One of the largest concerns today dealing with vehicle-related incidents is the electrification of vehicles. We deal with technology concerns in every single vehicle that we encounter, whether passenger or commercial. SRS safety systems are more and more comprehensive, but materials and vehicle construction techniques coupled with this issue is what is injuring the vehicle’s occupants. So, take those and add them to the additional issues of alternative fuelled vehicles. Take a seat, sit back, and lend me your ear!
For the most part electric vehicles (EV) and hybrid electric vehicles are not hugely different from conventional-drivetrain vehicles to manage and mitigate in terms of extrication, so long as you can remember simple common-sense guidelines. Power isolation is critical and that applies across the board today. Chock the vehicle so it cannot move, then make sure to shut off and remove the vehicle key from the vehicle and place it in your apparatus. Why? We cannot rely upon our hearing to ensure that the vehicle is turned off due to stop/start and EV/hybrid technology. We need to physically shut the vehicle off. The key removal is like a lock-out tag out in confined space. Most ignition keys today are wireless, so they need to be out of the range of the vehicle, and at least 15ft so a good rule of thumb. Now here is a tip: if there is a family in the vehicle, check to ensure that you have all the vehicle keys. Remember, just because you took the driver’s key does not mean there is not another key present, which the car may switch to. This action does two especially important things: first, it depowers all the vehicle SRS safety systems so that they are electronically dead; second, if the vehicle is an EV or hybrid, it starts the depower of the high-voltage circuit. There is a drain time associated with this, depending upon the vehicle, which is no more than a few minutes. That is half of power isolation. The second half is to take the 12V battery out of the loop. Today’s best practice is to double cut both battery cables. Now with today’s vehicles we need to identify interior items that are powered that might need to be operated before 12V battery power is removed. The other issue is finding the 12V battery following crash damage and the simple fact that in over 50% of vehicles the battery is no longer in the front in the engine bay. If not, then more than likely it will be in the rear of the vehicle. High-end vehicles can have multiple batteries as well. So that is power isolation, and you should be doing this on every injury-producing MVC. The other common-sense guideline is remembering that orange-cable device connections are industry standard for high-voltage power (40V or more) so do not cut them or mess with them in any way! There really is no reason to do so and after 20 years of hybrids being on the streets, now EVs have all the high-voltage cabling away from where tool evolutions would normally be done. However, there are a handful of exceptions for extrication dealing with EVs and hybrids but more on those later.
One of the best ways to assist yourself at a vehicle-related incident is to have your smartphone and/or tablet equipped with the right apps to give you data on scene. We are all professionals and we all want to strive for a better outcome for every patient we encounter. This sort of information is now a critical on-scene tool to help in making mitigation and management choices. Where is the 12V battery and is there more than one? Can my power hydraulic rescue tools cut, push, sever vehicle components? Is this vehicle an EV or a hybrid or a conventional? All these types of questions and more involve time, effort and energy. And remember trauma is the disease of time! All these questions gobble up precious time and we need to put time back onto our side. So, let us talk about these apps. This whole field has rapidly expanded in the past ten years. The longest one around and the gold standard for many to hold to is Moditech CRS (Crash Recovery Software). This started out as software on a laptop based in 2004 but today is a smartphone- and tablet-based app. The correct vehicle can be found by its number/licence plate, VIN number, scanned QR code and manual search. The app then shows a glass cutaway of the vehicle with colour-coded hazards. If the vehicle is an alternative-fuel vehicle, a splash screen alert advises you that the vehicle is such and needs to be depowered. The app then walks you through the primary, secondary and tertiary methods of shutting down the vehicle. The app advises on any high-strength reinforcements and what force is needed to sever them. Vehicle fire tactics are given as well. The app has a database available for all regions of the world. This app is not free but does not cost a lot either.
Rescue Code is a similar app with glass cutaway vehicles and colour-coded hazards much like Moditech but simpler and with no in-depth background information like Moditech. North American vehicles are not featured on this app but can be figured out by comparison. This app is manual search only. Along with Rescue Code, Rescue Sheets is also based along the same lines. Rescue Sheets is paired off the ISO refs for alternative-fuelled labelling and has more information than Rescue Code. Both Rescue Code and Rescue Sheets are free. However, Rescue Sheets does not currently work in North America and it is unknown when or if it will be. NFPA makes an app that is just for EV and hybrid vehicles, which uses Moditech CRS screen shots and has good background information. The NFPA app is focused on North American vehicles, but it is free. Lastly there are two vehicle manufacturers who place vehicle Rescue Sheet information right onto the vehicle and it is available all the time. The first is Mercedes Benz who from November 2013 have fitted a QR code sticker on the inside of the fuel filler door and another on the inside of the driver door opening on the B post. You scan them with your phone or tablet and then that vehicle’s Rescue Sheet is displayed. What about prior to that date? As older vehicles come into the dealer for service, the dealer retrofits them with the correct QR sticker. Someone looks out for us; they just need to tell more of us. The second manufacturer is GM and they only do this on their EV and hybrid vehicles. Same location and device as Mercedes Benz. So rescuers check these apps out, load them up on your device, or a device to be used on scene, and you will be surprised how much they empower you and put you at ease. Another thing to remember is that these apps can be a great learning tool for training as well. The best thing about all these apps is they are available on all platforms – iOS, Android, Windows.
Back to our physical operations. Extrication-wise EVs and hybrids have but a few differences to conventional-drivetrain vehicles. Most of our tool evolutions performed on the vehicle structure are away from the high-voltage battery, cables and electric motors. Therefore, I feel that these vehicles, if you perform power isolation, are the same hazard level as a conventional-drivetrain vehicle. This is especially important. So, all the best practices that you use for technology concerns in conventional-drivetrain vehicles need to be done here as well. But there are some considerations to be aware of. Watch for oddly weighted vehicles in precarious placements for stabilizing due to the placement of the high-voltage battery. Watch when lifting the bottom of the vehicle due to the HV cables and/or floor being the HV battery, trunk tunnelling could be impossible due to HV battery placement (the same goes for the floor) and always to remember to pull interior trim to check for SRS cylinders. And remember, even with power isolation, if you cut through an uninflated SRS curtain cylinder, it will go off. Also do not forget, SRS side-curtain cylinders can be found on either end of the curtain bag, in the middle above the B post and even inside the curtain bag itself around the B post area.
Here are three specific technology concerns for extrication that are directly related to an EV or hybrid vehicle. The latest version of the Toyota Prius Solar Roof needs to be covered with a heavy-duty tarp that is lightproof to halt its ability to generate 60V power to the HV battery. Also, the actual cable from the solar roof to the HV battery is in the driver-side C post and this should not be cut through while energized. Fire concerns are the same as any alternative-fuel vehicle, but the solar roof does add additional concerns. Europe and the Far East will see these latest versions, but North America does not as the glass roof will break upon roll over.
Next is the concern of the ultra/super capacitors in stop/start systems. I believe the concerns with these were drain time and what action was the tipping point of that drain time start. Another concern was the location. Certain rescue-tool operations might damage the unit and it is a significant respiratory concern for patients and rescuers. Currently only Mazda fields vehicles with these devices in North America, but in Europe and the Far East many other manufacturers do.
The last vehicles to mention specifically are Tesla models. All their vehicles use a floor-mounted HV battery pack. You need to use caution when lifting the vehicle with any tool, but be sure to crib as you go. The biggest concern is dash displacement. This is a vehicle where a conventional dash roll will not work well without a crumple zone relief cut. But a dash lift really needs to be used with due caution. You do not want to crush the floor and in doing so crush power cells in the HV battery. Doing that would start a thermal runaway in the HV battery, i.e. FIRE!
We will explore the fire issues in part 2 of this feature.
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