OTish ... egines being ejected in crash

Jethro_uk presented the following explanation :

Maybe a bit of a freak happening - there is not that much to keep them in place in a crash, unless it is a head on, where contact with the other vehicle will stop its progress.

engine mountings, half shafts...exhaust

unless it is a head on, where contact with the

There's a problem with the batteries of electric cars in a crash.

Or to put it another way...

Engine mountings - rubber, designed for compression loads, not tension

Half-shafts - clipped in

Exhaust - usually a flexible joint, but even if solid, very brittle after a couple years of 800*C.

One of our young Field Techs hit a lamp post fairly square on (Mk3 Escort) and the gearbox was found a few yards up the road. ;-(

He was ok but his girlfriend passenger suffered some serious injuries (but survived etc).

Cheers, T i m

Does seem a little odd. Its not like powerboats where the pod with the crew is ejected is it.

Maybe the fixings are just not up to the job these days as they strive for lightness and crushability. Brian

Quite and it could be considered something like that should actually be restrained in the event of such an incident, like the top end on top fuel dragsters and their retaining straps?

I guess there would always be the situation that if a car that hits something hard then spins down the road with the engine on a 'restraining cable' it could act like a mace! ;-(

Cheers, T i m

Not actually head on, IMHO. What it shows clearly is the strength of the passenger cell. It looks to me as though the second car has just sheared the front off.

Not remotely comparable to the Le Mans crash of 1955

Or this one

This one ended up about 200 feet(!) from the car it was ejected from, but the circumstances have not yet been satisfactorily explained:

I imagine that could be quite serious: there's a lot of mass and a lot of energy stored in the batteries and if the battery gets short-circuited in a crash the result could be catastrophic, but I should think spectacular. Some years ago there was a thread here about firemen refusing to tackle house fires if the house had solar panels on the roof, which could expose the firemen to high voltages. Is there a risk of something similar happening with an electric car?

But is an electric car actually any greater a hazard than a car with a tank-full of petrol?

But how much further might the "car+engine" have travelled if they hadn't separated? Momentum is conserved in a crash, although it is true that energy is not, so if the parts had been more strongly connected, more energy could have been absorbed in trying to separate them, leaving less energy in the fragments to do collateral damage.

I'm still pretty sure it won't have been a head-on collision (although one would need to see a plan view of the location of the bits post-accident to be sure).

Certainly a "fireball" type crash of a petrol vehicle has the potential to cause a lot of injuries, even though it rarely does.

I'm sure firemen now have a well thought-out protocol for tackling houses with solar panels.

Very much so, petrol doesn't burn by itself. I can assure you a Lithium battery has all the ingredients for a large, self contained, explosion.

I?m pretty sure that the electric car the Hammond crashed carried on bursting into flames for 5 days. You don?t get that happening with petrol.

Tim

Electric car batteries are in a strong steel box and there is an anti-collision switch.

But they are in the floor usually so you have nothing between you and the crash.

James May said something on TGT about so many thousand (8,000) cells, and each cell popping into flames every seconds ... it worked out to be about 5 days.