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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

#161

Post by pasta »

owlmirror wrote: post #152
pasta wrote: post #151

Earlier quoted context omitted.

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…

Today's cars are so much more complex than old cars. Yet almost all of them are much more reliable than old cars.

I don't think simple == reliable.

A wheel made of solid wood is very simple. But the choice of material is poor.

So there are a lot more factors involved to make something reliable.

Getting stuck in the dirt might be more dangerous than a wheel with 1000 parts that gets you out of a nasty situation.

Also: people assume that these new tires are going to replace all tires. But I think this is just a extra tool in a big toolkit.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#162

Post by owlmirror »

pasta wrote: post #161
owlmirror wrote: post #152

Earlier quoted context omitted.

>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…

Today's cars are so much more complex than old cars. Yet almost all of them are much more reliable than old cars. I don't think simple == reliable. A wheel made of solid wood is very simple. But the choice of material is poor. So there are a lot more factors involved to make something reliable. Getting stuck in the dirt might be more dangerous than a wheel with 1000 parts that gets you out of a nasty situation. Also:…

>Today's cars are so much more complex than old cars. Yet almost all of them are much more reliable than old cars.

That's debatable. Evey person who owns a vintage car, pre electronics area will tell you that. I'm sure there are improvement in new cars which made them more reliable but not because of increased complexity. Maintainability of modern cars is a mess.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#163

Post by kbutler »

asfdsfggtfd wrote: post #130
killjoywashere wrote: post #100

Earlier quoted context omitted.

Nothing against 20-year-olds, I was one. I know what I did and what my friends did. I'm no angel. But if was running the engineering team on this, I'd make sure everyone had in their mind "the driver is maximally amped-up, young, and male.

What does them being male have to do with anything? Are you implying that being male means that they must be reckless? Or that if they were female they would automatically be careful and gentle? Careful throwing around those negative stereotypes. EDIT: The driver is likely to be getting shot at. This is going to be an order of magnitude more important than slight gender differences.

https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/...

"Motor vehicle crash fatalities were higher for males than females in all age groups, while the male population is equal to or less than the female population in all age groups."

Particularly in the 21-30 age group, males had 3x the fatalities of females.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#164

Post by evgen »

what-the-grump wrote: post #153
evgen wrote: post #143

Earlier quoted context omitted.

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?

Infrequently. The US were early proponents of combined arms tactics. Find heavy armour? Call in artillery or air support -- one of the advantages of owning the airspace over the battlefield.

Oh, and the only Tiger tanks that got close to Moscow are the captured ones on display at Kubinka.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#166

Post by mulletbum »

laumars wrote: post #144
TaylorAlexander wrote: post #129

Earlier quoted context omitted.

Never mind those folks with the rifles pointed at us! They’d never shoot someone whose busy changing a wheel!

Wouldn't you still have that same problem if an ordinary wheel gets damaged?

I think the probability of damage is higher is what they are thinking. I would say that the complexity is far higher in this case, so it is easier to pop 5 bolts and swap a tire then swap.....bolts, then unhook whatever is controlling them.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#167

Post by willyt »

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…

Tommy Roaster is the translation from German for their nickname for British tanks. The German tanks were much better than the British tanks according to this primary source[0]. I don't know about Sherman tanks.

[0] https://soundcloud.com/historyhit/captain-david-render-tank

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#168

Post by jessriedel »

basicplus2 wrote: post #112
msravi wrote: post #111

Earlier quoted context omitted.

You forgot "radioisotopic": https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...

i wonder if this would be a good use of nuclear waste..

It's not. The material used for radioisotope thermoelectric generators needs to have the appropriate half-life (not too long so that it actually produces a useful amount of power per mass, not too short so that it's doesn't exhaust itself) and it needs to not produce destructive types of radiation (which will fry electronics in addition to killing people). The vast majority of nuclear waste doesn't have this property.

https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...

The closest thing to what you're looking for appears to be Americium-241, discussed in the above link, which apparently can be extracted from nuclear waste, but it's not a very good choice.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#169

Post by mulletbum »

owlmirror wrote: post #162
pasta wrote: post #161

Earlier quoted context omitted.

Today's cars are so much more complex than old cars. Yet almost all of them are much more reliable than old cars. I don't think simple == reliable. A wheel made of solid wood is very simple. But the choice of material is poor. So there are a lot more factors involved to make something reliable. Getting stuck in the dirt might be more dangerous than a wheel with 1000 parts that gets you out of a nasty situation. Also:…

>Today's cars are so much more complex than old cars. Yet almost all of them are much more reliable than old cars. That's debatable. Evey person who owns a vintage car, pre electronics area will tell you that. I'm sure there are improvement in new cars which made them more reliable but not because of increased complexity. Maintainability of modern cars is a mess.

And maintainability is exactly the argument here. I do not know everything about these new tires, but like many people advocating here, I would rather just let the air out of my tires to get through the mud and re-inflate them then deal with the complexity that seems to be shown here.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#170

Post by kogepathic »

ygra wrote: post #106
godelmachine wrote: post #99

Earlier quoted context omitted.

I Googled for "B-61 Mod 10 replacing radioisotopic thermoelectric generators" and I got this → https://en.wikipedia.org/wiki/B61_nuclear_bomb and upon further searching, this → https://en.wikipedia.org/wiki/Thermoelectric_generator I need to ask if thermoelectric generator was a part of the B61 nuclear bomb? Please explain.

If so, I guess it'd be a valid way of ensuring the warhead still has power after a decade or two.

Command and Control (by Eric Schlosser) is a great book if you're interested in the history of US nuclear weapons.

According to the author, most warheads in the US arsenal are (or were) equipped with single-use thermal batteries that are activated during the firing sequence.

Thermal batteries were originally developed by German scientists, but the concept was taken further in the 1950s when the US armed forces were looking for a more reliable and less maintenance intensive power source for their nuclear weapons once fired.

[1] https://books.google.com/books?id=H0-CJckES44C&lpg=PT133&ots...

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