T-54/T-55 Medium Tank

The T-54 and T-55 tanks are a series of main battle tanks (according to some sources) although not recognised medium tanks (the very concept of "main battle tanks" was applied only to tanks beginning with T-64A, armed with 125-mm tank gun) that were designed in the Soviet Union. The first T-54 prototype appeared in March 1945, just as the Second World War ended. The T-54 entered full production in 1947 and became the main tank for armored units of the Soviet Army, armies of the Warsaw Pact countries, and others. T-54s and T-55s were involved in many of the world's armed conflicts during the late 20th and early 21st century.

as MBT by Soviet and Russian sources, instead classifying them as

The T-54/55 series eventually became the most-produced tank in history. Estimated production numbers for the series range from 86,000 to 100,000. They were replaced by the T-62, T-64, T-72, T-80, and T-90 in the Soviet and Russian Armies, but remain in use by up to 50 other armies worldwide, some having received sophisticated retrofitting.

Soviet tanks never directly faced their NATO Cold War adversaries in Europe. However, the T-54/55's first appearance in the West in 1960 spurred the United States to develop the M60 Patton.

T-54

Production of the initial series of T-54s began slowly as 1,490 modifications were made. The Red Army received a tank that was superior to World War II designs and theoretically better than the newest tanks of potential opponents. The 100 mm gun fired BR-412 series full-calibre APHE ammunition, which had superior penetration capability compared to the T-34 that it replaced.

The serial production version, designated T-54-1, differed from the second T-54 prototype. It had thicker hull armour (80 mm on the sides, 30 mm on the roof and 20 mm on the bottom). As production ramped up, quality problems emerged. Production was stopped and an improved T-54-2 (Ob'yekt 137R) version was designed. Several changes were made and a new turret was fitted. The new dome-shaped turret with flat sides was inspired by the turret from the IS-3 heavy tank; it is similar to the later T-54 turret but with a distinctive overhang at the rear. It also had a shorter bustle. The fender machine guns were removed in favour of a single bow-mounted machine gun. The transmission was modernized and the track was widened to 580 mm. The T-54-2 entered production in 1949, at Stalin Ural Tank Factory No. 183 (Uralvagonzavod). In 1951, a second modernization was made, designated T-54-3 (Ob'yekt 137Sh), which had a new turret without side undercuts, as well as the new TSh-2-22 telescopic gunner's sight instead of the TSh-20. The tank featured the TDA smoke generating system. A command version was built, the T-54K (komandirskiy), with a second R-113 radio.

T-54A and T-54B

In the beginning of 1950s, the personnel of the OKB-520 design bureau of the Stalin Ural Tank Factory No. 183 (Uralvagonzavod) had been changed considerably. Morozov was replaced by Kolesnikow, who in turn was replaced by Leonid N. Kartsev in March 1953. The first decision of the new designer was to fit the 100 mm D-10T tank gun with the STP-1 "Gorizont" vertical stabilizer. The new tank gun received the designation D-10TG and was fitted into the T-54's turret. The new tank received night vision equipment for the driver and was designated T-54A (Ob'yekt 137G). Originally, this had a small muzzle counter-weight, which was later replaced with a fume extractor. It was equipped with an OPVT wading snorkel, the TSh-2A-22 telescopic sight, TVN-1 infrared driver's periscope and IR headlight, a new R-113 radio, multi-stage engine air filter and radiator controls for improved engine performance, an electrical oil pump, a bilge pump, an automatic fire extinguisher and extra fuel tanks. The tank officially entered production in 1954 and service in 1955. It served as a basis for T-54AK command tank, with additional R-112 radio set (front line tanks were equipped with R-113 radio set), TNA-2 navigational device, ammunition load for the main gun decreased by 5 rounds and the AB-1-P/30 charging unit, which was produced in small numbers. In October 1954 a T-54A tank, designated as T-54M (Ob'yekt 139) served as a testbed for new D-54T and D-54TS 100 mm smoothbore guns and "Raduga" and "Molniya" stabilization systems, which were later used in the T-62. These were not completely successful, so further T-55 development continued to use the D-10 series guns. It was fitted with V-54-6 engine developing 581 hp (433 kW). It never went into production.

A new version, based on T-54A, designated T-54B (Ob'yekt 137G2), was designed in 1955. It was fitted with a new 100 mm D-10T2S tank gun with STP-2 "Tsyklon" 2-plane stabilizer. It entered production in 1957. During the last four months of production, the new tanks were equipped with an L-2 "Luna" infrared searchlight and TPN-1-22-11 IR gunner's sight, and OU-3 IR commander's searchlight. Modern APFSDS ammunition was developed, dramatically enhancing the penetrative performance of the gun to keep it competitive with NATO armor developments. T-54B served as the basis for T-54BK command tank which had exactly the same additional equipment as the T-54AK command tank.

T-55

Trials with nuclear weapons showed that a T-54 could survive a 2–15 kt nuclear charge at a range of more than 300 metres (980 ft) from the epicenter, but the crew only had a chance of surviving at 700 metres (2,300 ft). It was decided to create an NBC (nuclear, biological, and chemical) protection system which would start working 0.3 seconds after detecting gamma radiation.

The task of creating a basic PAZ (Protivoatomnaya Zashchita) NBC protection system offering protection against the blast of a nuclear explosion and (radioactive) particulate filtration, but not against external gamma radiation or gas, was given to the KB-60 design bureau in Kharkov and was completed in 1956. The documentation was sent to Uralvagonzavod. It was decided to increase the tank's battle capabilities by changing the tank's construction and introducing new production technologies. Many of those changes were initially tested on the T-54M (Ob'yekt 139). The tank was fitted with the new V-55 12-cylinder 4-stroke one-chamber 38.88 litre water-cooled diesel engine developing 581 hp (433 kW). Greater engine power was accomplished by increasing the pressure of the fuel delivery and charging degree. The designers planned to introduce a heating system for the engine compartment and MC-1 diesel fuel filter. The engine was to be started pneumatically with the use of an AK-150S charger and an electric starter. This eliminated the need for the tank to carry a tank filled with air. To allow easier access during maintenance and repairs, it was decided to change hatches over the engine compartment. To increase the operational range, 300 litres (66 imp gal; 79 US gal) fuel tanks were added to the front of the hull, increasing the overall fuel capacity to 680 litres (150 imp gal; 180 US gal). 

The ammunition load for the main gun was increased from 34 to 45, with 18 shells stored in so called "wet containers" located in hull fuel tanks (the concept for which came from Kartsev's cancelled Ob'yekt 140. The ammunition load included high explosive-fragmentation and anti-tank rounds and designers also planned to introduce the BK5M HEAT rounds which penetrated 390 millimetres (15 in) thick armour. The TPKU commander's vision device was replaced by either the TPKUB or TPKU-2B. The gunner received a TNP-165 vision device. The loader's hatch-mounted 12.7 mm DShK anti-aircraft heavy machine gun was dropped, because it was deemed worthless against high-performance jets. The tank was supposed to be equipped with the "Rosa" fire protection system. The tank had a thicker turret casting and the improved two-plane gun stabilization system from the T-54B, as well as night vision fighting equipment. To balance the weight of the new equipment, the armour on the back of the hull was thinned slightly.

The T-55 was significantly superior to the IS-2 Heavy Tank in all respects, including the rate of fire of the gun (at least four compared to less than three rounds per minute). Despite somewhat thinner frontal turret armour (200 millimetres (7.9 in) instead of 250 millimetres (9.8 in)) it compared favourably with the IS-3, thanks to its improved antitank gun and better mobility. Heavy tanks soon fell from favour, with only 350 IS-3s produced. The old model of highly mobile medium tanks and heavily armoured heavy tanks was replaced by a new paradigm: the "main battle tank". Parallel developments in the West would produce similar results. Katsev combined all the ongoing improvements being offered, or planned, on the T-54 into one design. This became the Ob'yect 155, and entered production at Uralvagonzavod 1 January 1958 as the T-55. It was accepted for service with the Red Army on 8 May. It suffered a significant lapse in one area: there was no antiaircraft machinegun, which had been present on the T-54.

After 1959, it served as a basis for the T-55K command tank which was equipped with an additional R-112 radio set, an AB-1-P/30 fuel powered accumulator charging unit, and TPN-1-22-11 night vision sight. All this additional equipment made it necessary to decrease the ammunition load for the main gun to 37 rounds and eliminate the bow machine gun. In the beginning of the 1960s, a T-55K was experimentally fitted with a Uran TV relay apparatus for battlefield surveillance. The tank was fitted with an external camera, the picture from which was relayed to a receiver in a BTR-50PU command vehicle. There was an observation camera mounted on a folding mast which was in turn mounted on a UAZ 69 car. The range within which the picture could be relayed varied between 10 and 30 kilometres (6.2 and 19 mi).

In 1961, a T-55 tank was used to test the "Almaz" TV complex which was supposed to replace the standard observation devices right after a nuclear explosion or while fording a body of water. There was a camera mounted on the hull for the driver and two cameras mounted on the turret, one for aiming and one for observation, and the picture from the cameras was relayed to two control screens. The tank had the front hull fuel tanks and bow machine gun removed. The commander was seated in the driver's usual position while the driver sat next to him. The cameras allowed battlefield observation and firing during daytime at ranges between 1.5 and 2 kilometres (0.93 and 1.2 mi). Because of the low quality of the equipment, the trials gave negative results. In the beginning of the 1960s, the OKB-29 design bureau in Omsk was working on adapting the tank to use a GTD-3T gas turbine engine developing 700 hp (522 kW). One T-55 tank fitted with this gas turbine engine passed trials but was deemed unsatisfactory and the design did not go into production.

The Omsk OKB-29 group tested three experimental T-55 tanks (designated Ob'yekt 612) between 1962 and 1965 that were fitted with an automatic gearbox controlled by electro-hydraulic systems. The trials found that such gearboxes were prone to frequent breakdowns in tanks. At the same time the Ob'yekt 155ML, a T-55 fitted with a launcher for three 9M14 "Malyutka" (NATO code: AT-3 Sagger) ATGMs mounted on the rear of the turret, was tested. Along with standard tanks a flamethrower-armed version was designed (designated TO-55 (Ob'yekt 482)), which was produced until 1962. It was fitted with 460 litre tanks filled with flammable liquid instead of the frontal hull fuel tanks. The flamethrower replaced the coaxial machine gun. This was a much better way to mount a flamethrower than in the experimental Ob'yekt 483, based on the T-54 tank, where the flamethrower replaced the main gun. TO-55 flamethrower tanks were withdrawn from service in 1993.

During the 1950s, the T-55 remained a significantly smaller and lighter tank than its NATO contemporaries—the U.S. M48 Patton and the British Centurion—while maintaining good firepower and reliability but light armor. The 100-mm D-10T tank gun had a larger bore than its Western counterparts.

In January 1945, some captured German tanks and vehicles were shipped to the Ordnance Research and Development Center, Aberdeen, Maryland, for tests and examination. The criteria for penetration in the tests was for at least fifty percent of the mass of the projectile to penetrate the armor. The M3 90 mm gun, firing the most widely equipped T33 armor-piercing round penetrated roughly 6 inches (150 mm) of steel armor at 100 metres (330 ft), while the T30E16 HVAP round penetrated 10.5 inches (270 mm) at the same range. These tests were carried out before the T-54/55 tank entered production, so it was not known how the popular 90 mm gun on the M46, M47, M48 and other western tanks would perform against the armour of the post-World War II Soviet tanks.

The data shows that the T33 AP round would fail to penetrate the frontal armour of the T-54/55 at any range, while the T30E16 HVAP round would only be able to penetrate the armour within 700 metres (2,300 ft). The T33 round could penetrate the side armour of the turret at about 800 metres, while the T30E16 HVAP round could do this at any practical range.The most popular anti-armor round the Soviets used for the D-10 tank gun was the 100 mm BR-412 APHE, first used on the SU-100 tank destroyer during World War II with an 80% probability of penetrating 135 millimetres (5.3 in) of steel armour at 1,000 metres (3,300 ft) fired from the D-10S tank gun. The BR-412D and BR-412B rounds developed in 1946–1950 had slightly superior performance over the 90 mm T33 and the M82 armor-piercing rounds.

This disadvantage lasted until the Soviet tanks began to be surpassed by newer Western developments like the M60 Main Battle Tank and upgraded Centurions and M48 Pattons using the 105 mm rifled Royal Ordnance L7 gun. Due to the low velocity of rounds from the 100 mm gun, and the tank's simple fire-control system, the T-54/55 was forced to rely on HEAT shaped-charge ammunition to engage tanks at long range well into the 1960s, despite the relative inaccuracy of this ammunition at long ranges. The Soviets considered this acceptable for a potential European conflict, until the development of composite armor began reducing the effectiveness of HEAT warheads and sabot rounds were developed for the D-10T gun.

Specifications (T-55)
Weight	36 tonnes (39.7 ST)
Length	6.45 m
Width	3.37 m
Height	2.40 m
Crew	4
Armour	hull front 100 mm @60°, turret front 205 mm (rounded), hull side 80 mm @0°, lower hull side 20 mm @0°, turret side 130 mm (rounded), hull rear 60 mm @0°, turret rear 60 mm (rounded), hull top 33-16 mm, turret top 30 mm, hull floor 20 mm
Main armament	D-10T 100 mm rifled gun
Secondary armament	7.62 mm SGMT coaxial machine gun, (12.7 mm DShK heavy machine gun)
Engine	Model V-55(V-54) V-12 water-cooled. 38.88-l diesel 581 hp (433 kW)
Power/weight	14.6 hp/tonne
Transmission	Mechanical synchromesh, 5 forward, 1 reverse gears
Suspension	Torsion bar
Ground clearance	0.425 m
Fuel capacity	580 l internal, 320 l external (less on early T54), 400 l jettisonable rear drums
Speed	48 km/h (30 mph)

Source : Wikipedia

BT-7 Light Tank

The BT-7 was the last of the BT series of Soviet cavalry tanks that were produced in large numbers between 1935 and 1940. They were lightly armoured, but reasonably well-armed for their time, and had much better mobility than other contemporary tank designs. The BT tanks were known by the nickname Betka from the acronym, or its diminutive Betushka.

The successor of the BT-7 Tank would be the famous T-34 medium tank, introduced in 1940, which would replace all of the Soviet fast tanks, infantry tanks, and medium tanks then in service.

Development

The first prototypes of the BT-7 had a distinctive canted-ellipse shaped turret mounting both the main gun and a coaxial machine-gun. The specification also called for the project to allow for installation without any significant change to the framework of new guns: the 76 mm KT-26 or PS-3 main gun (a short-barreled howitzer) and the 45 mm 20K model 1932/38, a long-barreled, high-velocity gun useful against tanks, but less effective than the 76 mm gun against infantry.

In the rear of the turret there was housed a rotating drum-type magazine for 18 76 mm shells or a radio station. The prototype underwent an extensive testing program in the summer and autumn of 1934. As a result of this testing, it was felt that a machine-gun was unnecessary on a tank with a 3-man crew, especially as it made the assembly of the turret more complicated.

Therefore, in early 1935, the tank went into production with a simpler design, incorporating the turret from the BT-5. (However, the idea of wheeled/tracked vehicle with a 76 mm cannon was not abandoned and the plant was commissioned to develop a new BT-7 turret from the turret of the T-26-4.) In the production model, a cylindrical turret housed a 45 mm 20K gun with a DT-model machine-gun. On some of the tanks, a model 71-TC radio with frame antenna was installed.

The crew consisted of three men: the commander (who also served as the gunner); the loader and the driver. In 1937 the company launched production of the BT-7 with a conical turret. Main armament remained the same, but the ammunition was increased to 44 rounds. All serving tanks now installed the DT machine gun in the rear niche. For the firing of the gun and coaxial machine gun at night, the tank was equipped with two special projector-type headlamps, and a mask placed on the gun. Subsequently, these lights were retrofitted to earlier models of the tank. Improvements were also made to the drive wheels, caterpillar tracks and gearbox by 1938.

In parallel with the main modification, 154 BT-7A artillery tanks were produced between 1936 and 1938, fitted with a larger turret and a 76 mm KT-type gun, 50 rounds of ammunition (40 in a tank with a portable radio).

In 1938, four experimental BT-8 tanks mounted with V-2 diesel engines were produced. After comparative tests of the BT-7 and BT-8, the diesel tanks were put into production in 1940 (under the designation BT-7M) with the powerplants being produced in a separate plant of the Voroshilovets factory to ensure supply. From December 1939, the BT-7A went into production with some minor modifications - additional bracing for rigidity, a manhole underneath, and a smaller air filter. The diesel tanks showed much-reduced fuel costs, and the petrol-powered tanks were soon placed into reserve.

Several experimental tanks were conceived based on the BT series, for example the wheeled BT-IS, designed by N.F. Tsyganov, a platoon commander in the 4th Armoured Regiment of the Ukraine Military District and self-taught designer. The type successfully passed field tests but was not ordered in bulk. Another Tsyganov design was the S-2 "Cherepaha" (turtle, черепаха), with a new design of hull and turret. There was also the command tank KBT-7 with a fixed turret, the OT-7 mounting a flamethrower, the KhBT-7 designed to protect from toxic contamination and lay smokescreens, the SBT bridgelayer and the TTBT-7 and Thubten-7 radio-controlled tanks (known at the time as Teletanks). Finland converted 18 captured tanks into BT-42 assault guns.

Shortly before Operation Barbarossa, the

BT-7 underwent an up-armour programme. In 1940, Mariupol Ilyich Iron and Steel Works produced 50 sets of hinged homogeneous armor for the BT-7M, which increased the weight of the test tank to 18 tons. On the installation of these kits to military units, unfortunately, nothing is known. Between 1935 and 1940, between 270 and 5,328 BT-7 tanks of all modifications (except BT-7A) were built.

Specifications (variant BT-7-2)
Weight	13.9 tonnes (13.7 long tons; 15.3 short tons)
Length	5.66 m (18 ft 7 in)
Width	2.29 m (7 ft 6 in)
Height	2.42 m (7 ft 11 in)
Crew	3
Armour	Hull: 6-22 mm Turret: 10-15 mm
Main armament	45 mm L/46
Secondary armament	2 x 7.62 mm DT machine gun
Engine	Mikulin M-17T (V-12) gasoline 450 hp (at 1,750 rpm)
Power/weight	32.37 hp/tonne
Transmission	Chain drive (tracks: sliding gear)
Suspension	Christie
Ground clearance	0.305 m (1 ft)
Fuel capacity	360 litres (95 US gal)
Operational range	Road: 430 km (270 mi) Off-road: 360 km (220 mi)
Speed	Road: 72 km/h (45 mph) Off-road: 50 km/h (31 mph)
Steering system	steering stick

Source : Wikipedia

AMX-13 Light Tank

The AMX-13 is a French light tank produced from 1953 to 1985. It served with the French Army and was exported to over twenty-five other nations. Named after its initial weight of 13 tonnes, and featuring a tough and reliable chassis,^[1] it was fitted with an oscillating turret built by GIAT Industries (now Nexter) with revolver type magazines which was also used on the Austrian SK-105 Kürassier. Including prototypes and export versions there are over a hundred variants including self-propelled gun, anti-aircraft systems, APCs, and ATGMversions. Total production of the AMX-13 family is approximately 7,700 units, around 3,400 of which were exported.

History

The tank was designed at the Atelier de Construction d'Issy-les-Moulineaux (AMX) in 1946 to meet a requirement for an air-portable vehicle to support paratroopers, the first prototype ran from 1948. The compact chassis had torsion bar suspension with five road-wheels and two return rollers; the engine runs the length of the tank on the right side with the driver on the left. It features an uncommon two-part oscillating turret where the gun is fixed to the turret and the entire upper turret changes elevation. The turret is set to the rear of the vehicle and holds the commander and gunner. The original 75 mm gun, allegedly modelled on the German 7.5 cm KwK 42 L/70 gun (used, among others, in the Panther tank) but firing very different ammunition from a shorter barrel, was fed with an automatic loading system in two six-round magazines located in the turret's bustle. The twelve rounds available in the loaders meant that the crew could engage targets quickly, however once those rounds were expended the vehicle had to retreat to cover and the crew reload shells from outside the vehicle.

Production began at ARE (Atelier de Construction Roanne) from 1952, with the first tanks delivered the following year. In 1964 production was transferred to Creusot-Loire at Chalon-sur-Saône, as the ARE moved to building the AMX 30 MBT, and the numbers produced declined significantly.

From 1966 the 75mm high-velocity gun was replaced by a 90 mm (the AMX-13/90) medium velocity gun firing more effective HEAT ammunition, with the French upgrading all existing base models to this specification. By the early 1970s export models were available with an even more potent 105mm gun. Although there were many variants on the turret the basic chassis was almost unchanged until 1985 when changes including a new diesel engine, fully automatic transmission and newhydropneumatic suspension were introduced.

Production halted with the Model 1987. After sales support and upgrades are still offered through GIAT Industries (now Nexter).

The AMX-13 tank was phased out of service with the French Army in the 1980s. Current French armoured vehicles with a similar role are the ERC 90 Sagaie and the AMX 10 RC.

Specifications
Weight	13.7 t (30,000 lb) empty 14.5 t (32,000 lb) combat
Length	4.88 m (16 ft 0 in) hull 6.36 m (20 ft 10 in) with gun
Width	2.51 m (8 ft 3 in)
Height	2.35 m (7 ft 9 in)
Crew	3 (Commander, gunner and driver)
Armour	10–40 mm (0.39–1.6 in)
Main armament	75 mm (or 90 mm or 105 mm) with 32 Rounds
Secondary armament	7.5 mm (or 7.62 mm) coaxial MG with 3,600 Rounds, 7.62 mm AA MG (optional), 2×2 smoke grenade dischargers
Engine	SOFAM Model 8Gxb 8-cyl. water-cooled petrol 250 hp (190 kW)
Power/weight	15 hp/tonne
Suspension	Torsion bar suspension
Operational range	400 km (250 mi)
Speed	60 km/h (37 mph)

Source : Wikipedia

Type 97 Chi-Ha Medium Tank

The Type 97 Chi-Ha  (九七式中戦車 チハ Kyunana-shiki chu-sensha chiha)  was a medium tank used by the Imperial Japanese Army during theSecond Sino-Japanese War, the Battles of Khalkhin Gol against theSoviet Union, and the Second World War. It was the most widely produced Japanese medium tank of World War II, although the armor protection was considered as average in the 1930s.^[2] The 57 mm main gun, designed for infantry support, was a carry over from the 1933 Type 89 medium tank. Later it was replaced by a 47 mm gun that was more effective against armor. The 170 hp Mitsubishi engine was a capable engine for the tank in 1938,^[2] and – notably for the time – it was an air cooled diesel. After 1941, the tank was less effective than most Alliedtank designs.

The Type 97's low silhouette and semicircular radio antenna on theturret distinguished the tank from its contemporaries. The crudesuspension was derived from the Type 95 Ha-Go light tank, but used six road wheels instead of four.

History and Development

With the Type 89 Chi-Ro fast becoming obsolete in the late 1930s, the Imperial Japanese Army (IJA) began a program to develop a replacement tank for infantry support. Experience during the invasion of Manchuria determined that the Type 89 was too slow to keep up withmotorized infantry. The new medium tank was intended to be a scaled-up four-man version of the Type 95 Ha-Go light tank, although with a two-man turret, thicker armor, and more power to maintain performance.

The Tokyo factory of Mitsubishi Heavy Industries completed a prototype designated Chi-Ha. The second prototype was completed in June 1937. Although the requirement was for a 47 mm cannon, it retained the same short-barreled 57 mm cannon as the Type 89B tank.

However, at the time IJA was more interested in the lighter Chi-Ni prototype proposed by Osaka Army Arsenal, because it was less expensive and had the same 57 mm gun.

The Second Sino-Japanese War broke out on 7 July 1937. Peacetime budgetary limitations were removed, and the more expensive Mitsubishi Chi-Ha model was accepted as a new Type 97 medium tank.

Design

Type 97 hull was of riveted construction with the engine in the rear compartment. In the forward compartment, the driver sat on the right, and bow gunner on the left.The commander's cupola was placed atop the turret. Internal communications were by 12 push buttons in the turret, connected to 12 lights and a buzzer near the driver.

The Type 97 was initially equipped with a Type 97 57 mm main gun, the same caliber as that used for the earlier Type 89 I-Go tank. The cannon was a short-barreled weapon with a relatively low muzzle velocity, but sufficient as the tank was intended primarily for infantry support. The gun had no elevation gear.

The tank carried two 7.7 mm Type 97 machine guns, one on the front left of the hull and the other in a ball mount on the rear of the turret. The latter could not be remounted on top of the turret for anti-aircraft use.^{[citation needed]} The turret was capable of full 360-degree traverse, but the main gun had a second pair of trunnions, internally allowing a maximum 10-degree traverse^{[citation needed]} independently of the turret.

The thickest armor used was 33 mm on the gun mantlet and 26 mm on the turret sides.

Power was provided by an air-cooled "V-12 21.7 liter diesel Mitsubishi SA12200VD" engine, which provided 170 hp (127 kW).

Production

The Type 97 medium tank was manufactured by Mitsubishi Heavy Industries (1,224 units) and Hitachi Industries (355 units), as well as some limited production in the Army's Sagami Arsenal. A total of 2,123 vehicles was constructed from 1938 to 1943, of which 1,162 units were the standard Type 97 and 930 units were the improved Type 97-kai version. The remainder were various specialized variants produced in small numbers.

The number of Type 97 medium tanks produced was slightly lower than of the Type 95 Ha-Go light tanks, but larger than any other tank fielded by Empire of Japan. The following numbers of units were produced each year:

Type 97 tank (57 mm gun):

• 1938: 110
• 1939: 202
• 1940: 315
• 1941: 507
• 1942: 28
• Total: 1,162

Type 97-Kai tank. (47 mm gun):

• 1942: 503
• 1943: 427
• Total: 930

Total production of the 57 mm & 47 mm gun Type 97 medium tanks was 2,092. Although production peaked in 1943 it was the last year any Type 97 was produced, as factories switched to the new tank designs, most notably the Type 1 Chi-He.

Specifications (Type 97 Chi-Ha as of 1941)
Weight	15 tonnes (14.76 tons)
Length	5.50 m (18 ft 1 in)
Width	2.34 m (7 ft 8 in)
Height	2.33 m (7 ft 8 in)
Crew	4
Armor	8–26 mm (33 mm on gun mantlet)
Main armament	Type 97 57 mm Tank Gun
Secondary armament	2 × 7.7 mm Type 97 machine guns
Engine	Mitsubishi SA12200VD air-cooled V-12 diesel (21.7 litres) 170 hp (127 kW) at 2,000 rpm
Power/weight	11.3 hp/tonne
Suspension	Bell crank
Operational range	210 km (130 mi)
Speed	38 km/h (24 mph)

Source : Wikipedia

About KV Tanks (Kliment Voroshilov tank)

Kliment Voroshilov - 1 Heavy Tank

The Kliment Voroshilov (KV) tanks were a series of Soviet heavy tanks, named after the Soviet defense commissar and politicianKliment Voroshilov and used by the Red Army during World War II. The KV series were known for their extremely heavy armour protection during the early part of the war, especially during the first year of the German invasion of the Soviet Union.

They were almost completely immune to the 3.7 cm KwK 36 and howitzer-like, short barreled 7.5 cm KwK 37 guns mounted respectively on the early Panzer III and Panzer IV tanks fielded by the invading German forces. Until better guns were developed by the Germans it was often the case that the only way to defeat a KV was with a point-blank shot to the rear.

Prior to Operation Barbarossa (the German invasion of the USSR), about 500 of the over 22,000 tanks then in Soviet service were of the KV-1 type. When the KV-1 appeared, it outclassed the French Char B1,^[2] the only other heavy tank in operational service in the world at that time. Yet in the end it turned out that there was little sense in producing the expensive KV tanks, as the T-34 medium tank performed better (or at least equally well) in all practical respects. Later in the war, the KV series became a base for development of theIS (IS - Iosif Stalin) series of tanks.

Development

Kliment Voroshilov - 2 Heavt Tank

After disappointing results with the multi-turreted T-35 heavy tank, Soviet tank designers started drawing up replacements. The T-35 conformed to the 1920s notion of a 'breakthrough tank' with very heavy firepower and armour protection, but suffered from poor mobility. The Spanish Civil War demonstrated the need for much heavier armor on tanks,^{[citation needed]} and was the main influence on Soviet tank design just prior to World War II.

The doctrine of Soviet deep battle called for the existence of relatively immobile, but heavily fortified, siege tanks that were supposed to keep pressure on enemy troops during the siege phase. Thus, the requirements for KV-1 were heavily skewed towards a potentially not-so agile, but heavy tank that was supposed to dominate the field.

Several competing designs were offered, and even more were drawn up prior to reaching prototype stage. All had heavy armour, torsion-bar suspension, wide tracks, and were of welded and cast construction. One of the main competing designs was the SMK, which in its final form had two turrets, mounting the same combination of 76.2 mm and 45 mm weapons. The designers of the SMK independently drew up a single-turreted variant and this received approval at the highest level. Two of these, named after the People's Defence Commissioner were ordered alongside a single SMK. The smaller hull and single turret enabled the designer to install heavy frontal and turret armour while keeping the weight within manageable limits.

When the Soviets entered the Winter War, the SMK, KV and a third design, the T-100, were sent to be tested in combat conditions. The KV outperformed the SMK and T-100 designs. The KV's heavy armour proved highly resistant to Finnish anti-tank weapons, making it more difficult to stop. In 1939 production of 50 KV was ordered. During the War, the Soviets found it difficult to deal with the concrete bunkers used by the Finns and a request was made for a tank with a large howitzer. One of the rush projects to meet the request put the howitzer in a new turret on one of the KV tanks.

Initially known as Little Turret and Big turret, the 76-mm-armed tank was designated as the KV-1 Heavy Tank and the 152 mm howitzerone as KV-2 Heavy Artillery Tank.

The KV's strengths included armor that was impenetrable by any tank-mounted weapon then in service except at point-blank range, that it had good firepower, and that it had good traction on soft ground. It also had serious flaws: it was difficult to steer, the transmission (which was a twenty year old Caterpillar design) was unreliable (and was known to have to be shifted with a hammer),ford shallow rivers, so they had to be left to travel to an adequate bridge. As applique armor and other improvements were added without increasing engine power, later models were less capable of keeping up to speed with medium tanks and had more trouble with difficult terrain. In addition, its firepower was no better than the T-34. It took field reports from senior commanders "and certified heroes", who could be honest without risk of punishment, to reveal "what a dog the KV-1 really was.

 and the ergonomics were poor, with limited visibility and no turret basket. Furthermore, at 45 tons, it was simply too heavy. This severely impacted the maneuverability, not so much in terms of maximum speed, as through inability to cross many bridges medium tanks could cross. The KV outweighed most other tanks of the era, being about twice as heavy as the heaviest contemporary German tank. KVs were never equipped with a snorkeling system to

While initially the Soviets made a lot of poor defense decisions, worsened by recent "cleansings" of Soviet military command, the KV-1 was unlike anything the German army had expected to encounter, and some of the battles against numerically superior Axis forces became legendary. Even though the operations of the KV family of tanks were severely hampered by restrictions due to its weight, it was a fearsome and formidable weapon through most of the Second World War.

Further Development

By 1942, when the Germans were fielding large numbers of long-barrelled 50 mm and 75 mm guns, the KV's armor was no longer invincible. The KV-1's side, top, and turret armor could also be penetrated by the high-velocity MK 101 carried by German ground attack aircraft such as the Henschel Hs 129, requiring the installation of additional field-expedient appliqué armour. The KV-1's 76.2 mm gun also came in for criticism. While adequate against all German tanks, it was the same gun as carried by smaller, faster, and cheaper T-34medium tanks. In 1943, it was determined that this gun could not penetrate the frontal armour of the new Tiger,^[8] the first German heavy tank, fortuitously captured near Leningrad. The KV-1 was also much more difficult to manufacture and thus more expensive than the T-34. In short, its advantages no longer outweighed its drawbacks.

Nonetheless, because of its initial superior performance, the KV-1 was chosen as one of the few tanks to continue being built following the Soviet reorganization of tank production. Due to the new standardization, it shared the similar engine (the KV used a 600 hp V-2K modification of the T-34's V-2 diesel engine) and gun (the KV had a ZiS-5 main gun, while the T-34 had a similar F-34 main gun) as the T-34, was built in large quantities, and received frequent upgrades.^{[citation needed]}

When production shifted to the Ural Mountains 'Tankograd' complex, the KV-2 was dropped. While impressive on paper, it had been designed as a slow-moving bunker-buster. It was less useful in highly mobile, fluid warfare that developed in World War II. The turret was so heavy it was difficult to traverse on uneven terrain. Finally, it was expensive to produce. Only about 300 KV-2s were made, all in 1940-41, making it one of the rarer Soviet tanks.

As the war continued, the KV-1 continued to get more armour to compensate for the increasing effectiveness of German weapons. This culminated in the KV-1 model 1942 (German designation KV-1C), which had very heavy armour, but lacked a corresponding improvement to the engine. Tankers complained that although they were well-protected, their mobility was poor and they had no firepower advantage over the T-34 medium tank.^{[citation needed]}

In response to criticisms, the lighter KV-1S was released, with thinner armour and a smaller, lower turret in order to reclaim some speed. Importantly, the KV-1S also had a commander's cupola with all-around vision blocks, a first for a Soviet heavy tank. However, the thinning-out of the armor called into question why the tank was being produced at all, when the T-34 could seemingly do everything the KV could do and much more cheaply. The Soviet heavy tank program was close to cancellation in mid-1943.

The appearance of the German Panther tank in the summer of 1943 convinced the Red Army to make a serious upgrade of its tank force for the first time since 1941. Soviet tanks needed bigger guns to take on the growing numbers of Panthers and the few Tigers.

A stopgap upgrade to the KV series was the short-lived KV-85 or Objekt 239. This was a KV-1S with a new turret designed for the IS-85, mounting the same 85 mm D-5T gun as the SU-85 and early versions of the T-34-85; demand for the gun slowed production of the KV-85 tremendously and only 148 were built before the KV design was replaced. The KV-85 was produced in the autumn and winter of 1943-44; they were sent to the front as of September 1943 and production of the KV-85 was stopped by the spring of 1944 once the IS-2 entered full scale production.

Successor

A new heavy tank design entered production late in 1943 based on the work done on the KV-13. Because Kliment Voroshilov had fallen out of political favour, the new heavy tank series was named the Iosif Stalin tank, after Iosif (Joseph) Stalin. The KV-13 program's IS-85 prototype was accepted for production as the IS-1 (or IS-85, Object 237) heavy tank. After testing with both 100 mm and 122 mm guns, the D-25T 122 mm gun was selected as the main armament of the new tank, primarily because of its ready availability and the effect of its large high-explosive shell when attacking German fortifications. The 122mm D-25T used a separate shell and powder charge, resulting in a lower rate of fire and reduced ammunition capacity. While the 122mm armour piercing shell had a lower muzzle velocity than similar late German 7.5 cm and 8.8 cm guns, proving-ground tests showed that the 122mm AP shell could defeat the frontal armour of the German Panther tank, and the HE shell would easily blow off the drive sprocket and tread of the heaviest German tank or self-propelled gun. The IS-122 replaced the IS-85, and began mass production as the IS-2. The 85 mm gun saw service in the lighter SU-85 and T-34-85.

Models

he Soviets did not recognize different production models of KV-1 during the war; designations like model 1939 (M1939, Russian: Obr. 1939) were introduced later in military publications. These designations however are not strict and describe leading changes, while other changes might be adapted earlier or later in specific production batches. Designations like KV-1A were applied by the Germans during the war.

KV-1

KV-1 1939

• Model 1939 – First production models, these tanks were prone to frequent breakdowns, but were highly resistant to anti-tank weapons during the Winter War. These tanks were armed with the 76 mm L-11 tank gun, recognizable due to a recuperator above a barrel. Most tanks were lacking the hull machine gun. 141 were built.
• Model 1940 (German designation: KV-1A) – Used the F-32 76 mm gun and a new mantlet. The main production model by the time of the German invasion.
• Model 1940 s ekranami ("with screens") or KV1-E – with additional bolted-on appliqué armour and F-32 gun.
• Model 1941 (KV-1B) – Up-armoured with 25 to 35 mm added to the turret, hull front and sides. Turret was now cast instead of welded. This tank was armed with the longer-barrelled F-34, and later ZiS-5 76.2 mm tank guns.
• Model 1942 (KV-1C) – Fully cast turret with thicker armour or welded turret with thicker armour, again up-armoured and used an improved engine and the 76 mm ZiS-5 tank gun.
  • KV-1S – A lighter variant of late 1942 with higher speed, but thinner armour. A new, smaller, cast turret and redesigned rear hull were used. 1370 were built.
• Panzerkampfwagen KV-IA 753(r) and Panzerkampfwagen KV-IB 755(r) - The KV-1 in German service. Some were fitted with a high-velocity KwK 40 L/43 75-mm gun, the same gun used in a Panzer IV Ausf F2.

• KV-2 (334) – A heavy assault tank with the M-10 152 mm howitzer, the KV-2 was produced at the same time as the KV-1. Due to the size of its heavy turret and gun, the KV-2 was slower and had a much higher profile than the KV-1. Those captured and used by the German Army were known as (Sturm)Panzer kampfwagen KV-II 754(r) and often used for artillery observation due to its height.
• Т-150 (Object 150) - Experimental tank based on KV-1. Armor - 90mm, Weight - 51 tons. New 700 hp engine. Turret had a cupola but was in all other ways identical to the turret of the KV-1. One prototype was constructed in 1941 and was destroyed defending Leningrad.
• KV-3 (Objects 221, 222, and 223) - Experimental tanks based on KV-1. Longer chassis (7 rollers per side). The first design (Object 221) was never built, but it was supposed to have a 85mm gun. The same thing happened to Object 222, but it was supposed to have a F-32 76.2mm gun. The Objects 221 and 222 both retained the T-150's modified KV-1 turret. Object 223's hull was built and was tested with weights to simulated the new conical turret (housing a 107mm ZiS-6 cannon) that was designed for it. Object 223 had up to 120mm of sloped armor. The German invasion of Russia halted these plans and the only prototype hull was destroyed.^[9]
• KV-4 (Object 224) - A project for a Super-heavy tank. It was an in-case-of-emergency weapon and it was never to be built unless Russia started to lose the war with Germany. About 20 different designs were proposed, but it was cancelled in favour of the IS series tanks. Different versions would have been between about 85 and 110 tonnes. Armour from about 120 to 150 mm. Armament 107mm ZiS-6 cannon. Different variants had various auxiliary weapons: 45mm, 76mm cannons, machineguns and flamethrowers in addition to their main gun.
• KV-5 (Object 225) - A cancelled project for a heavy tank. Armament was to be a 107 mm ZiS-6 gun in a large turret and machine-gun in a small secondary turret. Weight was projected as about 100 tons, and the tank was to have 150-180mm of armor. Project development began in June 1941, however was cancelled due to the Siege of Leningrad, when all developmental operations at the Kirov Plant were halted. The project fell out of favour from the more advanced heavy tank designs, and no prototype was built.
• KV-6 (Object 226) - According to an order to the Chelyabinsk Tractor Factory in June 1941, A tank indexed KV-6 was to be designed from the KV-1 with 90mm of armor and a 76mm gun model 1940. Nothing ever came of this design.
• KV-7 (Object 227) - Experimental selfpropelled gun based on KV-1 armed with 3 cannons: two 45mm model 1932/34 and one 76mm F-34 (this version of the KV-7 was also called the U-13). 200 rounds of ammunition was carried for the 45mm guns and 93 rounds for the 75mm gun, and the tank had 100mm of frontal armor. One unit was produced and tested in 1941.

KV-7-2 (improved variant)(also called U-14) had two 76mm F-34 cannons, and 85mm of frontal armor. Vehicles were not taken in service primarily because they could not fight tanks (the KV-7s only had 15 degree gun traverse to each side) and they could not combat concrete bunkers due to the small caliber of the guns. After the failure of the KV-7 it was decided to put one 152mm gun in the casemate instead of there smaller guns; this led to the development of the SU-152.

• U-18 - Experimental selfpropelled gun. KV-7 armed with 152 mm ML-20 howitzer. Vehicle was projected in 1941. Wooden mockup was constructed. Project was cancelled, but this vehicle was a first step towards SU-152 design.
• U-19 - Experimental selfpropelled gun armed with 203mm B-4 cannon. The vehicle was to have 75mm of frontal armor, 60mm on the side, and the roof was to be 30mm (the roof would have been removable to facilitate loading). It was projected to weigh 66 tons, but the project was not very successful and was cancelled within a year.
• SU-152 - See http://en.wikipedia.org/wiki/SU-152
• ZiK-20 - The ZiK-20 was very similar to the U-19, but had 105mm of frontal armor, and 75mm of side armor and was to mount a ML-20 gun. By the time was wooden mockup was made the KV-1 was phased out of production. However just before the project was cancelled a blueprint was draw up to equip the ZiK-20 with a Br-2 152.4mm gun; and to offset the weight the frontal armor was to be reduced to 75mm (or 60mm on the KV-1S chassis)
• SU-203 - SU-152 equipped with 203mm M-4 mortar, the SU-203 was never built.
• KV-8 (42) – A KV-1 fitted with the ATO-41 flame-thrower in the turret, beside a machine gun. In order to accommodate the new weapon, the 76.2mm gun was replaced with a smaller 45 mm Gun M1932, though it was disguised to look like the standard 76 mm (The cannon was placed inside 76mm tube).
  • KV-8S (25) – The same as KV-8, but based on KV-1S. Was equipped with ATO-42 flamethrower (improved version of ATO-41).
  • KV-8M - Upgraded version of KV-8S. Was equipped with two flamethrowers. Two prototypes was constructed.
• KV-9 (Object 229) - A KV-1 with short 122mm U-11 cannon. One prototype was constructed and proved in 1941.
• KV-10 (Object 230) - Also known as KV-1K. A KV-1 with 4 rocket launchers on the sides of hull. Each launcher contained two 132mm M-13 rockets. Early variant of KV-1K had 2 launchers on the back of hull, each contained 6 rockets. One prototype was constructed and tested in 1942. Not taken in service.
• KV-11 (Object 231) - KV-1 armed with 85mm F-30 cannon. Projected in 1942. Not built.
• KV-12 (Object 232) - Experimental chemical tank. Was equipped with 4 external toxin tanks on the back of chassis. Tanks surrounded with 30mm armor. Not taken in service.
• KV-13 (Object 233) - Prototype of a medium tank. Designation for an advanced redesign of the KV series, which was resulted in the production of the IS series.
  • IS Model 2 - A KV-13, with turret and armanent from KV-9. One prototype was construcred and proved in 1943. Tank had lost competition to IS Model 1 and was not taken in service.
• KV-14 (Object 236) – Prototype designation for a 152 mm self-propelled gun, accepted for service as the SU-152.
• KV-85 – A KV-1S with the 85mm D-5T cannon in a new turret, with the ball mounted hull machine gun removed and the hole welded shut, 148 of these tanks were produced in the second half of 1943 until the spring of 1944 as a stopgap until the IS tank series entered production. This tank had its original turret, but later models were equipped with IS-1 turret.
  • KV-85G - KV-1S with 85mm S-31 cannon. Turret and mantlet remained from conventional KV-1S. This variant was a competitor of KV-85 during proving. It lost competition and was not taken in service.
  • KV-152 - A KV-1S with short 152mm S-41 cannon. One prototype was made in 1943. Not taken in service.
  • KV-100 - A KV-85 with the 100mm D-10T cannon. One prototype was made in 1944. Not taken in service.
  • KV-122 - A KV-85 with the 122mm D-25T cannon. One prototype was made in 1944. Not taken in service.
• KV-220 (Object 220) - Experimental tank based on KV-1. Longer chassis (7 rollers per side). Armor - 100mm. New 850 hp V-2SN engine with turbocharging. New diamond-shaped turret. 85mm F-30 cannon. One prototype was constructed in 1941, and was destroyed.

Source : Wikipedia