Darpa Literally Reinvented the Wheel for Army Combat Vehicles
taskandpurpose.com
taskandpurpose.com
Edit: "anti-user" may be to harsh. Let's say "developers first, users second".
That was not what I was talking about. I was talking about HN attitude toward that book and HN attitude in general regarding the position wrt users/developers. Crowd here are happy to cry about user hostility because of the walled gardens, closed source, whatever, but given a choice many will go the path of the least resistance and choose the technologies and approaches that make it easier to have some kind of result without much consideration about UX or accessibility of said result. Fast and cheep to develop is winning agains enjoyable to use. Sure, it is not 100% true, but the trend is quite obvious, imho.
In case anyone here thinks I was not long enough on HN to criticise it: I've been here for the 9 years now.
https://jalopnik.com/the-legendary-world-war-ii-jeep-had-a-d...
In WW2 the Japanese sent a captured American Jeep to Toyota for them to copy. This was the Toyota J. The J was redesigned into the 40. The 40 was redesigned into the 70.
Other than the overall 4WD front engine body-on-frame design, I do not believe that there are any carryover components nor unique design features of the Willeys in the 70.
Yep, haven't heard that acronym since I ETS'd ~6 years ago.
Concession: id be damned if I told you that we didn’t goose the new guy bending over the explosives from time to time.
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.
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...
https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...
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.
I was confused as to how many PnC of search strings I had to create. Thanks for that :)
Hey, those are from Amarillo!
When I was about 20, I was out driving around and decided to see how fast my Oldsmobile could go, on a long, straight county road. Got up to about 110 and decided to slow down when I popped over a low hill and saw the road making a 90° right turn in front of a tall chain link fence with razor-wire on the top. I made the turn, but I assume emergency medical assistance would have arrived quickly---the fence was Pantex.
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.
Being young and male correlates strongly with high testosterone, the effects of which you can Google for. Being young and male also correlates with higher incidences of road traffic accidents than most other demographics.
The effects of testosterone are far from as simple as you suggest. It tends to lead to higher competitiveness. This is not quite the same as recklessness.
Meanwhile during normal usage the driver (of whatever gender) is likely to be getting shot at. This will tend to have a larger affect than their gender.
Yes, and millions of young men in the US who are shorter than millions of young women. What’s your point? Young men are still disproportionately more likely to be in road traffic accidents.
Re testosterone, the keywords you should be searching for are “risk taking behaviour”.
I’m curious also what percentage of time you think the average military driver is being shot at is.
And in the military, given how e.g. the draft has never applied to women. Times are changing, but very, very slowly, and there will always be a gender disparity due to physical differences (e.g. strength, see also: almost every sport)
Or to make a summery of the summery of the study: there is an association of risk aversion when going from low levels of testosterone to very low levels, but "male with high testosterone" is not supported in that study as increased risk taking behavior vs males with normal levels of testosterone.
No -- being shot at is 0-2% of your time deployed. The rest is waiting around.
"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.
In my experience men and women tend to be about equally hard on things. The male outliers tend to create more maintenance work by being hard on chassis/suspension ("hold my beer and watch this"). The female outliers tend to create more maintenance work by keeping quiet about problems (usually having to do with fluids not in their proper places) for far too long.
The most expensive driver is the kind that blindly follows directions/orders into a dumb situation.
Source: Did fleet maintenance in high-school.
edit: The words "in my experience" and "outliers" were used for a reason. I'm not claiming that all men will get a mini-bus airborne if given the opportunity or that all women will ignore an obvious puddle in a parking spot. I am stating what patterns I observed in the noteworthy cases of neglect. There's a million uncontrolled variables, maybe we were just a really scary maintenance department and none of the women wanted to talk to us or something. I'm not claiming that a bunch high school teachers a decade ago is a sample that accurately represents the rest of the population. Maybe the way buses were assigned to teams (pseudorandom) resulted in the observed failure pattern.
Attention to detail
“I’ve always been impressed by how women take care of
their machines” Smith says. “They keep them clean and
don’t leave trash in the cabs. If there was a drop of
oil coming out of a wheel or something small like that
they let you know about it.”
Ok, well my undocumented assertion is roughly the opposite. Where does that leave us?
>I'd be happy to look at any statistics you can provide that show "equally hard on things".
Post on /r/mechanicadvice, dump out the 80% that were written by someone who's never actually turned a wrench and sift through what's left?
Regarding trash specifically I think the difference between a company vehicle and a personal vehicle is going to make a bigger difference than gender.
I guess it leaves us at, "Statistically, three times as many young adult male drivers have fatal accidents than equivalent young female drivers, despite having a smaller population."
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.
- How did you choose this route/destination out of the thousands of possibilities?
- Was there any specific goal beyond spending a bunch of time on a bike and seeing a big chunk of the world?
- Was your time almost entirely spend riding, or did you spend a lot of time in the places where you stopped?
- Camping? Hotels? Staying at friends' houses?- more or less at random, it is IMO one of the more interesting routes you can start in Europe, opposed to e.g. the Panamericana or BAM.
- not really, I just wanted to explore the world (and still do, haha)
- Maybe 2/3 of the time was spent riding, the rest of the time I spent exploring places and waiting for visa.
- all three of them!
They were technical nightmares.
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 just touches the surface, the barrel was too short, the 'tech' for being able to shoot on the move did not work and you needed five of the things to take out one German tank, four as cannon fodder (complete with the guys inside) and one to sneak around the back to get that German tank whilst it was busy taking out the other four.
The 5 Shermans vs 1 Panzer myth is much disputed however where there is smoke there is fire and I would not want to be in one. Plus, by the time that the Americans rocked up to fight WW2 - which was late to the party - the Germans had run out of oil so their tanks were running on recycled coal dust extract rather than the diesel fuel required.
The shoddy design of the Sherman Tank was no matter though, the 'allies' were expected to pay for these useless behemoths after the war so this was the military-industrial-complex and built-in-obsolescence at its finest.
Meanwhile the Soviets had a much more serious war on their hands so their hardware wasn't about making a quick buck. It had to be fit for purpose. The same thinking happens today hence we have toy planes like the F-35 where everyone and his pet congressman is getting a backhander vs. the fit for purpose planes of Russia, as advertised over the skies of Syria and doing much better in the global arms trade.
The T-34 was fit for purpose for certain, as long as the purpose was to leave a trail of broken-down tanks from factory to battlefield. Prior to 1944 more T-34s were lost to mechanical problems than to enemy action.
Oh, and the only Tiger tanks that got close to Moscow are the captured ones on display at Kubinka.
[0] https://soundcloud.com/historyhit/captain-david-render-tank
Thus senior military leadership is keenly interested in readiness. This requires training, R&D, and intelligence. "Are my officers and troops more physically and mentally prepared than the enemy's?" "What's the best weapon I've got?" and "What's the best weapon they've got?" are critical questions.
See T. R. Fehrenbach's "This Kind of War" for the US's brutal baptism into the darker side of their role as a superpower, a war no American wanted to get involved in. The short-hand in history for this necessity of readinesss is Task Force Smith (2).
(1) https://smile.amazon.com/dp/1574883348
(2) https://en.wikipedia.org/wiki/Battle_of_Osan#Task_Force_Smit...
You mean in an uncontested airspace, with no AA to speak about, disregarding any collateral damage because there is no one to hold them accountable (unlike US forces that are panned by US press)? Right, those plane may be fit for that purpose. Meanwhile, US&allies measure up their planes against each other during Red Flag, where both F-22 and F-35 have stellar performances. FIY, the only time Su-s (of Indian airforce) were there they were outgunned pretty heavily and had a very tough time protecting the engines from foreign object damage. Pretty bleak if you ask me
... and Russia still managed to lose about 1/3 of their carrier's planes.
http://militera.lib.ru/research/suvorov12/06.html
I have heard the book this is from is somewhat inaccurate, but it makes for a good read.
NASA does really rather well with high reliabilty. The Martian rovers have managed without a service.
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!".
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.
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.
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.
Most modern cars can hit 100k miles with only regular and cheap maintenance. That's a huge step up.
Materials are better, as are engineering, but those are a wash complexity-wise.
The major complexity increase has been antilock braking/traction control/stability control, all of which are (I hope!) designed to fail back to their older mechanical state. Their reliability has improved considerably, but my 2004 Corvette may need another brake controller rebuild and the brake controller on my 1995 BMW motorcycle's primary purpose seems to be to test for low-voltage conditions when I start the bike.
I do like the example of fuel injectors vs. carburetors. The carburetors were a lot more mechanically complex, and quite difficult for a non-expert to get right. Fuel injectors are easy. a good example of just how much a simple micro-controller can make a system seem a lot more simple.
And actually, it's an old thing, in that Model T conversion kits came out in 1922.[0] Also, later, for mud and sand.
0) http://www.modeltfordsnowmobile.com/lcmainbriefhistory.htm
However I wonder why they accept the complexity/reliability problems I assume come with this solution instead of going with added (engageable on demand) tracks.
If one of the tires goes flat, then there's built-in redundancy from the other ones and it could be replaced in the field if needed, but no one's going to be able to overhaul this track mechanism without a shop.
This still fails for that purpose though.
One car weighs ~3500 lbs. If I keep 35psi of air pressure in the tires, that works out to ~100in^2 of contact patch. With four wheels, that's 25in^2 per wheel or 5in square.
This looks like the tread-extended contact patch is more like 12in long times the original width, or 60in^2. That halves the weight per square inch.
You don't. Off road you lower the tire pressure significantly.
From here you'd keep iterating - learning, improving, trying various approaches.
Maybe the track version is meant to be used only rarely, when the vehicle is truly stuck. So you’re either wasting time digging yourself out with a shovel and saving on maintenance, or you switch to tracks to get out of the ditch and then perform maintenance right after you get back to the base. So long as maintenance is not deferred it seems preferable to do the latter.
If such a wheel/track is ever used for real, it might be on something very different, and not on the front lines. And possibly larger or smaller than this.
I also worry about what a hand grenade or small IED will do to this contraption, compared to what it will do to a conventional tyre. Even if it is as strong, it likely still will increase mean time between repairs, as, when one breaks down, it’s more likely that one will have a regular tyre at hand than that one has one of these.
This is of a piece with the F-35.
The US donated (I’m sure with wink wink strings attached) to us, Slovenia, some years ago and it was quickly found that they are too large and cumbersome for our foresty mountanous terrain. They’d get stuck all the time on tiny roads or between trees.
I think these days they’re used for paraded to show we have them but day to day the military keeps using their trusti Puchs from who knows when. Tiny and manouverable.
Certainly in "foresty mountanous terrain" since that isn't particularly rare. Exists inside of the US. Exists on both borders of the US. Etc.
Producing a military optimized for "blowing up unsophisticated enemies in desserts" seems like a very shorted sighted way to spend the military budget.
(None of the above should be taken as me defending spending so much on the military as a whole, just on the allocation of the budget within the military to all sorts of terrain when taking the size of the current budget as a given).
The US military has dedicated units and training facilities for virtually every environment on Earth.
A lot of jungle wars before that.
I think the general desertiness of war theatres only applies in the last 30 years or so and is not likely to persist forever.
They need equipment for future wars, which are very difficult to predict. Also, the military's main purpose is to deter enemies by having capability. Enemies would be thrilled if the US military couldn't operate in wooded areas.
https://vignette.wikia.nocookie.net/starwars/images/8/88/Var...
We can sell you some lightly used units from our last imperial war. They have excellent maintenance records. And comes with a 5 year, or 50,000 mile warranty, whichever comes first.
https://www.jqpublicblog.com/air-force-lacks-resources-retri...
A vehicle beached at the frame on sand is a very common occurrence in the desert, and it's fairly trivial to get out if you have a shovel, brains, and are physically well. It's just some work, but sand is incredibly easy to excavate by hand, even from underneath a vehicle.
A better design would have been to flatten the wheel into an more oblong or even an egg shape, like snowmobiles or tanks have. However, it requires more mechanical displacement and adjustements.
We would also need to deal with the fact that just flattening one side of the wheel would make for a shorter perimeter than that of the circle; the tread is a loop of a constant length, and it needs to be kept fairly taut to function in both wheel and tread mode.
Agree with the perimeter consideration.
It doesn't look like their whole wheel rotates though.
We add grams to balance wheels to prevent damage to suspensions etc, this thing seems just a dream for vehicle applications.
Though "Never attribute to malice that which is adequately explained by stupidity." Back in '90 or so I was on the ground crew for a jump they were doing to impress some Soviet generals and they jumped with too high winds which resulted in two arty canons and a sheridan tank burning in (they got to oscillating so bad the chutes collapsed) and three planes worth of troops ending up in the trees. Bad day to jump but made for an interesting day on the ground.
Thinking further on the heavy drop thing, from what I remember the crew who's vehicle it was were the ones doing most of the rigging with the riggers mostly just checking their work. Too many eyes for it to be an accident methinks.
"Johnny Lodern: One issue is they where dropped from seperate aircraft, each crew is supposed to inspect cargo before drop, so there is more than 1 person at fault if it was not equipment failure."
I’ve seen plenty of tanks get stuck but honest to god I don’t ever recall a HMMWV getting stuck. I used to try to get my HMMWV stuck. That thing is geared so low it just walked out of soup up to the hood. Tracks are advantageous when more surface area is needed to spread the weight out, like soft wet ground (mud) or very fine loose (think sand dunes). It will be nice to have the added mobility for certain missions but I don’t see this becoming organic to most units. The vast majority of missions just don’t need these wheels and they look like they’ll break.
If you modify the vehicle you can support this without changing the hub and shaft/extension, just change the wheels and add tracks. But I'm assuming they wanted to work with a mostly stock vehicle.
Capitalized as if it's a movie title, is strangely unsettling to me.
[0] - https://en.wikipedia.org/w/index.php?title=List_of_wars_on_concepts&redirect=noI'd also like the inventor to use it for a year.
All the tech that went into this wheel, might coincidentally open other doors, that lead to still other doors...
There's all kinds of companies making conversion kits to such (non-shape-shifting) small tracks for trucks and SUVs, not sure if there's a military example of that exact style.
This video https://youtu.be/ZZYT2nYd46o shows the gang rotate near 40 seconds and at end you can see it used in water (6:33)
Being the scenes on its construction https://youtu.be/26n3RsXNyKE and it still exists as of 2016
The internet was born of a DARPA project, Siri was made with technology spun off from another. Project MAC was filled with groundbreaking research and development of AI and operating systems. All modern operating systems can trace their lineage back to Project MAC. The origins of GPS are also from an earlier DARPA project.
Most DARPA projects will never be used in an operational environment, but the technology discovered and lessons learned inevitably find their way into other projects and technologies.