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Toxn

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Posts posted by Toxn

  1. On 12/2/2023 at 1:37 PM, Renegade334 said:

     

    The algorithm must be twitchy today - I've had the same videos pop up in my feed.

     

    Of note: the chobham demonstration clearly shows flames and off-gassing by something in the armour (2:02-2:08). The array is also about the right thickness for NERA - around three times that of a bare RHA target.

  2. Time is a strange thing. A few years ago, I put together a weapon for a competition that was intended to be the ultimate in one-upmanship. The Stumpy was basically an armoured brick, armed with a high-velocity 85mm cannon and four 250mm missiles. The missiles were sketched out relatively thinly at the time, and used a combination of open-source rocket calculators and what I'd recently read about how radar systems worked to come up with something plausible.

     

    Flash forward to the present, and I stumble upon a ridiculously detailed article by Iron Drapes on Soviet ATGMs. Besides making me deeply impressed with whoever came up with Metis, this allowed me to connect some dots that I hadn't before. So, in the interests of future competitions, let me lightly re-imagine and flesh out California's most dangerous anti-tank asset:

     

    Ultra-Heavy ATGM, Large Universal Body 

     

    The LUB missile is an ultra-heavy ATGM (or perhaps an anti-tank cruise missile), weighting in at around 95kg with its launch motor (and 80kg in flight). The missile fits in a 250-mm wide box with its wings and tails folded up, the body being a 20x170cm cylinder tapering to an ogive at the tip. The fins are relatively large, as the missile itself travels fairly slowly (around 200m/s in its sustainment stage, dropping to around 100m/s at the very end of its flight profile). Due to the generous size of the wings, the missile flies at a very slight up angle (about 5 degrees). The missile is also somewhat unusual in not rotating in flight. This is because it has a wing and tail fin setup more common to a small aircraft, with elevon and rudder control. The elevons and rudder are actuated by gas-powered actuators housed in the wing roots, fed off of the gas generator assembly that also powers the engine turbopump and electronics. The missile also features a small set of canard wings to help balance out the moment of lift generated by the main wings.

     

    Getting an 80kg missile up to speed is no easy task, so the LUB has a dedicated solid propellant launch motor which mates to the tail of the missile. The motor uses the quasi-recoilless design found on some old soviet missiles, and falls away almost immediately after launch. Once free from the tube, the missile's main engine fires up. Due to some frankly puzzling internal political shenanigans, this is in the form of a small liquid rocket motor burning hydrogen peroxide and kerosene (effectively a scaled-down B.S. 605 RATO unit). The engine produces around 1.3kN of thrust for ten seconds or so, feeding off of two 6.3l oxidiser and fuel tanks (the first ahead of the motor and the second wrapped around it). The engine exhausts directly out of the rear of the missile, and its turbo-pump stage includes a small generator and flywheel to power the electronics.

     

    At the missile's heart sits a frankly enormous 190mm shaped charge, capable of penetrating just over 1m of RHA. It can do so because of the generous stand-off distance built into the missile - the shaped charge shoots through the electronics bay, which is hollow in the centre so as not to disrupt jet formation. Near the tip of the missile is a 75mm precursor charge, itself able to comfortably punch through 400mm of RHA. Both charges are set off by a VT fuze buried in the nose, with the charge timing being handled by the flight computer in the electronics bay. In the event that being able to punch all the way an MBT frontally is not needed, the LUB can also be fitted with a 20kg HE payload, roughly equivalent to two 155m shells. 

     

    The control scheme for the missile is unusual, and relies on a radio beacon buried in the rear of the right wing assembly. This is picked up by a spin-scan receiver mounted on the launch controller, which allows the controller to work out how far off track the missile is. The controller then sends a command signal back to the missile, which is picked up by a directional horn antenna in the back of the left wing assembly. Both the beacon and command signals can be coded to limit jamming. This also allows multiple missiles to be salvo launched and independently guided.

     

    Guidance commands are processed by the flight computer, which uses a pyrotechnically-spun gyroscope to orient the missile. Other sensors include a pitot tube to gauge flight speed. The guidance computer is a marvel of early transistor-era electronics, and is capable of executing various simple flight programs (such as the post-launch program) in addition to its normal operations.

     

    After launch, the missile executes pitch up maneuver and a 45 degree roll to bring the wings to level, Thereafter it levels off to an angle calculated to maintain altitude and waits for the receiver to pick it up. Kinematically, the missile can travel for over 6km, although the CEP increases as range increases. One approach to mitigate this is to have a larger antenna and gunner's spotting telescope, preferably raised off the ground. This allows the missile to be used well beyond the range of any possible return fire, which is useful because of how bulky it is. For vehicle-mounted units where the launch angle can be adjusted, the missile also includes a close in "flying torpedo" mode, where the missile flies straight and level at whatever angle it was launched from. This helps to mitigate the inherent minimum range imposed by the LUB's initial flight profile (around 200-300m), but is quite inaccurate and of dubious value given that the system as a whole is built for long-range fires.

     

    Besides the HE model, there have also been some thoughts given to creating other variants of the LUB for different roles. The missile itself was originally meant to be modular, with various payloads, electronics and engine configurations being swapped in and out as needed. Presently, the only real use of this capability has been to trial a version which uses a more conventional solid rocket motor instead of the very expensive peroxide/kerosene unit used on the base model.

     

    The LUB is a classically Californian product - phenomenally complicated and expensive for what it provides, and saddled with a certain amount of neo-atomic era hubris and corporate nepotism. On the other hand, it effectively performs and end-run around the cycle of escalating armoured vehicle designs (that the PRC was losing), by providing a weapon that can stop all foreseeable threats. It is a demonstration of overkill, with little regard for the concept of "good enough".

     

     

  3. 52 minutes ago, Dominus Dolorem said:

    Does it include aerodynamic simulation?

     

    I have an older copy of X-plane on a disk, would that work?

    That's what makes x-plane unique - it can perform basic aerodynamic simulations and extract a basic flight model out on its own.

     

    IIRC, older X-plane models don't work in X-plane 10 or 11.

  4. 17 hours ago, Dominus Dolorem said:

    If I may ask, how would one go about designing a plane and it's missiles?

     

    Which simulation programs will be used?

    The plan right now is to use X-plane, which is a flight simulator that includes a designer function. The designer also includes some stock weapons that you can add - but you can design missiles for it too.

     

    The two issues are that X-plane is typically quite expensive to get a hold of, and the learning curve on the plane designer is steep.

  5. A rare point of unqualified praise for WW2 German vehicles, and especially anything touched by Kniepkamp:

     

    PzIII_cut.jpg

     

    The layout of the Pz III is compact and efficient given the components it carried. So I can see why the engineers pinned so many hopes on making it the only medium tank in production, especially when compared to the zoo that the Germans ended up with in practice. Pity about the small turret ring, though. And the endless issues in getting the suspension and transmission right.

  6. This one might have been LoooSeR'd already:

     

    It's strange - I'm a military gear nut in many ways, but seeing the gear in action is always chilling for me. It's way too easy to imagine the panic of those tank crewmen as they frantically looked this way and that through the tiny fields of view afforded by their optics. And then they died horribly to a vehicle that they probably only caught sight the moment before it fired at them.

  7. On 11/20/2021 at 2:03 AM, Sturgeon said:

     

    Next full comp, which will be no earlier than next year, will be a strike fighter competition.

    So I finally got a copy of X-plane 11 (thanks steam sales!) and have been looking through the plane designer that comes with the game (https://developer.x-plane.com/manuals/planemaker/). 

     

    Although I haven't fiddled around too much with it yet, it seems to be perfectly feasible to use it to design aircraft for competitions. I had hoped that we could run a competition using paper designs, select the finalists and then build and compare them in X-plane (saving everyone the hassle of all having a copy of the game in order to participate), but looking into the details of how the plane maker works this probably won't be possible.

  8. I got GHPC and am currently playing Warpact. So far the game has firmly convinced me of the merits of laser rangefinders, thermals and good fire control in general, and made me annoyed that whatever side you're playing suddenly becomes as dumb as a brick for some reason when playing randomly-generated campaign missions. AI vehicles on your team (at least the ones that you're not immediately leading) will just sit there, while the enemy actually maneuvers. So presently the only way to succeed in by frantically hopping from platoon vehicle to platoon vehicle to shuffle all the units about.

     

    If they ever get around to giving all the vehicles commander's instructions (presently only available for M60, M1 and M2), putting in more dynamic environmental opponents (dismounted infantry, aircraft, artillery etc), making the maps more usable, allowing units to inform each other of things via radio, and making your own AI buddies a bit less dumb, then it could be an amazing game.

  9. On 8/20/2022 at 12:47 AM, Lord_James said:


    I probably don’t remember enough of the movie to comment, but I do remember that a major plot point was the bad guy was making people blow up with his “miracle cure” or whatever. I may or may not have fallen asleep for the rest of the movie. 

    Yeah, as a side effect of unlimited energy/virus/etc.

     

    A movie where the villains are literally growing bombs inside themselves (complete with uncanny pregnancy and tumour imagery; intense hunger for protein, nitrogen and energy sources; wasted limbs etc) would be positively Cronenbergian.

  10. On 8/20/2022 at 5:24 PM, Jeeps_Guns_Tanks said:

    I hope it is time for this men in tights movies, this super hero bullshit, to die, like Vampire and Zombie movies.  

     

    We need more movies like Topgun Maverick, where the airplane is the hero, not some degenerate in tights.

    I haven't seen the new one, so I can't comment on that, but I thought that shirtless volleyball was the hero in Top Gun?

  11. 6 hours ago, Lord_James said:


    Wasn’t this the plot to iron man 3?

    No, that was more "mumble mumble virus.... mumble infinite energy... blah blah regeneration... bullshit".

     

    Dudes regrowing limbs on the fly and heating up hot enough to palm-slice through steel is solidly on the fantasy biology end of things.

  12. Relatedly, I've seriously thought about trying to found high-energy biology as a field:

    https://xkcd.com/2656/

     

    As a post-graduate, I looked into the possibility that plant nitrating enzymes (eg: the whole nitrate reductase pathway) along with plant tissue specific promoters could be used to effectively grow a bomb. It wasn't very serious enquiry or anything, but as far as I can tell it's a perfectly feasible project to carry out.

  13. 12 hours ago, LoooSeR said:

    Both of those are fairytale stuff. Would like to see more serious take on that concept.

    I've actually wanted to have a go at a more scientifically-grounded version of Tyranids/Zerg, but I suspect that once you try to do so the result looks nothing like the material it is based on.

  14. I remember being struck by the idea of an alien ecosystem (in a book whose name I absolutely cannot remember and cannot find online) where multiple ecosystems exist on the same planet as effectively giant organisms in their own right. So the characters are traipsing through and amongst what amounts to the cells of a continent-sized body.

  15. 2 minutes ago, TINDALOS said:

    Although I'm not a fan of Putin and definitely not a fan of Assad, Xi, Lukashenko etc, I still appreciate how the whole "liberal rule based international world order" got slowly debunked and dismantled in recent years... I would like to see those Pax Americana preachers' emotion after maybe one month.

    See, I think we'll miss the concept once it's gone and we go back to the 18th or 19th centuries.

     

    But goddamn was its biggest exponent also the biggest hypocrite.

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