6 ms·

I wonder if we'll see more standardization in electric vehicles so that fire departments don't need specific vehicle training to know what to cut and where. Al

I wonder if we'll see more standardization in electric vehicles so that fire departments don't need specific vehicle training to know what to cut and where. Although we haven't seen that yet with hybrids (that also contain potentially hazardous batteries) that have been around longer.

phkahler 7y ago
Typically there is a relay at the battery to cut high voltage to the rest of the vehicle. Also, some components have requirements to discharge internal capacitance (and hence the bus) in a short time. A crash should trigger all this, but I suppose from a safety POV you can never be completely certain.
- benj111 7y ago
  I was thinking internal fuses for each cell, then you've nothing worse than a couple of volts.
imglorp 7y ago
I wonder this too. Military jets have a "RESCUE" lever by the canopy to disarm the ejection seats. I wonder why cars don't have something standard and simple like that. If every car model needs unique training on what secret cuts to make in what order, that's a fail.
- toomuchtodo 7y ago
  Tesla vehicles disengage the high voltage contactors when an accident is detected. You still don't want to cut through parts that can't be de-energized (ie do not push through the floor pan into your energy storage system). There is also a "first responder cut loop" which does the same, similar to the mentioned "RESCUE" lever on an aircraft cockpit.
  - avs733 7y ago
    >Tesla vehicles disengage the high voltage contactors when an accident is detected. Great! Is there a visual indication that has occurred (see for example F1: https://www.racecar-engineering.com/tech-explained/f1-2014-explained-what-are-the-lights-on-the-roll-hoop-for/ https://www.racecar-engineering.com/tech-explained/f1-2014-e...). If not, >You still don't want to cut through parts that can't be de-energized (ie do not push through the floor pan into your energy storage system). You're right! That's why these things are standardized and labeled (http://www.solotogrouptravel.com/wp-content/uploads/2014/01/Sign-on-Peru-Airplane.jpg http://www.solotogrouptravel.com/wp-content/uploads/2014/01/...) >There is also a "first responder cut loop" which does the same, similar to the mentioned "RESCUE" lever on an aircraft cockpit. The point isn't the function it's the labeling. As noted in other discussions (https://jalopnik.com/tesla-model-3-teardown-by-engineering-firm-reveals-qual-1822678045 https://jalopnik.com/tesla-model-3-teardown-by-engineering-f...) of the model 3...there are no externally visible markers of where to cut until you open or remove panels and the markings themselves are unclear. The front first responder loop requires a 12V battery be connected to the vehicle if the frunk won't open under vehicle power. None of this is about whether or not such systems exist...all of this is about the design and indication necessary of those systems in emergency situations. All F1 cars have different manufacturers...but they all have the same iconography and processes for disarming potentially energized systems (e.g., put the car in neutral, put out a fire, check if car is electrically safe). That commonality means it is easy to train first responders AND for first responders to know what to/not to do in an emergency.
    - deleted 7y ago
      [deleted]
    - brooksgarrett 7y ago
      I'm willing to bet my Hurst spreaders will get the frunk open sans battery. If you're cutting the car, it's already totaled and limiting damage to the frunk would be the last concern on my mind.
      - mrpippy 7y ago
- HeWhoLurksLate 7y ago
  I don't think I want to have a "kill power" switch on the side of my vehicle where a random up-to-no-good kid (or adult) can kill power to my car while I'm driving it. Disclaimer: I ride a bike.
  - nexuist 7y ago
    For what it's worth, there actually are kill switches on the sides of the ICE buses that service my university campus. Opening the little hatch and pushing the button disconnects power from the battery and kills the engine. I imagine it's useful in situations where the engine has caught fire and you need to stop fuel flow ASAP. I've never heard of people abusing it, probably because everyone on board the bus including the driver could easily ID the wrongdoer. Of course, private personal vehicles are a different story.
- Animats 7y ago
  Most US electric cars now have a cable marked with a yellow and red first responder cut point tag. You can see that briefly in the video. You cut the cable on both sides of the tag, so that the remaining ends can't touch, and the battery is isolated. There are where-to-cut guides.[1] [1] https://www.ncdoi.com/OSFM/RPD/PT/Documents/Coursework/EV_SafetyTraining/EV%20EFG%20Classroom%20Edition.pdf https://www.ncdoi.com/OSFM/RPD/PT/Documents/Coursework/EV_Sa...
  - imglorp 7y ago
    I think you also want to disable unfired airbags after the car has stopped crashing. There are cases where rescuers leaned in on passenger side, putting pressure on seat, and had the airbag deploy on them. I think there's other concerns that cutting door sills can cause deployments. Oh and killing the engine would be good too.
toss1 7y ago
In amateur and pro sportscar racing, all cars are required to have a prominent kill switch that cuts the main power from the electrical system, and this is just with 12V ignition and accessory systems. It's always seemed like a great idea , and I expect that the only reason it isn't done in ordinary street cars is that the companies never liked reminding people of the potential of accidents (with some exception by Volvo & occasional others selling superior safety).

phkahler 7y ago

Typically there is a relay at the battery to cut high voltage to the rest of the vehicle. Also, some components have requirements to discharge internal capacitance (and hence the bus) in a short time. A crash should trigger all this, but I suppose from a safety POV you can never be completely certain.

benj111 7y ago
I was thinking internal fuses for each cell, then you've nothing worse than a couple of volts.

imglorp 7y ago

I wonder this too. Military jets have a "RESCUE" lever by the canopy to disarm the ejection seats. I wonder why cars don't have something standard and simple like that. If every car model needs unique training on what secret cuts to make in what order, that's a fail.

toomuchtodo 7y ago
Tesla vehicles disengage the high voltage contactors when an accident is detected. You still don't want to cut through parts that can't be de-energized (ie do not push through the floor pan into your energy storage system). There is also a "first responder cut loop" which does the same, similar to the mentioned "RESCUE" lever on an aircraft cockpit.
- avs733 7y ago
  >Tesla vehicles disengage the high voltage contactors when an accident is detected. Great! Is there a visual indication that has occurred (see for example F1: https://www.racecar-engineering.com/tech-explained/f1-2014-explained-what-are-the-lights-on-the-roll-hoop-for/ https://www.racecar-engineering.com/tech-explained/f1-2014-e...). If not, >You still don't want to cut through parts that can't be de-energized (ie do not push through the floor pan into your energy storage system). You're right! That's why these things are standardized and labeled (http://www.solotogrouptravel.com/wp-content/uploads/2014/01/Sign-on-Peru-Airplane.jpg http://www.solotogrouptravel.com/wp-content/uploads/2014/01/...) >There is also a "first responder cut loop" which does the same, similar to the mentioned "RESCUE" lever on an aircraft cockpit. The point isn't the function it's the labeling. As noted in other discussions (https://jalopnik.com/tesla-model-3-teardown-by-engineering-firm-reveals-qual-1822678045 https://jalopnik.com/tesla-model-3-teardown-by-engineering-f...) of the model 3...there are no externally visible markers of where to cut until you open or remove panels and the markings themselves are unclear. The front first responder loop requires a 12V battery be connected to the vehicle if the frunk won't open under vehicle power. None of this is about whether or not such systems exist...all of this is about the design and indication necessary of those systems in emergency situations. All F1 cars have different manufacturers...but they all have the same iconography and processes for disarming potentially energized systems (e.g., put the car in neutral, put out a fire, check if car is electrically safe). That commonality means it is easy to train first responders AND for first responders to know what to/not to do in an emergency.
  - deleted 7y ago
    [deleted]
  - brooksgarrett 7y ago
    I'm willing to bet my Hurst spreaders will get the frunk open sans battery. If you're cutting the car, it's already totaled and limiting damage to the frunk would be the last concern on my mind.
    - mrpippy 7y ago
HeWhoLurksLate 7y ago
I don't think I want to have a "kill power" switch on the side of my vehicle where a random up-to-no-good kid (or adult) can kill power to my car while I'm driving it. Disclaimer: I ride a bike.
- nexuist 7y ago
  For what it's worth, there actually are kill switches on the sides of the ICE buses that service my university campus. Opening the little hatch and pushing the button disconnects power from the battery and kills the engine. I imagine it's useful in situations where the engine has caught fire and you need to stop fuel flow ASAP. I've never heard of people abusing it, probably because everyone on board the bus including the driver could easily ID the wrongdoer. Of course, private personal vehicles are a different story.
Animats 7y ago
Most US electric cars now have a cable marked with a yellow and red first responder cut point tag. You can see that briefly in the video. You cut the cable on both sides of the tag, so that the remaining ends can't touch, and the battery is isolated. There are where-to-cut guides.[1] [1] https://www.ncdoi.com/OSFM/RPD/PT/Documents/Coursework/EV_SafetyTraining/EV%20EFG%20Classroom%20Edition.pdf https://www.ncdoi.com/OSFM/RPD/PT/Documents/Coursework/EV_Sa...
- imglorp 7y ago
  I think you also want to disable unfired airbags after the car has stopped crashing. There are cases where rescuers leaned in on passenger side, putting pressure on seat, and had the airbag deploy on them. I think there's other concerns that cutting door sills can cause deployments. Oh and killing the engine would be good too.

toss1 7y ago

In amateur and pro sportscar racing, all cars are required to have a prominent kill switch that cuts the main power from the electrical system, and this is just with 12V ignition and accessory systems. It's always seemed like a great idea , and I expect that the only reason it isn't done in ordinary street cars is that the companies never liked reminding people of the potential of accidents (with some exception by Volvo & occasional others selling superior safety).