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0 pointsGibbon16y ago0 comments

I have wondered about an electric tank. Some advantages. Doesn't require air. No thermal signature. Quiet potentially. Instant power. No diesel fuel to catch fire. No hydraulic system. Potentially redundant drive and actuators.

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5 comments · 3 top-level

nordsieck6y ago· 2 in thread

Sure. That's all good stuff.

But fundamentally, EVs really only work well when vehicles can recharge on a grid. The Military wants to be able to operate away from the grid.

TeMPOraL6y ago

With all this talk US military has been doing about the changing theater of war in XXI century, about how it needs to refocus on effective operations in urban areas, I wonder: do they always assume that the power grid will be off? If not, then there may be some utility in a light and fast electric vehicle that parasites off enemy's power grid (and has solars or diesel aggregate as backup).

Also, did the military consider hybrid vehicles for similar role? They have the capacity to operate off-grid, and also switch to completely silent when tactically useful.

nordsieck6y ago

> do they always assume that the power grid will be off? ... Also, did the military consider hybrid vehicles for similar role?

I want to be up front - I'm far from privy to the military's decision making, which is byzantine and absurdist on a good day.

However, I think I can pretty safely say that the issue is not whether the military assumes that the grid will be off, but rather they don't assume that the grid will be on.

I think the closest they might get is a plug-in hybrid. However, that adds quite a bit of weight and complexity to a vehicle. I honestly don't know one way or the other how well that would work for armored vehicles, which are typically quite a bit heavier than you're probably used to thinking.

For example: homemade armor is typically 1/4" hardened steel plate welded to the outside of vehicles (thin skinned trucks, etc.) - about 2x the thickness of the Cybertruck's body. I'd assume that most purpose built armor kits are even heavier than that.

playeren6y ago

Electric motors still have a thermal signature, although obviously way smaller than a combustion engine + exhaust. Also, diesel doesn't really catch fire that easily (some tanks even proudly 'wear' extra fuel cans on their sides). Diesel is still very, very energy dense compared to batteries (for the time being), so for any campaigns away from established infrastructure, you'd rather be hauling diesel than batteries.

https://en.wikipedia.org/wiki/Stridsvagn_103#/media/File:Str...

https://en.wikipedia.org/wiki/Energy_density#/media/File:Ene...

nullc6y ago

> No thermal signature.

That's isn't how thermodynamics works.

It could have a reduced thermal signature but infrared cameras are so absurdly sensitive so it isn't obvious to me that a reduction would be a big advantage.

> Potentially redundant drive

Diesel-electric would have the same redundancy advantages: https://oshkoshdefense.com/engineering-solutions/propulse/

> No diesel fuel to catch fire.

Diesel is relatively hard to get to burn as liquid fuels go... lithium chemistry batteries aren't particularly known for being fire free.

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