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Collimatrix

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Everything posted by Collimatrix

  1. Collimatrix
    Ah, so that does sound like flash processing, or something fairly similar to it. I am... not entirely clear on how flash processing works, chemically speaking. You can do some interesting things with it that do not make sense to me. The nanostructured bainite that has been of interest for armor applications lately has an extremely lengthy heat treatment process that requires that the steel be held at temperature for multiple days. But flash bainite processing can produce a comparably strong microstructure in mere seconds. Given how bainite actually forms, I don't understand how this is not just magic.
  2. Collimatrix
    I'm not sure if strong conclusions can be taken from that one video. Different ammo types produce radically different amounts of recoil. Discarding sabot training ammo doesn't produce too much recoil, while HE-FRAG is firing a big, heavy shell with a lot more momentum. Aside from that, it occurs to me that the 120mm armed tanks listed are all heavier than the 125mm armed ones, although the weight of the K2 and T-14 overlap. How a tank responds to the recoil of its gun firing is a function of the total momentum of the shot, the mass of the vehicle, the moment of inertia about the recoil axis (which is affected by which way the turret is facing), suspension stiffness, suspension damping, and recoil system length and forces. You are correct in thinking that the stabilizer doesn't have very much to do with it. In addition, I suspect that the K2 may enjoy very low recoil when firing from a stationary position, as it has adjustable suspension. The rear hydropneumatic stations can be filled with additional gas pressure, which increases the K* of the stations, which reduces the amount that the tank rocks when firing provided the gun is pointed more or less forward. The most effective way for light vehicles to deal with high trunnion loads from their cannons is to have very long recoil lengths for their cannons' recoil systems, but this comes at a cost. The longer the recoil path of the cannon, the more empty space needs to be reserved to accommodate the movement of the breech. This makes the turret more voluminous and taller. I don't think that it's a significant cost driver. *Compressed gas doesn't act exactly like a spring, but close enough.
  3. Collimatrix
    Aha, I stand corrected.
  4. Collimatrix
    Rough translation anyone? This looks like flash processing to me.
  5. Collimatrix
    Agreed. It's a bit puzzling that MPF has escaped the axe, but OMFV didn't.
  6. Collimatrix
    Very interesting, thank you!
  7. Collimatrix
    At the behest of @Lord_James, this shall be the thread for general discussion of conventional passive metallic armor. Whether it's steel, titanium, magnesium, exotic laminates of all three, this is the thread for it. In answer to your earlier question, Lord_James, relatively small amounts of boron, in steels that have the appropriate levels of carbon, form intergranular barriers that dramatically slow the diffusion of carbon out of the austenite crystals during quenching. Long story short, this means that the depth of material that can be effectively hardened is much greater.
  8. Collimatrix
    One of the persistent mysteries I am trying to solve is why exactly the Swiss purchased the Dragon ATGM system, which was a pile of crap, when MILAN existed, which is only a few pounds heavier and also actually works. I found this publication, which contains an article on Swiss bicycle troops. As of 1994, the Swiss had three entire regiments of bicycle infantry. I thought this might be an answer; even though MILAN is only a little heavier than Dragon, for a bicycle-borne infantryman, a few pounds could make the difference. But no, this is not the explanation. The article states that the antitank companies of the bicycle regiments were motorized.
  9. Collimatrix
    Indeed. Most of the early work on what would become the HK and CETME family of rifles was initially done in France by ex-Mauser employees. They later moved to Spain, which they seem to have preferred for its relaxed economic protectionism, drier climate, and slightly fascist dictatorship.
  10. Collimatrix
    Small wheels also have higher rolling resistance, and at high speeds tend to wear their rubber out faster.
  11. Collimatrix
    Interesting. The long pitch tracks I knew about, although there are practical limitations there, as the longer pitch tracks tend to be noisier and wear out faster. The pneumatic road wheels are, I must admit, a surprise. Do you have a link?
  12. Collimatrix
    Apparently the British goofed around with interleaved road wheels, albeit because they cloned captured German half-tracks.
  13. Collimatrix
    Holy shit, it's SuperComrade!
  14. Collimatrix
  15. Collimatrix
    Ah, yeah, that's not great metallurgy for tank armor by postwar standards, but it definitely sounds like they had big enough foundries to make the parts. I did not realize that the Czech T-72 turrets were domestically produced!
  16. Collimatrix
    What was the state of Czech casting foundries at the time? IIRC, the big cat mantlets were the biggest armor castings the Germans could make.
  17. Collimatrix
    I had heard vaguely that a design concept for the Czech post-war TVP project was mocked up with interleaved road wheels, but that this was rejected. I never saw a picture or anything. So, yeah, a napkin drawing of a napkin drawing, according to rumor. Post-war, most designers seem to have been content with other ways of reducing the MMP of their tanks.
  18. Collimatrix
    What report is that from? I would be very interested to see the whole thing if you have it. I did find this picture of a TOW missile in flight, you can see it's significantly nose-up: Edit: Derp, I just posted the same picture you found.
  19. Collimatrix
    If you'd done several seconds of research you would know that this isn't true, and would have avoided looking like an idiot. Do you have a humiliation fetish or something? The additional height of a torsion bar isn't the diameter of the torsion bar itself. Torsion bars almost never touch the floor of the hull. It's almost like they need big bearings for the swing arms or something. Again, you need only have taken several seconds to ascertain whether this was true or not. For the love of Robert Hooke, that's not what "strain" means.
  20. Collimatrix
    A patent that looks like it might be for the SU-57 air intake: https://patents.google.com/patent/RU2460892C1/ru Very interesting shock wave geometry.
  21. Collimatrix
    You categorically do not understand what you're talking about. That's not the theory at all. I'm slightly curious if you read this nonsense somewhere or came up with it on your own, but only slightly curious, so please don't belabor me with a large amount of detail. Having more points of articulation on a suspension does not affect the force experienced by the chassis or crew. When the tank is at rest the road wheels will exert the tank's weight against the ground via the suspension springs. When the tank is going over an obstacle, the vertical component of the acceleration will be buffered by the travel of the independent suspension stations. If there are more of these stations, then they will have lower K values of their springs, otherwise the suspension would just get stiffer from having more stations. There will be a very slight difference in response from having more unsprung mass. Having more points of articulation does increase the tendency for the tank to pitch in response to acceleration and deceleration, but for the number of roadwheels typical for tanks this distinction is immaterial. Interleaved roadwheels are equivalent to overlapped ones in terms of ground pressure reduction. Point me to any serious engineering analysis that says otherwise. You need to learn that words mean things. "Strain" has a very specific, mathematical meaning, and you are badly abusing the word here.
  22. Collimatrix
    Thank you very much!
  23. Collimatrix
    Does anyone have a copy of History of the Shillelagh Missile System? The original link to it on the Redstone Arsenal page is dead.
  24. Collimatrix
  25. Collimatrix
    Chinn has this to say: "If it were possible, it would be highly desirable to be able to compute exactly what size and shape of orifice should be used, or to know in advance how the configuration of the passage leading from the barrel to the gas cylinder will affect the variation of the cylinder pressure with respect to time. Unfortunately, accurate solutions to these problems and to problems of a similar nature can not be obtained analytically because of the complexities involved in predicting the flow of the turbulent and high velocity gases produced by the propellant explosion." I suspect that such analysis could be done today with computer voodoo, but that for the vast majority of existing gas operated designs, the engineers applied some rules of thumb to get themselves close, and then iterated from there.
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