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The Japanese air force has been reduced to the Special Ed Flying Circus.
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| # ? Jun 11, 2012 23:09 |
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| # ? May 19, 2013 09:54 |
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I had to double-check, but Grey's planes didn't actually start getting downed or even damaged until he started bombing the Japanese airfield. I hope the Kido Butai never puts out to sea again, or it would be a complete massacre.
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| # ? Jun 11, 2012 23:27 |
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RZApublican posted:I hope the Kido Butai never puts out to sea again, or it would be a complete massacre. Why would you say these things? On the topic of the day: Apparently, the IJA is now crewing it's planes with complete rookies a couple of months or so ahead of schedule. Hopefully, they won't be able to pull bullshit-numbers out of their arse to compensate for this as we get closer to Japan.
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| # ? Jun 12, 2012 01:13 |
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Serpentis posted:Hopefully, they won't be able to pull bullshit-numbers out of their arse to compensate for this as we get closer to Japan. Don't forget that the AI gets enough industry bonuses that it effectively has infinite planes. So yes, they will pull bullshit-numbers.
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| # ? Jun 12, 2012 01:24 |
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Serpentis posted:Why would you say these things? The Musashi has to survive, it just has to 
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| # ? Jun 12, 2012 01:27 |
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El Disco posted:Don't forget that the AI gets enough industry bonuses that it effectively has infinite planes. So yes, they will pull bullshit-numbers. This. It's astounding how many planes we'll end up seeing...
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| # ? Jun 12, 2012 03:35 |
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How long does it usually take for a sunk ship to show up on the list? I found 4 AO + 2DD north of PH and smashed them hard with my CVs. I didn't get any sunk but they were all full of fuel and heavy damage + heavy fires(and I saw a lot of "Fuel cargo burning") and the next day I could only spot the DDs running for home. I'm almost positive they all sunk. But it has been two weeks and I don't see them in the sunk ships list. On topic, I am so glad Grey hasn't been shanked yet.
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| # ? Jun 12, 2012 04:31 |
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goatface posted:From some internet digging that pulled up some references to Jane's, the Brooklyn class cruisers (which that was one of) cost an average of $18.5m to build. So for 230 planes to be of equivalent cost they'd need to cost ~$80,000 a piece. Strategically though I would imagine that any warship is much harder to replace. A lot of small industrial plants can be converted to produce airplanes or airplane parts, but only a limited amount of shipyards can build a cruiser, and you need some serious heavy industry just to build major parts such as guns, engines etc.
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| # ? Jun 12, 2012 11:35 |
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apseudonym posted:How long does it usually take for a sunk ship to show up on the list? I found 4 AO + 2DD north of PH and smashed them hard with my CVs. I didn't get any sunk but they were all full of fuel and heavy damage + heavy fires(and I saw a lot of "Fuel cargo burning") and the next day I could only spot the DDs running for home. I'm almost positive they all sunk. It depends on when intelligence gets reports that they were sunk, or the Japanese govt admits that they were sunk. Unless your bombers watched them slip below the waves, you don't "know" that they're sunk. Intelligence is really spotty about reporting things sunks, and things that sunk manage to get un-sunk, then resunk, etc. Take a look at earlier intelligence reports years ago (oh man!) for this happening in this thread.
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| # ? Jun 12, 2012 15:51 |
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RZApublican posted:The Musashi has to survive, it just has to No, the Valiant has to survive, and it will  And yes, I forgot about the ridiculous industry bonuses the AI gets. Sadly.
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| # ? Jun 12, 2012 15:53 |
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Volmarias posted:It depends on when intelligence gets reports that they were sunk, or the Japanese govt admits that they were sunk. Unless your bombers watched them slip below the waves, you don't "know" that they're sunk. It'd be interesting to load this game from the Japanese side and see how horribly GH mangled their navy once the war is over.
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| # ? Jun 12, 2012 15:58 |
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  The Skipjack takes a load of hits.  At Urippu-Jima, the Japanese begin to use Zeros as suicide planes.  We continue the bombing campaign further inland.   We drive off a Japanese ship hunting the Enterprise. I know there are more carriers in that group, but lets face it, you only care about one of them!  The Japanese sneak more bombers past our CAP, and the Nassau takes the brunt of it.  When they go for some proper carriers however, they get butchered.  Our strike on Pagan is a little pitiful.  We take out some fortifications at Morotai.  On Guam, we need to rest up until we get fresh troops, incoming from Rabaul.   Chiang Mai continues to go our way, but the Japanese refuse to break.    The Liscome Bay succumbs to her wounds.  A shame, but I've got to give you guys something to complain about. 
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| # ? Jun 12, 2012 16:22 |
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Guam is going to be a tough nut to crack. You're going to need bombardments and such to weaken the defenders, and don't overtax your troops.
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| # ? Jun 12, 2012 16:53 |
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What kind of fuckup names an island Pagan. That's just asking for all kinds of trouble.
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| # ? Jun 12, 2012 16:58 |
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Grey Hunter posted:Chiang Mai continues to go our way, but the Japanese refuse to break. Attackers out of supply reduces their AV by 7x 
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| # ? Jun 12, 2012 18:46 |
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Nenonen posted:Strategically though I would imagine that any warship is much harder to replace. A lot of small industrial plants can be converted to produce airplanes or airplane parts, but only a limited amount of shipyards can build a cruiser, and you need some serious heavy industry just to build major parts such as guns, engines etc. There was a programme just on BBC 4 about a plane factory in Wales that decided to break the record for how fast a bomber could be built. I shall allow Wikipedia to say the rest: http://en.wikipedia.org/wiki/Vickers_Wellington posted:As a propaganda and morale boosting exercise, in October 1943 workers at the Vickers Broughton factory gave up their weekend to build Wellington number LN514 against the clock. The bomber was assembled in new world record time of 23 hours 50 minutes, and took off after 24 hours 48 minutes Plane builders were FAST.
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| # ? Jun 12, 2012 21:31 |
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goatface posted:Plane builders were FAST. The record for building a "Liberty" cargo ship was four days. Not sure that I'd want to take to sea on a ship that only took four days to build.
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| # ? Jun 12, 2012 21:36 |
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Zeroisanumber posted:The record for building a "Liberty" cargo ship was four days. Not sure that I'd want to take to sea on a ship that only took four days to build. They had a tendency to crack in half IIRC. Something about it being welded rather than riveted. Think they just attached a plate with rivets in the weak areas to correct this.
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| # ? Jun 12, 2012 21:57 |
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Zeroisanumber posted:The record for building a "Liberty" cargo ship was four days. Not sure that I'd want to take to sea on a ship that only took four days to build. That was a publicity stunt, but still pretty neat. Ship in question lasted into the Sixties, as I recall. Re: the cracking in half thing, I believe it was because of the extreme temperatures in the North Atlantic doing some metallurgical sabotage.
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| # ? Jun 12, 2012 22:10 |
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Bondematt posted:They had a tendency to crack in half IIRC. Something about it being welded rather than riveted. Think they just attached a plate with rivets in the weak areas to correct this. They fixed that though right? and the ships made after that were just fine.
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| # ? Jun 12, 2012 22:20 |
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The Merry Marauder posted:Re: the cracking in half thing, I believe it was because of the extreme temperatures in the North Atlantic doing some metallurgical sabotage. We're taught in undergraduate metallurgy classes that this is the classic example of ductile-brittle transition, and also that it's an incorrect classic example (a great many of these examples are, actually) because (if I can remember this correctly; it was over five years ago) the actual phase transition to the brittle bcc phase in those steels only occurs at temperatures well below the North Atlantic in winter, and the actual problem was mostly due to the welding and the nature of the design, which has a lot of stress concentrations in it. Ilanin fucked around with this message at Jun 13, 2012 around 01:32 |
| # ? Jun 13, 2012 01:26 |
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Ilanin posted:We're taught in undergraduate metallurgy classes that this is the classic example of ductile-brittle transition, and also that it's an incorrect classic example (a great many of these examples are, actually) because (if I can remember this correctly; it was over five years ago) the actual phase transition to the brittle bcc phase in those steels only occurs at temperatures well below the North Atlantic in winter, and the actual problem was mostly due to the welding and the nature of the design, which has a lot of stress concentrations in it. Ha! Well, paint me blue and call me a smurf. I should have a talk with my old prof.
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| # ? Jun 13, 2012 01:48 |
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Ilanin posted:We're taught in undergraduate metallurgy classes that this is the classic example of ductile-brittle transition, and also that it's an incorrect classic example (a great many of these examples are, actually) because (if I can remember this correctly; it was over five years ago) the actual phase transition to the brittle bcc phase in those steels only occurs at temperatures well below the North Atlantic in winter, and the actual problem was mostly due to the welding and the nature of the design, which has a lot of stress concentrations in it. That's interesting as hell, thanks for sharing! I wonder if there's any more information available; I'd love to know just how much stress it takes to break a ship in half.
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| # ? Jun 13, 2012 03:59 |
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Log082 posted:That's interesting as hell, thanks for sharing! I wonder if there's any more information available; I'd love to know just how much stress it takes to break a ship in half. probably ~400Mpa  http://www.matweb.com/search/DataSh...f08db22a53e2421 That's really just a stab in the dark on what kind of steel they would have used. (and with no welds/joints ect)
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| # ? Jun 13, 2012 05:29 |
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The question of "how much stress does it take to break a ship in half" doesn't really have a sensible answer. That's because of existence of joints, sharp corners and similar which all act as stress concentrations, sometimes elevating local stress to more than double the global stress level on the system. Under normal conditions there are enough slip systems (it's complicated) active in the metal that it can accomodate these large local stresses through plastic deformation, but below a certain temperature an atomic rearrangement occurs which deactivates most directions of slip and the only thing left for the metal to do is snap - and, due to the way a Liberty ship is put together, there's practically nothing to stop a crack once it's started. What I'm not sure about is whether the temperatures in a North Atlantic winter are actually cold enough to cause enough slip systems to be frozen out. Certainly that was the consensus opinion amongst materials scientists in the 1950s; and it's physically plausible enough. I recall my lecturers telling me that it wasn't actually sufficiently cold (certainly for mild steel the ductile-brittle transition temperature is about -60 C) to explain the cracking entirely, and a better design of ship made from the same materials would have been OK, but I can't figure out what I've done with the relevant set of notes, so can't confirm. In the transition range where these ships probably were, it's all going to be a question of strain rates. If you apply a gradual stress, the metal can accomodate it; if you hit it with an impact stress, the hull can't deform in time and cracks. All of this is talking about breaking something by applying a single force though, which I doubt was what actually happened. My guess is that the problem was more likely to be fatigue - gradual growth of small cracks or holes until you reach the critical crack length at which it takes less energy to grow the crack than you get out from relaxing the stress on the material. As the material becomes more brittle with decreasing temperature, the critical crack length decreases, so something that wasn't going to be a problem can suddenly become catastrophic. Ilanin fucked around with this message at Jun 13, 2012 around 12:17 |
| # ? Jun 13, 2012 12:03 |
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Ilanin posted:The question of "how much stress does it take to break a ship in half" doesn't really have a sensible answer. Sure it does. That is, generally it takes less pressure under the keel than that provided by the detonation of a MK-48 torpedo. I'm sure there are some specific cases where that doesn't apply but for > 99% of all ships it totally holds true.
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| # ? Jun 13, 2012 12:25 |
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Murgos posted:Sure it does. That is, generally it takes less pressure under the keel than that provided by the detonation of a MK-48 torpedo. I'm sure there are some specific cases where that doesn't apply but for > 99% of all ships it totally holds true. I imagine a Nimitz or Ford-class supercarrier would survive a couple of Mk. 48s.
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| # ? Jun 13, 2012 13:46 |
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BrooklynBruiser posted:I imagine a Nimitz or Ford-class supercarrier would survive a couple of Mk. 48s. They are the 1% #OccupyEnterprise
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| # ? Jun 13, 2012 14:32 |
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Ilanin posted:The question of "how much stress does it take to break a ship in half" doesn't really have a sensible answer. That's because of existence of joints, sharp corners and similar which all act as stress concentrations, sometimes elevating local stress to more than double the global stress level on the system. Under normal conditions there are enough slip systems (it's complicated) active in the metal that it can accomodate these large local stresses through plastic deformation, but below a certain temperature an atomic rearrangement occurs which deactivates most directions of slip and the only thing left for the metal to do is snap - and, due to the way a Liberty ship is put together, there's practically nothing to stop a crack once it's started. Thanks for that. I never expected to learn something about metal stress and fatigue in a LP. 
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| # ? Jun 13, 2012 14:45 |
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Ilanin posted:The question of "how much stress does it take to break a ship in half" doesn't really have a sensible answer. That's because of existence of joints, sharp corners and similar which all act as stress concentrations, sometimes elevating local stress to more than double the global stress level on the system. Under normal conditions there are enough slip systems (it's complicated) active in the metal that it can accomodate these large local stresses through plastic deformation, but below a certain temperature an atomic rearrangement occurs which deactivates most directions of slip and the only thing left for the metal to do is snap - and, due to the way a Liberty ship is put together, there's practically nothing to stop a crack once it's started. Well, I remember someone saying earlier in the thread (and, I think, reading on my own a while ago) that the problem was eventually fixed by bolting an extra plate over the joints that typically cracked, so that would likely point to a design failure, not a materials failure; this is especially true given that the ships pretty much came apart at the joints where they'd been welded. I'd guess, then, that the fatigue problem would have happened eventually anyway, and if anything the extreme cold just made it happen faster, but it's hard to say for certain without more information on just what went wrong. (Unrelated, Ilanin, but it sounds like you're in materials science? I have a BS in mechanical engineering, but the lab I worked in did high strain rate testing on metals and ceramics. It's nice to meet someone else in the field.)
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| # ? Jun 13, 2012 16:07 |
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Murgos posted:Sure it does. That is, generally it takes less pressure under the keel than that provided by the detonation of a MK-48 torpedo. I'm sure there are some specific cases where that doesn't apply but for > 99% of all ships it totally holds true. I thought it was the under pressure of the hole in the water before it all comes rushing back in that did the breaking in half. Buoyancy force at the bow and stern and none in the middle = snap
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| # ? Jun 13, 2012 16:37 |
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 One of the few remaining short range bases (Pagan?) hits our battleships.  Although Guam is still active.  It would be nice if I could order my Marines to take the airfeild.  At least there is no massed air cover as I originally feared.  We continue to suppress as many airfields as possible.  The attack on Guam is brutal. I need to hit this more.  The Japanse have not given up bombing in Burma, but I've been a bit distracted, and its not been very interesting – this is a large raid however.  Sapporo is hit once more.   The surprise today is no land battles! This is a real rarity, but everyone is moving or resting today. At Guam, the first invasion force is now almost unloaded, and will be heading back tomorrow, I'm moving the carriers to Rabaul before I send them and all the troops from Rabaul in to tip the balance. Until then, they will be bombarding. 
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| # ? Jun 13, 2012 16:45 |
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Ron Jeremy posted:I thought it was the under pressure of the hole in the water before it all comes rushing back in that did the breaking in half. Buoyancy force at the bow and stern and none in the middle = snap On a very large & dense ship maybe. The weight of the water displaced by the ship is exactly equal to the weight of the ship. I think that this would mean that the path of least resistance for any explosion under the keel is vertically in the Y axis as that is the only direction that doesn't have the nearly infinite weight of the mostly incompressible ocean behind it. I think that basically the ocean works to create a channel that directs most of the explosion directly into the hull of the ship, rather than outward away from the ship. A massive shaped charge if you will that uses physics to ensure it strikes directly at the center line of the ship.
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| # ? Jun 13, 2012 18:03 |
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That explanation seems strange to me. It might be right, but I would find it extraordinarily hard to believe that water to the sides and below an explosion exerts an infinite force back on the explosion. While water is not particularly compressible, it can and will displace, which is why underwater explosions are not limited to the diameter of the torpedo - they expand in a circle. And, while it's probably a tiny effect, any water that phase changes into a gas will be compressible. Instead, I think that the incompressible water helps transmit the force of the explosion better than air - that is, you lose less force over distance than you do with an explosion in atmosphere. Hence dynamite in a pond kills fish, and you can hear things farther away underwater than above water.
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| # ? Jun 13, 2012 20:03 |
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Murgos posted:On a very large & dense ship maybe. The weight of the water displaced by the ship is exactly equal to the weight of the ship. I think that this would mean that the path of least resistance for any explosion under the keel is vertically in the Y axis as that is the only direction that doesn't have the nearly infinite weight of the mostly incompressible ocean behind it. After long and rigorous research involving watching *several* youtube videos, I think there's a three parts to the damage of a torpedo exploding under the keel. 1) First pressure wave pushes up 2) The void pulls down (or rather the buoyancy force is no longer there) then finally 3) the overpressure bubble hits the surface (through the broken bits of the ship) and blows everything to poo poo.
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| # ? Jun 13, 2012 20:15 |
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So is there anything left of Sapporo at this point?
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| # ? Jun 13, 2012 20:53 |
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Pakled posted:So is there anything left of Sapporo at this point? Yes, definitely. Grey isn't bombing nearly hard enough to do more damage than the Japanese can rebuild immediately.
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| # ? Jun 14, 2012 00:20 |
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Log082 posted:Well, I remember someone saying earlier in the thread (and, I think, reading on my own a while ago) that the problem was eventually fixed by bolting an extra plate over the joints that typically cracked, so that would likely point to a design failure, not a materials failure; this is especially true given that the ships pretty much came apart at the joints where they'd been welded. I'd guess, then, that the fatigue problem would have happened eventually anyway, and if anything the extreme cold just made it happen faster, but it's hard to say for certain without more information on just what went wrong. Not in materials science, but did aero engineering at uni. This is something we looked at. It served as a 'poo poo back in the day' example, it was a good explanation of what was happening based on current day experience. Once metals really started to be exposed to high altitude and low earth orbit effects it turned out to be bullshit. It was just bad design.
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| # ? Jun 14, 2012 03:23 |
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All this talk about stress and fractures and metal fatigue reminds me of Italian tanks being riveted together, instead of being welded together. Supposedly British troops could break them apart with a well-placed hand grenade, if they didn't shake themselves apart first when they fired their main gun. I mean, not even the Japanese tiny-tim-tanks were THAT shoddily designed.
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| # ? Jun 14, 2012 04:51 |
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| # ? May 19, 2013 09:54 |
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gradenko_2000 posted:All this talk about stress and fractures and metal fatigue reminds me of Italian tanks being riveted together, instead of being welded together. Supposedly British troops could break them apart with a well-placed hand grenade, if they didn't shake themselves apart first when they fired their main gun. Rivets (apparently) have another issue. If you hit one with a bullet it would send the backside of the rivet flying around on the inside of the tank. O.o
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| # ? Jun 14, 2012 14:48 |
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