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Darpa Literally Reinvented the Wheel for Army Combat Vehicles

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Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#151

Post by pasta »

killjoywashere wrote: post #82

As a military officer, I pray these never make it past Test and Evaluation. They took essentially one part and turned it into 1000 parts. Anyone who has seen what 20 year old Marines do with these machines, let alone what happens in war, will appreciate that this is a fantastically horrible idea in a war zone. I need high reliability, not high zoot. Let NASA have high zoot.

But what if test and evaluation prove they are more reliable than tires filled with air?

I understand what you are trying to say but maybe the same discussion happened when they started using air tires instead of solid wheels: "What if your drive over a rock and all air floats out!? I pray they never start using air tires!".

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#152

Post by owlmirror »

pasta wrote: post #151
killjoywashere wrote: post #82

As a military officer, I pray these never make it past Test and Evaluation. They took essentially one part and turned it into 1000 parts. Anyone who has seen what 20 year old Marines do with these machines, let alone what happens in war, will appreciate that this is a fantastically horrible idea in a war zone. I need high reliability, not high zoot. Let NASA have high zoot.

But what if test and evaluation prove they are more reliable than tires filled with air? I understand what you are trying to say but maybe the same discussion happened when they started using air tires instead of solid wheels: "What if your drive over a rock and all air floats out!? I pray they never start using air tires!".

>But what if test and evaluation prove they are more reliable than tires filled with air?

That won't happen. Just the fact that there are so many moving parts, controlled by microcontrolelrs, all with multiple independent fail points makes the idea that these are more reliably just absurd. The only question is, is the trade off of less reliability worth the advantage they provide. I don't see it, but maybe there are some applications which I'm not aware of were you really really need these abilities.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#153

Post by what-the-grump »

evgen wrote: post #143
Theodores wrote: post #136

Earlier quoted context omitted.

No, no, no, the comedy tank of the era was the Sherman Tank. https://medium.com/war-is-boring/the-m-4-sherman-tank-was-he... Favourite quote: Hence, the Sherman’s grim nickname—Ronson, like the cigarette lighter, because “it lights up the first time, every time.” Everything was wrong about it and the Russians that got given these on Lend Lease knew that they had been given a death sentence. Aforementioned article jus…

This is the sort BS stories that capture the imagination of people who don’t know what they are talking about but are trivially disproven by actual facts and statistics. At US entry to the war the Sherman has equivalent tank and crew losses due to fire as similar tanks from other countries and by the end of the war The Sherman was the _least_ likely tank to suffer an ammunition fire of all the major tanks fielded in…

Did the US engage the Germans in heavy armor combat similar to that of the Russia’s e.g when Hitler was trying to take Moscow?

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#154

Post by donquichotte »

teekert wrote: post #150
donquichotte wrote: post #110

Earlier quoted context omitted.

As a guy who rode a motorcycle from Central Europe through Central Asia to Mongolia, the last part largely off-road, I wholeheartedly agree. Simplicity is key. As a traveler, if your "wheel 4.0" has a software bug or breaks down in the middle of the desert, it is inconvenient enough. I can only imagine the consequences this would have in a war scenario.

It's also pretty annoying if your are stuck in the middle of the desert because you opted not to use wheel 4.0. In the end it's all about statistics. What is more likely to happen? A wheel 4.0 fail, or getting stuck with wheel 1.0 (where 4.0 would have helped)... The first likelyness is constantly decreasing with wheel 4.1, 4.2, 4.9 etc whereas the first one stays constant. At least at some point in time wheel 4.0 sh…

In reliability engineering, the failure rate for a complex system is the sum of the individual failure rates of its components [1]. I will let you do the math.

[1] https://en.wikipedia.org/wiki/Failure_rate#Additivity

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#155

Post by what-the-grump »

killjoywashere wrote: post #102
cwyers wrote: post #92

Earlier quoted context omitted.

I've seen 20-year-old Marines maintain EA-6B Prowlers, I'm sure they can figure out DARPA's fancy new wheels.

Nothing against 20-year-old Marines. I was 20 once too and recall some choice decisions I made, friends made, others made. It's not their ability I'm worried about. It's their judgement.

To a point, looking at the political landscape today I’d say I trust the 20 year olds over the 65 year olds. Even if you can’t get the 20 year olds to pay attention.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#156

Post by baruch »

JulianMorrison wrote: post #142
Angostura wrote: post #138

Earlier quoted context omitted.

> Let NASA have high zoot. NASA does really rather well with high reliabilty. The Martian rovers have managed without a service.

To be fair, nobody has been shooting at them.

Nobody also peed on their wheels either. But they do need to handle quite a bit of dust and there is no one around to grease them. The APCs I had to use wouldn't survive that long without service.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#157

Post by Jacq5 »

The idea seems ok, but let's do this in practice. High costs, small efficiency. Especially I like to think about what happens if one part breaks. Now you just have to change the wheel, but in this case, you would have to spend precious time while getting to the problem and then fixing it. Seems really unpractical.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#158

Post by Jacq5 »

JulianMorrison wrote: post #142
Angostura wrote: post #138

Earlier quoted context omitted.

> Let NASA have high zoot. NASA does really rather well with high reliabilty. The Martian rovers have managed without a service.

To be fair, nobody has been shooting at them.

[dead]

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#159

Post by Radle »

killjoywashere wrote: post #82

As a military officer, I pray these never make it past Test and Evaluation. They took essentially one part and turned it into 1000 parts. Anyone who has seen what 20 year old Marines do with these machines, let alone what happens in war, will appreciate that this is a fantastically horrible idea in a war zone. I need high reliability, not high zoot. Let NASA have high zoot.

I agree, but not when it comes to self driving vehicles. For those better than normal wheels is enough. There's no way to change a brocken wheel anyway.
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