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After bus fire, CT pulls electric fleet from service

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Re: After bus fire, CT pulls electric fleet from service

#81

Post by olyjohn »

Cthulhu_ wrote: post #15
viraptor wrote: post #13

Earlier quoted context omitted.

> If your EV runs out of juice, you have to have it towed to a charging station. Maybe that's the situation near you currently, but as EVs get more popular, these services will as well. It's just inevitable. https://thedriven.io/2022/02/01/melbourne-start-up-launches-...

I'm sure AA vehicles will - if they already aren't - be supplied with a generator to put some juice back into electric vehicles on the roadside. Probably lighter, more compact, and less hassle than carrying around spare batteries.

It's gonna need to be a huge generator, or else they're gonna be sitting there all day. If you watch Long Way Up... take a look at the huge diesel trucks they need to have just to put the generator on the back to charge up the motorcycles.

Re: After bus fire, CT pulls electric fleet from service

#82

Post by woodruffw »

I think it's fantastic that smaller-to-midsized towns are bringing EV buses into service, but I'll mention my perennial bugbear again: all of these towns had dedicated trolley service under a century ago. The lines were torn up and replaced with less frequent, traffic encumbered bus routes.

Hamden, for example, had three lines between it and New Haven[1].

[1]: http://www.hamdenhistoricalsociety.org/trolleys.html

Re: After bus fire, CT pulls electric fleet from service

#83

Post by GiorgioG »

mrguyorama wrote: post #77
Cpoll wrote: post #72

Earlier quoted context omitted.

> Compare that to 45k ICE vehicles fires every year and it appears that EVs are significantly less likely to catch fire. You haven't provided enough information to make a comparison. Googling some numbers, Tesla has sold 2MM cars, so taking that 97 number we get 0.00004 fires per Tesla. US has 275MM cars, and (2022 - 2012) * 45000 = 450000, so we have 0.00163 fires per ICE car. Conclusion: If those numbers are correc…

I bet if you control for vehicle age and economic status, EVs combust at the same rate as gasoline vehicles

"In 2017, 70% of the cars to catch fire were more than 10 years old."

https://housegrail.com/car-fire-statistics/#1_There_were_212...

Re: After bus fire, CT pulls electric fleet from service

#84

Post by olyjohn »

sleepybrett wrote: post #69
billyo wrote: post #26

We need more electric trolley busses. This whole battery nonsense is ridiculous

Seattle has a great many of them but the lines for them to run on only exist in certain place, granted they are the densest places. But running that pair of electric lines everywhere is a big infrastructure project for any city.

They're willing to tear up the streets, install rails and run those slow-ass streetcars down the middle of the road.

Also I imagine that getting enough power to your charging facility to charge 50+ buses up overnight isn't going to be any small feat either.

At least with the overhead lines, you don't have to worry about charging. You don't have to carry heavy, expensive batteries either. Though you do get the occasional "derailment" where the bus comes off the line. But the bus drivers are able to fix that themselves.

Re: After bus fire, CT pulls electric fleet from service

#85

Post by KennyBlanken »

DoingIsLearning wrote: post #11
atlasunshrugged wrote: post #2

IMO this is an aspect of the shift to EV's that I don't hear all that many people talking about- is the gov giving enough resources/training to local emergency services providers to deal with these sorts of fires and the disposal of the EV materials after a fire. Totally surmountable, but I feel like I don't hear the federal gov talk about it much and instead the focus is on more chargers and tax credits to eliminate…

> is the gov giving enough resources/training to local emergency services providers to deal with these sorts of fires and the disposal of the EV materials after a fire. The main immediate threat is not disposal or even fire itself but the release of hydrogen fluoride _during_ a fire. You have to avoid airway and eye exposure at all cost with HF. This is probably the main difference in an EV emergency response as oppo…

> The main immediate threat is not disposal or even fire itself but the release of hydrogen fluoride _during_ a fire. You have to avoid airway and eye exposure at all cost with HF. This is probably the main difference in an EV emergency response as opposed to other chemical fires.

At any chemical or vehicle fire, firefighters are wearing SCBAs.

> The second main issue is securing an electrically safe chasis during crash and vehicle extraction (if you need to start chopping the car up to extract someone), you need to know what to cut and when.

HV cables are extremely clearly marked (bright orange, a color not used for any other component.)

HV cables run directly from the battery to the inverter. Extraction involves prying doors / cutting door hinges / cutting roof pillars. Not chopping up the floor.

HV cables are not energized after a crash because every battery, EV or hybrid, has an internal contactor that fails safe. There is also usually a clearly marked physical plug that can be pulled.

I love it when people jump on internet forums and talk authoritatively and demonstrate they know absolutely nothing about the subject at hand.

Re: After bus fire, CT pulls electric fleet from service

#86

Post by KennyBlanken »

bdamm wrote: post #70
DoingIsLearning wrote: post #11

Earlier quoted context omitted.

> is the gov giving enough resources/training to local emergency services providers to deal with these sorts of fires and the disposal of the EV materials after a fire. The main immediate threat is not disposal or even fire itself but the release of hydrogen fluoride _during_ a fire. You have to avoid airway and eye exposure at all cost with HF. This is probably the main difference in an EV emergency response as oppo…

Many models have a pyro fuse in the battery pack high voltage hook-up that blows when the airbags deploy. Also common is that if the 12V battery is disabled, the high voltage pack is also disabled. And many models simply disconnect the high voltage pack when in park (or soon thereafter). So while you're right that there's not a common standard, the common reality is that the packs aren't dangerous in a crash. Regulat…

All EVs and hybrids have contactors inside the battery pack and if it is not energized, there is no high voltage present anywhere in the vehicle outside the pack.

Re: After bus fire, CT pulls electric fleet from service

#87

Post by KennyBlanken »

londons_explore wrote: post #8
nathanaldensr wrote: post #3

Earlier quoted context omitted.

The entire point is that you can't "deal" with it. Since car batteries contain the fuel and the oxidizer, there isn't a way to separate them short of blowing the whole thing up. Fires can stop and start spontaneously, and often do (see pictures and videos of Teslas on fire in junkyards).

Electric cars could totally be designed to be re-ignite-proof. For example, you'd have the battery pack detect a breach - for example through a lack of pressurised coolant. That would then trigger each battery cell to have a PTC resistor discharge it - that could be entirely mechanical. The PTC resistors would discharge the battery in a few hours, maintaining the battery temperature at say 120C. As water is doused on…

> The PTC resistors would discharge the battery in a few hours, maintaining the battery temperature at say 120C

Thermal runaway in lithium ion batteries starts at 100C and is a significant danger at 60C.

Maybe learn more about subjects before you come up with all these opinions on how things should be done.

Re: After bus fire, CT pulls electric fleet from service

#88

Post by KennyBlanken »

bragr wrote: post #6
nathanaldensr wrote: post #3

Earlier quoted context omitted.

The entire point is that you can't "deal" with it. Since car batteries contain the fuel and the oxidizer, there isn't a way to separate them short of blowing the whole thing up. Fires can stop and start spontaneously, and often do (see pictures and videos of Teslas on fire in junkyards).

This is not really true. There are tools and agents to address lithium fires, but you have to have them. If you just try to put them out with water, you're going to be there all night fighting reignition.

Lithium ion battery fires are not lithium fires.

Water is the recommended method because it is the most effective way to stop thermal runaway.

If you don't believe me, google "lithium ion battery fires water"

Re: After bus fire, CT pulls electric fleet from service

#89

Post by txsoftwaredev »

jeffbee wrote: post #31

Battery buses are a solution ahead of their time. Any old bus is better than car-based transportation, so shifting modes from car to bus is more important than changing the energy source of the bus. If shifting from car to bus is impossible because of built environment, that's the first priority. Buses powered by batteries should be way down at the end of the TODO list. If you absolutely insist on having buses that a…

A bus is only better if it is full of passengers, which is not always the case.

Re: After bus fire, CT pulls electric fleet from service

#90

Post by tapoxi »

billyo wrote: post #26

We need more electric trolley busses. This whole battery nonsense is ridiculous

Bostonian here, I used to commute on one every day (MBTA 71 and 73), but they were taken out of service earlier this year, for eventual EV replacement.

The problem with electric trolley busses is that they can't pass each other, they perform very poorly in rain, frequently disconnect, and they need constant maintenance of the overhead wiring. I do miss it because it was a local landmark, but an EV bus will be much nicer to have.

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