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Found 12 results

  1. The idea to produce a Romanian MBT was considered after 1968 invasion of Czechoslovakia and it started at the beginning of 70s when Romanian Communist Party embarked in an effort of industrialization of the country. Along with MBTs, an entire variety of armored vehicle was produced ranging from APCs and IFVs to SPGs. I'll start with tanks and I will gradually add posts to this thread. Keep in mind that I am not a specialist and I am open to advice/suggestions. There is very little reliable info available online, some sources give contradictory information but I’ve selected the info from reliable sites and included some considerations of military personnel who served on this tank or worked in the said factories(mainly from http://www.rumaniamilitary.ro website articles and comments); I tried to avoid internet articles, some are poorly documented and contain mistakes and even urban legends. Pretty often Romanian TR tanks series are mistakenly considered T-55s local copies which is quite wrong. Although Romania received the license of T-55 from USSR, it never produced this tank but rather imported it from USSR and Czechoslovakia due to WP internal rules of importing equipment of each other. The Czechoslovak products were preferred due to their better quality/reliability. TR-77-580 The first Romanian tank project yielded results in 1972, as a strategic part of the national defense doctrine. One of the reasons for which Romania’s political leadership accelerated industrialization was for military purposes, including tanks. The first Romanian tank was supposed to be medium one, with a 500 hp engine and was to be named with the TR designation, an acronym for Romanian Tank. The factory was supposed to be located in Marsa, in Sibiu county, in Romania’s western area however subsequently staff and production were moved to ‘August 23rd’ Enterprises in Bucharest where it were put into use various machines received from China. Another reason was the fact that Romanian Army did not considered T-55s as suitable for its doctrine and they requested a better armored medium, with better cabin for crew, better armor, NBC, anti-nuke protection and more ammo stored and better firepower. The only chapter were the first series (TR-77-850) failed was the maneuverability since the tank was 11 tons heavier and only the second generation engine of 850 HP solved this issue (middle 80s). The fist experimental model, the TR-77, came out in 1976, as a pre-mass production. After tests, the TR-77-580 came out and that same year, mass production started, with a target of 210 tanks a year. Compared with T-55, Romanian TR-77-580 had a stretched hull and an extra road wheel on each side to be able to fit the new engine, but the first series received the 580 HP engine and only later the 800 HP was gradually added. Just by looking at the tank, you may be mistaken that it was either a T-54 or a T-55, however this is basically a T-55 on steroids with double the armor, lengthened hull, a domestic anti-tank gun that looks similar to the D-10T (which was continuously improved and developed until 90s), and two extra pairs of roadwheels that are smaller in diameter. Armor: Unlike the T-55, the TR-77 got a thick stratified armor with 320mm on the turret front, and 200mm of armor on the hull (2 100mm plates), along with armored side skirts unlike the rubber side skirts of the T-55AM. This is already superior to the nominal armor of any other tank of its category with just RHA, and stratified armor is of course even better. The armor was theoretically better than the M60A1, T-62, Leopard I, and even the Chieftain. The use of a frontal 200 mm was at first controversial, and had a direct impact on the weight, of around three tons. Chief feature of the series is more than double the armor of T-55 using new technologies. At 200 mm thickness, it surpasses M60 even if only laminated type of armor; turret has 320 mm stratified which makes it one of the best armored tanks compared with most Western models of the same era. Gun: The TR-77-580 is armed with Romanian rifled 100mm A308 which is a variant of the 100mm anti-tank gun (M1977/A307) which also had a naval version (A430). It used 100mm BM 412 Sg ammunition that some sites claim that it is APDS but it’s mainly said to be a form of APFSDS ammunition. This ammo come later into service, at the same time with TR-85 (which was developed in middle 80s based on the experience acquired with TR-77 and using Chinese help). Other ammo used was BK-412 as HEAT ammunition, OF 412 as HE. It has a stabilizer, electric horizontally and hydraulic vertically. The gun itself was very resistant and it wasn’t uncommon to shot 250 rounds to a single exercise which I think says a lot about its durability. Rate of fire is from 7 to 15 rounds per minute, limited only by loader and muzzle velocity is 900 m/s for HE and 1400 m/s for APFSDS-T. Maneuverability: During its development, TR-77-580 was designed for a 830-860 hp engine allegedly derived from the Leopard I. Also Romanian engineers studied Israeli Centurions captured by Syria. This was partially the reason why the tank was lengthened and why it has 2 more road wheels than the T-55 and later it was upgraded with new engine and these variants were named TR-800/TM-800. For the first series it was used a local copy of the T-55’s V-55U engine which put out about 580 HP hence the name of the tank. The TR-77-580’s road wheels are evenly spaced out while the TR-800/TM-800 and the TR-85 has 2 widely spaced out wheels in the front while the back 4 are very close together. The delay in development of the 860 HP engine made the acceleration weaker than T-55s one. Probably mobility wise it is on par with Chieftain. Variants: TR-77-580 – Basic variant, chief feature of the series is more than double the armor of T-55 and is stratified. At 200 mm thickness, it surpasses M60 and deserves 12 FAV; turret has 320 mm stratified; It could be seen in the first pictures from this post. TR-77-580M – One of the first upgrades was to a LRF and ballistic computer; here is a pic with a TR-77-580 TR-77-580M1 – Main feature was its back elongated turret for better accommodation of crew, more ammo stored which would result in a better ROF than T-55s (9 rounds per minute). The pic shows one stripped of equipment and ready to be phased out; The number of tanks of this variant was small because they considered that it needs the 800 HP engine first. It was tested in 1979 by 912th Tank Battalion in Murfatlar although other sources claim is a late model. In middle/late 80s this model received 830 HP engine. The models in the photos are now exposed in a military units (not active anymore) and are stripped of equipment (skirts, boxes, MG, periscopes, IR projector, thermal sleeve and bore evacuator on the gun). Starting in 1983, a decision was made to raise the number of produced tanks to 500, once the new TR-85 model came out. By 1985, only 406 Romanian TR-77-580 tanks were made. To resume this tank weighed 42 tons, had a 580 hp Diesel engine, a top speed of 50 km/h, and a range of 380 km. It had an electric-hydraulic stabilizing system and 200 mm armor on frontal glacis and 380 mm stratified one on turret. Its armament was a 100 mm cannon that could fire six shots a minute, two machine guns and a crew of 4.
  2. Top Speed in Tanks

    Tank design is often conceptualized as a balance between mobility, protection and firepower. This is, at best, a messy and imprecise conceptualization. It is messy because these three traits cannot be completely separated from each other. An APC, for example, that provides basic protection against small arms fire and shell fragments is effectively more mobile than an open-topped vehicle because the APC can traverse areas swept by artillery fires that are closed off entirely to the open-topped vehicle. It is an imprecise conceptualization because broad ideas like "mobility" are very complex in practice. The M1 Abrams burns more fuel than the Leo 2, but the Leo 2 requires diesel fuel, while the omnivorous AGT-1500 will run happily on anything liquid and flammable. Which has better strategic mobility? Soviet rail gauge was slightly wider than Western European standard; 3.32 vs 3.15 meters. But Soviet tanks in the Cold War were generally kept lighter and smaller, and had to be in order to be moved in large numbers on a rail and road network that was not as robust as that further west. So if NATO and the Warsaw Pact had switched tanks in the late 1950s, they would both have downgraded the strategic mobility of their forces, as the Soviet tanks would be slightly too wide for unrestricted movement on rails in the free world, and the NATO tanks would have demanded more logistical support per tank than evil atheist commie formations were designed to provide. So instead of wading into a deep and subtle subject, I am going to write about something that is extremely simple and easy to describe in mathematical terms; the top speed of a tank moving in a straight line. Because it is so simple and straightforward to understand, it is also nearly meaningless in terms of the combat performance of a tank. In short, the top speed of a tank is limited by three things; the gear ratio limit, the power limit and the suspension limit. The tank's maximum speed will be whichever of these limits is the lowest on a given terrain. The top speed of a tank is of limited significance, even from a tactical perspective, because the tank's ability to exploit its top speed is constrained by other factors. A high top speed, however, looks great on sales brochures, and there are examples of tanks that were designed with pointlessly high top speeds in order to overawe people who needed impressing. When this baby hits 88 miles per hour, you're going to see some serious shit. The Gear Ratio Limit Every engine has a maximum speed at which it can turn. Often, the engine is artificially governed to a maximum speed slightly less than what it is mechanically capable of in order to reduce wear. Additionally, most piston engines develop their maximum power at slightly less than their maximum speed due to valve timing issues: A typical power/speed relationship for an Otto Cycle engine. Otto Cycle engines are primitive devices that are only used when the Brayton Cycle Master Race is unavailable. Most tanks have predominantly or purely mechanical drivetrains, which exchange rotational speed for torque by easily measurable ratios. The maximum rotational speed of the engine, multiplied by the gear ratio of the highest gear in the transmission multiplied by the gear ratio of the final drives multiplied by the circumference of the drive sprocket will equal the gear ratio limit of the tank. The tank is unable to achieve higher speeds than the gear ratio limit because it physically cannot spin its tracks around any faster. Most spec sheets don't actually give out the transmission ratios in different gears, but such excessively detailed specification sheets are provided in Germany's Tiger Tanks by Hilary Doyle and Thomas Jentz. The gear ratios, final drive ratios, and maximum engine RPM of the Tiger II are all provided, along with a handy table of the vehicle's maximum speed in each gear. In eighth gear, the top speed is given as 41.5 KPH, but that is at an engine speed of 3000 RPM, and in reality the German tank engines were governed to less than that in order to conserve their service life. At a more realistic 2500 RPM, the mighty Tiger II would have managed 34.6 KPH. In principle there are analogous limits for electrical and hydraulic drive components based on free speeds and stall torques, but they are a little more complicated to actually calculate. Part of the transmission from an M4 Sherman, picture from Jeeps_Guns_Tanks' great Sherman website The Power Limit So a Tiger II could totally go 34.6 KPH in combat, right? Well, perhaps. And by "perhaps," I mean "lolololololol, fuck no." I defy you to find me a test report where anybody manages to get a Tiger II over 33 KPH. While the meticulous engineers of Henschel did accurately transcribe the gear ratios of the transmission and final drive accurately, and did manage to use their tape measures correctly when measuring the drive sprockets, their rosy projections of the top speed did not account for the power limit. As a tank moves, power from the engine is wasted in various ways and so is unavailable to accelerate the tank. As the tank goes faster and faster, the magnitude of these power-wasting phenomena grows, until there is no surplus power to accelerate the tank any more. The system reaches equilibrium, and the tank maxes out at some top speed where it hits its power limit (unless, of course, the tank hits its gear ratio limit first). The actual power available to a tank is not the same as the gross power of the motor. Some of the gross horsepower of the motor has to be directed to fans to cool the engine (except, of course, in the case of the Brayton Cycle Master Race, whose engines are almost completely self-cooling). The transmission and final drives are not perfectly efficient either, and waste a significant amount of the power flowing through them as heat. As a result of this, the actual power available at the sprocket is typically between 61% and 74% of the engine's quoted gross power. Once the power does hit the drive sprocket, it is wasted in overcoming the friction of the tank's tracks, in churning up the ground the tank is on, and in aerodynamic drag. I have helpfully listed these in the order of decreasing importance. The drag coefficient of a cube (which is a sufficiently accurate physical representation of a Tiger II) is .8. This, multiplied by half the fluid density of air (1.2 kg/m^3) times the velocity (9.4 m/s) squared times a rough frontal area of 3.8 by 3 meters gives a force of 483 newtons of drag. This multiplied by the velocity of the tiger II gives 4.5 kilowatts, or about six horsepower lost to drag. With the governor installed, the HL 230 could put out about 580 horsepower, which would be four hundred something horses at the sprocket, so the aerodynamic drag would be 1.5% of the total available power. Negligible. Tanks are just too slow to lose much power to aerodynamic effects. Losses to the soil can be important, depending on the surface the tank is operating on. On a nice, hard surface like a paved road there will be minimal losses between the tank's tracks and the surface. Off-road, however, the tank's tracks will start to sink into soil or mud, and more power will be wasted in churning up the soil. If the soil is loose or boggy enough, the tank will simply sink in and be immobilized. Tanks that spread their weight out over a larger area will lose less power, and be able to traverse soft soils at higher speed. This paper from the UK shows the relationship between mean maximum pressure (MMP), and the increase in rolling resistance on various soils and sands in excruciating detail. In general, tanks with more track area, with more and bigger road wheels, and with longer track pitch will have lower MMP, and will sink into soft soils less and therefore lose less top speed. The largest loss of power usually comes from friction within the tracks themselves. This is sometimes called rolling resistance, but this term is also used to mean other, subtly different things, so it pays to be precise. Compared to wheeled vehicles, tracked vehicles have extremely high rolling resistance, and lose a lot of power just keeping the tracks turning. Rolling resistance is generally expressed as a dimensionless coefficient, CR, which multiplied against vehicle weight gives the force of friction. This chart from R.M. Ogorkiewicz' Technology of Tanks shows experimentally determined rolling resistance coefficients for various tracked vehicles: The rolling resistance coefficients given here show that a tracked vehicle going on ideal testing ground conditions is about as efficient as a car driving over loose gravel. It also shows that the rolling resistance increases with vehicle speed. A rough approximation of this increase in CR is given by the equation CR=A+BV, where A and B are constants and V is vehicle speed. Ogorkiewicz explains: It should be noted that the lubricated needle bearing track joints of which he speaks were only ever used by the Germans in WWII because they were insanely complicated. Band tracks have lower rolling resistance than metal link tracks, but they really aren't practical for vehicles much above thirty tonnes. Other ways of reducing rolling resistance include using larger road wheels, omitting return rollers, and reducing track tension. Obviously, there are practical limits to these approaches. To calculate power losses due to rolling resistance, multiply vehicle weight by CR by vehicle velocity to get power lost. The velocity at which the power lost to rolling resistance equals the power available at the sprocket is the power limit on the speed of the tank. The Suspension Limit The suspension limit on speed is starting to get dangerously far away from the world of spherical, frictionless horses where everything is easy to calculate using simple algebra, so I will be brief. In addition to the continents of the world not being completely comprised of paved surfaces that minimize rolling resistance, the continents of the world are also not perfectly flat. This means that in order to travel at high speed off road, tanks require some sort of suspension or else they would shake their crews into jelly. If the crew is being shaken too much to operate effectively, then it doesn't really matter if a tank has a high enough gear ratio limit or power limit to go faster. This is also particularly obnoxious because suspension performance is difficult to quantify, as it involves resonance frequencies, damping coefficients, and a bunch of other complicated shit. Suffice it to say, then, that a very rough estimate of the ride-smoothing qualities of a tank's suspension can be made from the total travel of its road wheels: This chart from Technology of Tanks is helpful. A more detailed discussion of the subject of tank suspension can be found here. The Real World Rudely Intrudes So, how useful is high top speed in a tank in messy, hard-to-mathematically-express reality? The answer might surprise you! A Wehrmacht M.A.N. combustotron Ausf G We'll take some whacks at everyone's favorite whipping boy; the Panther. A US report on a captured Panther Ausf G gives its top speed on roads as an absolutely blistering 60 KPH on roads. The Soviets could only get their captured Ausf D to do 50 KPH, but compared to a Sherman, which is generally only credited with 40 KPH on roads, that's alarmingly fast. So, would this mean that the Panther enjoyed a mobility advantage over the Sherman? Would this mean that it was better able to make quick advances and daring flanking maneuvers during a battle? No. In field tests the British found the panther to have lower off-road speed than a Churchill VII (the panther had a slightly busted transmission though). In the same American report that credits the Panther Ausf G with a 60 KPH top speed on roads, it was found that off road the panther was almost exactly as fast as an M4A376W, with individual Shermans slightly outpacing the big cat or lagging behind it slightly. Another US report from January 1945 states that over courses with many turns and curves, the Sherman would pull out ahead because the Sherman lost less speed negotiating corners. Clearly, the Panther's advantage in straight line speed did not translate into better mobility in any combat scenario that did not involve drag racing. So what was going on with the Panther? How could it leave everything but light tanks in the dust on a straight highway, but be outpaced by the ponderous Churchill heavy tank in actual field tests? Panther Ausf A tanks captured by the Soviets A British report from 1946 on the Panther's transmission explains what's going on. The Panther's transmission had seven forward gears, but off-road it really couldn't make it out of fifth. In other words, the Panther had an extremely high gear ratio limit that allowed it exceptional speed on roads. However, the Panther's mediocre power to weight ratio (nominally 13 hp/ton for the RPM limited HL 230) meant that once the tank was off road and fighting mud, it only had a mediocre power limit. Indeed, it is a testament to the efficiency of the Panther's running gear that it could keep up with Shermans at all, since the Panther's power to weight ratio was about 20% lower than that particular variant of Sherman. There were other factors limiting the Panther's speed in practical circumstances. The geared steering system used in the Panther had different steering radii based on what gear the Panther was in. The higher the gear, the wider the turn. In theory this was excellent, but in practice the designers chose too wide a turn radius for each gear, which meant that for any but the gentlest turns the Panther's drive would need to slow down and downshift in order to complete the turn, thus sacrificing any speed advantage his tank enjoyed. So why would a tank be designed in such a strange fashion? The British thought that the Panther was originally designed to be much lighter, and that the transmission had never been re-designed in order to compensate. Given the weight gain that the Panther experienced early in development, this explanation seems like it may be partially true. However, when interrogated, Ernst Kniepkamp, a senior engineer in Germany's wartime tank development bureaucracy, stated that the additional gears were there simply to give the Panther a high speed on roads, because it looked good to senior generals. So, this is the danger in evaluating tanks based on extremely simplistic performance metrics that look good on paper. They may be simple to digest and simple to calculate, but in the messy real world, they may mean simply nothing.
  3. 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.
  4. 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
  5. So on my recent trip to Japan (protip: don't fly for 19 hours with your kids), I took some time out from family to visit Yushukan museum. To bring you all up to speed, this place is the museum attached to the controversial shrine that Japan and China are in a perpetual snit over. The shrine itsef is actually pretty anodyne, if fairly imposing and charmless. The museum, however, is pretty fucking sinister. Anyway, I'm sure you didn't click this just to see me repost content, so here are my impressions. 1. Revisionism deluxe If you've gotten the impression by now that this place has an agenda, you are absolutely correct. Japanese soldiers are always described in glowing terms ('honourable actions', 'noble warriors', 'honoured dead' etc.), war crimes are ignored whenever they aren't completely rewritten as laudable or necessary (Manchuria is described as an operation to bring regional stability, for instance) and the Emperor was a saint. It gets to the point of being almost admirably ballsy, such as the train from the Burma railway parked at the entrance without any comment whatsoever. Or when the brochure specifically highlights a Japanese flag signed by 25 of the most well-known ‘alleged’ war criminals as a key exhibit. In terms of the content of the museum, it is at pains to remind the viewer about Japan’s glorious martial past (glossing over the whole civil war aspect), how it was pushed into a hopeless war by the perdifery of the US/colonial powers, and how the noble sacrifice of its people/Emperor lead to... something, I guess? Sadly, a lot of the place is off-limits to cameras so I can’t show you some of the truly egregious stuff. Finally, the amount of memorialisation gets to sort of strange levels. There are statues, displays and plaques commemorating the brave souls who died in the war – including, and I can’t make this stuff up, a special statue depicting the sailors who died testing a suicide diving suit that the empire was working on in its final hours. There is an entire wing of the museum dedicated to photos and mementos of dead soldiers, sailors and airmen. There is also a section devoted to providing bibliographical accounts (including displays of uniforms and equipment) of the men – again eliding any reference to crimes or atrocities. 2. Suicidepalooza Part of this focus on heroic struggle seems to be to include every possible reference to suicidal actions that it can. Every field gun displayed, for instance, helpfully included a note on how the crew had fought to the last man. This also extended to suicide weapons. The museum has an Ohka sitting up in the hall (which I wasn’t supposed to photograph, but did anyway), a Kaiten at the centre of the same room, a Shinyo sitting to the side and a model of Kairyu sitting next to it. Each helpfully notes the exact number of airmen/sailors who perished during testing or use. Finally, the Zero sitting in the entranceway and the Judy sitting in the hall both make mention of their later careers as planes intended for ‘special mission’ purposes. There was also an interview with one of the surviving kamikaze pilots playing on repeat in the main hall. My suspicion here is that the obsessive focus on suicide craft has some special meaning to the Japanese nationalists who effectively fund and run the place that I am unable to grasp. This is interesting, as I’ve generally found that the best possible way to get people to contemplate the insanity of total industrial warfare is to talk about Japanese suicide craft and the reasoning that went into their creation. Generally, once you’ve explained this stuff in detail to a person they’re, like, 50% of the way to either total pacifism or a wholehearted embrace of America’s post-war role as the most munificent empire in history. 3. Odds and sods Every museum has some interesting little bits and pieces hidden away, and this one was no different. For me, it was seeing the astonishingly crude nature of pre-Edo bows (which were, sadly, verboten for purposes of photography). One of them was literally a bronze-capped branch (complete with copious knots) about 25mm in diameter at the handle and steamed into the familiar yumi shape. The others were various iterations of brutalist single-piece bowering, culminating in a square cross-section bow that looks like a direct ancestor of the modern Japanese bow. For the small arms nerds, there are a few machineguns and cannons to look at. There was also a single, lonely Chi-Ha to give the armour nerds some succour. Finally, outside of the museum there was an example of a weirdo-gun: a bronze cannon which was taken in an re-rifled at the end of its life. 4. Conclusion All in all, I found the visit interesting but a bit ominous. Worse, I fear that this sort of thing is more portentous in terms of where Japan is headed than anyone wants to admit. I guess I can only hope that the country, which seems to be going through some sort of transition, doesn’t begin indulging in its worst tendencies again as pax Americana wanes.
  6. Pretty much what it says on the tin. These are time to kill charts for tier X tanks with a primary focus on different guns, rather than different tanks. All reload times are based on the stated rate of fire of the gun: Vents, rammer, BIA, or crew skill level are not factored in to these graphs. All times where started on the first shot, because it is assumed that a tank will not go into an engagement without being loaded. For the heavies, I tried to take tanks that had similar DPM because the 120mm and 122mm guns can have middle of the road medium tank levels of DPM on certain tanks, and I felt that this would not make a good comparison. This is why I selected the T110E5 and IS-4 instead of the FV215b and 113. This is also more representative of tanks that one would encounter, considering the popularity of the E5 and IS-4 compared to the FV215b and 113. For autoloaders, I used only heavy and medium tanks. This was mostly to reduce the clutter, and because TD's and arty have substantially different play styles. It turns out that all tier X medium tanks really only mount one of three guns; the L7, the U-8TS/D-54, and a single example of and M62 clone on the 121. So for comparison, I tended to higher DPM mediums because I could find examples of each gun that were fairly close to each other. This was mainly determined by the U-8TS, because it has consistently high DPM among all tanks that carry it. There is an exception now with the T-22SR, however tank is so rare that it is hardly ever encountered in public matches. Also, tier X medium tank DPM is substantially divergent (~500) among tanks that are armed with the L7 or clones thereof.
  7. Shortly after Jeeps_Guns_Tanks started his substantial foray into documenting the development and variants of the M4, I joked on teamspeak with Wargaming's The_Warhawk that the next thing he ought to do was a similar post on the T-72. Haha. I joke. I am funny man. The production history of the T-72 is enormously complicated. Tens of thousands were produced; it is probably the fourth most produced tank ever after the T-54/55, T-34 and M4 sherman. For being such an ubiquitous vehicle, it's frustrating to find information in English-language sources on the T-72. Part of this is residual bad information from the Cold War era when all NATO had to go on were blurry photos from May Day parades: As with Soviet aircraft, NATO could only assign designations to obviously externally different versions of the vehicle. However, they were not necessarily aware of internal changes, nor were they aware which changes were post-production modifications and which ones were new factory variants of the vehicle. The NATO designations do not, therefore, necessarily line up with the Soviet designations. Between different models of T-72 there are large differences in armor protection and fire control systems. This is why anyone arguing T-72 vs. X has completely missed the point; you need to specify which variant of T-72. There are large differences between them! Another issue, and one which remains contentious to this day, is the relation between the T-64, T-72 and T-80 in the Soviet Army lineup. This article helps explain the political wrangling which led to the logistically bizarre situation of three very similar tanks being in frontline service simultaneously, but the article is extremely biased as it comes from a high-ranking member of the Ural plant that designed and built the T-72. Soviet tank experts still disagree on this; read this if you have some popcorn handy. Talking points from the Kharkov side seem to be that T-64 was a more refined, advanced design and that T-72 was cheap filler, while Ural fans tend to hold that T-64 was an unreliable mechanical prima donna and T-72 a mechanically sound, mass-producible design. So, if anyone would like to help make sense of this vehicle, feel free to post away. I am particularly interested in: -What armor arrays the different T-72 variants use. Diagrams, dates of introduction, and whether the array is factory-produced or a field upgrade of existing armor are pertinent questions. -Details of the fire control system. One of the Kharkov talking points is that for most of the time in service, T-64 had a more advanced fire control system than contemporary T-72 variants. Is this true? What were the various fire control systems in the T-64 and T-72, and what were there dates of introduction? I am particularly curious when Soviet tanks got gun-follows-sight FCS. -Export variants and variants produced outside the Soviet Union. How do they stack up? Exactly what variant(s) of T-72 were the Iraqis using in 1991? -WTF is up with the T-72's transmission? How does it steer and why is its reverse speed so pathetically low?
  8. Main Battle Wank

    I thought this deserves its own thread. Where do you see tank design going in the next few decades? Where do you think it should go? Here is where I think things will go: -Western tank development will be depressing. Every country will want their own indigenous tank design, and upon learning that they are lolnotevenclose to competent to actually make a first-rate MBT, they'll ask someone who is and end up making something that is practically identical to a Leo 2 or Leclerc, only without parts interchangeability. -Except for the tracks, ammo and engine, because all new Western MBTs will have the same Diehl tracks, MTU powerpack and Rheinmetall 120mm cannon. -Anyone who deviates from this formula will soon learn that all the engineers who actually design tanks hung up their hats in the early 1990s, and that re-building that knowledge base is hard. Being unwilling to put actual work into the problem, any tank designed that isn't based around these proven components will be a gigantic shitshow, and having wasted hundreds of millions of dollars, the country in question will throw up their hands and quietly buy T-90s or T-14s. -The vast majority of tank armor will be increasingly refined NERA, possibly with perforated stand off screens or those wedge thingies from Leo 2A5 to improve performance against LRPs. This fact, abundantly evinced by pictures of damaged tanks and tanks undergoing repair and overhaul, will continue to baffle and elude journalists. -The USA, Turkey, Franco-German consortium, South Korea and Japan will be the only "Western" countries still able to produce MBTs, and all will heavily lean on German-designed tracks, engines and guns. Turkish MBTs and other AFVs will be materially designed by South Korean firms to Turkish specifications. Italy and the UK will both lose their ability to design MBTs, the UK will actually lose their ability to make them, which will be rationalized by saying that MBTs are obsolete. Crystal ball cloudy for Poland, Czech Republic, and whatever tank production capability remains in Romania and former Yugoslavia. -The Russians will re-acquire the lead they had in tank design throughout most of the Cold War, with the Chinese playing second fiddle. Chinese first-line tanks will be quite good, but they will sell hilarious, hot-rodded type 59s to export customers (alongside hilarious hot-rodded J-7s) instead of their good stuff. Russia will sell the good stuff, and once they manage to replicate the parts they needed to source from abroad, it will be really good. The Ukrainian tank industry will remain gutted, and the glorious Kharkiv tank design lineage will fade into obscurity.
  9. This is wonderful. I learned: 1) The leo 1 had poor hull armor, but excellent turret armor! 2) Chieftain's armor was 16 inches thick! 4) The T-64 was the Soviet's own version of the leopard(?!) Actually, the materials science stuff seems solid, and jives with what I've heard before (but how much of that is people repeating this article?).
  10. 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.
  11. Images of the Good Old Days

    http://477768.livejournal.com/2898982.html A bunch of (French?) cartoons about the happy times when armies practiced for the end of the world up and down the European countryside.
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