noted, and could run over rescuers while they're standing in front of it. "It would be like being run over by a big electric golf cart," he said.
To prevent this, rescue workers need to block the wheels, get inside the vehicle, put it in "park" or set the emergency brake, and turn the ignition off. Then the vehicle is truly shut down, Moore said, and rescuers can work to shut down the 12-volt electrical system.
The 12-volt battery may be located under the hood or in the trunk, but rescuers need to find it and cut the power to insure that the high voltage power is isolated to the high voltage battery.
Once this is done, "Really at that point you're dealing with a conventional vehicle except that there is a high voltage battery on the vehicle," Moore said. Emergency scene operations will not require working directly on the high-voltage battery pack, and it should not pose any further threat. "You could be electrocuted at an accident if for some reason you decided to physically tear into the high voltage battery itself, which is inconceivable," he said.
Moore also noted the safety precautions engineered into the vehicles. For example, if the air bags deploy, or if water reaches the level of the high voltage battery, the high voltage power shuts down.
In addition, all manufacturers make the high voltage wiring and connections orange. Also, if the battery is in the trunk, the wiring runs underneath the car, not through it. "What they've done on purpose, is they've avoided putting wiring in any of the areas that we typically cut during an extrication," Moore said.
"Hybrid vehicles are hazardous and they can kill us, but with a couple of simple steps, we can quickly take this new technology and manage it and make the crash scene into a routine scenario," he said.
Moore stressed that all manufacturers of hybrid vehicles sold in the U.S. offer emergency response guide books at their web sites. "They are totally free, downloadable, and they are a great training document that would allow any responder group - ambulance, police or fire department - to begin to become aware of how to deal with hybrid vehicles."
- University of Extrication
- Toyota/Lexus Alternate Fueled Vehicles Emergency Response Guides
- Honda Emergency Response Guide for Hybrid Vehicles
- Ford Escape Hybrid Emergency Response Guide
- IAFF - Hybrid Vehicles and Emergency Response
- NHTSA - Approaching Alternative-Fueled Vehicle Crashes
- NHTSA - Disconnect Vehicle Batteries Safely