T-54 and T-55 MBT's

Development

In 1944, the Soviet Union designed a new medium tank called the T-44. This was produced in small numbers between 1945 and 1949, but proved unreliable in service. Main improvements over the earlier T-34/85 were its torsion bar suspension, transverse-mounted engine and transmission, well-shaped hull and a turret with a similar shape except that it did not have the thick turret neck. The tank had a crew of four as the bow machine gunner was eliminated in favour of a fixed machine gun firing forwards, a feature later adopted for the T-54. The turret of the T-44 was a modified T-34/85 turret without the prominent collar at the turret base. The T-44 was used in combat towards the end of the Second World War and again during the Hungarian uprising of 1956. Rebuilt T-44s, known as T-44Ms, were still in service in the 1970s and they have also been used for training. The T-44 was followed by the T-54, the first prototype of which was completed in 1946 with production following in 1947 in Khar'kov. No production figures for the T-54 and T-55 have been released but it is estimated that over 50,000 were built in the Soviet Union with production also being undertaken in China (as the Type 59), Czechoslovakia and Poland. Production of the T-55 is believed to have continued at the Omsk tank plant until as late as 1981, long after the T-62 had gone out of production. Whereas the T-54 MBT was designed by the Morozov Bureau at the Malyshev Plant at Khar'kov in the Ukraine under the designation of Obiekt 137 (or B-40), the T-55 series was developed by the Kartsev Bureau at Nizhnyi Tagil which later went on to design the T-62 and subsequently the T-72 and T-90 MBTs.

Description

The all-welded hull of the T-54 is divided into three main compartments: driver's at the front, fighting in the centre and the engine and transmission at the rear. The driver is seated at the front of the tank on the left and is provided with a single-piece hatch cover that swings to the left. There are two periscopes provided forward of this hatch, one of which can be replaced by an infrared periscope which is used in conjunction with the infrared light mounted on the right side of the glacis plate. The driver's infrared system is known as the TVN-2. A narrow board mounted at right angles to the glacis plate stops water rushing up the glacis plate when the tank is fording shallow rivers. To the right of the driver is space for ammunition stowage, batteries and a small fuel tank. A hull escape hatch is provided behind the driver. The turret is a one-piece casting with the top, which consists of two D-shaped pieces of armour welded together down the centre, welded into position. The commander is seated on the left of the turret, with the gunner on the same side but in a more forward position. The commander has a cupola which can be traversed through 360, with a single-piece hatch cover that opens forwards with a single periscope each side. A TPK-1 sight with a single periscope either side is mounted in the forward part of the cupola top. When in action the commander is constantly rotating his cupola for possible targets. On sighting a target he lines it up with his TPK-1 sight and then slews the turret onto the target. The gunner then lays the gun accurately onto the target and fires the main armament. The gunner has a TSh 2-22 sight with a magnification of x3.5 or x7. The loader is seated on the right of the turret and is provided with a periscope and a single-piece hatch cover that opens to the rear. The T-54 does not have a rotating turret floor, but the later T-55 has a partial floor, as does the T-62.

The engine is mounted transversely at the rear of the hull. The T-54 uses an electrical start-up system for the engine as its primary means, with a compressed air system for back-up in cold weather. The T-55 uses a compressed air engine start-up system primarily, with an electrical back-up. This is due to the fact that the T-55 has an AK-150 air compressor to refill the air pressure cylinders, unlike the T-54.

The torsion bar suspension consists of five single rubber-tyred roadwheels with a distinct gap between the first and second roadwheels. The drive sprocket is at the rear and the idler at the front. There are no track-return rollers. The first and fifth roadwheel stations are provided with a hydraulic shock-absorber. The all-steel track has steel pins that are not secured at the outer end and are free to travel towards the hull. A raised piece of metal welded to the hull just forward of the sprocket drives the track pins back into position each time they pass. Like the T-62, the T-54 and T-55 are now being fitted with a new track. The T-54 and T-55 can be fitted with a snorkel for deep fording. Two types of snorkel are available, a thin one for operational use and a thick one for training. These snorkels take between 15 and 30 minutes to fit and on reaching the far bank are blown off. The operational snorkel is mounted over the loader's periscope and, when not fitted, is carried disassembled at the rear of the turret, or at the rear of the hull. The thicker snorkel is mounted over the loader's hatch cover. The tank normally crosses the river in first gear and navigates with the aid of an onboard gyro-compass. The T-54 was not originally fitted with an NBC system; it was installed on later production tanks and subsequently refitted to earlier production models. The tank can lay its own smoke screen by injecting diesel fuel into the exhaust on the left side, producing a cloud of smoke some 300 m long which lasts for approximately two minutes. To extend the tank's operational range, two drum-type fuel tanks can be fitted at the rear. On the right running board are four flat light steel tanks. The first, second and fourth tanks each contain 93 litres of fuel, while the third contains lubricating oil. The driver can select which fuel tanks to use first, for example the drums at the rear, followed by the three external tanks and finally the main fuel tanks. There are three stowage boxes on the left running board, the first one for tools and other maintenance equipment, the second for gun-cleaning equipment and the third for infrared equipment. Mounted at the very rear of the hull is an unditching beam. When the T-54 entered service it was not fitted with night vision equipment. The first production tank to have this fitted was the T-54B and early tanks were then refitted with it. The tank is normally fitted with the following equipment: an infrared driving light which is used in conjunction with the driver's infrared periscope and has a range of 40 to 60 m; an infrared searchlight with a range of 400 m mounted on the forward part of the commander's cupola and another infrared searchlight to the right of the main armament with a range of 800 to 1,000 m. Main armament of the T-54 is a 100 mm D-10T (originally called the M1944) rifled tank gun which was originally developed around naval gun ammunition and also used in a modified form in the SU-100 assault gun. The D-10T has a horizontal sliding wedge breech block with the recoil system consisting of a hydraulic buffer and a hydropneumatic recuperator. The weapon has a maximum range in the indirect fire role of 14,600 m and can fire the types of ammunition shown below.

An average rate of fire for a T-54 is 4 rds/min. The D-10T gun is not stabilised but the D-10TG, first fitted to the T-54A, is stabilised in the vertical plane only, while the D-10T2S, which is stabilised in both planes, is fitted in the T-54 and later production vehicles and has been refitted in earlier tanks. The turret traversing and gun elevating system was manual on early tanks but later models have full power traverse and elevation with manual controls for use in an emergency. Mounted to the right of the main armament is a 7.62 mm SGMT machine gun and a similar weapon fixed in the centre of the glacis plate fires forward and is operated by the driver by pressing a button on the right steering lever. Mounted at the loader's position is a 12.7 mm DShKM anti-aircraft machine gun.

Status Production complete. Pakistan has 50 plus 1,300 Type 59 in service In addition they are used by a number of irregular units in the Middle East and elsewhere and some countries also use them for training. Under the continuing CFE talks some of the figures are being substantially reduced.

COMPANY NAME : Three former Soviet tank plants