After bus fire, CT pulls electric fleet from service

Umm, it did. In CT. Last month. https://archive.ph/FZ2wv

Shooting the battery pack won't cause the pack to do anything quickly. People would still have plenty of time to get out.

Complacency.

These lines would be unambiguously better (cheaper, much simpler materials, much less embodied carbon, faster and more reliable if given a proper right of way) than a bunch of electric buses in shared traffic so it makes sense to bring them up.

It's not safe on HN to tell the more obvious lies about EVs, renewable power, climate change etc. that are popular in certain circles due to the more technical audience so you get a lot of people with unusually strong views about how obsolete tech X is actually better for the planet than the solution that experts in the field have settled on.

Can't have people believing that experts and democratic governance is capable of performing even basic functions or the next stop is communism.

I don't understand this point. Buses don't have inherently fixed routes, so that isn't why they go down the road empty. It's because, in many places, their routes haven't been replanned to compensate for suburban sprawl, and their service is bad.

The fixed-route nature of trolleys is not an inherently bad thing. In fact, it was the dominant (and eminently sustainable) form of urban expansion for over 75 years[1]. It turns out that fixed routes mean stability, which in turn means that businesses feel comfortable investing in long-term presence. Residents similarly find them desirable, since they can be certain that their streetcar won't be taken away from them (unlike a bus).

[1]: https://en.wikipedia.org/wiki/Streetcar_suburb

I'm surprised this comment is so controversial.

Imagine if a bus had on demand stops, rather than stopping at 50 empty stops to get from point a to b. Those 49 extra stops are why nobody uses buses. It literally takes 4 flipping hours to go as what it takes 20 minutes by car, all while on a mostly empty bus, taking a fixed route, with fixed stops. Maybe it's better in other parts of the country, but in every city I've lived in, including San Jose, the nobody uses the buses, because nobody has that kind of time.

Trolleys for congested down town areas, sure.

Yep, this is another perfectly good reason to want them: they're just pleasant to look at. They instill civic pride in a way that a street with honking cars cannot.

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.

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 onto the battery, it will boil off.

As soon as the battery temperature cools below 120C, then every cell is guaranteed to be discharged.

Add to the fact that the fuel is Lithium and you’re in for a badddddd time

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. Regulation could push this just a little further and mandate pyro fuses in pack hookups, which would reduce the probability of electrocution to first responders and occupants to basically zero, since nobody would try to cut through the floor of the vehicle in an extraction (where the pack cells are, and the most dangerous part when it comes to randomly cutting cross sections.)

> 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.

The cutoff is to stop the electricity from leaving the battery, and electrifying the rest of the car. Nothing more fun that getting electrocuted just touching a car. F1 cars are also Hybrids, and if you watch F1 drivers exit a the car after a crash, they do a little hop off the car. Making sure not to touch the car and the ground at the same time. They also have little indicators that show if there is current running into the car's body. I will venture that an F1 hybrid system is at least as advanced, if not more-so, than a common consumer hybrid system. At the least, I wish Commercial EVs had that same electrification indicator.

Cutting that wire is largely, to de-power airbags and the like. Airbags DO go off unexpectedly, and can inure a responder quite effectively. Cutting the power is a normal step in any big motor vehicle incident, EV or ICE.

Tesla and others do publish all this information with nice diagrams and handy mobile apps, and we study them. However, this doesnt fix the problem of the Huge Energy load in the battery itself. Even if that energy cant get out of the battery through wires, it can still burn like crazy inside (and outside) the battery case(s).

Even then, a much lower capacity is required if the trolley bus will spend the majority of it's lifecycle on a catenary.

Yeah but a city like sf has run those for decades very safely.

All modern trolleybuses have either batteries or diesel engines for detours.

Infrastructure costs aren't "enormous", that would be if you're putting rails in the ground for trams.

My city has a large fleet of fuel cell buses and has had them for over a decade, which suggests you don’t know what you are talking about.

In London that makes sense because they already have a decent mode share. I suspect the bus mode share in Hamden, Connecticut is 1% or less.

Which happens how often?

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.

Trolley busses can overtake each other, either by having a passing loop built in to the overhead wires or by briefly dewiring and rewiring the bus. Modern trolley busses can travel short distances off-wire and some can even rewire themselves automatically.

The only reason MBTA has had so many problems with unintended dewiring is that they have done little to no maintenance on the overhead wires for the last half century. You can expect that the same will happen sooner or later to whatever charging infrastructure they build for battery electric busses. That is, assuming that they even that far and don't just pull a bait-and-switch as soon as the wires are down.

Lithium batteries are dangerous in a way gasoline tanks are not: while a punctured tank (say, due to a unlucky collision with a piece of debris or a crash) is dangerous, it does not guarantee a fire or explosion. A punctured lithium cell will almost always burn.

There are also more ways to screw up a battery. Overcharging, manufacturing defects, and so forth. A gas tank is literally a chunk of cast metal with a pump in it.

Additionally, metal fires are severely hard to fight. Gas fires can be extinguished in the usual ways, but a self-oxidizing metal fire require special considerations, and that's if it can be reasonably extinguished at all. That isn't even mentioning the need to de–energize the battery before attempting a rescue.

You're both widely overestimating the fire risk. It shouldn't even be a consideration from the consumer perspective. The color of the car probably matters more.

Diesel is generally considered a safer fuel than gasoline, it's a lot less gaseous or flammable.

That said, yeah it's not like ICE vehicles are any safer when it comes to fire hazards. They're probably easier to extinguish though; EV fires are a pain, to the point where fire brigades bring in containers, fill them with water and dump EV car wrecks into them until they've stopped reacting.

Gasoline doesn’t burn. Gas+air mixture burns and the concentration of gas has to be surprisingly low for the reaction to work - 1 part gas for 14.7 parts air.

Batteries provide their own air and will burn submerged underwater, if they want to. The firefighting protocol is “Contain fire and wait, sometimes for days”. That’s why the containment cell is designed to be nigh impervious and fire is unlikely. But once a fire starts, good luck.

When was the last time you heard of a gasoline fire in a modern vehicle? Why is it that EV fires are so common?

> Other than being afraid of new technology.

... but then you resorted to ad hominem. Why would someone have to be "afraid" of new technology in order to have serious and legitimate concerns about it?

To help you out a bit, we also saw very bad lithium battery issues in laptops about ten years ago (just search youtube), to the point where airlines were seriously considering banning laptops and phones from being brought on board (and did ban one version of the Galaxy Note, IIRC). That was resolved, so it stands to reason that as EV improves, the risk of catastrophic fires will improve as well.

(Of course, those batteries were not being violently and physically damaged, so it's unknown whether software will be able to assist with accident-situations with an EV.)

But ICE engines have had over 100 years of continuous testing and deployment on a mass scale. The risks and dangers are fairly well known now. EV's lag far behind that. Perhaps they should be deployed in smaller passenger vehicles before attempting trucks and buses.

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.

Fuel injectors, filters, and pumps in unleaded cars can also be damaged when the vehicle runs out of gas. I believe fuel injectors are always damaged when run dry but not necessarily to the point of failure.

And they retired the program sometime in 2019.