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    (M4A3E8, ultimate production Sherman) This is a work in progress, please feel free to comment, or help me with info and links. Click here to see the new The Sherman Tank Website! All content is still discussed and previewed in this thread. If you have feedback or want to help with the content, this thread is the best place to do it. The Epic M4 Sherman Tank Information Post. SHERMAN: M4: M4A1: M4A2: M4A3: M4A4: M4A6: M50: M51 The Sherman tank over the last several decades has had its reputation severely soiled by several documentaries, TV shows, and books, all hailing it as a death trap, engineering disaster, or just a bad tank. The Sherman tank may be the most important, and arguably the best tank of the war. The only other contender for the best tank award would be the Soviet T-34. These two tanks are very comparable and would fight each other in later wars, staying very comparable through their service lives. This post will cover why the Sherman was a better tank than anything Germany, Italy or Japan produced during the war, on both a tactical and strategic level. I will not be reproducing the work of others, and will link to the places that already cover some information. I will cover all the major changes made to the each Sherman model. I will try and cover the many post war variants as well, but that could take months, there are a lot of variants of this venerable tank, including ones that involve putting the engine from one hull type into another hull type and or tanks modified by other countries with no feedback from the American designers. I’ll try and get civilian use in here as well. Some variants have heavily modified turrets, or replaced it with a new one. Basic Sherman History: The Big Stuff To really know why the Sherman was designed the way it was, you have to know about the M3 Lee. The M3 was the predecessor of the M4. It was based on M2 medium, the US Army’s only foray into modern medium tank design, and was the fastest way a tank could be designed with a 75 mm M3 canon fitted. The US lacked the jigs to make a turret ring big enough to house a gun that large in a turret; the Lee went into production while the turret ring problem was being solved, by mounting the gun in a sponson mount. It had become clear to the US Army that the 75mm canon would be needed based on feedback from the British, and observations of how the war was developing in Europe. One of the reasons for the reliability of the M4 design was the use of parts that started their design evolution in the M2 medium and were improved through the M3 production run. Over the life of M3 Lee and M4 Sherman the designs were continually improved as well, so a final production, M3, or M4A1, bared little resemblance to an initial production M3 or M4A1, yet many parts would still interchange. This is one of the reasons the Israelis had so much success updating the Sherman to the M50 and M51, these tanks used early small hatch hulls, that never had HVSS suspension installed, but the hulls took the updated suspension with few problems. When the Lee went into production, though it was far from an ideal design, it still outclassed the German and Italian armor it would face, and its dual purpose 75mm gun would allow it to engage AT guns with much more success than most British tanks it replaced. It was reliable, and well-liked by its users. When the British got enough Shermans, the Lees and Grants were sent to the Far East and saw use until the end of the war fighting the Japanese. The Lee excelled at infantry support, since it had a 37mm canon that could fire canister rounds, along with the 75mm gun and a lot of machine guns. Many of these Lee tanks ended up in Australia after the war. Lee variants: The Combat RV (early M3 Lee) M3 Lee: This was the first version of the tank and used a riveted hull with the R975 radial engine powering it, the suspension and tracks were very similar to the M2 medium. Early production tanks had an M2 75mm instead of the improved M3 gun. These tanks had a counter weight mounted on the shorter barrel. All Lees had a turret with 37mm M5 gun. The early production version had two hull mounted, fixed .30 caliber machine guns, another mounted coaxially with the 37mm gun, and another in a small turret, mounted on top of the 37mm turret for the commander. They built nearly 5000 of these tanks. The M3 was improved on the production line with things like removal off hull machine guns, and hull side doors. The mini turret mounted M1919A4 was not a popular feature, and was hard to use, but it remained on all Lees, and were only deleted from the Grant version produced exclusively for the British. If this version had a major flaw, it would be the riveted armor plates could shed rivets on the inside of the tank and these rivets bounced around like a bullet. This was bad for the crew, but, rarely resulted in a knocked out tank. A field fix for this was welding the rivets in place on the interior of the tank. Most of the M3 Lees produced went to the British. (cast hull M3A1) M3A1 Lee: This version of the Lee had a cast hull, and R975 radial power. It was really the same as the base Lee in most respects including improvements. 300 built. These cast hull tanks have a very odd and distinctive look. They look almost like a M3 Lee was melted. This hull casting was huge and more complicated than the M4A1 casting. Most of these tanks were used in the United States for training. M3A2 Lee: This Lee had a welded hull and the R975 powering it. 12 built. This version was more of a ‘proof of concept’ on welding a hull than anything. M3A3 Lee: Another welded hull but this one powered by the GM 6046 Twin Diesel. 322 built, like the base Lee, with the same improvements. This is the first vehicle the 6046 was used in, and most of the bugs were worked out on this model. M3A4 Lee: This version had a riveted hull and was powered by the A-57 multibank motor. This motor was so large the hull had to be stretched for it to fit; it also required a bulge in the top and bottom of the hull to fit the cooling fan. They also had to beef up the suspension, and the suspension units designed for this would become standard units on the Sherman. This would be the only version of the Lee with the improved bolt on offset return roller VVSS, otherwise this tank was very much like the base M3. 109 built. This motor’s bugs were worked out on this tank and would go on to power a large chunk of Sherman production. (Monty's M3A5) M3A5 Grant: Another welded hull, powered by the GM 6046 Twin diesel with a new bigger turret to house British radios. 591 built. This new turret deleted the small machine gun turret on the roof of the 37mm turret. This version was used only by the British. The famous General Montgomery’s personal M3A5 is on display in England, at the Imperial War Museum in London. . . . The majority of Lee and all Grants saw service with the British, and many Lees went to the Soviet Union. They were generally well liked by both nations and more reliable than most of its British and German contemporaries. These tanks were better than the enemy tanks they faced until the Germans up gunned the Panzer IV series. When they were replaced with M4s of various types the M3 were shipped to the Far East for use in Burma and New Guinea. The Japanese had no tank that could take on a Lee, let alone a Sherman. Using soldiers as suicide bombers, and mines still worked though, there was also a pesky 47mm AT gun, but it was rare. They saw limited use in the US Army’s hands some seeing combat in North Africa, because US combat units lost their Shermans to replace British losses, and a few were used in the PTO. The Sherman owes it success to the lessons learned producing the Lee and from its use in combat. The 75mm gun and automotive systems, even the more complicated ones, would be perfected in the Lee and re-used in M4, and the Sherman only had one motor not tested in the Lee first. Many of the Lee variants were produced at the same time and the numbering system was more to distinguish between hull and engine types, not to model progression like in aircraft, and other tanks. This practice was carried over to the M4 series as were all the engines used in the Lee. Many people familiar with the way the United States designated aircraft during the war figure it was carried over to tanks and think an M3A1 was an improved M3, and an M3A2 was an improved A1. This is not the case, as many of these versions were produced at the same time, and they all received the same sets of improvements, though some factories took longer to implement things than others. The M4 went into production as soon as the jigs for the turret ring were produced and ready to be used. Production actually started on the cast hull M4A1 first, with the welded M4 following right behind it. Like the Lee, there were many version of the Sherman in production at the same time. There are many photos of Lee’s coming off the production line, with Shermans in the line right behind the last Lee, so there was no real gap in production between the two tanks at most of the factories. The Sherman variants: The Design Matures First off, Americans referred to the Sherman as the M4, or M4 Medium, or Medium, the Sherman name was not commonly used until post WWII. The British came up with the name for the M4 and referred to it with their own designation system that will be covered in more detail later. They also named the Lee, and Stuart, and at some point the US Army just stuck with the naming scheme. The full story behind this is still a minor mystery, with US war time documents confirming the ‘general’ names were at least used on paper by the US Army during the war. Now let’s cover the factory production versions of the Sherman. Also keep in mind, it is very hard to define just how a Sherman may be configured without really knowing where and when it was produced. In some rare cases, large hull, 75mm armed Shermans got produced with normal ammo racks, when the norm for large hatch hull tanks was wet ammo racks. . . . (this is a very early production M4 with DV ports that are not welded closed and have not had armor added over them) M4 Sherman: These tanks used the same R975 motor as the M3, and M3A1. The vast majority of the bugs in this automotive system were worked out before the M4 even started production. This really helped give the Sherman its reputation for reliability and ease of repair. The M4 had a welded hull with a cast turret mounting the M3, 75mm gun. Early variants had three hull machine guns, and two turret mounted machine guns. The hull guns were all M1919A4 .30 caliber machine guns, two fixed, and one mounted in a ball mount for the co-drivers use. The fixed guns were deleted from production very rapidly. The turret armament remained unchanged for the whole production run: Using the M3 75mm gun with the M1919A4 coaxial machine gun and M2 .50 caliber mounted on the roof. The turret would be the same turret used on all early Shermans and would be interchangeable on all production Shermans. This version was not produced with the later improved T23 turret but did get some large hatch hulls in special variants. There were two variants of the M4 to be built with the large hatch hull. The first, the M4(105) was a large hatch hull mated to the 105mm howitzer, on the M52 mount, in the standard 75mm turret. These hulls did not have wet ammo racks or gyro stabilizers, and the 105mm turrets had an extra armored ventilator, the only turrets to have them. The M4 (105) gun tanks had a special mantlet, with four large screws in the face, unique to 105 tanks. Production started in February of 44, and continued well into 45, with late production M4(105) tanks getting HVSS suspension. These tanks were used as replacements for the M7 Priest in tank units, and spent most of their time being used as indirect fire support, like the M7 they replaced. One other variant of the M4 to get the large hatch hull(100 or so small hatch casting were made as well), this was the M4 ‘hybrid’, this hull was welded, but used a large casting very similar to the front of the M4A1 on the front of the hull. It was found that most of the welding hours building the welded hull tanks were spent on the glacis plate. They figured by using one large casting, incorporating the hatches and bow gun would save on welding time and labor costs. (This is an M4 hybrid, large hatch tank. but with no wet ammo racks) These M4 hybrids were used by the British to make Ic Fireflies. They liked the 75mm turret these tanks came with since they already had a loaders hatch, this saved them time on the conversion since they didn’t have to cut one. These large hatch M4s did not get the improved T23 turret, but did have wet ammo racks and all the large hatch hull improvements. Most of these tanks were shipped to Europe or the Pacific, making survivors rare. The M4 along with the M4A1 were the preferred US Army version of the Sherman until the introduction of the M4A3. This tanks was made in five factories from July of 42 to March of 45, 7584 produced. (this image is a small hatch M4A1 with DV ports welded closed and add on armor over them, not the very early turret with small mantlet. The suspension on this tank was probably updated from the early built in roller type during a depot rebuilt. Image from the awesome sherman minutia site) M4A1 Sherman: This was virtually the same tank as the M4, with the same motor and automotive systems and armament. The key difference was the cast upper hull. This huge upper hull casting was one piece. This was a very hard thing to do with casting technology at the time, and something the Germans could not have reproduced, they lacked the advanced technology, and facilities needed to do so. Everything from hatches to wheels, and turrets, and guns were interchangeable with the M4 and other Sherman models. This version saw production longer than any other hull type. It also saw all the upgrades like the improved large hatch hull with wet ammo racks, the T23 turret with 76mm gun, and HVSS suspension system. It was 30 of these M4A1 76 HVSS tanks that were the last Shermans ever produced. The M4A1 was also the first to see combat use with the improved M1 gun and T23 turret during operation Cobra. Three factories produced 9527 M4A1s with all turret types from Feb 42 to July of 45. The US Marines used one Battalion of these tanks on the Cape Gloucester campaign, small hatch M4A1 75 tanks. This was the only use of this tank by the Marines. (M4A2 75 mid production with improved drivers hoods, from this angle you can not tell the difference between an M4 M4A2, M4A3, image courtesy of the sherman Miniutia site) M4A2 Sherman: This version of the Sherman used a welded hull nearly identical to the M4, but with a pair of vented armored grates on the rear hull deck. The M4A2 tanks used the GM 6046 twin diesel. This version was produced with all the improvements the other types got, like the large hatch hull with wet ammo racks, the T23 turret with improved M1 gun, and HVSS suspension. This version would see very limited combat in US hands, most being shipped to Russia with a few early hulls going to the Brits and USMC. This was the preferred version for Soviet lend lease deliveries, since the USSR was using all diesel tanks. It was produced in six factories with 10,968 of all turret types produced from April of 42 to July 45. A little trivia about this version, the Sherman used in the movie Fury, was actually a late production M4A2 76 HVSS tank. The only way you can tell a late A2 from a late A3 is by the size of the armored grills on the back deck. They did a great job of hiding this area in the movie. The Marines operated a lot of small hatch and a fairly large number of large hatch M4A2 tanks, until the supply of 75mm armed version dried up in late 1944. Then they switched over to large hatch M4A3 75w tanks, but there were some A2 holdouts amongst the six battalions. (this is an M4A3 large hatch 75mm tank, it has wet ammo racks and a hatch for the loader.) M4A3 Sherman: This would be the base for what would be the final Sherman in US Army use, seeing action all the way out to the Korean War in US Army hands. This tank had a welded hull just like the M4, A2, and A4, but used a new motor. The Ford GAA V8, this motor took some time for its bugs to be worked out, so unlike say, the Nazi Germans, the US Army didn’t use it until it was ready for serious production. When it was, it became the preferred US Army version of the tank in both the 75mm and 76mm armed tanks. It would see all the improvements, and be the first hull type to take the HVSS suspension system into combat for the US Army. The M4A3E8 or M4A3 tank with T23 turret and HVSS suspension bolted on would be the final and ultimate US Army Sherman. It would be produced in three factories with all turret types, 12,596 built in total between June 42 and June of 45. After WWII when the Army wanted to standardize on one Sherman type, any M4A3 large hatch hull they could find would have a T23 turret and HVSS suspension installed on it. The Army was so thorough in these conversions no M4A3 large hatch 75mm gun tanks are known to have survived with the original turrets installed. Any M4A1 HVSS 76 and M4A2 HVSS 76 tanks in Army inventory would have been robbed of their suspensions and turrets so they could be installed on M4A3 large hatch hulls. (an M4A3E2 Jumbo with correct M3 75mm gun) The M4A3E2 Jumbo, Fishers fat and special baby! FTA was the sole producer of one very special variant of the Sherman, the M4A3E2 Jumbo. This version of the Sherman was the assault Sherman, though not expressly designed for it, was manufactured to be able to lead a column up a road and take a few hits from German AT guns or tanks so they could be spotted without having to sacrifice the tank. It had a lot of extra armor, and could take a lot of hits before being knocked out, but was still not impervious to German AT gun fire. Only 254 of these tanks were produced, and all but four were shipped to Europe for use by the US Army. They were all armed with the M3 75mm gun. There was a surplus of M1A1 76mm guns in Europe due to an aborted program re arm 75mm Sherman tanks with the guns. Many of the Jumbo’s ended up with these guns, but none were ever factory installed. The tank was no different in automotive components from the M4A3 tanks, with the sole difference being the slightly lower final drive gear ratio, going from a 2.84:1 ratio in the base Shermans, to 3.36:1 on the Jumbos. This reduced the top speed slightly but helped the tank get all the extra armor moving. The Jumbos were well liked by their crews and in great demand; no more were built though, the only batch being produced from May to July of 1944. Had the invasion of Japan been needed, a special Jumbo with larger turret that included a flame thrower was considered, but we all know how that story ended. This version of the Sherman was issued to the Marines when the M4A2 75mm tanks went out of production. The version they would have been issued, would all have been large hatch M4A3 75w tanks, and they may have gotten some with HVSS. (this is an M4A4, the best way to tell is the extra space between the road wheels) M4A4 Sherman: This tank is the oddball of Sherman tanks. It had a welded hull and used the A-57 multibank motor. A tank motor made from combining five car motors on one crank case. As complicated as this sounds, it was produced in large numbers and was reliable enough to see combat use, though not in American hands in most cases. In US use they tried to limit it to stateside training duty. The Brits found it more reliable than their native power plants, and liked it just fine. This version never got the improved large hatch hull or T23 turret with M1 gun. Most were shipped to the Brits via lend lease and many were turned into Vc Fireflies, making it the most common Firefly type. The Free French also got at least 270 of these tanks in 1944. The Chinese also received these tanks through lend lease but not many. The US Marines operating these tanks in the states as training tanks, 22 of them for two months before they were replaced by M4A2s. This tank had a longer hull, like its Lee cousin to accommodate the big A-57 motor. It was the first Sherman version to go out of production. It was produced in one factory (CDA) from July of 42, to November of 43 with 7499 built. The A4 has the honor of being the heaviest and largest standard Sherman. The larger hull to accommodate the A57 motor, and the motor itself added weight. The British used these tanks extensively in combat. These tanks show up in British test reports as well, often pitted against tanks like the Cromwell in reliability or other tests, and usually coming out ahead. Anyone who has ever changed the spark plugs on their car should really be able to appreciate how hard a motor made by tying five six cylinder automobile engines together, on one crank would be. . . . All Sherman variants share a lot of details and most spare parts interchange. Only the motors really call for different parts. All early Sherman tanks had 51mm of armor at 56 degrees on the front hull, and 76mm on the front of the turret. The 56 degree hulls are called small hatch hulls because the driver and co-driver had small hatches that forced them to twist sideways to get in and out. They also started out with direct vision ports along with periscopes for crew vision. Even the cast tanks matched these specs and the hatches from a cast tank could be used on a welded tank. These early hulls had some of the ammo racks in the sponsons above the tracks. Not a great place for ammo, but not an uncommon one for it either. As they improved the hull, they added plates over the direct vision ports and eventually removed them from the castings. Large plates were eventually welded over the ammo racks on the sides, and this extra armor was eventually just added into the casting on the cast hulls. It’s safe to say no small hatch tanks were factory produced with a 76mm gun or improved T23 turret. The major hull change came when they upgraded the drivers and co drives hatches making them bigger. They also thickened the front armor to 64mm but reduced the slope to 47 degrees to fit the new driver’s hatches. The M4 (hybrid and 105 only), M4A1, A2, and A3 were produced with these improved large hatch hulls. Many of these improved large hull tanks had the original 75mm gun and turret. Even the M4A3 with HVSS suspension was produced with the 75mm gun and turret. Most of the large hatch production was with the new and improved T23 turret. These larger hatch hulls would still accept the majority of the spares the older hulls used and the lower hull remained largely unchanged and would accept all the suspension types. Any large hatch M4A3 hull was likely converted to an M4A3 76 HVSS post WWII. Through the whole production run minor details were changed. The suspension saw many different version before the final HVSS type was produced. The track types also changed and there were many variants made from rubber and steel, or steel. There were even at least six different types of road wheel! There are so many minor detail changes, the scope is to big to cover in this post, needless to say, the only other tank I know of with so many minor changes over the production run was the Tiger, and in the Tigers case it’s just sad, with so few produced, it means almost no two tigers were the same. This was not the case for the Shermans and the changes did not slow production down at all and in many cases were just different because a particular part, like an antenna mount, or driver’s hood, could have been sourced from a different sub-contractor, and the parts may look different, but would function exactly the same. Tiger parts are not good at interchanging without modification, and a crew a craftsmen to custom fit them. The changes made to the Sherman were either to incorporate better parts, or to use a locally made substitute part for one in short supply, so making their own version allowed them to continue production without a slowdown. To really get a handle on these differences there are two really great sources. This is the easy, way: Sherman Minutia site a great site that really covers the minor detail changes on the Sherman tank very well. You can spend hours reading it and looking over the pictures. It explains little of the combat history of the Sherman but covers the minor changes on the vehicles themselves very well. You can spend hours on this site learning about minor Sherman details. It is also a primary source for this post. Another great way is to get a copy of: Son of a Sherman volume one, The Sherman design and Development by Patrick Stansell and Kurt Laughlin. This book is a must have for the Sherman plastic modeler or true enthusiast. It is filled with the tiny detail changes that took place on the Sherman production lines from start to finish. They cover everything from lifting eyes to ventilators, casting numbers, to most minor change to the turrets. Get it now before it goes out of print and the price skyrockets. I liked it so much I bought two! The turret saw continual change as well, but remained basically the same. The 75mm gun never changed but its mount and sighting system did. The turret lost the pistol port, and then gained it back. It gained a rotor shield over time and an extra hatch. All these detail changes are covered on the site above and in the Son of a Sherman book. The important thing to note was the tank saw continual improvement to an already reliable, and easy to produce design. The Sherman was easy to produce for an industrial nation like the USA, but beyond Nazi Germany’s technical capabilities for several reasons, like large casting and the gun stabilization system, or even multiple reliable motors to power the tens of thousands of tanks made. In the basics section I’m only going to cover one more thing. The Sherman tank was not as blind as the tanks it faced. The M4 series, from the first production tank, to the final Sherman that rolled off any of the production lines, were covered in periscopes or view ports for the crew. The gunner had a wide angle periscope that had incorporated the site for the main gun, and they very quickly added a telescopic site to go with it. The commander had a large rotating periscope in his rotating copula. The loader had a rotating periscope and the driver and co-driver had two, one in their hatch, and another mounted in the hull right in front of them once the DV ports were deleted (non-rotating). Later version added a direct vision cupola and a periscope for the loader in his new hatch. All these periscopes could be lowered and the port closed, and if damage easily and quickly replaced from inside the tank. All this gave the Sherman an advantage in spotting things outside the tank; they were still blind, just not as blind as most of the tanks they would face. Finding an AT gun in a bush could be very challenging for any tank, and infantry if not scared off by the presence of a tank in the first place can sneak up on one pretty easy. This was a big advantage when it saw combat and throughout the tanks career it was always one of the best if not the best tank of the war. It was reliable, the crew had a good chance of spotting enemies before other tank crews, the gun was stabilized, fast firing, and accurate. It was as good or better than most of the tanks it faced, even the larger German tanks. These tanks were largely failures, with only long debunked Nazi propaganda propping up their war record. The Sherman has the opposite problem. Sherman Builders: Just How Many Tank Factories Did the US Have Anyway? They Had 10 and 1 in Canada. Most of the information in this section will be a summation of the section in Son of a Sherman. Other stuff I had to dig around on the internet for. Anyone who has more info on the tank makers, please feel free to contact me. Parts from all these tank makers would interchange. Many used the same subcontractors. I don’t think anyone has tried or if it’s even possible to track down all the sub-contractors who contributed parts to the Sherman at this point. Some of the manufactures were more successful than others, some only producing a fraction of the total Sherman production, others producing large percentages. By the end of production, all the US and her allies needs for Shermans were being handled by just three of these factories. American Locomotive (ALCO) ALCO also produced M3 and M3A1 Lees, and made Shermans up to 1943. They were a fairly successful pre-war locomotive manufacturer founded in 1901 in Schenectady, New York. They also owned Montreal Locomotive works. ALCO made several version of the Sherman, and stayed in the tank game until the late 50s, helping with M47 and M48 production. The company went under in 1969. Baldwin Locomotive Works (BLM) Baldwin was another early producer, building three versions of the Lee, The M3A2, M3A3, and M3A5. They mostly built small hatch M4s, with just a handful of M4A2(12). They were out of the Sherman game by 1944 and out of business by 72. They were founded in Philly in 1825, and produced 70,000 steam locomotives before it died. (M4A4 and M3s being built side by side at CDA, photo courtesy of the Sherman Minutia site ) Chrysler Defense Arsenal (CDA) Chrysler Defense Arsenal is kind of special. It was a purpose built tank factory, funded by the US Government, and managed and built by Chrysler. Construction on the factory started in September of 1940. Completed M3 Lee tanks were rolling of the line by April of 1941. This was before the factory was even finished being built. It was built to stand up to aerial bombing. They produced M4A4, and M4 tanks as well and M4 105s, M4A3(105)s, and M4A3 76 tank and nearly 18,000 of them. Chrysler was the sole producer of M4A3E8 76 w Shermans, or the tank commonly known and the Easy 8. They produced 2617 units, but post war many A3 76 tanks were converted over to HVSS suspension. A very big chunk of the overall Sherman production came from this factory and it went on to produce M26 Pershing tanks. Chrysler built this factory in a suburb of Detroit, Warren Township Michigan. Chrysler used it’s many other facilities in the Detroit area as sub manufacturers, and many of their sub-contractors got involved too. CDA not only produced the tanks, it had the capacity to pump out huge numbers of spare parts. CDA lived into 90s before Chrysler defense systems got sold off to General Dynamics. It took part in making the M26, M46, M47, M48, M60 and M1 tanks. Federal Machine & Welder (FMW) I couldn’t find much out about FMW, Son of a Sherman says they were founded in Warren Ohio in 1917. They produced less than a thousand M4A2 small hatch tanks. They were slow to produce them, making about 50 a month. They were not contracted to make any more Shermans after their first 540 total, 1942 contract. They did build some M7, and M32 tank retrievers. They were out of business by the mid-fifties. Fisher Tank Arsenal (FTA) Fisher Tanks Arsenal (FTA) has a lot of common with Chrysler Defense Arsenal, except this time Uncle Sam went to Fisher Body, a division of General Motors. Fisher decided to build the tank plant in Grand Blanc, south of Flint Michigan. The factory broke ground in November of 1941 and the first M4A2 Sherman rolled off the line in January of 1942, before the factory was fully built. The M4A2 was something of this factory specialty, in particular early on, with them producing a large number of the small hatch M4A2 sent off to Russia, and a few of the rarer large hatch 75mm gun tanks, around 986 small hatch tanks, and about 286 large hatch tanks. They also produced nearly 1600 large hatch, 76mm gun tanks, or the M4A2 (76)w. These tanks went exclusively to Russia as part of Lend Lease. These tanks were ordered over four different contracts and the final ones off the production line were all HVSS tanks. The HVSS suspension may have seen combat with the Russians before the US Army used it. Oddly, this factory also produced M4A3 76w tanks, but never with the HVSS suspension. Fisher produced a significant number M4A3 and Large hatch 75mm tanks at their factory, but nowhere near their M4A2 production. Ford Motor Company (FMC) Ford was a surprisingly small player in the Sherman tale. They are very important in that they developed the Ford GAA V8 covered earlier, and a lot of spare parts. But they only produced 1690 small hatch Shermans between June of 42 and Oct 43. They built a few M10s as well. All these tanks and tank destroyers were produced at their Highland Park facility. After 1943, they stopped building tanks, and wouldn’t get back into until the 50s, and even then it was just for a large production run over a short time, of M48s. Lima Locomotive Works (LLW) Lima was one of the first producers of the cast hull M4A1. It did not produce any Lee tanks. Its production capacity had been taken by locomotives to the point just before Sherman production started. They produced the first production M4A1, that was shipped to England, named ‘Michael’, and it’s still on display at the Bovington Museum. They produced Shermans from February of 42, to September of 1943, producing M4A1s exclusively, and they built 1655 tanks. The war was a boon for Lima, they’d been in business since 1870, and the contracts from the military for locomotives really helped them out. Post war, they failed to successfully convert to diesel electric locomotives and merged with another firm. Montreal Locomotive Works (MCW) MLW was owned by American Locomotive. They produced some wacky Canadian tank based off the Lee chassis, called the Ram, and Ram II, these floppy creations were only armed with a 2 pounder in the Rams case, and a 6 pounder, in the Ram IIs case, and they produced almost 2000 of the wacky things, what’s that all aboot? They eventually got around to producing a proper Sherman tank, the M4A1 “Grizzly”, producing only about 188 tanks. A very few had an all metal track system that required a different sprocket. Other than that, there was no difference between a grizzly and an M4A1 manufactured by any other Sherman builder. Don’t believe the Canadian propaganda about it having thicker armor! Pacific Car & Foundry (PCF) PCF was founded in 1905 in Bellevue Washington. The only west coast tank maker, PCF produced 926 M4A1s from May of 1942, to November of 1943. As soon as production stopped they started production on the M26 tractor, the truck portion of the M26 tank transporter. They never got back into tank production, but still exist today as PACCAR Inc., one of the largest truck makers in the world. Pressed Steel Car (PST) PSC was one of the big boys of Sherman production, and they also produced the final M4s made, a group of 30 M4A1 76 HVSS tanks. PSC was founded in Pittsburg in 1899, but their tank factory was in Joliet, Illinois. They were the second manufacturer to make the tank and across all the versions they made, they produced 8147 Sherman tanks. They started tank production with the M3 Lee in June of 41, and stopped production on that in August of 1942. They then produced the M4A1 from March of 42, to December of 43, and the standard M4 from October of 42 to August of 43. They were one of the final three tank makers to stay in the tank making business after 1943, along with CDA and FTA. PSC would produce large hatch M4A1 76 tanks, including HVSS models late in the run, totaling more than 3400 M4A1 tanks. They produced 21, M4A2 76 HVSS tanks, towards the end of 45. They were out of business by 56, with no tank production after those final 30 M4A1 76 HVSS tanks. Pullman Standard (PSCC) Pullman Standard was a pretty famous luxury train passenger car maker, and another company that made rolling stock combined into one company. Pullman Palace Car Co was founded in 1867, or there about. I’m sure some train geek will be dying to fill me in on the company’s history but I’m not really going to look deeply into it. It does make for one of the more interesting stories about a Sherman tank producer. Their main tank factory was in Butler, Pennsylvania. And they helped produce some Grant tanks before they started Sherman production. They produced the M4A2 from April of 42 to September of 43, and produced 2737 tanks. They also produced 689 standard M4 Sherman tanks from May of 43, to September of 43. Soon after these contracts were finished the US Government broke the company up due to some anti-trust complaint. … The thing to remember about all the Sherman makers is each one had a small imprint on the tanks they produced. So, yes, an M4A1 small hatch tank was the same no matter who made it and all parts would interchange with no modification needed, but the tanks from different makers still had small, cosmetic differences. They may have been something like nonstandard hinges on the rear engine doors to the use of built up antenna mounts instead of cast. Or wide drivers hoods or narrow, to where the lift rings on the hull were and how they were made or even Chrysler's unique drive sprocket they put on all their post A4 tanks. None of this meant the parts couldn't be salvaged and used on another Sherman from another factory without much trouble. Some factories may have produced tanks faster than others, but they all produced them within the contracts specification or they were not accepted.
  2. 14 points
    I've been meditating a lot lately on humans that I hate. I would say "people I hate," but once I take to hating a someone enough I de-classify them as a person. I've been focusing on hate more because I've realized that there is no point in marinating in negative emotions. What I had mistaken for righteous indignation was really jealousy. I'm not angry at the fraudulent because I hate fraud; I'm angry because they're talentless hacks and I could do a far better job. But I'm lazy, so you, my talented reader, you must do a better job, and become a more ravenous, vicious, and unstoppable leech than ever these mediocre reprobates could dream. I got the idea when I was reading the latest drivel from our favorite poly sci majors, and I realized that the authors are fundamentally parasitic con artists, and, more to the point, half-assed ones. The article is only worth reading if you want to heckle it. It has no factual content. The funniest part is probably where they're talking up the threat of firearms made on 3D printers, and then bring up the Ghost Gunner, which isn't a 3D printer. It's a fucking mill. You know, an example of that old-fashioned subtractive manufacture that's supposed to be obsolete now. This is as intellectually honest as hyping the threat of being stung to death by zebras in the streets, and pointing out that tapirs will bite your fucking arm off as evidence of the severity of the threat. I am, of course, heartened to see that these worms have doubled down on their claim that 3D printing is somehow applicable to clandestine manufacture of nuclear weapons, and are, as before, aggressively misunderstanding fundamental facts about isotope enrichment. If there's anything that these scum are good at, it's ignoring basic fucking nuclear physics. But other than that, it's not a particularly slick attempt to sew panic and profit thereby. The best possible result from this sort of scaremongering is that some useless government regulatory agency will be set up to strangle 3D printing with useless regulations. This useless agency will have some number of jobs that will be filled with poly sci majors and other unemployable refuse. Anyone employed in this hypothetical useless agency would work nine to five in a cubicle, watching whatever their favorite deviant sort of porn is, calling in sick about a third of the time, and occasionally writing internal correspondence that will be beautifully devoid of meaning. Is this sort of soul-raping mediocrity anyone's idea of a big steal? Because if getting a fake job at a fake agency to police a fake threat is your notion of making it, please enclose yourself in a running incinerator. You have some sort of pathogen that causes you to aspire to being a moderate nuisance, and that sort of plague needs to stop now. The problem with these people is that their lies are small. As we all know, big lies are better than little ones. Don't stretch the truth; snap it right the fuck off. The only thing standing between you and gigantic yachts made of cocaine is a sentimental attachment to the truth. The lord of this world will only reward you fully if you embrace him fully. Highly successful liars don't embroider the truth, they dispense with it entirely. Consummate your marriage to darkness and falsity, and receive glorious rewards. Don't say that the Eisenhower administration should have been more aggressive in defense spending and research. Say that the Soviets have more bombers and more missiles. You'll get to be president of Camelot, fuck Marilyn Monroe and will be spared the indignity of old age. Don't say that 3D printing could change the way nuclear weapons are made in the future. Claim that the Iranians and North Koreans, and hell, that the South Africans all made their nuclear weapons by using 3D printers. When asked for evidence of your nonsense, point to the South African invasion of Sudan. Say so with absolute arrogance and an unshakable air of moral superiority. If you are loud and persistent enough, and lie outrageously enough, Satan will come through. Don't shill for big coal companies by claiming that coal gasification technology will improve atmospheric conditions. That's only stretching the truth. You've got to go all the way, and just burn regular coal that you painted with Elmer's glue. Your enemies will end up under review, and you'll get millions in tax credits. Satan delivers. Praise Satan. But you have to be willing to go all the way with Satan. Satan despises spineless, cowering wretches who sin a little to get ahead but still consider themselves fundamentally decent people. Satan came through for the solar roadways bastards. Satan came through for Leroy Jenkins. Trust in Satan, and you will excel. Don't you trust Satan? Do you think that Satan is ignorant of your duplicity? You cannot serve two masters. Drink deep or taste not.
  3. 13 points
    Hello, my friends and Kharkovites, take a sit and be ready for your brains to start to work - we are going to tell you a terrible secret of how to tell apart Soviet tanks that actually works like GLORIOUS T-80 and The Mighty T-72 from Kharkovites attempt to make a tank - the T-64. Many of capitalists Westerners have hard time understanding what tank is in front of them, even when they know smart words like "Kontakt-5" ERA. Ignoramus westerners! Because you are all were raised in several hundreds years old capitalism system all of you are blind consumer dummies, that need big noisy labels and shiny colorful things to be attached to product X to be sold to your ignorant heads and wallets, thats why we will need to start with basics. BASICS, DA? First - how to identify to which tank "family" particular MBT belongs to - to T-64 tree, or T-72 line, or Superior T-80 development project, vehicles that don't have big APPLE logo on them for you to understand what is in front of you. And how you can do it in your home without access to your local commie tank nerd? Easy! Use this Putin approved guide "How to tell appart different families of Soviet and Russian tanks from each other using simple and easy to spot external features in 4 steps: a guide for ignorant western journalists and chairborn generals to not suck in their in-depth discussions on the Internet". Chapter 1: Where to look, what to see. T-64 - The Ugly Kharkovite tank that doesn't work We will begin with T-64, a Kharkovite attempt to make a tank, which was so successful that Ural started to work on their replacement for T-64 known as T-72. Forget about different models of T-64, let's see what is similar between all of them. T-72 - the Mighty weapon of Workers and Peasants to smash westerners Unlike tank look-alike, made by Kharkovites mad mans, T-72 is true combat tank to fight with forces of evil like radical moderate barbarians and westerners. Thats why we need to learn how identify it from T-64 and you should remember it's frightening lines! The GLORIOUS T-80 - a Weapon to Destroy and Conquer bourgeois countries and shatter westerners army And now we are looking at the Pride of Party and Soviet army, a true tank to spearhead attacks on decadent westerners, a tank that will destroy countries by sucking their military budgets and dispersing their armies in vortex of air, left from high-speed charge by the GLORIOUS T-80! The T-80 shooting down jets by hitting them behind the horizont
  4. 13 points
    *cracks fingers* Something that has interested me for a while, are shape stabilised projectiles. As in, projectiles that are stable due to their shape. Everybody has heard of rotation stabilised and fin stabilised projectiles, but shape stabilised is kind of different. I guess most of you here have seen shape stabilised projectiles without actually knowing how and why they work. Geek sidenote: Fin stabilised projectiles are actually fin and rotation stabilised. As I said, shape stabilised projectile have a stable flight path due to their unique shape. Figure 1: A 84mm Carl Gustav shape stabilised HEAT-round Note the slightly ogive front and the stand-off, which are characteristic of shape stabilised projectiles (SSP). Both features are absolutely crucial for the SSP to work. I'm going to throw you guys into the deep end by showing a .gif of the airflow in front of an SSP. Here's a link because I can't embed .gifv apparently The first thing you should notice is the air circulating in some-sort of pocket, and that this airflow is subsonic. Before I continue, here's the airflow in front of a blunt projectile: Clicketyclick While that projectile has a subsonic airflow in front of it as well, it is not circulating. Here's the airspeed of both projectiles as a normal picture: Figure 2: Airspeed in front of an SSP Figure 3: Airspeed in front of a blunt projectile It's clear that an SSP has a ogive-shaped subsonic airpocket in front of the projectile. This basically emulates the ogive of a normal rotation stabilised projectile. In other words, it makes it more aerodynamic. But does that airpocket stabilise the projectile? No it does not. So why is this projectile stabilised? The key is in what happens when it starts to tumble. Right now, there is nothing stopping the projectile from tumbling, and that's the interesting thing. There is literally nothing stopping the projectile from tumbling, except... the projectile itself. Lets take a look at what happens when an SSP starts to tumble. (If I remember correctly, I rotated the projectile 10 degrees) First off, the airflow in front of the projectile. It's fairly obvious that the airflow has changed. Lets check that again, but this time as a picture. Figure 4: Airflow in front of a tumbling SSP Again, it's obvious that the airflow has changed. The subsonic pocket has mainly shifted to one side and the air itself isn't really circulating in the pocket. This change causes a huge change in the Cd of the projectile. Let me show you why. Figure 5: Pressure in front of a tumbling SSP Next, the pressure in front of an SSP flying straight. Figure 6: Pressure in front of an SSP flying straight Please note the approximate pressure in front of both projectiles. The tumbling projectile has, on one side, twice the pressure as the projectile that's flying straight. Very interesting. What's even more interesting is that the pressure occurs on the opposite of the side it's turning to! The projectile is turning upwards, but the pressure builds up at the bottom. This pressure forces the projectile to start turning down again, forcing the projectile in a state where the pressure on all sides is equal. Voila, a shape stabilised projectile. But... why does it work? The subsonic airpocket is created by the stand-off and that little flange, or whatever you want to call it. The dimensions and placement of both are equally important. The stand-off and its side create the airpocket and the flange give the airpocket the required shape. The stand-off size can vary, but the flange size and placement is very important. If the flange is too far forward or too far back, the airpocket will be either too small or too big. Why does the size of the pocket matter? Because of this: Figure 7: Subsonic pocket in front of an SSP I changed the parameters slightly and made all airflow above Mach 1 red. Whatever is not red, is trans- or subsonic. The interesting thing to note here, is the pocket extends to the edge of the projectile (if I made the projectile better it should be exactly on the edge). (Sidenote: Here's the same picture of an SSP at a 10° angle) While the airpocket does not start at the flange, the flange determines where the pocket starts. If, at this velocity, the flange was further back, there would be supersonic flow hitting the front of the projectile, massively increasing drag. If the flange was further forward, the airpocket would be further forward too. This would mean the airpocket would not end at the edge of the projectile, but further out. Creating an airpocket which is wider than the projectile. This would allow the projectile to tumble a bit, because pressures wouldn't change much unless there is supersonic flow hitting the projectile. It is also possible to change the size of the airpocket by changing the front of the projectile itself. If the radius connecting the front and the stand-off is too big, the airflow inside the pocket would disrupt the circulation. The same would happen if the radius is too small. The angle of the front is important as well, but I haven't expermented that much with it so I don't know how important it exactly is, but it has an effect on the airflow. By the way, if the flange did not exist at all, the airpocket would start at around a third to half of the stand-off. Which would completely ruin the airpocket. Without a flange, the stand-off itself would have to be way bigger and longer to create the same kind of airpocket. But Bronezhilet, I hear you cry, if the airspeed changes, the pocket changes as well! I'm glad you brought that up, because you are right. A shape stabilised projectile only works properly within a certain flight envelope. If the projectile is moving too fast, the airpocket would compress allowing supersonic flow to hit the front of the projectile. Which in turns increases drag. By a lot. If the projectile is moving too slow the airpocket widens, allowing the projectile to tumble a bit before it would stabilise. I've been brainstorming with Colli a bit, and we've come to the conclusion that is why some projectiles are both shape stabilised and fin stabilised. When the projectile is moving too slow for shape stabilisation, the fins would keep it pointing in the right direction. And that concludes today's lesson. Thank you for reading.
  5. 13 points
    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.
  6. 12 points
    The mean goons over on SA roped me into writing an effortpost, so I figured it's only fair that you freeloaders get to enjoy it too. So, suspensions. I'm going to introduce the book as well because it's probably the most Soviet book that ever existed. It is called TANK. What makes this book so Soviet? Well, here's the first paragraph of the introduction: "Under the guidance of the Communist party of the Soviet Union, our people built socialism, achieved a historical victory in the Great Patriotic War, and in launched an enormous campaign for the creation of a Communist society." The next paragraph talks about the 19th Assembly of the CPSU, then a bit about how in the Soviet Union man no longer exploits man (now it's the other way around :haw:), then a little bit about the war again, then spends another three pages stroking the party's dick about production and growth. The word "tank" does not appear in the introduction. The historical prelude section is written by someone who is a little closer to tanks and might be a little less politically reliable, since they actually give Tsarists credit for things. I guess they have to, since foreigners are only mentioned in this section when they are amazed by Russian progress. The next chapter is a Wikipedia-grade summary of various tank designs that gives WWI designs a pretty fair evaluation, then a huge section on Soviet tank development, then a tiny section on foreign tanks in WWII mostly consisting of listing all the mistakes their designers made. The party must have recuperated since the intro since we're in for another three pages of fellatio. Having read so far, you might think that there is very little value in this sort of book, but then the writing style does a complete 180 and the rest of the book is 100% apolitical and mostly looks like this. Which is what we care about, so let's begin. Bonus points to anyone who can identify what the diagram above is about. Sorry in advance if my terminology isn't 100% correct, there aren't exactly a lot of tank dictionaries lying around. The book skips over primitive unsprung suspensions of WWI and starts off with describing the difference between independent suspensions and road-arm suspensions. In the former, every wheel is independently sprung. In the latter, two or more wheels are joined together by a spring. Some suspensions have a mix of these designs. For example, here's a simple road-arm suspension used in some Vickers designs and their derivatives. The two road wheels are connected by a spring and to the hull by a lever. A weight pushing down on top of the pair of wheels is going to compress the spring that's perpendicular to the ground, bringing the wheels closer together. Here's a more complex road-arm suspension, with four wheels per unit instead of one, also AFAIK first used by Vickers and then migrating to an enormous amount of designs from there. This suspension provides springiness through a leaf spring that you can see above the four road wheels. The two pairs of wheels don't have their own springs. The black circles in the image show where the suspension elements can turn, keeping the tank flat while hugging the terrain. Here's another road-arm suspension, similar to the first one. In this case, the spring is made of rubber instead of metal. Otherwise, the design is very similar. Two rubber bungs on the bottom of the axles prevent the wheels from slamming into each other too hard. This design was used by French tanks and nobody else. For some reason, volute spring suspensions are completely absent from this section. This is the best image of a Vertical Volute Spring Suspension (early Shermans) that I could find. It's kind of similar to the first image, except the spring is a volute spring, and it's vertical instead of horizontal. Later Shermans used horizontal volute springs. Of course, as the book points out, these suspension elements are very easy to damage externally and knocking out one part of the suspension will typically take out the rest of the assembly, so independent suspensions are the way to go. The best way to do this are torsion bars. The bar is attached to a lever that holds your road wheel. As pressure is applied to the road wheel, the bar subtly twists, remaining elastic enough to reset once the pressure is off. This image is kind of weird, but the part in the center is the part on the far left, zoomed in, showing you where the lever and the opposite side's torsion bar are attached. As you can see, road wheels in a torsion bar suspension are going to be a little off on one side, unlike what you're used to on cars and such. Now, since torsion bars are metal bars on the floor, they are going to make your tank taller. If you want a tank that's as short as possible at the expense of width, you may want to consider a Christie like suspension. Here, much like in torsion bars, the pressure is transferred inside the tank, but instead of a bar to absorb it, it's a spring in a vertical (or angled) tube. In most tanks with this kind of suspension, the springs are on the inside, but if you want to make the tank roomier on the inside, you can have them on the outside too. If you're really fancy, you can put a spring within the spring like in this diagram. Since this is a Soviet tank book, you gotta have a huge T-34 diagram. Here it is. The T-34 uses Christie springs, which you can see in the diagram. The road wheel configuration is a mix of the externally dampened and internally dampened "Stalingrad type" road wheels. The former have more rubber for absorbing hits from terrain, but the latter use less rubber. When you're in Stalingrad and you have to make tanks with a rubber deficit, that's the kind you want. When road wheels from other factories were available, they would go in the front and then the back to absorb most of the impact from harsh terrain features, and the steel-rimmed wheels went in the middle. The diagram shows how both types of wheels work. Rubber can't really take too much punishment, so the KV, being a heavy tank, went with internally dampened road wheels from the very beginning, with a ring of rubber on the inside around the axle. And finally, idlers. If you don't have big Christie type wheels, you gotta have idlers so your saggy track doesn't fall off. This diagram shows the rubber coating on an idler, and also how the rear idler can adjust to tighten the track. A loose track makes more noise, gets worn more, and is liable to slip off. Keep those tracks tight, and you'll be zooming towards glorious victory in no time flat! Now, the book ends and my own stuff begins. I mentioned rubber, but not what a headache it was to tank designers. In hot weather, the rubber in your tracks and wheels tends to fall apart. If you go fast enough, tires that don't have proper ventilation are going to melt too. There was a lot of pre-war panic in the USSR about the German PzIII being able to do 70 kph on tracks, but once the Soviets started building SU-76Is on the PzIII chassis they found out that the speed had to be limited to a whopping 25 kph to keep the wear to a reasonable level.
  7. 11 points
    Tied has been trying to get me to post here for months, and he has finally convinced me to join up. So without further ado here is a post I made on the SA forums since I see there isn't a T-80 thread. ________________________________________________________________________________ T-80 Program The T-80 MBT was another offshoot of the T-64 program. It entered service around the same time as the new generation of NATO tanks such as the Leopard 2, M1 Abrams and Challenger. While it was a capable and effective tank, it also carried a horrifically high price to deliver these qualities. Which considering the economic conditions of the USSR at the time of its introduction, could charitably be considered "negligent". To borrow a phrase, it was an example of "The best being the enemy of the good". Despite its problems, The T-80U was certainly aesthetic. Video "Made in the USSR: T-80 main battle tank". Origins The T-80 was a child of two lineages, primarily, the T-64 design from Kharkov, and secondly the various tank turbine engine projects that had existed in the USSR for decades. In 1971, the soviet tank industry began work on new designs that would replace the T-64 and T-72 after 1981. These new designs were nicknamed "Perspektivy" or "NST" from "New Standard Tank". There was a number of submissions, such as the unorthodox T-74 offered by Kharkov. Leningrad's Kirov KB offered the turbine powered Object 225 and the diesel Object 226, while Chelyabinsk offered the Object 780. Over time these projects were refined and replaced with the Leningrad Object 258, Chelyabinsk Object 785 and Kharkov adding the Object 480. Out of the three, only Kharkov remained enthusiastic about their project. Chelyabinsk had been moving away from the tank business after a change in management, and Leningrad had shifted their efforts onto a new T-64 remix, the Object 219T. After the problems with the T-64, along with Morozov's upcoming retirement, the army rejected the T-74. Turbines, a Primer. Interest in turbine engines for tanks had existed since the 1950's. Turbine technology offered engines that would be significantly smaller, lighter and more powerful than equivalent diesel engines. However they also had much higher requirements in terms of air filtering, maintenance and foremost, fuel. The appetites of a Turbine averaged at 240kg/hour of fuel to the 83kg/hour of a comparable diesel, a significant increase! These engines would also cost more than 10x equivalent diesels, an example figure is R9,600 for the V-46 to the R104,000 demanded of the GTD-1000. Object 219 Development The first experimental GTD-1000T turbine engine was mounted on a modified T-64 tank chassis. During early trials, it was found that the T-64 running gear would limit the top speed of the vehicle due to the extreme vibrations of the metal road wheels and the track at high speed. As a result, a new suspension was designed for the Obj.219 but with no attempted made to standardize this with the rival T-72's suspension. During trials from 1968 to 1971, various suspension and subcomponent options were explored. Dust ingestion was a significant problem for the new tank, leading to a redesign of the air filters and the fitting of rubber side skirts to reduce the amount of dust kicked up during movement. The Curse of the 5TDF lived on however and the engines had woefully low average times before failure, falling far below the targeted life of 500hrs. Trials also showed that the voracious fuel appetite of the engine forced the use of external fuel drums to meet the basic range requirement of 450km. Fuel consumption of the engine was an astounding 1.6 to 1.8 times higher than the T-64A. Wisely, Minister of Defense Andrei Grechko rejected plans to put the new Object 219 into production, citing that it offered no improvements to firepower or armor and consumed twice as much fuel as the T-64A. Unfortunately for the soviets, Grechko died in 1976 and replaced by Dmitry Ustinov, who immediately set about getting his pet project approved. Production was to start at LKZ and Omsk. Furthermore, any major tank system upgrades would be earmarked for priority use on the T-80 platform, such as new fire controls, stabilizers and etc. In the original production configuration, the much delayed T-80 was essentially a T-64A with a turbine engine and new suspension. In all other respects the vehicle was equivalent, armor, armament, fire control and etc. But not the price! The T-80 was hideously expensive at R480,000 to the R143,000 of the T-64A. Not to mention, the tank had already fallen behind the T-64's newest version; the T-64B (which cost R318,000 I might add). As a result, the T-80 did not last long in production, with about less than 200 tanks made between 1976 and 1978. T-80B Ustinov used his position to ensure that the T-80 would be the new standard tank of the Soviet Army, and it was imperative that the quality of its systems be brought up to the level of the T-64B. To achieve this, the systems of the T-64B turret such as the LRF, ballistic computer, autoloader, Kobra complex, and etc were adapted to a new T-80B turret. This turret used the same protective technology as well (combination-K) and offered the same protection. The hull was unchanged. This upgrade was designated the Object 219R. The T-80B would be the primary production variant of this tank. The T-80B was put into production in 1978 at LKZ and at Omsk in 1979. The T-80B would also later be fitted with Kontakt-1 ERA, Unfortunately there is not much to be said about the T-80B really as it was essentially a T-64B with a turbine engine that in cost more in total. T-80U The evolutionary links between the T-80B and what would become known as the T-80U were the Object 219A and 219V. The Object 219A would be a combination of a T-80B hull and a new T-64 turret that had been developed in Kharkov as another upgrade for their tank line, the Object 476. This time, rather than waste time and resources on another pissing match where a perfectly fine T-64 turret would be remade for the T-80, the turret was dropped in directly. This new combined effort would leave the LKZ responsible for the overall program, while Kharkov would continue to work on the turret and armament. The Object 476 turret included a new generation of technology, such as the 1A45 fire control system, a new 1G46 sight and new laminate armor in the turret. This new generation of Laminate armor had been developed at NII Stali, with two versions. A simpler “reflecting-plate” system that would be used in the T-72B. The Object 476 turret however used the more expensive “semi-active filled-cell” armor design. In this design, plates of steel were suspended in polymer filled cells backed by a plate of resin and another layer of resin. When penetrated by HEAT, the shockwaves from the detonation would cause the reverberation of the semi-liquid filler, degrading the penetrating jet. While the Object 219A was ready for production in 1982, only a handful were made for use in technology trials. The new tank would have to wait for new technology initiatives to bear fruit, such as the Refleks missile complex and Kontakt-5 ERA. The Refleks laser beam riding missile was a brother of the Svir mounted on the T-72B, and both had been based of the Bastion/Sheksna missiles developed for the T-55 and T-62 respectively. The Refleks and Svir offered the most penetration of all, at 700mm RHA equivalent, compared to the 600mm offered by Kobra. The range was also extended from 4km to 5km. Kontakt-5 ERA also provided an impressive degree of protection against HEAT, and in a first for ERA, against APFSDS rounds as well. Against KE rounds, it is claimed that it will degrade their performance by 20% to 35%. While integration of the object 476 turret with the 219A hull, the object 219V was fitted with a new GTD-1000F engine with a supercharger and the refleks missile complex. Both of these designs have been sometimes dubbed the T-80A, even though they were never accepted for service under this name. A new object 219AS merged the features of both the 219A and the 219V. Twenty were produced in late 1983 with eight sent for troop trials and the remainder used in factory and state trials. The Object 219AS was accepted for Soviet Army service in 1985 as the T-80U. Series production of this type began in 1987 at Omsk, which would be the primary producer of this type as production at LKZ had been winding down and Kharkov was busy retooling for the job. The T-80U would be the definitive version of this tank, and offered impressive protection against APFSDS (780mm), HEAT (1,320mm) on the turret front, a very high degree of cross country capability and high speed. However this astronomical performance also came with astronomical cost: a VNII Transmash study found that the T-80U offered only 10% improvement over the T-72B but cost 824,000Ru compared to only 280,000Ru; nearly three times more. After Ustinov popped his clogs in December 1984, his turbine fetish was finally pried from his cold, dead hands. The following death of Leningrad party-boss Romanov 7 months later in July 1985 removed the second major benefactor of the T-80 program. This cleared the way for a return to more conventional engines for the T-80. The pushback concerning turbine engines was focused primarily on cost. A GTD-1000 cost R104,000 which is ten times more than the R9,600 cost of the V-46 used in the T-72. Additionally, turbines had shorter running life, consumed an atrocious amount of fuel and were complicated and expensive to repair. Kharkov had been working on a diesel powered T-80 since 1976 (object 478), which used the new 6TD 1,000hp diesel that had been destined for the Object 476. This would be used in the new diesel powered T-80 Kharkov’s production of the T-80U had been limited, only reaching 45 until the government approved the creation of a new diesel powered T-80U. Kharkov had wanted to follow the tradition of the T-34, T-44, T-54 and T-64 and name the new tank the T-84. Their hopes were dashed and it was called the T-80UD (UD= Improved diesel), to avoid the embarrassment of acknowledging having not three, but actually four similar tanks in production. This slap fight over names had to actually go all the way up to Gorby’s desk in order to be resolved. The T-80UD was approved for trials in September 2nd, 1985 and for production in 1986. About 500 T-80UD were produced before the fall of the Soviet Union and eventually found life beyond death of revolution in one country, morphing into the Ukrainian T-84 program. ~Controversial Opinions Zone~ While I feel like I am about to trigger Lost Cosmonaut or T___A here. I feel that having now read about the tank I got say that I am flabbergasted and have no idea what the fuck the Soviets were thinking. The T-80 was a tank design that seemed to offer only the dubious benefit over its competition of a high speed and considerable power to weight ratio. While these two qualities may be very important on the tank show circuit, the famous “flying tank” demonstration, it is questionable just how much benefit this would confer over its older brothers the T-64 and T-72 on a real battlefield. Not to mention, this impressive performance came as a significant cost to fuel range. The engine would always be drawing the same quantity of fuel, be the tank rolling at maximum speed down a road or idling at a position. In short, and more technical terms, they were increasing their tactical mobility while severely compromising the operational mobility of the tank. When one considers that the armor and armament of the T-80U were effectively stolen from the T-64 program, and that the T-72 had managed to produce a roughly equivalent vehicle at a fraction of the cost, you have to ask, what was the point? The money and effort that had gone into the T-80 program would have been better spent on the T-64 and T-72 lines. Consider the benefits; T-64 could have been upgraded in line with the object 476 program which would have given a spiritual T-80UD much sooner. The T-72B could have received the upgraded fire controls, stabilizers and etc reserved for the T-80U that were eventually fitted anyway in the form of the T-72BU (aka T-90). Along this line of thought, the main thing that had been holding back the T-72 program was its designation as the “cheaper” line that was not deserving of the extra funding to turn a solid vehicle into a superior one (as what happened with the T-90). At the very least, you could justifiably assume that these options would be cheaper due to the lack of the expensive gas turbine. The only thing that I can really give separate praise for in my current impression was that the suspension. To what I gather, it is quite effective and offered a very smooth ride compared to the T-64 or T-72 suspension. But this system could have been adapted for either of these two tanks anyway which brings us back to the original question: what was the point, really? While the new generation of NATO tanks in the form of the Leopard 2, M1 Abrams and Challenger were a major step up, the soviets should have waited for a much more substantially improved design to appear, rather than making their bets with a fattened T-64 with a turbine stuck in it. While overall the tank was not a failure that we in the thread mock the Tiger2 for being (the T-80 at least didn’t set itself on fire, ho ho), it however does share the same fundamental problem in that it just wasn’t appropriate for the strategic needs of the state at the time of its production. It cost too much, consumed too much fuel and offered only mild performance increases over more workhorse designs
  8. 11 points
    Waffentrager

    The Japanese Ferdinand

    Disclaimer: Yeah naturally Japanese tanks arent a big focus here, so I usually ignore posting things of the matter here. But like the O-I article I posted here oh so long ago, this article comes with the results of some days spent in the archive reading and (continuing to do) translating pages of reports that havent been read in like, decades. So with that said, hope you enjoy. Still a matter I'm unfinished diving into. --------- Type5 Ho-Ri : The Japanese Ferdinand As of recently, I've gone through the Japanese National Archive files, looking through to find documents that relate to my studies. While I was there, I stumbled across something that caught my interest. Of said documents, the one of most importance was a file called "Military Secrets No.1". The reports were held by the Ministry of Defense, Army records section, Munitions Mobilization district. Contained in these files were a 3-page production chart of late war tracked vehicles of the Japanese army. Located within the chart I found a number besides the Type 5 Ho-Ri tank destroyer. A vehicle that until recently was only known to have made it to wooden mockup stages. In this lengthy article I will cover my findings on the tank project. Unfortunately visual representations of the tank are still being looked at. So I will use existing found sources for this. National Institute for Defense Studies " Military secret No.1 " In September of 1942, the Japanese Army Staff came to the realization that they had no choice but to design a series of tanks to compete with the arrival of the American Sherman tank. Three concepts were proposed by the Staff, each with their own gun selection; Kou (47mm), Otsu (57mm), and Hei (75mm). As combat data filtered back to Japanese high command, the model Kou concept would later merge with Otsu concept, becoming the basis for the design of the Type4 Chi-To. The Hei proposal would eventually lead to the development of the Type5 Chi-Ri. Additional impetus for new development projects came from a change in the Weapons Administration Headquarters Research Policy in July 1943, a change which was made as a result of analyzing and examining the situation of the tank warfare between the German army and the Soviet Union. Through analysis of this data, the Army's tank doctrine shifted to an emphasis on developing tanks which prioritized the anti-armor mission instead of prioritizing infantry support with limited anti-tank capability. Upon the promulgation of this policy, the Japanese Army decided to develop a series of tank destroyers alongside the medium tanks being designed. As a result, the Type5 Chi-Ri, Japan’s primary medium-tank project, would become the basis for a new anti-armor vehicle. This was a natural choice for IJA command; the Chi-Ri project was more mature. Additionally, it held the most advanced technology Japan produced at the time, technology which would become ubiquitous in the designs that would be made until Japan's defeat in 1945. Testing model of Chi-Ri. Used to trial the series of cannons and turrets designed for the tank. In the photograph it is captured by US forces after the gun had been dismantled for further trials. By Japan's defeat in 1945, three models of Chi-Ri entered production. The tank destroyer built upon the chassis of the Chi-Ri would eventually be called the Ho-Ri. Development of this vehicle began shortly after the development of the Chi-Ri, when it had been decided that the tank would use the coil spring suspension system that Japanese manufacturers were already familiar with. After this decision was made, the Army also began work on designing the tank destroyer’s superstructure and casemate. The first design the Army came up with mimicked the Chi-Ri chassis entirely, though the turret was replaced with a reinforced rear-mounted superstructure. The Experimental 10cm Cannon With the development of a new series of tank destroyers taking place, the Army decided to design and produce a new high capacity anti-tank gun to fit the role. On July 22 of 1943, the Army Military Customs Council began designing a 105mm caliber anti-tank gun. Once the design of the cannon had been completed, construction of the cannon took place around a steel shielding that was to be the Ho-Ri's superstructure plating. The trial placement was capable of traversing 10 degrees to the left and the right, elevating by 20 degrees, and depressing by 15. The gun weighed 4.7 tons, with a barrel length of 5.759 m. During one of the first council meetings that took place on the 30th of June, however, the council gave Major Ota and Lieutenant Colonel Neima of the Army Weapons Administrative Division, the two chief engineers of the Experimental 10cm project, the task of achieving the requirement that the gun meet 200mm penetration at 600 meters distance and 1000m/s velocity. Naturally, the tank gun was not capable of this, and, instead, the Experimental 10cm had a muzzle velocity of 915m/s with AP (900m/s with HE), and achieved a performance of 150mm penetration at a distance of 1000 meters. The 10cm Experimental Anti Tank gun relied on a system similar to the Type5 75mm Anti tank cannon in relying on an autoloading mechanism for the tank. This mechanism was known as a semi-automatic loading system, different to the ordinary "autoloader" you see in other vehicles. Unlike the typical autoloading system, the loading crew of the gun system placed the individual shells on the chamber, the system automatically ramming the shell into the breech and forwarding to operation. This gave the effect of automating half the loading routine, as the name suggests. The Experimental 10cm was put into service with the Ho-Ri in 1945. The technical name for the model to be used on the prospective production model was known as the Type5 10cm anti tank cannon. The shell rammer used a horizontal chain closing type, and the automatic loading machine was attached to the back of the gun. It was used because loading ammunition of 123 cm total length and 30 kg weight was deemed too strenuous on a small Japanese physique. Various artillery parts had been diverted and referred to in order to shorten the time of development. The autoloading machine adopted the mechanism of the Type3 12 cm AA Gun for inspiration. The automatic loading mechanism was a continual source of problems, but was repeatedly refurbished to eliminate the drawbacks. Photograph of the Experimental 10cm Anti tank cannon during trials. Note: The shielf and protector are used on Ho-Ri prototype. Gun was first tested separately and then placed in tank prototype. Ho-Ri Designs Originally, the Ho-Ri was to keep the secondary 37mm that had been mounted on the Chi-Ri design. The reason for this addition was due to the limited gun-traverse on casemate tank destroyers. Additionally, the primary cannon could only do so much for itself. Hence, to combat many anti tank threats which the Americans could have dedicated to the assault on Japan, the 37mm was seen as being an efficient method of providing additional firepower against infantry and combat vehicles. To this end, the 37mm gun offered a range of APHE and smoke shells. The 37mm was capable of an elevation of 20 degrees and depression of -15 degrees. The mount itself also offered a horizontal traverse of 20 degrees. The 37mm gun could also be used as a ranging device for the main cannon, however this most likely would not have been needed due to the high velocity of the main gun. Outline of the Ho-Ri design I. Technically entered modified construction of one of the 3 Chi-Ri units. The development of the Ho-Ri design was split into two concepts. One being a rear mounted superstructure on the Chi-Ri chassis with a central stationed engine, and the other having a centralized superstructure with a rear engine placement. The Ho-Ri engine selection was different from the traditional diesel that the Army had kept with for most of their tank production. Japan used a BMW designed gasoline V12 aircraft engine . The main reason for this change was due to industrial capacity of Japan reaching its peak, aircraft development was still a heavy priority and many assets were available for useage. The output of the tank was 550hp/1500rpm. The Ho-Ri II’s design also enabled the option of adding a 20mm AA station on the rear hatch for additional protection. However, the likelihood of it being useful is up for debate. In addition, central placement of the superstructure enabled 60 rounds for the main cannon to be stored instead of the Ho-Ri I’s 40 rounds. In terms of armour, both vehicles were to keep the Chi-Ri hull, hence the maximum frontal armour of these tanks was only 75mm. On the superstructure, however, armor thickness was increased to 100mm. By the time both designs, which had been developed in parallel, were presented to Army General Staff it was too late; the war was almost over, and the thickness of the armor was no longer sufficient against US armaments. Nevertheless, the design showed promise. Thus, while neither design was chosen for production, the Ho-Ri I was adopted as the main influence for the third revision of the tank. This third vehicle is commonly labeled as Ho-Ri III. Technically, however, none of the Ho-Ri vehicles were numerically designated. Ho-Ri III wooden mockup. Ho-Ri III took the basis of the Ho-Ri I, and revamped it to fit the needs of the military. The frontal plate of the tank was sloped at a 70 degree angle and increased to 120mm thickness. In this configuration, the tank was capable of withstanding most anti tank measures the Unites States could bring to the home islands of Japan. The designers of the tank built a wooden mockup form of the revision 3 design and presented it to the general staff, at an unknown date. The Ho-Ri kept its general composition the same as the prior designs, but this change was what the Army Staff ultimately decided to go with and schedule the Ho-Ri for prototype construction. The tank would have a crew total of 6; driver, gunner, two loaders, radio operator, and commander. The past designs made use of the 37mm that the Chi-Ri hull had present, however, with the chosen slope change on the Ho-Ri III, this was no longer present and a crew member spot was open. The 6th crew member was placed as the second loader to assist with the autoloading mechanism and provide shells for the primary loader. The construction of the prototype was completed in 1944. The tank achieved a speed of 40kmh during the trials. The tests were seen as a success, resulting in the Army ordering 5 units of the tank. The tank was put in service as the Type5 Ho-Ri, as the production model started in 1945. However, by the time of the war's end, the series of tanks only made it to 50% completion. Only one operable prototype had been completed fully. Reports of the trial are still being processed at this time [11/15/16]. My research continues. I have been spending days now trying to go through everything and get the details of the tank out to the light. Once all the documents are collected together and organized, translated, and put back together I will write a follow up article to this. You can view full post with all images on my blog post: http://sensha-manual.blogspot.com/2016/11/type5-ho-ri-japanese-ferdinand.html
  9. 11 points
    Waffentrager

    Japans Box Tank O-I

    O-I The O-I (オイ車 Oi-sensha) was a super-heavy tank prototype designed by the Imperial Japanese Army during the Second Sino-Japanese War after the Battles of Nomonhan in 1939. The O-I is one of the Second World War’s more secretive tank projects, with documentation regarding the tank being kept private for over 75 years at Wakajishi Shrine, Fujinomiya. Surviving files have been purchased by FineMolds Inc., and publicly previewed in mid-2015. The multi-turreted 150-ton tank was designed for use on the Manchurian plains as a supportive pillbox for the Imperial Japanese against the Soviet Union. The project was disbanded four years after the initial development began, deemed unsatisfactory for continuation in 1943 after the lack of resource material for the prototype. History and development After 1939, the Imperial Japanese Army quickly came to realize that previous forms of mechanized warfare were proved inefficient after their defeat at Khalkhin Gol. Development of the super-heavy project was spearheaded by Colonel Hideo Iwakuro, the head of the Ministry of War of Japan (陸軍省 Rikugun-shō). Iwakuro opposed Japan’s advances towards the Soviet Union in 1939, and with the Japanese defeat, he decided to initiate a project to construct a heavily armored tank capable of withstanding large-caliber field cannons. Iwakuro assigned Colonel Murata of the 4th Technical Research Group to design and construct the super heavy tank in 1939. Colonel Murata noted Iwakuro’s words as described; 「満州の大平原で移動トーチカとして使えるような巨大戦車を作ってほしい。極秘でだ。」 “I want a huge tank built which can be used as a mobile pillbox in the wide open plains of Manchuria. Top secret.” 「今の戦車の寸法を2倍に延ばして作れ。」 “Make the dimensions twice that of today’s tanks.” The 4th Technical Research Group began designing the super-heavy vehicle throughout 1940, attempting to meet Colonel Iwakuro’s vague instructions on the ultimate goal of the project. By March 1941, the research group had finished initial tank design and was ready to begin construction. The following month, a group of pre-selected engineers were chosen to partake in the building of the super-heavy tank. One recorded engineer was Shigeo Otaka, who stated they were sent to the 4th Technical Research Group’s previous headquarters in Tokyo. There, they were guided through a barracks containing multiple small fitting rooms, where they were to conduct meetings and reports on the progress of construction of the super-heavy vehicle. Towards the end of the barracks facility was a fully-enclosed room devoid of windows, with soundproofed walls to prevent external personnel from overhearing discussions related to the project. Each officer present possessed a portion of the project’s blueprint, which, when assembled, projected the full design of the tank, labeled "Mi-To". The name originated from a collection of the Mitsubishi industry and the city, Tokyo; given to the vehicle to uphold secrecy of the tank’s project. Colonels Murata and Iwakuro The chosen engineers voiced their concerns regarding the Mi-To’s design noting that previously, the largest-sized Japanese tank had been the prototype Type95 Heavy in 1934. Issues that had been noted with heavy tank experiments in the years preceding the Mi-To showing Japan’s generally unsuccessful testing on multi-turreted vehicles exceeding the weight of standard armored vehicles. However, with the threat of a second Russo-Japanese conflict becoming more apparent, the project continued despite the engineer’s doubts on the size and mobility of the vehicle. Four engineers who survived to record the dealing had with the project On April 14th 1941, the engineers began the construction of the Mi-To under secretive means. This entailed privately-made mechanical parts and equipment being shipped to the construction zone. Colonel Murata’s original concept was to complete the super-heavy tank three months after the initiation of Mi-To’s construction. This, ultimately, did not come into fruition; as technical issues on the project began to arise. Due to the limitation on material consumption by the government, the amount of parts that could be secretly shipped-in began to dwindle. By the first month of construction, essential construction resources had been depleted and the issues with the vehicle’s cooling system further caused delays. The construction of the Mi-To was postponed until January 1942, a delay of nine months. After the Mi-To’s construction was resumed, the hull was completed on February 8th 1942. The tank had reached near-completion and was being prepared for mobility testing. Mitsubishi built the four turrets for the tank in May of the same year. Initial assembly of the tank’s armament took place soon after the turret’s superstructures were completed. However; the project once again did not have the necessary resources needed for the few remaining parts required for the final assessment. Due to this, the primary turret was removed as it lacked a 35-millimeter-thick roof plate, which had not yet arrived. Thus, the project was put on standby, until further development could continue. The total weight of the vehicle at the time was 96 tons, due to the lack of remaining structural plates and absent 75mm bolted-on armor. O-I documents previewed by FineMolds The date on which the construction of the tank resumed is unknown, although active testing of the tank was scheduled for late 1943. The tank was unveiled to the Imperial Japanese Army’s highest command in 1943, and received a name change to O-I. This followed Japanese naming convention (O translating to Heavy, I for First, making it "First Heavy") that was standard. In his place was Lieutenant Colonel Nakano, Murata's assistant and colleague. Tomio Hara, head of the Sagamia Army Arsenal, was also present. Following the demonstration, senior officials within the IJA requested that field trials begin in August of the same year. The tank was disassembled at 2:00 AM one night in June of 1943 and sent to the Sagami Army Arsenal in Sagamihara, 51 kilometers from Tokyo. The vehicle arrived at the depot in June, and was reassembled and tested on the 1st of August. On the day of the trials, the O-I performed satisfactorily until the second hour of the tests. While maneuvering on off-road terrain, the tank sank into the ground by up to a meter; attempts at traversing the hull to extricate the vehicle proved fruitless, resulting in further sinking due to the vehicle’s suspension coils compressing. The tank was eventually towed out, and further testing was continued on concrete. However, the earlier damage to the suspension resulted in vehicle’s movement damaging the concrete, which in turn, further damaged the suspension bogies to the point that further testing could not continue. The trials were postponed, and later canceled the following day. Nevertheless, the trials conducted at the testing field were considered to be a success, and the vehicle was deemed ready for use in spite of its flaws. The engineers began disassembly of the tank on the 3rd of August due to resources being limited and the inability to maintain the tank in the field. Disassembly of the tank was completed on August 8th. Two days later, the engineers noted in a log that they were to inspect the parts and conduct research to fix the issues the O-I would face. The fate of the O-I after its field-trials which took place on the 1st of August is unclear. Russian reports claim the Japanese were in possession of a wooden O-I mock-up mounting a Daimler-Benz DB 601A engine in 1945, however other sources point to the scrapping of the remaining parts of the same year. The remains of the O-I reside at the Wakajishi Shrine, with a track link of the prototype still present. Remaining track link of the prototype O-I tank Design The O-I was conceived out of the necessity to produce an armored vehicle capable of withstanding modern weaponry being able to return fire with similar firepower. The O-I was designed to act as a mobile pillbox, supporting infantry and mechanized groups along the border of the Soviet Union. The tank had a length of 10.1 meters, width of 4.8 meters, and a height of 3.6 meters. The dimensions of the vehicle closely matched those of the Panzer VIII Maus. The tank was envisioned to have a standard thickness of 150 millimeters front and rear, in order to protect against common anti-tank weapons of the time, yet it was constructed with armor 75 millimeters thick. However, an additional armor plate could be bolted on to bring the total thickness of the armor to 150 millimeters. The use of additional armor allowed for ease of construction and transportation, while also providing the tank with additional defense. Side armor on the hull superstructure was 70 millimeters thick. The additional armor plates were 35 millimeters thick, but armor surrounding the suspension was only 35 millimeters thick. This made the tank’s theoretical armor on the side 75 millimeters. There were eight wheel-supporting beams located on both sides of the suspension area which added an additional 40 millimeters of armor to specific locations on the side of the O-I. 40 ladder pieces were placed around the tank to provide crew with the ability to climb onto of the vehicle with ease. The two 47mm cannons used in the two frontal turrets were also modified to fit the armor layout of the tank. The weapon’s barrels were reinforced with steel to secure them to the tank, due to the standard gun not adequately fitting into the turret. The tank was both designed and built with two inner armor plates to divide the interior into three sections; walls with two doors each and an ultimate thickness of 20mm. This allowed the crew and modules to remain relatively safe while the structure was kept safe with supporting stands. These supports allowed the interior armor plates to stay stable and also prevented collapse. Inside the O-I were two Kawasaki V-12 engines, both located in the rear, parallel lengthwise, to give room for the rear turret operator and transmission. The transmission copied that of the Type97 Chi-Ha’s, but used larger parts and gears making the total weight heavier. The vehicle had a coil spring system, with eight 2 wheeled boggies, totaling 16 individual wheels. Data Sheet Sources - O-I documentation, Finemolds - O-I project report notebook 1,2,3,4,5, and 6 (Finemolds) - JP Tank Perfect Guide - 日本の戦車 原乙未生 (Hara's book) (Old sources) - 帝国陸軍陸戦兵器ガイド1872-1945 - 日本陸軍の火砲 野戦重砲 - 戦車と戦車戦 - 太平洋戦争秘録 日本・秘密兵器大全 ---------------------- ​Since the article Soukou and Daigensui wrote long ago is filled with inconsistencies and errors, decided to make something thats actually accurate to the reports. Wrote it on Google Docs initially, posted it to WT earlier. Will be present on Ritas blog and eventually Wikipedia.
  10. 11 points
    Tied

    Tankograd T-62: Khruschev's bastard

    Source All Credit goes to: Mike Ennamoro and Tiles Murphy I highly recommend checking out there other articles, espically that on T-72 BLACK SHEEP Ask anybody politically savvy aged 50 and above and they will tell you that the unending string of proxy wars during the Cold War exuded a mostly artificial, but ever-present atmosphere of an imminent danger of a escalation into a full-blown nuclear world war. Fear and paranoia drove an age of accelerated technology growth predominantly concentrated in the military sector, producing various innovations which have crossed over into the non-military world. The proof is in our history textbooks today. The first rockets that sent satellites to space, for example, were modified ICBMs, and the Internet was originally a military project. New tanks sprang up like mushrooms after rain all over the world in approximately decadal increments, always to counter the last, always eclipsed by the next, but sometimes bordering on obsolescence from the moment they were created. One unfortunate example of the latter is the T-62. The T-62 is undeniably the least memorable among all of its world-famous post war era brothers - the T-54/55, T-64, T-72, T-80 and T-90 all come to mind - and it is also arguably the least historically significant among them all, but it was a step nonetheless in the evolutionary path to the modern T-14 we know today, and its relevance on the battlefield was certainly undeniable for the better part of two decades. The sentiment among the few amateur academic-enthusiasts that haven't forgotten the T-62's existence is that it was a highly mediocre design with a whopping gun, and in many ways, that is perfectly true from a technological standpoint in the evolution of armoured warfare during the Cold War. Between former Soviet tankers, however, the sentiment is slightly different. Many remember the T-62 fondly as a fairly reliable and endearing sweetheart that certainly had its own faults, but rarely ever disappointed - a sentiment echoed by Syrian and Iraqi tankers. The ones that lived, at least. Although woefully obsolete at present (it had already been totally purged from the Russian Armed Forces' inventories since 2013), it could at least boast of having the second most powerful tank cannon in the world for a few short years before being usurped by the T-64. Indeed, the sole reason of the T-62's existence was its pioneering smoothbore cannon. Tactically speaking, there were very few differences between it and its predecessor the T-54 in the mobility and armour protection departments, and the T-62 and the T-55, and indeed, both shared the same make of equipment to a large degree, thus simplifying both production and logistics. In fact, the technology of the T-62 was almost entirely derived from the T-55, and most of the interior instruments and controls are practically identical, making the transition from the T-54/55 to the T-62 wonderfully seamless. This degree of commonality wasn't entirely positive, though, because this meant that there was an unacceptable stagnation in armour technology - the type of stagnation seen on the American side of the Iron Curtain in their Patton series of tanks, which began service in the early 50's and dominated U.S Army tank units up til the early 80's. Had the designers decided to only continually modernize a T-54-type design like the Americans did with the Patton, then surely the Soviets would have never achieved the level of armoured superiority and technological excellence as they did in the late 60's, 70's and early 80's. The T-62 is an example of what Soviet tank armies could have been, but never was. It was flawed, redundant, unnecessary, and downright wasteful. But it was still valuable in its own little ways, and some of the technologies found in the T-62 even carried over to its successors. Many of its flaws (such as the U.S Army-propagated myth that it took 6 seconds to eject a spent shell casing) were in fact totally made up, but the tank was undeniably mediocre all the same. Tactically speaking, it had only a few advantages over its predecessor in the firepower department, but otherwise, the T-62 was nothing more than a more expensive T-55. It was plain to see that the T-62 was considered nothing more than a stopgap solution until the new and radically superior T-64 arrived on the scene, though it is some consolation that the T-62 was considered the most advanced Soviet main battle tank during its brief tenure. Being a mere evolutionary stepping stone, though, we can observe the way Soviet school of thought on mechanized warfare evolved with it. In the early 60's, tank riding infantry was still considered a core part of mechanized warfare. The armoured APC had arrived on the scene in the form of the wheeled BTR-152 and tracked BTR-50, but infantry were sometimes obliged to move and fight as one with a tank, and so to that end, the T-62 had handrails over the circumference of the turret for tank riders to hold on to. When the BMP-1 was introduced in 1966, it drove a major revision of contemporary tank tactics, and the shift in paradigm can be very well seen in the T-62's successors. The T-64 did not have any handrails, nor did the T-72, and the T-62M introduced in the late 60's abolished them too. The changes to the T-62 dutifully followed international trends too, most notably the global shift to jet power in the aviation industry. Too fast to be harmed by machine gun fire, the ground attack jet rendered the normally obligatory DShKM machine gun obsolete. The birth of the AH-1 Huey Cobra and the subsequent heavy use of helicopters for fire support and landing missions radically shifted the landscape, and the men and women at Uralvagonzavod obeyed. The DShKM was back by 1972. In the Soviet Union, the T-62 was produced from 1963 to 1975, with the first pre-production models appearing in 1961. After 1975, all "new" T-62s are actually simply upgraded, modified, or otherwise overhauled versions from the original production run. COMMANDER'S STATION The commander is seated on the port side of the turret, directly behind the gunner, and to his left is the R-113 radio station, created just as the T-62 first entered service in 1961. ' The R-113 radio operates in the 20.00 to 22.375 MHz range and has a range of 10 to 20 km with its 4 m-long antenna. It could be tuned into 96 frequencies within the limits of its frequency range. In 1965, the radio was swapped out for a newer and much more advanced R-123 radio. The R-123 radio had a frequency range of between 20 MHZ to 51.5 MHZ. It could be tuned to any frequency within those limits via a knob, or the commander could instantly switch between four preset frequencies for communications within a platoon. It had a range of between 16km to 50km. The R-123 had a novel, but rather redundant frosted glass prism window at the top of the apparatus that displayed the operating frequency. An internal bulb illuminated a dial, imposing it onto the prism where it is displayed. The R-123 had an advanced modular design that enabled it to be repaired quickly by simply swapping out individual modules. It is quite clear that the commander's station is the most habitable one by far in the very spartan T-62. The close proximity between all the turret occupants with each other and the shortage of breathing space makes the internal climate hot and humid, contributing to the overall discomfort. This is compounded by the fact that the crew isn't provided with any local ventilators such as fans or directed air vents, so it can get quite stuffy inside. However, the commander seems to be the most well off, since he sits right in front of the sole ventilator in the turret and he isn't required to exert himself physically, unlike the loader. Unique to the rest of the dome-shaped turret, the area around his station was cast to be devoid of any vertical sloping or rounding whatsoever, which was necessary to enable his rotating cupola to be installed. This meant that the debilitating effects of the ostensibly dome-shaped turret are completely lost on him. The cupola is mounted on a race ring. The fixed part constitutes half of the total size of the cupola, while the other half is occupied by the semicircular hatch, which has a maximum width of 590mm. The hatch opens forward, which is quite convenient for when the commander wants to survey the landscape from outside - perhaps with a pair binoculars - because being as thick as it is, the hatch is a superb bulletproof shield for protecting the commander from sniper fire. There is also a small porthole in the hatch. It is meant for an panoramic periscope tube for indirect fire. As befitting his tactical role, the commander's general visibility is facilitated by two TNPO-170 periscopes on either side of the primary surveillance periscope in the fixed forward half of the cupola, and further augmented by two more 54-36-318-R periscopes embedded in the hatch, aimed to either side for additional situational awareness. Overall, this scheme was sufficient for most purposes, but was deficient if compared to the much more generous allowance of periscopes and vision ports found on NATO tanks. The TNPO-170 periscope has a total range of vision of 94° in the horizontal plane and 23° in the vertical plane. The four periscopes in addition to the TKN-type periscope aimed directly forward gives the commander a somewhat acceptable field of vision over the turret's front arc. The use of periscopes instead of direct glass vision blocks presents pros and cons - for one, the lack of any direct vision means that the viewer's eyes is protected from machine gun fire or glass specks if the device is destroyed, but a bank of periscopes offer a much more limited panorama than vision blocks like the type found in the commander's cupola on the M60 tank. TKN-2 "Karmin" The original 1961 model of the T-62 featured the TKN-2 binocular periscopic surveillance device (above) mounted in the rotating cupola. It had a fixed x5 magnification in the day mode, with an angular field of view of 10°, allowing a nominal maximum detection range of a tank-sized target at approximately 3 km, though this was greatly dependent on geography as well as weather conditions. The periscope could be manipulated up by +10° and down by -5°, while the cupola would have to be turned for horizontal surveillance. The TKN-2 had an active night channel which picked up infrared light from the OU-3 IR spotlight attached to the periscope aperture to provide a limited degree of night vision to the commander. With a nominal viewing range of only about 300 to 400 m, the TKN-2 was all but useless for serious target acquisition at night, serving only to give away the tank's position the moment the spotlight was turned on. Performance could be improved with mortar-delivered IR flares, of course, but that doesn't count as an intrinsic merit of the device itself. Due to the fact that the periscope is unstabilized, identifying another tank at a distance is very difficult while on the move over very rough terrain. However, the commander is meant to bear down and brace against the handles of the periscope for improvised stabilization, which is adequate for when driving over a dirt road, but not when traversing over especially rough terrain. The periscope's small elevation allowance was for this purpose. The left handle has a thumb button for turning the OU-3 spotlight on or off. The OU-3 is a high-powered xenon arc lamp with an IR filter to create only infrared light. The filter isn't opaque, though, and the spotlight will glow faintly red. It is mechanically linked to the periscope, enabling it to elevate with the TKN-2. ^OU-3 IR spotlight with the IR filter removed to transform it into a regular white light spotlight^ TKN-3 "Kristal" In 1964, the revised T-62 was instead equipped with the TKN-3 pseudo-binocular combined periscope, which is a direct descendant of the TKN-2. Pseudo-binocular meaning that although the device has two eyepieces, the two optic tubes are combined to feed from one aperture, which the viewer sees out of. It has a fixed 5x magnification in the day channel with an angular field of view of 10°, and a fixed 3x magnification in the night channel with an angular field of view of 8°. The periscope can be manipulated up and down for elevation, and the commander's cupola must be turned for horizontal viewing. The TKN-3 was a sufficiently modern observation device of its time. It featured target cuing, was very compact, and had a relatively advanced passive light intensification system, but it wasn't stabilised, and featured only rudimentary rangefinding capabilities as a cost saving measure. It offered rudimentary night vision capability in two flavours; passive light intensification or active infrared. In the passive mode of operation, the TKN-3 intensifies ambient light to produce a more legible image. This mode is useful down to ambient lighting conditions of at least 0.005 lux, which would be equivalent to an overcast, moonless and starless night. In these conditions, the TKN-3 can be used to identify a tank-type target at a nominal distance of 400m, but as the amount of ambient light increases such as on starlit or moonlit nights, the distance at which a tank-sized target is discernible can be extended to up to 800m in dark twilight hours. Any brighter, though, and the image will be oversaturated and unintelligible. The active mode requires the use of the OU-3K IR spotlight, which is practically identical to the OU-3 performance-wise. With active infrared imaging, the commander can identify a tank at 800m, or potentially more if the opposing side is also using IR spotlights, in which case, the TKN-3 can be set to the active mode but without turning on the IR spotlight. Rangefinding is accomplished through the use of a stadiametric scale sighted for a target with a height of 2.7 m, which is the average size of the average NATO tank. Like the TKN-2, the TKN-3 is unstabilized, making it exceedingly difficult to reliably identify enemy tanks or other vehicles at extended distances while the tank is travelling over rough terrain, let alone determine the range. The left thumb button initiated turret traverse for target cuing, and the right thumb button turned the OU-3K spotlight on or off. The range of elevation is +10° to -5°, just like the TKN-2. The OU-3K spotlight is also directly mechanically linked to the periscope (the arm to which the spotlight is linked to can be seen in the photo above) to enable it to elevate with the TKN-3. Target cuing is done by placing the crosshair reticle in the periscope's viewfinder over the intended target and pressing the cue button. The system only accounts for the cupola's orientation, though, and not the periscope's elevation, so the cannon will not elevate to meet the target; only the turret will. Because the cupola did not was not counter rotated as turret traverse was initiated, it will be spun along with the turret as it rotates to meet the target cued by the commander, potentially causing him to lose his bearings. To prevent this, there is a simple U-shaped steel rung for him to brace with his right arm as he uses his left hand to designate the target. This wasn't as convenient as a counter rotating motor, of course, but it was better than nothing. Ventilation for the crew is facilitated by the KUV-3 ventilator, identifiable on the rear of the turret as a large, overturned frying pan-shaped tumor on the rear of the turret. A centrifugal fan inside the ventilator housing sucks in air and performs some low level filtration, ejecting dust and larger particles out of a small slit at the base of the housing (refer to photo above), and then released into the crew compartment, passing through a drum-shaped NBC filter unit inside the tank proper. The air can be optionally cleaned of chemical and biological contaminants by the filter in contaminated environments where the centrifugal fan is simply not enough. The filter unit also contains a supercharger to increase the positive pressure inside the tank to produce an overpressure, preventing chemical and biological agents from seeping into the tank. Notice the PVC pipe connecting it to the ventilation dome on the outside of the turret rear But being the commander is still a mixed blessing, because his seat is seated right in front of the hydraulic pump, subjecting him to more acoustic fatigue than anyone else in the tank (the green canister is the hydraulic pump). Nevertheless, the commander's station is the second most roomy one in the tank, besides the loader's station. Here in the photo below, you can see his seat back and the few pieces of equipment that he is responsible for. Sometime during the 70's, a select few T-62s received a shield of sorts over the commander's hatch. It is a sheet steel face shield with a canvas skirt draping down. Being so thin, the face shield is not bulletproof, though perhaps resistant to hand grenade fragments and small mortar splinters. Since it doesn't really do very well as ballistic protection, the main function of the shield appears to be to conceal the opening of the commander's hatch to disguise his exit from the prying eyes of snipers, and to keep away dust if the commander feels like sitting outside during road marches. Either way, not many T-62s received the addition, though almost all T-72s did. The reason for the bias is unknown. GUNNER'S STATION The gunner is squeezed into his corner of the turret, wedged between the turret wall to the left and the cannon breech to the right, and between the commander and the sights. It is so cramped that the commander must partially wrap his knees around him. As was, and still is common among manually loaded tanks, the gunner doesn't have a hatch of his own. Instead, he must ingress and egress through the commander's hatch. The biggest flaw with this layout is that if the commander is unconscious, incapacitated or killed, then the gunner will suddenly find it extremely difficult to leave the tank unless the commander was somehow completely vaporized. Even worse, if the tank has been struck, there is a very distinct possibility that the interior is catching fire. Plus, another flaw with the layout is if the turret was perforated through the front on the port side cheek, both the gunner and commander would be killed, effectively rendering the tank useless in combat. For extra visibility, the gunner has a single TNP-165 periscope pointed forward and slightly to the right, though for what exact purpose this lone periscope is meant for is unknown, since the field of view from it is so small that the gunner can't really see very much, nor can the commander seated behind him. It is more useful for the commander for checking directly in front of the tank. In addition to all of the necessary switches and toggle buttons to activate this and that, there are also some other odds and ends at his station, including a turret azimuth indicator, which is used to orient the turret for indirect fire. It is akin to a clock, having two hands - one for general indication measured in degrees, and the other in 100 mil increments for precise turret traverse. SIGHTING COMPLEX TSh2B-41 sight aperture port, with nuclear attack seal in place The gunner is provided with either a monocular TSh2B-41 or a TSh2B-41U (in later models) primary sight and a TPN-1-41-11 night sight, which also functions as a backup sight in the event of the failure or destruction of the primary sight. TSh2B-41 The TSh2B-41 is a monocular telescopic sight, functioning as the gunner's primary sight for direct fire purposes. It has two magnification settings, x3.5 or x7, and an angular field of view of 18° in the former setting and 9° in the latter setting. As was and still is common for all tank sights, it has an anti-glare coating for easier aiming when facing the sun. It comes with a small wiper to clean it from moisture, and it comes with an integrated heater for defrosting. Like most other tanks of its time, the T-62 lacked a ballistic computer, but it was also unusually deficient in the rangefinding department. For rangefinding, the gunner had to make use of a stadiametric ranging scale embossed on the sight aperture. Compared to optical coincidence rangefinders, stadia rangefinding was terribly imprecise, but also much simpler in both production and employment, and much more economical than, say, optical coincidence rangefinding. In fact, stadia rangefinding is essentially free, since all that is needed are some etchings into the sight lens. The savings made from the exclusion of an optical coincidence rangefinder were enormous, amounting to many thousands of rubles. Ranging errors of up to several hundred meters is often the norm, especially if some of the lower part of the target vehicle is obscured behind vegetation or other terrain features. It isn't uncommon for the first shot on faraway tank-sized targets to fall woefully short or fly clear over. Below is the sight picture: From left to right: APFSDS, HEAT, HE-Frag, Co-Axial Machine Gun When the gunner has obtained range data, he manually enters the necessary correction into the sighting system by turning a dial. The dial adjusts the sight to calibrate it for that range. Calibration is when the chevron is elevated or depressed to account for range. If the target is very far away, for example, then the chevron will be dropped significantly, forcing the gunner to sharply elevate the gun to line up the target with the chevron, thus forming a ballistic solution. Because APFSDS, HEAT and HE-Frag shells all have different ballistic characteristics, the gunner must refer to a set of fixed range scales drawn on the upper half of the sight in order to get the proper gun elevation. For instance, if the target is 1.6 km away, and the gunner wishes to engage it with high explosive shells, then he must line up a horizontal bar (which moves up and down with the targeting chevron but at different speeds due to a reduction gear) with a notch on the range scale for "OF" shells that says "16". If the gunner wishes to use APFSDS instead, then he need only line up the horizontal bar with the "16" notch on the "BR" scale. Then, the chevron will show how much supraelevation is needed in order to hit the target with the selected ammunition. The gunner will then lay the chevron on the target and open fire. The sight has an internal light bulb that when turned on, illuminates the reticle for easier aiming in poor lighting conditions such as during twilight hours or dawn. Unless the gunner had 20/20 vision and the tank was completely still, considerable ranging errors in the neighborhood of 100 or so meters was the norm, and as the distance from the target increased, the accuracy of the measurement decreased exponentially, deteriorating drastically past 2000 m. As such, it is more difficult hitting targets with lower velocity ammunition like HE-Frag and HEAT shells, and even harder for moving targets. However, the inclusion of near-hypersonic APFSDS ammunition in the T-62's loadout greatly helped counterbalance this issue, making it markedly easier for the gunner to hit both stationary and moving tank-type targets, while most targets requiring HE-Frag shells like machine gun nests and pillboxes and other fortifications would be stationary anyway, thus making pinpoint accuracy much less of a priority. Even so, on account of the extremely high speed of the APFSDS rounds fired from the 2A20 gun, the sight can be battlesighted at a very generous 1000 m, allowing the gunner to confidently hit a tank of NATO-type dimensions at any distance between 200 to 1600 m by aiming at center mass without needing to ascertain the range beforehand. However, one inescapable flaw of the TSh2B-41U was that it lacked independent vertical stabilization, being directly mechanically linked to the 2A20 cannon, forcing it to elevate with it when the loading procedure is underway. This causes the gunner to (very annoyingly) lose sight of anything he is aiming at at the moment, making the commander's the only pair of eyes to observe the 'splash' and give corrections or search for new targets. This led to the development of the independently stabilized TSh2B-41U.
  11. 11 points
    EnsignExpendable

    HEAT for Dummies

    Neat video showing off how HEAT shells work. The guy detonates 4 charges, one that's just explosive, one with explosive that has an indentation in it, then one with an explosive that has an indentation in it that's filled with metal, and finally, the same charge as in part 3, but at a small offset to focus the blast.
  12. 10 points
    Hello everyone! I've made some videos concerning topics of military, strategy, technology and so on. So far I'm getting pretty good feedback on them so maybe you too would be interested in seeing them. Here's one on Turkey vs Russia: hypothetical air war Or US AMRAAM D missile compared to Russian R-77-1 missile Or UK vs France: hypothetical war So tell me what you think!
  13. 10 points
    Collimatrix

    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.
  14. 10 points
    Sturgeon's House management does not endorse the views and statements contained in its user-generated content. All views and opinions expressed are those of the author and do not necessarily reflect the official doctrine on which populations are sub-human and must be exterminated.
  15. 10 points
    Today marks the 70th anniversary of the Trinity test. 70 years ago today, in a remote part of southern New Mexico, a fission chain reaction started on Earth for the first time in billions of years.
  16. 9 points
    Hello fellow members, a newcomer here. I just finished reading the exhaustive Ukrainian armor -thread among few other great threads, and felt like I shall contribute something to this forum in return. Hopefully I can drag other authors with me into this thread, but I restain the right to start the topic with the vehicle, of which retirement has caused most butthurt among Finnish armor community. That is, of course, the T-72M1, "Seittenkakkonen" (Finnish for "semdesyatdvoyki" / "seventytwo"). All data presented here is translated from public Finnish articles and seminarys. In this post I focus on the initial acquirement process of the T-72 from the USSR, and in later posts I will adress the NVA-deal, some interesting modifications and last, the disqualification of the T-72M1 in the FDF. A Nižni Tagili T-72M1, produced somewhere between 1985 and 1988, in AALTO-2004 exercise with reservist crew. The attached combat simulator equipment is Saab BT 41. Photo most likely courtesy of the FDF. T-72M1 in Finnish Service The acquisation and preparations During the 60's and 70's the Finnish land force's fist was one <sic> Armored Brigade, which main battle tanks were T-54's and T-55's delivered from 1959 to 1972. During 1975-1977, The parliaments defense commitee proposed the renovation of armored equipment. The next committee left its memo in 1981, which suggested acquiring armor from the USSR, utilizing possible bilateral trade. Such procedure was usual way of business in heavy machinery and equipment between Finland and USSR at the time. This would enable the FDF to form another war-time armored brigade. In May, 1979, The T-72 Ural, among armor workshop trucks and other armored vehicles was presented to the Finnish delegation in Vystrel training centre in Solnetshnogorsk. In December another delegation was sent to examine the T-72, first in theory at Malinovski armor academy and in practice at Vystrel. Memos from both trips review the T-72 very suitable for the FDF's usage, and to be a vast improvement in contrast to the T-55, but it was also considered to demand more service due its complexity. The buying process was initially started, but during may 1983 the Soviet counterpart notified for the Finns surprise that more modern, T-72M and T-72MK-tanks would be available. These vere reviewed by the Finns later in the same year. Later the acquisition refined to apply T-72M1 and T-72M1K's. Training in Odessa The process started to materialize, when a 22-men delegation formed of personel from the Headquarters, Armored Brigade and depots took a trip to Moscow in early September 1984, and continued from there to Odessa, where instructors and maintenance personell received their training. The journey memorandum is still held secret by the headquarters, but a good overview in to their studies was publicly presented by one of the participants in 2014. The course were held in military academy in Fontanskaya street. Gunnery took place in Khornomorskje, driving studies in Štepanivka near Kiev, and deep fording training was held near the town of Nikojalev. The academy was a combined arms cadet academy, and held participants from satellites such as Cuba, Nicaragua, Angola, Mosambik, Afganistan and Mongolia, but also equipement course students from a countries whose ties to the USSR were little looser, such a Finland and Algeria. The cadet courses lasted for five years, of which the first one consisted of only studies of Russian language. The delegation was led by colonel Tauno Ylänne, while their soviet counterpart was army captain. The students were split into three courses: The instructors, weapons and electrics, and service & maintenance. The Finns attending the course were no greenhorns; all had solid experience on the T-54 and the T-55, the most experienced elders even beyond that, from the T-34-85. They shared the views of acquisition delegations and considered the T-72M1 remarkably advanced in terms of fire control, night vision and loading automatics <no way...> compared to its predecessors. The cultural difference between the instructors and students was wide: The Soviets wanted to call their Finnish students comrades, which the delegation refused to accept. The instructors had gotten used to the low knowledge level of their students, thus for example the training for the command (K)-models navigation apparatus started from the basics of trigonometry. The Finns were taught like they had no prior experience of the armor branch, but these issues was to be solved quickly. Not every participant was fluent in Russian language, or understood it at all. The three interpreters included in the delegation could not be serving all need simultaneously, but with help of colleagues the students kept up. The Finns also had translated the technical documentation of the T-72 on their own, which greatly helped the self-studies. The translation was done by a major called Ari Puheloinen. He would later become the commander of the defense forces. A tankist to the bone, he left service for retirement in 2014, driving a BMP-2 in the streets of Helsinki. Instructor's training consisted of 300 hours, of which over a half was spent for combat vehicle course and a degree. Relatively little time was used for weapons and gunnery training, and the emphasis of the studies was on the cassette autoloader which represented new technology for the Finns. The maintenance group instead, focused on the repairs and evacuation, and also carried out a degree to attest their 336 hour training. The studies took place from Monday to Saturday, from 0800 to 1500 followed by a three hour self-study time. The method of theory followed by self-studies was seen successful, and was later to be applied on the training of conscripts. In the exams the Finns cheated abundantly : The interpreters had heard the correct narrations many times over, and despite of what the student sobbed them in Finnish, they provided the correct answers for the instructors. On the other hand, the Finns repeatedly broke the 2,8 km long tank driving tracks speed records for a great nuisance for their instructors. Practical training remained a bit thin; no full-calibre shots were fired, and deep fording was presented only as an exhibition. The combat frog, MT-LB was also presented for the students, and later it was chosen to be bought also. The students returned in Finland 27.10.1984. The tanks arrive The first 15 T-72M1's and T-72M1K's of the order of 60 tanks, crossed to border on a railbed 13.12.1984 and were transfered to Siikakangas depot for acceptance and modifications. Also a "work brigade" of two russian mechanics arrived to fix faults and deviations noticed in the acceptance checks. The new vehicles and its systems were put on several tests during 1985 in order to examine and clarify its features and performances. The tanks were localized with Finnish light package for road usage, Finnish plates in instruments, fire extinguisher and such minor things. The Odessa men were called in May for a week to recap their studies, exercise driving and perform so called "driving licenses" for the tank in order to start its usage on the Armour Brigade. The first batch on tanks, 3 T-72M1's and one T-72M1K was delivered from depot to the Armored Brigade in May, where they were used in public presentation and in additional training for the brigade staff. In autumn 1985, 10 tanks more were delivered and the conscript training (production of war-time troops) begun. In the next summer the Armored Brigade received next 13 tanks to start training in another Tank Company and a first T-72 cadet course. For the next decade they would be training two T-72's companies concurrently, until the second unit switched to modernized T-55's in 1996 in order to fulfill new troop production demands. The rest of the tanks were delivered in four batches, 15 in February 1985, 10 in December 1986, 10 in Apri 1987 and 10 in September 1988, respectively. All the delivered tanks, 54 T-72M1's and 6 T-72M1K were new and were shipped straight from Nižni Tagil. The exported vehicles represented a productions from November 1984 to August 1988, there were some degree of structural differencies, which caused minor problems with spare part fitment and documentation. Configuration was usual for the type, but the GO-27 gas/radiation meter lacked from all Nižni Tagili vehicles. This wasn't the case with Warsaw Pact T-72M1's. Later the war-time Armour Brigade rosters were adjusted and changed, which created a demand for three more T-72M1K's. These were amidst very interesting political situation, in December 1991. They were equipped with brand new radio gear R-173 and R-134 and new R-174 intercoms. Training equipment In addition to the tanks them selves, a large assortment of training equipment was acquired. It consisted of UDS-172 demonstration tank (a cage model of the T-72, nowadays shown at the Armour Museum), demonstration turret SAZ-172, autoloader training apparatus, demonstration main gun and broad range of cut-models of various equipment. In 1993 started training with three TOPT-3 turret simulators, which were modified in Finnish-Israeli co-operation. The modifications allowed to train the turret crews of whole platoon in a classroom. First usage experiences and maintenance When the users had got familiar with their new tanks and their most common faults and issues, a repair training was initiated with the Soviet counterpart, based on earlier agreements. The field maintenance troop was trained in Kiev, and the major overhaul training was held in Moscow, Atamanovka and Saransk. The Soviet union broke up meanwhile, and changes in organizations caused a few years break in the training. When the training resumed, qualitative problems arose as some of the organisations supposed to train the Finns weren't yet familiar with the T-72 them selves, as they had just took over functions which were had been located in the Baltic states. Additional training was bought from former DDR, where their biggest tank repair factory in Neubrandenburg, now operated by company called SIVG provided the Finns training for the repairs in transmission and sighting complex TPD-K1. Some testing equipment were also bought from SIVG, which proved to be excellent and some still remain in use while the T-72 is long gone. Discussions with the Russians in 1993 were held in order to find out at which phase and in what scale they applied interval repair to their vehicles. While the Russian procedure was not applied "as-is" in Finland, the discussions strengthened the Finnish perceptions of the tanks usual wear and tear. The overhaul literature and technical drawings were bought as full series in their whole broadness. Spare parts were bought per manufactureres guidelines, but adapted in the light of Finnish experiences. Repair equipment and tools was purchased both in metal and in paper (to be manufactured by the buyer, if necessary). Finnish repair volumes didn't correlate at all with huge quantities of Russian workshops, and thus it was not necessary to obtain a specific tool for every single work phase. After "just" couple years of use, malfunctions started to appear in the V-46-6 engine, on its head gaskets to be more specific. The problems were examined, among other means, by instrumenting one engine. The instrumentation proved that the cooling usage after heavy duty before engine switch-off had major effect on the internal temperatures of the engine. During repairs it was observed that measurement, machining if necessary, and hand-picking the bi-metal gaskets with accuracy of 1/100 mm cured the situation in some extent. Even thou the cooling was given big attention in use, the problem of coolant and pressure leaks between the block and the heads followed the tank thru its whole lifespan, and appeared to be unrelated to the origin of the engine; both Russian-made and later Polish-made engines suffered from it. The experiences with the T-72M1 in the FDF were mixed in their nature, when compared to our other tank at the time, the T-55M. The tactical mobility of the T-72 superior, but it suffered from its slow reverse speed in typical fire position action. It had less daily maintenance subjects and adjustments than the T-55, but the final drives in the sprockets was noticed to wear prematurely. 2E28M stabilizer, the autoloader and the sighting complex TPD-K1 suffered from small defects and malfunctions thru the lifespan. The ammunition provided to the T-72M1 was outdated, especially the 3BM15 APFSDS lacked performance. As for Fire Control Systems, the differences were such big in favor of the T-55M that it not a huge wrong to declare that the T-72M1 did not have one. Meanwhile the T-55M presented a superior night figthing capability with its gunners image intensifier, and its Belgian 100mm sabot ammo was considered capable for the mission. A Nižni Tagili T-72M1 on an OPFOR mission, 28.6.2012 in the Armored Brigades 70 year anniversary. This vehicle is a rare example, as it retains the fording tube. It was not usually carried in the Finnish T-72 .Photo: Niko Juvonen Sources: Panssariseminaari 2014. (The armour seminary 2014). Parolannummi 4.2.2014. Lecture: Colonel (ret.) Kari Haapanen : Odessan miehet - Suomalaiset T-72 koulutuksessa Neuvostoliitossa. (The men of Odessa - Finns in T-72 training in the USSR.) Panssarilehti 4/2014. (Armor magazine 2/2014) Esa Muikku: T-72 Suomessa. (T-72 in Finland) ISSN 1235-3469. Lecture, 4.11.2014, Armour Guild, Parolannummi, Hattula: M.Sc.(Tech.) Esa Muikku, Millog Oy technical chief: T-72 Suomessa 13.12.1984-28.12.2006.
  17. 9 points
    It's a very very long story so just a quick summary for now...got no time these days unfortunately 1. Daigensui(or Sumeragi; 스메라기) first appeared on Korean WOT forum 2 years ago. He introduced himself as a Korean-Japanese woman currently living in Canada and working as a consultator for WOT Japanese tank tree. Then he quickly succeeded in forming a group of fanboys, but not everyone liked him as his fanboys were somehow ruining the forum, and himself was problematic. 2. On June 7th 2014 some WOT players casted doubt on Sumeragi's gender. #Link1 #Link2 3. Then one of the forum members uploaded a series of evidences indicating that Daigensui is not a female, but actually an ex-marine named Kang Seung Jae(this part needs verification as some sources says that he was never a conscript). Other evidences also claim that Sumeragi is a male and banned from numerous forums for his lies, 4. That night the forum administrator(롤랑) invited Sumeragi to a private chat. Admin gave Sumeragi a time to defend himself, but the admin couldn't hear any repliy. 5. During the same period Korean Wargame RD players were complaining about M18 hellcat, which was never used by the ROK army. Then someone found out that it was Sumeragi's fault, and annoyed WRD players joined bashing him. 6. Sumeragi sent his explanations to the admin. #Link1 #Link2 Majority of the Korean WOT and WRD players concluded that Sumeragi's explanations aren't credible enough. 7. Admin made a phone call with Sumeragi. Phone number was from Vancouver, but "her" voice was definitely male's. So now he's kicked from Korean WOT and WRD forums, but that retard currently using a sockpuppet account according to the admin. p.s. He's also famous for pseudologia in other Korean gaming forums. According to Daigensui, he's... * a twenty-something female residing in Vancouver * a lesbian but engaged with "her" cousin * a smartass that graduated both Tokyo and Yonsei university * working in a major company owned by "her" relatives * so wealthy that he can invest $10million rightaway * a distant relative of current Japanese emperor
  18. 9 points
    Holy... What the.. It's fallshirmjager Otto Von Meatbunker, the bipedal sandbag! Use him for cover! Advance on our enemy using his considerable bulk as a shield! Really, does a Ju52 even have a way to carry external stores that large? Cause I cannot see Gefreiter Lardbody fitting through the troop door without using considerable amounts of butter.. And I'm assuming that's a reproduction uniform smock, something has me doubting the Germans ever made one like that in size "Hamplanet".
  19. 9 points
    Collimatrix

    Collimatrix's Terrible Music Thread

    Oh yeah, I can see Gwar doing a really superb live show. Out of respect for the next artist's litigious tendencies towards youtube videos, I will not be posting any audio/visual material. In the 1970s there was a terrible threat to civilization and apple pie and freedom and life itself. No, I'm not talking about punk rock or disco or Jimmy Carter's presidency, although those were all terrible mistakes. I am of course referring to that great rainbow scourge, the gays. The 1969 Stonewall riots began the campaign of gay imperialism. Things that had been safely heterosexual suddenly, overnight, became gay. The color purple. The word "gay." Song and dance numbers. Nazi uniforms. Tight pants. Dressing well. Reading books. By the end of the decade, only men with disgusting walrus mustaches, poor personal hygiene and no words in their vocabulary over four syllables long were safely straight, and the gays were coming for the mustaches too. Breeders were in retreat, and given that the gays had claimed grooming as part of their lebensraum, attracting a mate was getting pretty difficult. The entire globe would be partitioned between celibate, culture-less morlocks and an expanding army of flouncing, hard-bodied interior decorators. This is how the world ends; not with a bang, but a... a sound that is like a whimper, but gayer. But then in the 1980s, God stopped the gays in their tracks. The Moral Majority interpreted AIDS as God's judgment against the gays, but you shouldn't listen to them because they're retarded. God's instrument against the gays in the 1980s was Prince. Yes; Prince, who's early hits included "1999" and "Little Red Corvette," was in fact the defender of heterosexuality who allowed the next generation to be born (that generation would turn out to be the Millennials, but that's hardly his fault). Yes, the man wore a lot of purple and lace, which at first glance seems dubious, but you've got to understand that he was making those things straight again. Yes; Prince was the leader of the heterosexual reconquista. Let that sink in; without Prince, straight people would have been wiped out by the mid 1990's. Yes, the guy is a weirdo and a vegan, but I think that's entirely permissible in light of the fact that he saved humanity from extinction.
  20. 8 points
    Toxn

    Yushukan 2016: honoured heroes of honour

    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.
  21. 8 points
    Walter_Sobchak

    Tank Myths

    I'm sure a few tiger tanks broke through some bridges...
  22. 8 points
    Thunderf00t has been doing God's work lately: All three videos are good, but the last is the best. It is a brief glimpse of horrifying clarity into the minds of science fetishists. A science fetishist is someone who has come to believe (correctly, as it turns out) that the systematic approach towards understanding the universe (often called "science") is the best, and it will be the means by which all the clean, shiny and beautiful people of the future will lord it over the sticky, sickly, filthy peasant scum of the future. Having further reasoned (again, correctly) that they wish to be in the former, rather than the latter camp, science fetishists have decided that they will do anything to get on top of the most important trends of the future. They'll upvote shit on Facebook. They'll make viral videos on Youtube. They'll evangelize. They'll worship new gods and heroes. They'll throw money at visionaries. They will do anything short of actually making any effort to understand science. Just because Elon Musk is throwing money at something does not make it a good idea. Elon Musk is rich, and you are poor. Rich people have the luxury of throwing money at dumb ideas and not starving. Again, this is because they are rich. Every once in a while one of these dumb ideas turns out to be a fantastically profitable idea masquerading as a dumb idea, and the rich person makes their money back plus something. If the breaks are right this is sustainable, and thus it has turned into something of a sport for rich people, who call it venture capitalism. They like it even more than polo, camel racing or even competitive spitting on poor people because, in addition to being fun, it helps them feel smart and responsible. Feeling smart and responsible is a critical part of building up a rich person's confidence, which they need in order to establish social superiority over their most fearsome adversaries; other rich people. I'm sorry; did you think I was going to say poor people? No; rich people are not worried about poor people. Poor people like you don't matter. But you have to understand that venture capitalism is strictly a rich people sport. Speculation and investment of any sort is a rich people sport; you need the enormous thermal mass provided by enormous piles of money in order to stay on the good side of the law of large numbers. Oh yeah, sure, in theory a bunch of poor people could pool together their meager, filthy peasant money into some sort of serf penny pile and appoint a known expert to manage and diversify it for them and pay them pro rata. In some far off time and place with different pass-through taxation laws, different real economic growth and different trade commission regulations this probably could theoretically even have worked. Obviously, it would have worked even better for rich people, because everything works better for rich people because God loves them more. That's why they're rich. Or maybe you believe that rich people are that way because they know certain spells and incantations, or that they're all actually lizard people who have saved money on groceries by being ectothermic and have compounded those savings over centuries, or that they're all really devil worshippers who have exchanged their souls for worldly prosperity. Whatever; it doesn't matter. The bottom line is that superficially copying the habits of rich people will not make unwashed poor people such as yourself rich. If you want to become rich, you have two options. If think that you don't want to become rich you need to stop lying to yourself and realize that you really do want to become rich. Option one is to be lucky. I can offer no useful advice on that. Option two is to work hard and actually understand how in the fuck the world works, and then try to manipulate it into diverting some of its delicious, glorious money to you. On that I have little advice, save that throwing your money at obvious science fetishist bullshit is not going to help.
  23. 8 points
    3ds Max isn't very nice for telling you how much something will weigh and all that jazz, so I'm probably just going submit eye candy with backstory tacked on. That was pretty much my original goal anyway, but with less effort in mind on the eye candy part. Some parts still need to be worked on, but I'm fiddling with an extra armor variant as as well. Edit shows current head-on coverage I also added fenders/stowage space, rearranged wheel positions AGAIN, added a cap for filling up for fuel and other engine goodies, rear doors (subject to change), and a bunch of little tweaks here and there.
  24. 8 points
    "They keep telling us to work harder, and that if we don't keep these tigers going we'll be transferred to a panther unit as punishment."
  25. 8 points
    Virdea

    We Have A New Subforum

    Like the 6.8mm SPC?
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