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  1. Found a few higher resolution photographs from the recent North Korean military parade. We didn't have a topic for BEST KOREAN armored fighting vehicles, so here it is. New main battle tank, Abrams-Armata clone based on Ch'ŏnma turret design (welded, box-shaped turret) and Sŏn'gun hull design (i.e. centerline driver's position). The bolts of the armor on the hull front is finally visible given the increased resolution. It might not be ERA given the lack of lines inbetween. Maybe is a NERA module akin to the MEXAS hull add-on armor for the Leopard 2A5? Other details include an APS with four radar panels (the side-mounted radar panels look a lot different - and a lot more real - than the ones mounted at the turret corners) and twelve countermeasures in four banks (two banks à three launchers each at the turret front, two banks à three launchers on the left and right side of the turret). Thermal imagers for gunner and commander, meteorological mast, two laser warning receivers, 115 mm smoothbore gun without thermal sleeve but with muzze reference system, 30 mm grenade launcher on the turret, six smoke grenade dischargers (three at each turret rear corner) IMO the layout of the roof-mounted ERA is really odd. Either the armor array covering the left turret cheek is significantly thinner than the armor on the right turret cheek or the roof-mounted ERA overlaps with the armor. The first ERA/armor element of the skirt is connected by hinges and can probably swivel to allow better access to the track. There is a cut-out in the slat armor for the engine exhaust. Also note the actual turret ring - very small diameter compared to the outer dimensions of the turret. Stryker MGS copy with D-30 field gun clone and mid engine: Note there are four crew hatches. Driver (on the left front of the vehicle), commander (on the right front of the vehicle, seat is placed a bit further back), gunner (left side of the gun's overhead mount, next to the gunner's sight) and unknown crew member (right side of gun's overhead mount with 30 mm automatic grenade launcher mounted at the hatch). The vehicle also has a thermal imager and laser rangefinder (gunner's sight is identical to the new tank), but no independent optic for the commander. It also has the same meteorological mast and laser warner receivers as the new MBT. What is the purpose of the fourth crew member? He cannot realistically load the gun... The vehicle has a small trim vane for swimming, the side armor is made of very thin spaced steel that is bend on multiple spots, so it clearly is not ceramic armor as fitted to the actual Stryker. The tank destroyer variant of the same Stryker MGS copy fitted with a Bulsae-3 ATGM launcher. Note that there is again a third hatch with 30 mm automatic grenade launcher behind the commander's position. Laser warning receivers and trime vane are again stand-out features. The sighting complex for the Bulsae-3 ATGMs is different with a large circular optic (fitted with cover) probably being a thermal imager and two smaller lenses visible on the very right (as seen from the vehicle's point of view) probably containing a day sight and parts of the guidance system. Non line-of-sight ATGM carrier based on the 6x6 local variant of the BTR, again fitted with laser warning receivers and a trim vane. There are only two hatches and two windows, but there is a three men crew inside. There are a lot more photos here, but most of them are infantry of missile system (MLRS' and ICBMs).
  2. Well, if you include TUSK as armor kit for the Abrams, then you also have to include the different Theatre Entry Standards (TES) armor kits (three versions at least) of the Challenger 2. The base armor however was most likely not upgraded. The Leclerc is not geometrically more efficient. It could have been, if it's armor layout wasn't designed so badly. The Leclerc trades a smaller frontal profile for a larger number of weakspots. It uses a bulge-type turret (no idea about the proper English term), because otherwise a low-profile turret would mean reduced gun depression (breech block hits the roof when firing). There is bulge/box on the Leclerc turret roof, which is about one feet tall and located in the centerline of the turret. It is connected to the interior of the tank, as it serves as space for the breech block to travel when the gun is depressed. With this bulge the diffence between the Leopard 2's and Leclerc's roof height is about 20 milimetres. The problem with this bulge is, that it is essentially un-armored (maybe 40-50 mm steel armor); otherwise the Leclerc wouldn't save any weight. While the bulge is hidden from direct head-on attacks, it is exposed when the tank is attacked from an angle. Given that modern APFSDS usually do not riccochet at impact angles larger than 10-15° and most RPGs are able to fuze at such an angle, the Leclerc has a very weakly armored section that can be hit from half to two-thirds of the frontal arc and will always be penetrated. The next issue is the result of the gunner's sight layout. While it is somewhat reminiscent of the Leopard 2's original gunner's sight placement for some people, it is actually designed differently. The Leopard 2's original sight layout has armor in front and behind the gunner's sight, the sight also doesn't extend to the bottom of the turret. On the Leclerc things are very different, the sight is placed in front of the armor and this reduces overall thickness. This problem has been reduced by installing another armor block in front of the guner's sight, but it doesn't cover the entire crew. The biggest issue of the Leclerc is however the gun shield. It's tiny, only 30 mm thick! Compared to that the Leopard 2 had a 420 mm gun shield already in 1979. The French engineers went with having pretty much the largest gun mantlet of all contemporary tanks, but decided to add the thinnest gun shield for protection. They decided to instead go for a thicker armor (steel) block at the gun trunnions. Still the protection of the gun mantlet seems to be sub-par compared to the Leopard 2 (420 mm armor block + 200-250 mm steel for the gun trunion mount on the original tank) and even upgraded Leopard 2 tanks. The Abrams has a comparable weak protected gun mantlet, but it has a much smaller surface. The Challenger 2 seems to have thicker armor at the gun, comparable to the Leopard 2. Also, the Leclerc has longer (not thicker) turret side armor compared to the Leopard 2 and Challenger 2, because the armor needs to protect the autoloader. On the other tanks, the thick armor at the end of the crew compartment and only thinner, spaced armor/storage boxes protect the rest of the turret. So I'd say: Challenger 2: a few weakspots, but no armor upgrades to the main armor Leclerc: a lot of weakspots, but lower weight and a smaller profile when approached directly from the turret front M1 Abrams: upgraded armor with less weakspots, but less efficient design (large turret profile and armor covers whole turret sides) So if you look for a tank that is well protected, has upgraded armor and uses the armor efficiently, the current Leopard 2 should be called best protected tank.
  3. The LORD was with the men of Deseret. They took possession of the hill country, but they were unable to drive the people from the plains, because they had chariots of steel. —The Book of Latter Day Saints, Ch 8, vs. 3:10, circa 25th Century CE BULLETIN: ALL INDUSTRIAL-MECHANICAL CONCERNS SOLICITATION FOR ALL-TERRAIN BATTLE TANK The Provisional Government of the Lone Free State of Texas and The Great Plains issues the following solicitation for a new All-Terrain Battle Tank. The vehicle will be the main line ground combat asset of the Lone Free State Rangers, and the Texas Free State Patrol, and will replace the ageing G-12 Scout Truck, and fill the role of the cancelled G-42 Scout Truck. The All-Terrain Battle Tank (ATBT) will be required to counter the new Californian and Cascadian vehicles and weapons which our intelligence indicates are being used in the western coast of the continent. Please see the attached sheet for a full list of solicitation requirements. Submissions will be accepted in USC only. Supplementary Out of Canon Information: I. Technology available: a. Armor: The following armor materials are in full production and available for use. Use of a non-standard armor material requires permission from a judge. Structural materials: i. RHA/CHA Basic steel armor, 360 BHN. The reference for all weapon penetration figures, good impact properties, fully weldable. Available in thicknesses up to 4 inches (RHA) 8 inches (CHA). Density- 0.28 lb/in^3. ii. Aluminum 5083 More expensive to work with than RHA per weight, middling impact properties, low thermal limits. Excellent stiffness. Fully weldable. Available in thicknesses up to 4 inches. Mass efficiency vs RHA of 1 vs CE, 0.9 vs KE. Thickness efficiency vs RHA of 0.33 vs CE, 0.3 vs KE. Density- 0.1 lb/in^3 (approx. 1/3 of steel). For structural integrity, the following guidelines are recommended: For heavy vehicles (30-40 tons), not less than 1 in RHA/1.75 in Aluminum base structure For medium-light vehicles (<25 tons), not less than 0.5 in RHA/1 in Aluminum base structure Intermediate values for intermediate vehicles may be chosen as seen fit. Non-structural passive materials: iii. HHA Steel, approximately 500 BHN through-hardened. Approximately 1.5x as effective as RHA against KE and HEAT on a per-weight basis. Not weldable, middling shock properties. Available in thicknesses up to 1 inch. Density- 0.28 lb/in^3 iv. Fuel Mass efficiency vs RHA of 1.3 vs CE, 1 vs KE. Thickness efficiency vs RHA of 0.14 vs CE, 0.1 vs KE. Density-0.03 lb/in^3. v. Assorted stowage/systems Mass efficiency vs RHA- 1 vs CE, 0.8 vs KE. vi. Spaced armor Requires a face of at least 1 inch LOS vs CE, and at least 0.75 caliber LOS vs fullbore AP KE. Reduces penetration by a factor of 1.1 vs CE or 1.05 vs KE for every 4 inchair gap. Spaced armor rules only apply after any standoff surplus to the requirements of a reactive cassette. Reactive armor materials: vii. ERA A sandwich of 0.125in/0.125in/0.125in steel-explodium-steel. Requires mounting brackets of approximately 10-30% cassette weight. Must be spaced at least 2 sandwich thicknesses away from any other armor elements to allow full functionality. 81% coverage (edge effects). viii. NERA A sandwich of 0.25in steel/0.25in rubber/0.25in steel. Requires mounting brackets of approximately 10-30% cassette weight. Must be spaced at least 1 sandwich thickness away from any other armor elements to allow full functionality. 95% coverage. The details of how to calculate armor effectiveness will be detailed in Appendix 1. b. Firepower i. Bofors 57mm (reference weapon) - 85,000 PSI PMax/70,000 PSI Peak Operating Pressure, high quality steel cases, recoil mechanisms and so on are at an equivalent level to that of the USA in the year 1960. ii. No APFSDS currently in use, experimental weapons only - Spindle sabots or bourelleted sabots, see for example the Soviet BM-20 100mm APFSDS. iii. Tungsten is available for tooling but not formable into long rod penetrators. It is available for penetrators up to 6 calibers L:D. iv. Texan shaped charge technology - 4 CD penetration for high-pressure resistant HEAT, 5 CD for low pressure/ precision formed HEAT. v. The subsidy-approved GPMG for the Lone Free State of Texas has the same form factor as the M240, but with switchable feed direction.. The standard HMG has the same form factor as the Kord, but with switchable feed direction. c. Mobility i. Engines tech level: 1. MB 838 (830 HP) 2. AVDS-1790-5A (908 HP) 3. Kharkov 5TD (600 HP) 4. Detroit Diesel 8V92 (400 HP) 5. Detroit Diesel 6V53 (200 HP) ii. Power density should be based on the above engines. Dimensions are available online, pay attention to cooling of 1 and 3 (water cooled). iii. Power output broadly scales with volume, as does weight. Trying to extract more power from the same size may come at the cost of reliability (and in the case of the 5TD, it isn’t all that reliable in the first place). iv. There is nothing inherently wrong with opposed piston or 2-stroke engines if done right. d. Electronics i. LRFs- unavailable ii. Thermals-unavailable iii. I^2- Gen 2 maximum vi. Texas cannot mass produce microprocessors or integrated circuits vii. Really early transistors only (e.g., transistor radio) viii. While it is known states exist with more advanced computer technology, the import of such systems are barred by the east coast states who do not approve of their use by militaristic entities. Armor calculation appendix. SHEET 1 Armor defeat calculator 4in-54 1200 yd SHEET 2 Armor defeat calculator 4in-54 2000 yd SHEET 3 Armor defeat calculator 6in HEAT Range calculator
  4. Just read the following: https://www.ukrinform.net/rubric-ato/3667929-rheinmetall-in-talks-with-kyiv-on-supply-of-panther-tanks.html
  5. Inspired by Collimatrix's excellent topic in the Aviation section, my attempt at doing the same for tanks. Tank design is often represented as a trade-off between firepower, armour, and speed. But this ignores many other, equally important variables. Furthermore, this formula doesn't explain why the trade-offs are there in the first place. So here is my attempt to make things a bit more complicated. The Constraint: Compact, powerful and reliable engines – and the ability to use them Firepower and armour are the obvious features that made a 1940 tank obsolete in 1945. Yet even a 1945 tank is trivial compared to a WWI battleship. Or more modestly, the German 88mm, Soviet 85mm and US 90mm AA guns were prewar designs. Why not put them on a tank from the beginning? Were people just stupid back then? Up to a point, I would say ‘yes’. While it is unrealistic to think of 1945 combat aircraft, radar, or nuclear weapons in 1940 as the result of anything short of time travel, 1940 tanks could have been significantly better without anachronistic scientific or engineering breakthroughs. Like the assault rifle, this really was a case where the right people just didn't see the need or spend the money. However, it's not the only reason. A tank with a big gun and thick armour that can't move is just a pillbox. Like aircraft, WW2 tanks were fundamentally limited by their engine power. This is less obvious because additional power was typically used to ‘buy’ weight rather than speed. Yet the trend is clear. Shown below are the improvements in engine power for the German and British (cruiser) tank lines, which were in the war the longest. German Panzers I 100 hp II 138 hp III, IV 250-300 hp Tiger, Panther 690 hp British Cruisers I, II 150 hp III, IV, Crusader 340 hp (Liberty) Cromwell, Comet 600 hp (Meteor) Arguably, more powerful tank engines could and should have been introduced much earlier (the Liberty was first used in a tank as early as 1918). I will leave that aside, noting only that, relative to aircraft engines, tank engines were forced to use lower octane fuel for economic reasons (preventing tank use of the Napier Lion), and are harder to cool due to being inside a slow moving armoured box (this was a particular challenge with the Merlin's conversion to the Meteor). There's also the choice of diesel (compression ignition) vs. petrol/gasoline (spark ignition) engines. Diesels had higher torque and lower fuel consumption, but lower specific power, were heavier and cost more, and meant an extra type of fuel in your logistics train. Both Germany and the US decided against diesels for fear sufficient fuel would not be available. Once you have an engine, you still need to put power to the wheels through what the British call a ‘transmission’ and Americans call a ‘drivetrain’, which also does the steering since almost all tanks turn by making one track spin faster than the other. And you need a track that won't fall apart and a suspension that will stop the occupants falling apart. These were big problems during WW1 – the first tanks had no suspension at all! – and into the 1920s, but by the 1930s you could more or less use the power of the available engines. Even in 1945, however, the Panther and Comet were deliberately speed limited to around 30 mph. TRADE-OFFS OK, we have an engine of a given horsepower, and the ability to turn that horsepower into forward motion off-road with an acceptable degree of unreliability and discomfort. What choices do we have to make now? 1. Weight vs. mobility This is almost self-explanatory, but mobility is more than speed. Very roughly, multiplying the hp/ton ratio by two gives an approximate top road speed in mph, although looking at individual types this correlation is surprisingly loose. The 15 mph of the British infantry tanks was annoyingly slow, the 25 mph of most German tanks seemed good enough, and as mentioned above, anything over 30 mph arguably wore out the running gear and the occupants to little benefit. A high power-weight ratio was also useful to provide rapid acceleration to dash from cover to cover. But weight has other penalties that are less amenable to increased engine power: Reliability and maintenance time – pushing around more weight means more parts everywhere from the engine to the suspension will break. (US tracks lasted about 6000km on light tanks but only 2400km on medium tanks. See Exercise Dracula for the effect of maintenance downtime on overall mobility.) Fuel consumption – less range for the individual tank, more for the logistics train to haul. Bridging – if you can’t cross a bridge without breaking it, you may have to go a much longer long way round. Shipping – the M6 heavy tank was not adopted partly because it exceeded the 40-ton limit on many dockyard cranes. Tanks that were kept in service a long time such as T-34 and Panzers III and IV tended to creep up in weight as bigger guns and frontal armour were added, but for new designs bigger engines and better transmission, steering and track technology (and bridge building) roughly kept pace. Except when they didn't. 2. For a given weight: armour vs. internal volume The basic choice is a smaller box with thicker armour or a bigger box with thinner armour. Similarly, sloped armour will give more protection for a given weight, but reduces the internal volume. At the start of the war, most countries tried to armour the front, sides, and even rear to a similar standard, using mostly vertical armour. As (anti-)tank guns got more powerful, this became impractical, and focus shifted to improving the front armour, both by increasing thickness and sloping (sloping all round reduced the volume of the tank excessively, as in the pyramid shaped early T-34s). 3a. For a given volume: guns vs. crew vs. ammo vs. suspension... Everyone wants a bigger gun, but you need to fit other things in too. For example, a three-man turret crew (commander, gunner, loader) worked better than one or two men, because everyone could focus on one job. But when the British upgunned their Crusader and Valentine tanks from 2-pdr to 6-pdr guns, there was not enough room in the turret for the third man. Of course, if you run out of ammo, or your crew are bumping into something every time they move, your tank will not fight very well either. (A bigger gun has a double penalty: it reduces the room for other things, including ammo, and also makes each round bigger. The IS-2 looks stunning on paper, but remember that 122mm gun only has 28 rounds and has a slower rate of fire due to its separate loading ammunition.) The Soviets limited the height of their tank crews for this reason. If you just want to shoot an enemy soldier or two, the main gun is overkill, so almost all tanks have a ‘coaxial’ machine gun next to it in the turret. Is it worth having a second machine gun in the hull and someone to shoot it? This was nearly universal during the war but fell out of fashion soon afterwards, as bigger guns needed more room for ammunition. (I also imagine most people trying to sneak up on a tank didn't do so from the front.) A few designs even had little secondary MG turrets, a hangover from prewar, but these were quickly abandoned. Tank suspension is a whole topic of its own. Broadly the choice was between types that allowed more independent wheel movement for a better ride but took up valuable room inside the tank (and were harder to repair in the field) like Christie and torsion bar, and types that gave a worse ride but were completely external (and easier to repair) like VVSS/HVSS, leaf spring and Horstmann. Also, lots of small wheels are better to spread weight evenly and not sink into mud or snow, but fewer bigger wheels are better if you want to drive fast over bumps. The Germans tried to have the best of both worlds with many overlapping large wheels, which was complicated and tended to freeze solid in the Russian winter. And obviously you need fuel, and a radio or two, a boiler for tea if you're British, compressed air tanks for cold weather starts if you're Russian, and other stuff I haven't mentioned or thought of... 3b. For a given volume: height vs. width A taller tank is easier for the enemy to spot. A wider tank lets you have a bigger turret ring and therefore a bigger gun. So it seems like a low, wide tank is the ideal. But make your tank too wide and it can't fit on railways – the British were particularly constrained with a narrow railway loading gauge, but even the Germans had to put narrower tracks on their Tigers and Panthers to transport them by rail – or narrow roads and bridges. Also, height allows more ground clearance to get over obstacles and greater gun depression to shoot at the enemy while hull down. Finally, height can actually substitute for width to some extent in fitting a bigger gun: a tall hull as in the Sherman allows the turret ring to be extended over the tracks, or a tall turret as in the Challenger (and later Strv 74) allows the gun to recoil (and the crew to squeeze in) above the turret ring. Length tends to be the residual in the equation, within limits - too long and you can't steer, too short and the crew gets motion sickness. The Sherman was stretched as required to go from short radial to longer inline engines. Similarly the Challenger was basically a stretched Cromwell. 4. For a given sized turret/gun: AP vs. HE Tanks sometimes shoot at enemy tanks, but mostly at other, softer things. If you need to punch through armour with AP rounds, you want a high velocity gun (penetration increases with roughly the square of the velocity, but only linearly in calibre). If you want to blow things up, it's all about calibre (HE capacity increases with the cube of calibre, or even a bit more when you consider the minimum size of the fuze and thickness of the shell wall). So for a gun that will fit in a given sized turret, you can have a smaller calibre high velocity hole puncher or a larger calibre, low velocity HE lobber. While you can build specialised guns for each job (and even different tanks to put them in, as the Germans did, which is going a bit far), it's better to have one kind of gun that can do both reasonably well in most of your tanks, since you never know what they will run into. Conveniently, while tank armour increased throughout the war, common building materials and the human body stayed the same. Therefore, while AP rounds needed ever greater performance, HE didn't. Around 3 inch calibre, with increasing velocity as the war went on, proved a good compromise. The Americans and British both picked the medium velocity 75mm over the high velocity 6-pdr, as did the Soviets with the 76.2mm over their own 57mm AT gun. The higher velocity 76mm, 17-pdr and 77mm then gave the needed AP upgrade while the Soviets went for 85mm (probably because they already had the AA gun rather than any ideal calibre calculation). The Germans also ended up with high velocity 75mm guns on most of their late war tanks (except the 88s on the Tigers, again copied from the AA calibre). 5. For a given budget: quality vs. quantity Obviously, a bigger tank uses more steel and other resources, and fancy gadgets like better radios, optics and steering systems have a cost. The Tiger was hugely expensive compared to the German mediums (and, more speculatively, other countries' tanks). The Panther was surprisingly cheap for its size, but partly by skimping on the final drive, which crueled its reliability. This trade-off applies to distribution as well as production. If you need to move your tanks across the ocean like the Americans, or even by rail across the steppe like the Germans and Soviets, a bigger and better tank at the factory gate meant fewer delivered to the battlefield for the same freight tonnage. So we are back where we started with weight vs. mobility, except in terms of numbers rather than the individual tank's capability.
  6. Hi there! I'm a new user, and found this forum by way of a video on the so-called "reformers". The video also included a screencap of a thread in this forum about some guy called "Black Tails Defense" or something, in which the strangest tank was shown- something with a 145 millimeter... howitzer? The... sheer tomfoolery of putting a long-barrel world war one era howitzer with eighty rounds of ammunition in a forty-ton vehicle somehow designed to also float... I personally enjoy entertaining the concept of designing fictional tanks for fictional universes. However, I'm critically aware of how limited my knowledge on this subject is. Honestly, I was more really concerned with the external appearance of the tank to look as "realistic" as possible- no shot traps, no funny "turrets" like on whatever that Scorpion-thingy from HALO was, as well as worrying about details like how to make sure the tank doesn't break down mid-combat and the placement of critical systems like Optics, but I'd also like to know what kind of systems should you use (e.g. Turbine or Diesel, Horstmann or Torsion bar, etc etc) There's a little thing that I'm doing where I draw up tanks et cetera within the confines of Mid-Late 80s-90s - early 2000s doctrine, and I'd like to ask you, what makes a real tank tick for tanks of this era? How should you go about designing a tank? I'm aware of the fact that one should always design inside-up (critical components such as engine, gun, et cetera up), but what are some of the caveats and nuances inevitably intertwined into it? How should one go about the design process for designing a tank? What's a rough list of features you want to have, and others that you can sacrifice for any given role of a tank? I'm aware that this is like asking, "what should I put on a plane", but let's assume that it's for a tank stuck in, say, the Mid-late nineties, around the Gulf War - Kosovo period. Also, in addition to this, some common questions that I'd also like settled are; - Diesel, Turbine, or Petrol? Where/When/How should these engines be implemented? - Rifle or Smoothbore? This debate goes on forever and I'd like some sort of concrete answer. As far as I know, the only forces that use rifled guns use them either out of necessity or reliance on a certain specific type of round. - Why in god's name would you ever put a 145 millimeter howitzer on a tank? - Caliber: Is there an upper limit? Is it really worth going above 120mm/maybe 130mm at a stretch when combat won't even happen above the ranges that these guns are effective due to the distances that you can see with optics? At range, Artillery and Missiles have traditionally been more efficient. - Whither the Autoloader, or Nay? I've seen the Chieftain's video on it, but I personally would like your opinions on it. - Barrel loaded ATGMs- are they really all that they're cracked up to be? Why/why not? I'd like to strickly restrict this to Main Battle Tanks, as I'd rather ask about Infantry Fighting Vehicles later, in another thread. In short, how the 1990s Tank? Sincerely yours, Aussie_Mantis
  7. You've seen them before; poorly edited videos with an alternating loop of John Phillips Sousa and Weird Al, purporting to tell you about the various design mistakes armored fighting vehicle designers have made over the years: But does the maker of these videos one Blacktail Defense, know shit about AFV design himself? Haha, no, no he does not. Because of Sturgeon's House strict hate-speech enforcement laws, I am compelled to mention that Blacktail Defense is a furry. So know that should you click any of the links to his material, you will need to decontaminate yourself per protocol DG-12-23A with bleach. Blacktail Defense is a military reformer, a storied and interesting political movement in the United States that has gone from being a force of some consequence to being a ragtag group of scoundrels. I'm not going to say that they weren't idiots and scoundrels when they were of consequence, n.b. Military reformers are at they're strongest when they're on the attack. They're a lot like creationists that way; when they can hurl invective at (mostly imaginary) weaknesses within whatever it is they hate, they can look like concerned citizens campaigning for the taxpayer's right to have their money spent wisely and the soldier's right to have the best practical equipment. But give a military reformer some lined paper and a slide rule and tell them to come up with a design, rather than tear down an existing one, and you will quickly see that these people have no idea what they're talking about. Ready? This is taken directly from Blacktail's furaffinity page. Careful analysis shows that, no, this man has no idea what the everliving fuck he's talking about. Are you ready? No, you're not, but let's go ahead anyway. "The Tigerwolf may look vaguely similar to contemporary MBTs, such as the ubiquitous M1-series Abrams, but is in fact wrapped around a lot of design features and technology that are comlpetely alien to today's tanks." Blacktail is going to prove to you that he's a better tank designer than all those idiots at Chrysler by designing a tank using technologies that didn't exist at the time of the design of the Abrams. "For starters the crew is quite large, with a Commander, Driver, Gunner, TWO loaders, and an Engineer. Many designers favor a smaller crew, usually adding an autoloader to eliminate the Loader from the crew (like in the Russian T-64 through 90, the French Leclerc, and the Chinese Type 85 through 99)." ... What? "However, there are a lot of problems with a smaller crew. First, autoloaders work at a painfully slow pace (14 seconds to reload in a T-72), which gives manual-loading tanks a huge rate-of-fire advantage (just 4 seconds in the M1A1 Abrams)." "There's no autoloader either, as that only slows the ROF, requires smaller, less powerful and versitile ammo to be used, adds another complex, delicate set of moving parts to break, and only serves to expand the guantlet of things that can hurt you inside the vehicle.In fact, the Tigerwolf's main gun ammo is extremely large and heavy, and probably would break an autoloader --- it's would be an incredible feat of strength for a single Loader crewman to load in under 10 seconds." The Leclerc uses the same ammunition as the Abrams and Leopard 2. As for his 145mm smoothbore howitzer ammunition breaking an autoloader, does he not know that the Pz 2000 SPG has an autoloader for its 155mm gun? Of course he doesn't know that; Blacktail doesn't know what he's talking about. "The engineer is useful as well, because the large size of the Tigerwolf --- coupled with it's simple drivetrain (most modern tracked vehicles have a deceptively simple drivetrain) and small, flat engine (compred to a "Vee" or gas turbine) make for easy engine maintnance[sic] and repairs from inside the tank --- there's no need to abandon it if you lose a sparkplug while under small arms fire." Simple drivetrains, eh? Note that per the graphic, the Tigerwolf has a diesel wankel. Does Blacktail not know that diesel engines don't have spark plugs? Of course he doesn't know that; Blacktail doesn't know what he's talking about. (Diesel wankels don't exist. Three companies have tried making them; Rolls Royce, John Deere and some Japanese company I CBA to look up. None of the three ever got them to mass production. I'm not sure what the problem was.) "As for the armor, instead of using a large amount of steel and other metals, most of the Tigerwolf's armor is made up of thick panels and blocks of woven fabric Carbon 60 and 70 --- which are genarically[sic] known as "Fullerine". [sic] Fullerine has ove 100 times the tensile strength of steel, it's 10's of times lighter, and theoretically could be manufactured quickly and inexpensively. Essentially, the Tigerwolf has a sort of "Super Kevlar" armor, but unlike current Kevlars (which are made of polimers[sic] or composites), fullerine does not have a molecular structure that distorts or melts under heat or pressure --- a single piece of this new type of armor can withstand MANY direct hits from rounds with tank-killing power, KE and CE alike." Ah yes, fullerenes; every hack futurist's favorite crutch. Fullerenes have many interesting and useful properties, but their large-scale bulk mechanical properties may not be that amazing. Many materials have amazing strength at small scales, but disappointing strength at macro scales. Sapphire whiskers are an example. Moreover, high tensile strength (which is what fullerenes have going for them), does not necessarily imply that a material will make good armor. The properties that make materials effective against high-velocity threats are somewhat esoteric. Aluminum alloys, for instance, have a better strength to weight ratio than does steel, and while several of them do protect better on a weight basis than steel against lower velocity threats like artillery fragments and small arms fire, suffer badly against high-velocity penetrators and HEAT threats due to sheer failure modes that only exist at those higher velocity ranges. Also, why the fuck does Blacktail think that "Kevlars" melt under pressure? Aramids don't melt. "Even though it's much larger than an M1A1 Abrams, the Mk.75 Tigerwolf is over 30% lighter, and can swim over water obstacles, rather than slog though on the bottom. And because it floats, there are no depths that it cannot cross." This is how big a 40 tonne boat is. "Also important is it's low ground pressure, stemming from it's low 40-ton weight, super-wide tracks, low height, and enourmous horizontal size --- it has the ground pessure of a "Light Track" vehicle, like the M113 Gavin. This is important because almost half the world's surface is closed to heavy tracks (again, the M1A1 Abrams), due to thier height, ground pressure, and high centers of gravity. The Tigerwolf can directly cut across many areas that no existing or projected MBT will ever be able to --- not to mention traverse certain terrain features, such as bridges and paved roads, without damaging them." Is Blacktail under the impression that it's ground pressure that damages bridges? Jesus, if that were true the last thing you'd want to get anywhere near a bridge is a car. "As the Tigerwolf has 40% more power and torque than the M1, and weighs 30% less, it is 40% faster and could probably accelerate as quickly as a Humvee. This would make contemporary tanks very hard-pressed to cut-off a Tigerwolf, and no current or projected tanks could ever hope to pursue a Tigerwolf. Other advantages offered by the powerpack include a small number of moving parts, extremely low vibration and ocillation (inherent to Wankel Rotaries; not in piston engines), low heat emissions (less than in 700+ degree piston engines, or 1500+ degrees in Gas Turbines), a very small, flat, light engine block, and stonger individual components than in any current or projected tank engine, and a 5-speed AT, to take advantage of the high engine output. " Uh huh... So this is a magical wank(el) engine that has equal SFC to a diesel, rather than falling between a diesel and a turbine as existing ones do. "Other advantages offered by the powerpack include a small number of moving parts, extremely low vibration and ocillation (inherent to Wankel Rotaries; not in piston engines), low heat emissions (less than in 700+ degree piston engines, or 1500+ degrees in Gas Turbines), a very small, flat, light engine block, and stonger individual components than in any current or projected tank engine, and a 5-speed AT, to take advantage of the high engine output." WHAT THE FUCK KIND OF TURBINE REJECTS HEAT AT 1,500 DEGREES?! The highest turbine inlet temperature on record is 1,600C! Per Honeywell, AGT-1500's exhaust temperature is 500 C, but it's unclear if that is before or after it enters the recuperator. And if he's using bullshit Imperial units he's still wrong. If you don't know the difference between heat rejection temperature and turbine inlet temperature, you have no business discussing turbines. "All tanks require high firepower, and the Mk.75 Tigerwolf has plenty of it. The large size of the Tigerwolf's hull and turret enables a heavier-caliber howitzer to be used than on any tank currently in service --- a 145mm Smooth-Bore Howitzer. Because the German-designed M256 120mm smoothbore (M1A1, M1A2, Leopard 2, etc.) has a 40% larger punch than the British-designed M67 105mm Rifled-bore (the standard to which ALL other tank guns are judged --- used on too many tanks to list), the Tigerwolf's gun probaly has at least 20% more punch than the M256 --- enough to outrange any of today's tank guns, with enough penetration to destroy an M1A1 from well beyond it's maximum gun range." Any fictional Main Battle Wank needs to have a smitey, terrifying weapon... I'm not sure why Blacktail has saddled his design with a howitzer. Also, how many places on Earth are there where you can even see further than the engagement range of an M1's armament? "The Co-Axial MachineGun (COAX) fires 7x50mm rifle rounds, which combine the low cost and recoil of the 5.56x45mm NATO round, with the accuracy and penetration of the 7.62x51mm NATO round. 7mm rounds would also have a smaller casing daimeter than a 7.62mm round, which when coupled with significantly larger magazines and canisters, means the Tigerwolf totes one hell of a lot of MG ammo. As such, it is unlikely that a Tigerwolf will have to resupply MG ammo during a battle, and may even have thousands of rounds to spare --- if it is supporting friendly troops, the Tigerwolf may be able to spare a few thousand rounds for them." Someone doesn't know the difference between case head diameter and caliber. "A smooth ride and steady aim are achieved through hydropneumatic suspension and stabilization (versus the comparatively rougher torsion and hydraulics used in current and projected tanks) . The gun, turret, and hull each have thier own stabilization. While each of these are mechanically independant, they are balanced and co-ordinated via computer (which also feeds stability data to the gunnery computer, adjusting the GPS crosshairs in real time). This is unlike current tanks, whose ballistics comuters only react indirectly to the actual stability of the vehicle." I don't know what any of this means, except that Blacktail doesn't know how suspension and stabilization work. That's all I can stand. I'm done. Go read it if you want to, or not, whatever.
  8. Since Xlucine suggested it in the general AFV thread, here is a new version of the old Tank ID thread that used to exist at the WoT forums, back before the great exodus to SH. The rules are simple. Post a picture of some sort of AFV and everyone has to try to name what it is. Try to avoid posting a new picture until the previous picture is identified. Generally, the person who was first to correctly ID the picture in question gets to post the next picture, unless they want to pass. If a picture is not ID'd in a day or two, the person that posted it should say what it is and bask in their own sense of superiority. They should then post a new picture for the sake of keeping the thread moving. Please, no fictional tanks, paper napkin drawings that never made it to prototype or pictures where the vehicle in question is obscured or particularly hard to see. Also, if posting a picture of an unusual variant of a relatively common vehicle, be sure to note that you are looking for the specific variant name, not just the general family of vehicles it belongs to (for example, if I post a picture of a Panzer IV with the hydrostat drive, I would say in the post something like "What makes this Panzer IV unusual?" since everyone can ID a Panzer IV) It is perfectly ok to shame those that make spectacularly wrong guesses. That's just how we roll around here. I'll start
  9. ...actually nevermind i found this amazing site https://www.cybermodeler.com/armor/t-72/t-72_all.shtml and it has LOADS of pics and i'm happy...still how do you find high res images of tanks online ? i looked and looked but rarely found any,it can't be possible that people didn't take millions of 6000x4000 pics of tanks...right?
  10. I was recently looking at the Japanese wikipedia page for the Chi-Ha tank, and it had this section on the name of the tank: I have never heard of such nomenclature, and obviously I don't have access to such documents since I don't live in Japan. There is no reference for this part, so can anyone confirm that they actually did use "MTK" etc.?
  11. IDF had kept about 100 Tiran-6/T-62s since 1973, and remain service until 1990s. I wonder if there's any modification on Tiran-6, like changing the powerpack into 8V71T+XTG-411, adapting steering wheel. I also heard that British ROF had produce a batch of 115mm barrel for IDF, while MECAR or NEXTER produced high-performance APFSDS for 115mm gun. Did IDF really use these barrels for original barrel replacement? And about protection, did IDF put Blazer ERA on Tiran-6? Or they use more advanced APS like Trophy? Thank you.
  12. I'm sure that all the SH regulars will know this backwards and forwards, so this is more for the benefit of newer people, or people who stumble in via google, or people who want a quick link they can throw out as an answer to anyone who asks the question. So, what's with the goofy-ass road wheel design on German WWII AFVs? A puzzled and terrified worker struggles to comprehend and assemble the suspension of a tiger I You may have run into a variety of explanations for this running gear design; that it provided a smoother ride, that the design saved rubber, or possibly some other rubbish. Like the myth that frontal drive sprockets provide more traction (seriously, how in the hell is that supposed to make any sense?), these wrong explanations of the merits of interleaved road wheels seem to rise from some quote taken out of context. The interleaved road wheel running gear may have saved some rubber relative to an alternative design that was particularly wasteful of it. But interleaved road wheels are not particularly economic in this respect because, and I realize this is a complicated concept to explain so I'll try my best, they have more wheels. Interleaved road wheels do allow for large wheel diameters, and a larger diameter wheel will spread wear out over a larger circumference. So interleaved road wheels might allow for the rubber on the wheels to last longer, although their construction would require more in the first place. Interleaved road wheels would not improve ride quality either. The ride quality of a tank is not a function of the size or number of wheels it possesses, but of how they are sprung. So, it is possible that in certain competitive trials an interleaved road wheel design outperformed a design that lacked this feature. I could readily believe, for instance, that the tiger (H) had a better ride quality on rough terrain than the tiger (P), or that the SDKFZ. 251 had a smoother ride than the M3. However, this would be because the tiger (H) and SDKFZ. 251 have independently sprung road wheels on torsion bars while the tiger (P) and M3 do not. Torsion bar layout of the tiger II Volute spring suspension of the M3 half track So, what do interleaved road wheels do? They have two principal effects; one is a small benefit, and the other is an enormous detriment. The small benefit of interleaved road wheels is that they spread the weight of the vehicle out more evenly on the track links: The weight of a tank is not completely evenly spread out on the contact area of its tracks. This is because tracks are not rigid. If they were, they would be mainly ornamental and tanks' engines would just be for show. More of the weight of a tank is concentrated under the parts of the track that the road wheels are sitting directly on top of. Additionally, once a tank starts to sink into the soil a bit, larger road wheels work better than smaller ones because the larger ones have more contact area. But you can only fit so many large diameter road wheels in the space of a tank's hull. Dynamic! So, the only way to have lots of road wheels and have big road wheels at the same time is to interleave them. Simple as that. If you would like an exhaustive look at the development of the semi-empirical MMP equation, read this. The major, crippling downside to interleaved road wheels is that it makes changing the road wheels extremely time consuming. A pair of workers perform maintenance on a panther tank, and contemplate the futility of all human achievement Lucas Friedli reprints in his book on big cat maintenance a report from a training unit complaining that replacing the inner road wheels of a tiger tank took ten hours. That is completely outrageous, and was a contributor to the poor operational availability of the big cats. For this reason, interleaved road wheels have rarely been used after World War Two; only on a few French prototypes and a Swedish APC: PBV 302 variant with interleaved road wheels Some bizarre French tank
  13. I haven't found an appropriate thread where to put some interesting rare stuff related to WW2 development, be it industrial one or makeshift field modifications. Let's start with two things. The first one is a relatively recently found rarity from Swedish archives - a drawing of ČKD/BMM V8H-Sv tank. The drawing and a letter was found by WoT enthusiasts in Swedish archives in 2014 (the original announcement and the drawing source is here). The drawing is from a message dated 8th September 1941. One of the reasons why this drawing was not known before may be that the Czech archives were partially destroyed by floods in 2002. Anyway it is an export modification of the V-8-H tank accepted into Czechoslovak service as ST vz.39 but never produced due to the cancelation of all orders after Münich 1938 (for the same reason negotiations about licence production in Britain failed). Also later attempt to sell the tank to Romania failed due to BMM being fully busy with Wehrmacht priority orders. The negotiations with Sweden about licence production of V8H-Sv lasted till 1942, at least in May 1942 Swedish commission was present in Prague for negotiations. The tank differed compared to the base ST vz.39 in thicker armor with different front hull shape (armor 60 mm @ 30° on the hull front and also 60 mm on the turret; all sides were 40 mm thick). The tank was heavier (20 tons) and had the LT vz.38 style suspension with probably even larger wheels. The engine was still the same Praga NR V8 (240-250 Hp per source). The armament was unchanged with 47 mm Škoda A11 gun and two vz.37 HMG. The commander's cupola was of the simple small rotating type similar to those used on AH-IV-Sv tankettes. It is known that the Swedes officially asked to arm the tank with 75 mm gun, replace the engine with Volvo V12 and adding third HMG to the back of the turret. In the end the Swedes decided to prefer their own Strv/m42. Source of the drawing The second is makeshift field modification found on Balkans. It appears Ustasha forces (and possibly some SS anti-partizan units) used several Italian M15/42 medium tanks with turrets from Pz.38(t). There are several photos of such hybrids but little more is known. On one photo it is possible to see Ustasha registration number U.O. 139. Few more photos of such hybrid. It appears that the source of all those photos to be found on the internet is this book, Armoured units of the Axis forces in southeastern Europe in WW2 by Dinko Predoevic.
  14. 70 years ago, January the 2nd, 1951. To the North of Seoul, in the mountains and hills near Go-yang-tong(高阳洞), British 1RUR dug in and fought against advancing PVA forces. 1RUR got a task force called Cooperforce to support, this is a tank unit from Royal Tank Regiment and Royal Artillery, equipped with Cromwell tanks. When Matthrew Ridgeway assigned the order of withdraw in this afternoon, the US force covering British force's left flank quickly escaped from their sector, leaving the British were completed unawared and uncovered. When the night falls, was cold and dark in the valley. 1RUR had to withdraw in the darkness. All of a sudden, a US spotter aircraft flew over the valley, drop some illumination flares upon the retreating convoy. Fierce battle broke out when flares fall down, PVA firing from all directions, the cold valley became deadly kill zone. Some PVA soldiers put away their rifles, assaulting with hand grenades, satchel charges and Bangalore torpedoes. They even set up mortars on the hill, laying shells with direct fire. 200 British soldiers and artillerymen were killed or captured in one night. 1RUR's Battalion Commander Tony Blake was believed KIA. Cooperforce was completely knocked out, all 12 tanks were destroyed or captured by light infantry. Leader Ashley Cooper were also killed.
  15. So I got a request recently from {NAME REDACTED} as to whether we have a how-to guide or something for competitions. After a few moments of bitter, bitter laughter at the decade-plus of my life that I've spent cobbling together things that can maybe, sort-of, squint-your-eyes produce a facsimile of a realistic vehicle, I thought I'd share my process: Note: I was half-right - we definitely have supplementary info for aspiring pretend tank designers pinned to this very board. Finally, I'm inviting our forum grognards and past winners to share their process for folk that haven't been here since before the last ice age, so that all can benefit.
  16. Since we don't have a thread for British and Commonwealth tanks of WWII, I thought I would start one. Check out this manufacturers instructional video on the Crusader.
  17. Hi guys, Does anyone know of any military studies that analyzed the reload speeds for different tanks? The question occurred to me when I watched this video tour of the T-55's interior: https://youtu.be/TEDhB9evPvw At the 10:00 mark, Mr. Moran demonstrates how the loader would put a shell into the tank's cannon, and the effects of the turret's small size and of the loader's awkward seating make it clear that the process would be slow. My question is: how slow? Side question: Am I right to assume that storing the tank shells all over the inside of the turret like that is an inherent design flaw of the T-55 that makes it inferior in that regard to modern tanks? Thanks in advance.
  18. Hi guys, I recently read about upgrade packages to old tanks like the M-60 and T-55, but kept seeing comments from people saying they would still be obsolete. Is this because the M-60 and T-55 are made entirely of steel (and not composite) armor? I have this theory that thick steel armor is probably totally obsolete, and is just dead weight in the age of lighter weight composite armor. You can bolt on upgrades to an M-60 or T-55, but you're still hamstrung by the fact that either tank will be carrying around tons of useless steel. Am I right? Also, if we wanted to upgrade old tanks like that, wouldn't the best idea be to develop a new turret--with lighter, modern composite armor and better technology inside--and just drop it into the old tanks? The hulls would still be made of heavy steel, but that could be helped a bit by adding applique armor. Here are some of the upgrades I read about: https://youtu.be/NG89Zh9qQrQ http://www.army-guide.com/eng/product1907.html
  19. Restricted: for Operating Thetan Eyes Only By order of Her Gracious and Serene Majesty Queen Diane Feinstein the VIII The Dianetic People’s Republic of California Anno Domini 2250 SUBJ: RFP for new battle tank 1. Background. As part of the War of 2248 against the Perfidious Cascadians, great deficiencies were discovered in the Heavy tank DF-1. As detailed in report [REDACTED], the DF-1 was quite simply no match for the advanced weaponry developed in secret by the Cascadian entity. Likewise, the DF-1 has fared poorly in the fighting against the heretical Mormonhideen, who have developed many improvised weapons capable of defeating the armor on this vehicle, as detailed in report [REDACTED]. The Extended War on the Eastern Front has stalled for want of sufficient survivable firepower to push back the Mormon menace beyond the Colorado River south of the Vegas Crater. The design team responsible for the abject failure that was the DF-1 have been liquidated, which however has not solved the deficiencies of the existing vehicle in service. Therefore, a new vehicle is required, to meet the requirements of the People’s Auditory Forces to keep the dream of our lord and prophet alive. Over the past decade, the following threats have presented themselves: A. The Cascadian M-2239 “Norman” MBT and M-8 light tank Despite being approximately the same size, these 2 vehicles seem to share no common components, not even the primary armament! Curiously, it appears that the lone 120mm SPG specimen recovered shares design features with the M-8, despite being made out of steel and not aluminum like the light tank. (based on captured specimens from the battle of Crater Lake, detailed in report [REDACTED]). Both tanks are armed with high velocity guns. B. The Cascadian BGM-1A/1B/1C/1D ATGM Fitted on a limited number of tank destroyers, several attack helicopters, and (to an extent) man-portable, this missile system is the primary Cascadian anti-armor weapon other than their armored forces. Intelligence suggests that a SACLOS version (BGM-1C) is in LRIP, with rumors of a beam-riding version (BGM-1D) being developed. Both warheads penetrate approximately 6 cone diameters. C. Deseret tandem ATR-4 series Inspired by the Soviet 60/105mm tandem warhead system from the late 80s, the Mormon nation has manufactured a family of 2”/4” tandem HEAT warheads, launched from expendable short-range tube launchers, dedicated AT RRs, and even used as the payload of the JS-1 MCLOS vehicle/man-portable ATGM. Both warheads penetrate approximately 5 cone diameters. D. Cascadian HEDP 90mm rocket While not a particularly impressive AT weapon, being of only middling diameter and a single shaped charge, the sheer proliferation of this device has rendered it a major threat to tanks, as well as lighter vehicles. This weapon is available in large numbers in Cascadian infantry squads as “pocket artillery”, and there are reports of captured stocks being used by the Mormonhideen. Warhead penetrates approximately 4 cone diameters. E. Deseret 40mm AC/ Cascadian 35mm AC These autocannon share broadly similar AP performance, and are considered a likely threat for the foreseeable future, on Deseret armored cars, Cascadian tank destroyers, and likely also future IFVs. F. IEDs In light of the known resistance of tanks to standard 10kg anti-tank mines, both the Perfidious Cascadians and the Mormonhideen have taken to burying larger anti-tank A2AD weaponry. The Cascadians have doubled up some mines, and the Mormons have regularly buried AT mines 3, 4, and even 5 deep. 2. General guidelines: A. Solicitation outline: In light of the differing requirements for the 2 theaters of war in which the new vehicle is expected to operate, proposals in the form of a field-replaceable A-kit/B-kit solution will be accepted. B. Requirements definitions: The requirements in each field are given in 3 levels- Threshold, Objective, and Ideal. Threshold is the minimum requirement to be met; failure to reach this standard may greatly disadvantage any proposal. Objective is the threshold to be aspired to; it reflects the desires of the People’s Auditory Forces Armored Branch, which would prefer to see all of them met. At least 70% must be met, with bonus points for any more beyond that. Ideal specifications are the maximum of which the armored forces dare not even dream. Bonus points will be given to any design meeting or exceeding these specifications. C. All proposals must accommodate the average 1.7m high Californian recruit. D. The order of priorities for the DPRC is as follows: a. Vehicle recoverability. b. Continued fightability. c. Crew survival. E. Permissible weights: a. No individual field-level removable or installable component may exceed 5 tons. b. Despite the best efforts of the Agriculture Command, Californian recruits cannot be expected to lift weights in excess of 25 kg at any time. c. Total vehicle weight must remain within MLC 120 all-up for transport. F. Overall dimensions: a. Length- essentially unrestricted. b. Width- 4m transport width. i. No more than 4 components requiring a crane may be removed to meet this requirement. ii. Any removed components must be stowable on top of the vehicle. c. Height- The vehicle must not exceed 3.5m in height overall. G. Technology available: a. Armor: The following armor materials are in full production and available for use. Use of a non-standard armor material requires permission from a SEA ORG judge. Structural materials: i. RHA/CHA Basic steel armor, 250 BHN. The reference for all weapon penetration figures, good impact properties, fully weldable. Available in thicknesses up to 150mm (RHA) or 300mm (CHA). Density- 7.8 g/cm^3. ii. Aluminum 5083 More expensive to work with than RHA per weight, middling impact properties, low thermal limits. Excellent stiffness. Fully weldable. Available in thicknesses up to 100mm. Mass efficiency vs RHA of 1 vs CE, 0.9 vs KE. Thickness efficiency vs RHA of 0.33 vs CE, 0.3 vs KE. Density- 2.7 g/cm^3 (approx. 1/3 of steel). For structural integrity, the following guidelines are recommended: For light vehicles (less than 40 tons), not less than 25mm RHA/45mm Aluminum base structure For heavy vehicles (70 tons and above), not less than 45mm RHA/80mm Aluminum base structure. Intermediate values for intermediate vehicles may be chosen as seen fit. Non-structural passive materials: iii. HHA Steel, approximately 500 BHN through-hardened. Approximately twice as effective as RHA against KE and HEAT on a per-weight basis. Not weldable, middling shock properties. Available in thicknesses up to 25mm. Density- 7.8g/cm^3. iv. Glass textolite Mass efficiency vs RHA of 2.2 vs CE, 1.64 vs KE. Thickness efficiency vs RHA of 0.52 vs CE, 0.39 vs KE. Density- 1.85 g/cm^3 (approximately ¼ of steel). Non-structural. v. Fused silica Mass efficiency vs RHA of 3.5 vs CE, 1 vs KE. Thickness efficiency vs RHA of 1 vs CE, 0.28 vs KE. Density-2.2g/cm^3 (approximately 1/3.5 of steel). Non-structural, requires confinement (being in a metal box) to work. vi. Fuel Mass efficiency vs RHA of 1.3 vs CE, 1 vs KE. Thickness efficiency vs RHA of 0.14 vs CE, 0.1 vs KE. Density-0.82g/cm^3. vii. Assorted stowage/systems Mass efficiency vs RHA- 1 vs CE, 0.8 vs KE. viii. Spaced armor Requires a face of at least 25mm LOS vs CE, and at least 50mm LOS vs KE. Reduces penetration by a factor of 1.1 vs CE or 1.05 vs KE for every 10 cm air gap. Spaced armor rules only apply after any standoff surplus to the requirements of a reactive cassette. Reactive armor materials: ix. ERA-light A sandwich of 3mm/3mm/3mm steel-explodium-steel. Requires mounting brackets of approximately 10-30% cassette weight. Must be spaced at least 3 sandwich thicknesses away from any other armor elements to allow full functionality. 81% coverage (edge effects). x. ERA-heavy A sandwich of 15mm steel/3mm explodium/9mm steel. Requires mounting brackets of approximately 10-30% cassette weight. Must be spaced at least 3 sandwich thicknesses away from any other armor elements to allow full functionality. 81% coverage (edge effects). xi. NERA-light A sandwich of 6mm steel/6mm rubber/ 6mm steel. Requires mounting brackets of approximately 10-30% cassette weight. Must be spaced at least 1 sandwich thickness away from any other armor elements to allow full functionality. 95% coverage. xii. NERA-heavy A sandwich of 30mm steel/6m rubber/18mm steel. Requires mounting brackets of approximately 10-30% cassette weight. Must be spaced at least 1 sandwich thickness away from any other armor elements to allow full functionality. 95% coverage. The details of how to calculate armor effectiveness will be detailed in Appendix 1. b. Firepower i. 2A46 equivalent tech- pressure limits, semi-combustible cases, recoil mechanisms and so on are at an equivalent level to that of the USSR in the year 1960. ii. Limited APFSDS (L:D 15:1)- Spindle sabots or bourelleted sabots, see for example the Soviet BM-20 100mm APFSDS. iii. Limited tungsten (no more than 100g per shot) iv. Californian shaped charge technology- 5 CD penetration for high-pressure resistant HEAT, 6 CD for low pressure/ precision formed HEAT. v. The general issue GPMG for the People’s Auditory Forces is the PKM. The standard HMG is the DShK. c. Mobility i. Engines tech level: 1. MB 838 (830 HP) 2. AVDS-1790-5A (908 HP) 3. Kharkov 5TD (600 HP) ii. Power density should be based on the above engines. Dimensions are available online, pay attention to cooling of 1 and 3 (water cooled). iii. Power output broadly scales with volume, as does weight. Trying to extract more power from the same size may come at the cost of reliability (and in the case of the 5TD, it isn’t all that reliable in the first place). iv. There is nothing inherently wrong with opposed piston or 2-stroke engines if done right. d. Electronics i. LRFs- unavailable ii. Thermals-unavailable iii. I^2- limited 3. Operational Requirements. The requirements are detailed in the appended spreadsheet. 4. Submission protocols. Submission protocols and methods will be established in a follow-on post, nearer to the relevant time. Appendix 1- armor calculation Appendix 2- operational requirements Addendum 1 - more armor details Good luck, and may Hubbard guide your way to enlightenment!
  20. Sturgeon's House started with a community of people who played tank games. At the time, most of us were playing World of Tanks, but I think there were a few Warthunder and even Steel Beasts players mixed in there too. After nearly five years, we must be doing something right because we're still here, and because we've somehow picked up a number of members who work with, or have worked with tanks in real life. I know that @AssaultPlazma served as an Abrams loader, @Merc 321 and @Meplat have helped maintain and restore privately-owned armor, and @Xlucine has volunteered in a tank museum. I'm sure I'm missing several more! So, what are your favorite personal tank stories?
  21. Let's say you're developing a tank with a unique (AKA non-historical) gun for one of our competitions here on SH. It would be nice to have an idea of the size of the gun, its shells, and what their performance both in terms of shell weight and velocity but also penetration, wouldn't it? Well, fortunately there is a way to do this with reasonably accurate results using your solid modeling software and some free to use browser tools. First, you want to have a general idea of the size and performance of your gun. For this example, I decided I wanted an optimized, high velocity 85mm caliber gun with a case about as big as the 7.5cm KwK 42 (as it happened, I ended up with a case that had significantly greater volume, but that fact is unimportant for this example). The cartridge I decided on has a 130mm wide rim and a 640mm long case, of course in 85mm caliber. My first step was to model this case in SolidWorks: You will also need to model your projectile, in this case a tungsten-carbide cored APCR round: Next, we need a bit of freeware: A Powley computer. Originally developed by DuPont engineers for small arms ammunition, the Powley computer is an accurate enough tool to use for much larger tank rounds as well! When you click the link, you'll be greeted with this screen: You'll note the dimensions are in inches and this thing called "grains" (abbreviated "gn"). The grain is an archaic Imperial mass unit equal to 1/7000th of a pound which is still used in the small arms field, today. Another quirk of small arms has the case capacity - a volume measurement - listed in grains as well. This is in fact grains of water (gn H2O), or the weight of water that will fill the case to the top. To find this, simply multiply the volume in cubic centimeters by 15.43 - which is also the exchange rate between the metric gram and grains mass. Finding the volume of the case is easy with a solid modeling program; simply model the interior as a solid and find the volume of that solid: Filling in my Powley inputs gives me this: Note that I typically use the diameter of the projectile across the driving bands for "Bullet Diameter", but it really makes very little difference. So far, though, we haven't actually produced any results. That's because our gun is well outside the bounds of DuPont production IMR powders, hence the output "Much slower than (IMR) 4831" in the lower left. So, we need to override the computer by checking the box next to the blue "Pressure" function, and typing in a pressure value in CUP that is reflective of tank guns of whatever era we are trying to represent. My tank gun is trying to represent something from about the late 1940s/early 1950s, so I'm going to use 45500 CUP EDIT: USE 41000 CUP for APCBC and 42800 CUP FOR APCR (or better yet, do your own calibration!): This gives me an estimated muzzle velocity of 3,964 ft/s for my L/50 barrel. Not bad! Note the outputs on the left, which tell you a bunch of fun facts about your round but aren't terribly relevant to what we're doing here today. Next, we need to put this gun's performance in terms of penetration. The way I like to do this is through comparative analysis. The first thing we need is to know to find penetration the ballistic performance of our round. We can estimate this using JBM's ballistic calculator and a few rules of thumb. When opening the calculator, the first thing you'll see is this: We care about basically none of these settings except BC, velocity, and maximum range. Caliber, projectile weight, chronograph distance, etc are all pretty irrelevant to us. Keep the environmental settings (temperature, pressure, etc.) set to their defaults. First, change the ballistic coefficient type from G1 to G7 using the dropdown menu. Then, change the muzzle velocity from 3000 to whatever the muzzle velocity was that was calculated by the Powley computer. Finally, set the maximum range to your desired distance - in my case 2,000 yards. For my round, I now have inputs that look like this: We also need to get some idea of how fast our projectile loses velocity, something we can't know for certain without actually building a real gun and test firing it - or at least without some really sophisticated simulations. However, projectiles with the same shape tend to fly the same way, and that's something we can exploit here. To figure this out, we need a graph showing us the performance of a real-life gun. Fortunately, there is a handy one for an IRL gun similar to what I'm designing, the 90mm M3 from World War II, and its M304 HVAP-T, which is broadly similar in construction and shape to my 85mm APCR projectile: Based on this chart, we see that the M304 should drop from its 3,350 ft/s muzzle velocity to about 2,500 ft/s at 2,000 yards. Doing a little trial and error with JBM tells me that this means the M304 has a G7 ballistic coefficient of about 1.13. Now, our projectile will not have the same ballistic coefficient, due to it being a different size and mass. But, we can figure out what its ballistic coefficient would be by finding its sectional density and comparing that to the sectional density of M304. To find sectional density, take the projectile's weight in grains and divide it by the square of the projectile's diameter in inches, times 7000. So for M304, we get: And for my 85mm, we get: This means that the ballistic coefficient for an identical-shape projectile with our size and weight will be about 1.019/1.330 - or 76.6% as much - as that of the 90mm M304. That means a BC of 0.866 G7 should be approximately correct for my 85mm APCR round. Let's plug that in: And then scroll down to the bottom to click "calculate", which gives us a big ol' chart that goes out to 2,000 yards: O-Kay! Now we have some data. It looks like at 2,000 yards, my projectile holds about 2,800 ft/s striking velocity. It's important to note here that what we really care about isn't the striking velocity of the projectile per se, but the velocity and energy of the projectile's core. The core is what's actually doing a lot of work to the armor, so for now let's stop thinking in terms of the whole projectile, and take a look at these two cores, that of the M304 90mm HVAP, and that of my 85mm APCR round. The core of the 90mm M304 is an approximately 8 pound lump of tungsten-carbide that is about 45mm in width. My penetrator is also 8 pounds, but it's longer and thinner in proportion - just 40mm wide, rather than 45mm. This means my penetrator will penetrate more armor at a given striking velocity, and we can estimate how much more by taking the specific energy of the rounds and comparing them. That is, the energy in Joules of the penetrator alone, divided by the penetrator's diameter squared: So the specific energy at 2,000 yards is about 826J/mm^2. Now, we need to find out at what impact velocity the M304 penetrator produces this same specific energy. Do do that, we go backwards, using the figures for M304: Therefore, the equivalent impact velocity for my 85mm APCR round at 2,000 yards is 3,150 ft/s for the M304. That means, in theory, that the M304 would have to impact a target at 3,150 ft/s to produce equivalent penetration of RHA to my 85mm APCR striking at just 2,800 ft/s. Now, we head back to that chart: On the left side of the graph, we put our cursor on the line that corresponds to approximately 3,150 ft/s velocity, and follow it over until it hits the curved line that corresponds with the angle of plate we care about - arbitrarily, let's pick 20 degrees. Then, we follow that point straight down until it hits the x-axis: Therefore, we estimate that at 2,000 yards, my 85mm has just over 10 inches of RHA penetration - not bad at all for a lowly APCR round!
  22. Anti-air bobcat design to take away driver's hearing in maximum efficiency SH11 155mm SPG
  23. 各位最近可能在WT论坛上见过这张图片,在一些争论陆上自卫队90式战车的讨论串里: Some of you may have seen this pic recently on WT forum, in some thread arguing the protection of JGSDF Type 90: Discussion on WT forum 我就直说吧,表格里的中文注解说了,这不过是个“猜想”,GUESSING。 To be straight, the Chinese annotation in the table said it is just a GUESSING. 注解内容可能完全是编造的,但不幸的是,不同语言间的障碍使你们无法看穿这点。 This annotation could be totally nonsense but unfortunately a barrier between languages prevent you guys see throught it. 实际上,这又是一份关于陆上自卫队10式战车的文件,说的并不是90式。 In fact, again, this document itself is about JGSDF Type 10 MBT, not Type 90. 同样的花招,不一样的人,是吧? Same trick, different people, huh? ↑陆上自卫队的10式战车规格书 JGSDF specification handbook of Type 10 MBT ↑59页,附录B,性能(规定)以及诸元 page 59, Appendix B, performance (regulations) and data 下面简要说说这些性能规定如何编写、如何加密。 Let's talk about these regulations and how they were made and encrypted. 大家可能知道日语中有平假名和片假名,和拉丁语中的字母还有大写字母是差不多的。 You may know that Japanese have Hirakana and Katakana, like Latin have letters and capital letters. 正如图中所示,一些最关键的数值和描述用平假名、片假名、罗马字(拉丁字母)隐去了。 As you can see, some of the most crucial numbers and descriptions are covered by a Hirakana or Katakana or Romaji(Latin letters). 这些数值和描述被归在一起,编入附属的手册,称为“别册”。 These numbers and descriptions were collected and listed in some append book, called Bessatsu(別冊). 在查阅别册时,就好比在看试卷的答题卡。但如果把别册里面的数值和描述涂黑,你就根本不知道说啥。 When you look up to the append book, just like viewing the answer sheet of an exam paper. But when numbers and descriptions were censored, you'll never know what it said. 比如说,正面防护: For example, the frontal protection: “耐弾性 - 正面 - 正面要部は、【あ】に射距離【え】m相当存速において、貫徹されない。” 读起来是这样的: 耐弹性 - 正面 - 正面重要部位可抵御【あ】以相当于射击距离【え】米存速的射击,不会贯穿。 It read like this: Protection - Frontal - Frontal crucial part should withstand 【あ】 firing at a distance of 【え】meter speed reduce equivalent, and not penetrate. 【あ】代表某种弹药,可能是尾翼稳定穿甲弹,但不知道是量产弹种还是实验弹种。 【あ】stands for certain type of ammunition, probably APFSDS, but don't know whether it is production shot or experimental. 【え】代表某个射击距离,可以是1000、1500或2000(米),但这么远的距离,炮弹会受到风力和重力影响,故无法精确瞄准靶车的防护区域。 【え】stands for certain firing distance, could be 1000 , 1500 or 2000 (meters), but on such a long distance, shot could be effect by wind and gravity, thus cannot aim on the protection area of target vehicle precisely. 一个常见的解决方式是在更近的距离上开火,比如说200到550米,同时减少推进药量,使得穿甲弹的终点速度符合特定距离的速降。这是一种等效方法。 The usual solution is to fire from a much closer range, from 200 to 550 meters, while reducing the propellant charge so that the end speed of AP shot could match the speed drop on certain distance. This is an equivalant method. 有的人争辩说90式战车可以抵挡另一辆90式战车发射的穿甲弹(JM33),距离大约250米。这一说法源自一段未知视频片段,具体什么视频他们自己也没看过。较近的射击距离是为了能更好的瞄准,为此可能使用了减装药来模拟远距离终点速度,但也无法证明。 Some people argue that Type 90 MBT can withstand AP shot (JM33) firing from another Type 90 MBT, on a distance about 250 meters. The source of this statement came from an unknown video clip, which they have never seen. Firing on closer range is for better aim, and they could have use reduced charge to simulate a much longer range, but we cannot prove.
  24. Part 5 of a multi-part series. This one's got the goods. Sherman and firefly. Early crusader. Early Valentine. The British really went through a phase where they slapped 2 pounders onto everything. Father. Son. Holy ghost. Comet, aka Hipster Centurion. Centurion, aka The entire History of South African tanks post-WW2. T-shirt cannon Churchill. Combat engineers get no respect. This thing is tiny and has an insane steering system. Somehow this thing is even smaller. Those twin barrels are for a flamethrower of some sort, because the Italians were world-class optimists.
  25. Sooooo...after doing a site-wide search and perusing Google, I'm surprised not to have found anything about tank suspension, other than a somewhat doubtful thread on the WoT forums. Would my learned colleagues of SH be able to assist me in understanding and identifying the different types of tank suspension? I think I've got leaf-spring more or less mastered, as well as both VVSS and HVSS (thanks, JGT!) but was somewhat embarrassed not to be able to differentiate between the suspension of a Type 97 Chi-Ha and an FV4201 Chieftain. UPDATE: I think I understand tank suspension better now. Thanks, everyone!
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