By Les Baker
Published Thursday, August 16, 2012
| From the October 2012 Issue of FireRescue
Advancements in vehicle technology and safety features are occurring at such a steady rate that it seems unreasonable for responders to maintain an effective working knowledge of how those advancements impact every single make and model of vehicle. Further, even with the advancements in mobile data terminals, phone and mobile tablet computer applications, and supplemental documents, the needed information may not be readily accessible—and if it is, it may not be based on the latest vehicle models. To some extent, the industry has become over-saturated with information to such a point that it can be difficult to process in a usable timeframe on an emergency scene. With that in mind, the intent of this column is to provide digestible, simplified information related to mitigating incidents involving hybrid/electric vehicles.
“Special” Is Now “Everyday”
Hybrid/electric vehicles and the technology used to configure these systems are safe and simple. The components are usually hidden within the vehicle, away from the patient compartment area, and are controlled by several layers of redundant safety features. When the vehicle has undergone significant damage during a motor vehicle collision, it’s likely that the system has already controlled itself. Typically, responders will not be forced to significantly change their tactics to accommodate these vehicles.
Hybrid/electric vehicles have transitioned from a “special” vehicle to an “everyday” vehicle. With the exception of only one or two models, hybrid/electric vehicles no longer have a distinct appearance. They come in nearly all shapes and sizes. Anything from a small passenger vehicle to a large dump truck may now be a hybrid/electric vehicle, and the only defining characteristic is a sticker or tag that may not even be visible after a collision. Not even taking into account any damage secondary to a motor vehicle collision, these tags are only visible within a few feet of the vehicle.
The Hybrid Approach
Until proven otherwise, responders should assume that all vehicles on the roadway are hybrid/electric vehicles. Taking this approach provides responders with the necessary tools to handle any type of vehicle. Think about this in terms of hazmat response. What if hazmat containers or vehicles didn’t require placards and labels—but still had the inherent risk, of course? Emergency responders would have to approach every incident as a hazmat scene and take the necessary precautions. Once the presence of hazardous materials was ruled out, they could continue with “regular” operations.
As part of treating every vehicle the same, responders must still have same goals: provide a safe work zone and provide direction for implementation and action. Further, when possible, we need to be careful to not overcomplicate our processes by developing redundant or conflicting standard procedures for any type of response, including hybrid/electric vehicle response.
Regardless of whether you have access to the ignition, the initial steps should remain the same:
- Immobilize/stabilize vehicles, including chocking the wheels. This step nearly eliminates any horizontal movement of a vehicle, an issue that is particularly important for hybrids since they may still be running even when the engine isn’t emitting sound. Choose the most appropriate wheel based on vehicle position and potential tactics. At a minimum, chock one wheel on the front and one on the rear of the vehicle.
- Observe the dash for vehicle running status by looking for a “Ready” light or dash illumination. When we operate our personal vehicles, the dash is usually the first thing we look at during start up and the last thing we look at during shut down. Consider the dash the information center of the vehicle, even with wrecked vehicles.
- Make initial patient contact and use power-related options (moving seats, lowering patient windows, unlocking doors, etc.) to maximize access to patients.
Completing these initial steps assists with scene safety for the responders and quick access to the patients.
After the initial steps have been completed, responders should have access to the ignition through a door or window or via interior rescuer. Once access to the ignition is possible, follow these steps:
- Place the vehicle in park and set the parking brake.
- Turn the ignition off (whether via button or key). If a smart key is present, press the power button once because it is not necessary to remove keys.
- Confirm the “Ready” light/dash illumination is off, and turn off headlights to avoid high-intensity discharge (HID) ignition and shock hazard. (HID lighting systems run on the 12-volt system with high voltage and low amperage. Its main hazards are a non-lethal electrical shock and potential ignition source. Other than manipulating the switch, there is no way to mitigate them prior to accessing the engine compartment.)
- Locate and disconnect the 12-volt battery.
In limited situations, when no access or timely access to the ignition is available, follow these steps:
- Locate and disconnect the 12-volt battery.
- For hybrid/electric vehicles, remove the high-voltage disconnect switch (an orange plug located on the high-voltage battery pack), pull fuses/relays in the fuse block under the hood by starting with largest/highest amp fuse first, or cut the fuse block or engine wiring if there is no access to fuses.
When it comes to cutting power cables, responders should either cut or disconnect the negative side first and, if possible, ensure complete 12-volt disconnect by addressing the positive side. This step can be confirmed by observing the hazard lights stop blinking.
Finally, confirm power down. Even with standardized procedures, treat all vehicles as if the system is energized and, if in doubt, avoid coming into contact with any high-voltage wires or components to avoid the risk of serious burns or shock.
It would be unreasonable to assume that responders could quickly accomplish either set of steps at every single motor vehicle collision prior to beginning disentanglement tactics. There are times when issues such as vehicle positioning and patient location may delay the complete process. In those cases, stabilize the vehicle(s) and begin typical disentanglement procedures. The likelihood of contacting the hybrid/electric vehicle components during common procedures, including roof, side, dash, and tunnel tactics, is minimal. Add to that the fact that responders should be stripping applicable trim and identifying vehicle components prior to push, pull or cut operations, and the odds are increased that you’ll be able to complete the tactic without contacting these components.
Treat all vehicles as if they were hybrid/electric vehicles. Follow the extrication process outlined above while preventing further movement and initiating power down procedures as soon as possible. Simply stated, we should disable the 12-volt system that powers the auxiliary systems in a vehicle and disable the higher current system that powers the propulsion system. Don’t be afraid to interact with the vehicle and mitigate the scene appropriately.
A special thanks to Matt Stroud and MGS Tech for their technical support.
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