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

Renault NC-31 Light Tank

In 1928 Renault succeeded in his attempt to get his Renault NC accepted as the basis for further light infantry tank development; he was granted an order to build two prototypes. The Army called this project the Char D, Renault used the designation NC28. Of the two prototypes, the first was fitted with the twin machine gun turret of the SRA Char de Bataille prototype. Also a new suspension system was tested incorporating the special chenille légère ("light track") designed by Colonel Balland, which was optimised for high speeds. As this vehicle was a derivative of the NC1, it was later indicated with the designation NC2, creating confusion with the earlier project of that name; mNC3 gun tank, and ordered a pre-series of ten vehicles in December 1929. These had the Renault factory designation NC31, after the intended year of delivery. Renault merely had to build the hulls at a price of 400,000FF each; the cast turrets were, as usual in France, separately ordered with the Schneider company; they were of the ST1 type (Schneider Tourelle 1). As this turret was much wider than the Renault FT turret used on all previous NC models, Renault broadened the hull accordingly; the typical tapering nose point of the Renault FT was abandoned. The ten hulls were delivered between May and November 1931: after an interval of ten years after the delivery of the last Char 2C in 1921, French tank series production for the home market was thus resumed.
any later books assumed they were one and the same vehicle. The Army made a choice in March 1929 for the second prototype, the

The ten pre-series hulls were tested by the 503e Régiment de Chars de Combat. Many shortcomings were discovered by the Commission de Bourges, the French Infantry matériel commission. Steering was difficult, the suspension too weak and the exhaust pipes overheated the engine compartment. Nevertheless the type was accepted for mass production — the commission had little choice in this as the main series had already been ordered — provided that changes were made. The strangely squeezed ST1 turret, the first ten of which were delivered from November 1930, was rejected though as being unacceptably cramped and unbalanced. To prevent that each time the gun was loaded, the breech had to be lowered into the fighting compartment or otherwise the round could not be shoved in, the main armament had been placed in a very forward position. The ST1 turrets were therefore again removed from the first ten vehicles.

Specifications
Weight	14 metric tons
Length	5.76 m
Width	2.16 m
Height	2.40 m
Crew	3
Armor	40 mm
Main armament	47 mm SA34 tank gun
Secondary armament	2x 7.5 mm Reibel machine gun
Engine	Renault V-4 74 hp
Suspension	vertical springs
Operational range	90 km
Speed	18.6 km/h (11.6 mph)

Source : Wikipedia

BT-2 Light Tank

The BT tanks (Russian: Быстроходный танк (БТ), Bystrokhodny tank, lit. "fast moving tank" or "high-speed tank"^[1]) were a series of Sovietcavalry tanks produced in large numbers between 1932 and 1941. They were lightly armoured, but reasonably well-armed for their time, and had the best mobility of all contemporary tanks of the world. The BT tanks were known by the nickname Betka from the acronym, or its diminutiveBetushka.^[2]

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

Design

The BT tanks were "convertible tanks". This was a feature designed byJ. Walter Christie to reduce wear of the unreliable tank tracks of the 1930s. In about thirty minutes the crew could remove the tracks and engage a chain drive to the rearmost road wheel on each side, allowing the tank to travel at very high speeds on roads. In wheeled mode the tank was steered by pivoting the front road wheels. However, Soviet tank forces soon found the convertible option of little practical use in a country with few paved roads, and it consumed space and added needless complexity and weight. The feature was dropped from later Soviet designs.

Christie, a race car mechanic and driver from New Jersey, had tried unsuccessfully to convince the U.S. Army Ordnance Bureau to adopt his Christie tank design. In 1930, Soviet agents at Amtorg, ostensibly a Soviet trade organization, used their New York political contacts to persuade U.S. military and civilian officials to provide plans and specifications of the Christie tank to the Soviet Union. At least two of Christie's M1931 tanks (without turrets) were later purchased in the United States and sent to the Soviet Union under false documentation in which they were described as "agricultural tractors."^[3] Both tanks were successfully delivered to the Kharkov Komintern Locomotive Plant (KhPZ). The original Christie tanks were designated fast tanks by the Soviets, abbreviated BT (later referred to as BT-1). Based both on them and on previously obtained plans, three unarmed BT-2 prototypes were completed in October 1931 and mass production began in 1932. Most BT-2s were equipped with a 37 mm gun and a machine gun, but shortages of 37 mm guns led to some early examples being fitted with three machine guns.

The sloping front hull (glacis plate) armor design of the Christie M1931 prototype was retained in later Soviet tank hull designs, later adopted for side armor as well.

The BT-5 and later models were equipped with a 45 mm gun.

Source : Wikipedia

T-26 Light Tank

The T-26 tank was a Soviet light infantry tank used during many conflicts of the 1930s and in World War II. It was a development of the British Vickers 6-Ton tank and was one of the most successful tank designs of the 1930s until its light armour became vulnerable to newer anti-tank guns. It was produced in greater numbers than any other tank of the period, with more than 11,000 manufactured.During the 1930s, the USSR developed 53 variants of the T-26, including flame-throwing tanks, combat engineer vehicles, remotely controlled tanks, self-propelled guns, artillery tractors, and armoured carriers. Twenty-three of these were series-produced, others were experimental models.

The T-26 together with the BT was the main tank of the Red Army's armoured forces during the interwar period. The T-26 was the most important tank of the Spanish Civil War and played a significant role during the Battle of Lake Khasan in 1938 as well as in the Winter War in 1939–40. Though nearly obsolete by the beginning of World War II, the T-26 was the most numerous tank in the Red Army's armoured force during the German invasion of the Soviet Union in June 1941 The T-26 fought the Germans and their allies during theBattle of Moscow in 1941–42, the Battle of Stalingrad and the Battle of the Caucasus in 1942–1943; some tank units of the Leningrad Front used their T-26s until 1944. Soviet T-26 light tanks last saw use in August 1945, during the defeat of the Japanese Kwantung Armyin Manchuria.

The T-26 was exported and used extensively by Spain, China and Turkey. Captured T-26s were used by the Finnish, German, Romanian and Hungarian armies.The tank was reliable and simple to maintain, and its design was continually modernised between 1931 and 1941. No new models of the T-26 were developed after 1940.

Design

The Soviets did not simply replicate the Vickers 6-Ton. Like its British counterpart, the T-26 mod. 1931 had a twin-turreted configuration and was designed to carry two machine guns, mounting one in each turret. A major difference between the Soviet T-26 mod. 1931 and the British 6-Ton were higher turrets on the T-26, with an observation slit. Soviet turrets had a round firing port for the DT tank machine gun, as opposed to the rectangular ports used by the original British design for the Vickers machine gun. The front part of the hull was also slightly modified.

Hulls of twin-turreted T-26s were assembled using armoured plates riveted to a frame from metal angles. Some tanks, produced in 1931, had sealing zinc shims at the hull bottom between armoured plates for fording water obstacles. After problems with rain entering the engine compartment, a special cover was installed over an air outlet window after March 1932. Some T-26s produced at the end of 1932–1933 had a riveted and welded hull. The T-26 mod. 1931 had two cylindrical turrets mounted on ball bearings; each turret turned independently through 240°. Both turrets could provide common fire in front and rear arcs of fire (100° each). The disadvantage of such configuration was that all the tank's firepower could not be used at once on the same side. Four modifications of turrets existed, and they were mounted on tanks in different combinations (for instance, a tank with a riveted hull could have riveted and welded turrets).

The hull and turrets of the T-26 mod. 1931 had a maximum armour thickness of 13–15 mm (until 1938, see below), which was sufficient to withstand light machine gun fire. Many twin-turreted tanks of the first series had 10 mm armour plates of low quality, which could be penetrated by 7.62 mm armour-piercing bullets from 150 m.

In 1933, the Soviets unveiled the T-26 mod. 1933. The Model 1933, with a new single cylindrical turret carrying one 45 mm cannon and one 7.62 mmmachine gun, became the most common T-26 variant. The 45 mm 20K tank gun was based on the Soviet 45 mm anti-tank gun 19K (mod. 1932). The T-26 could carry up to three secondary DT 7.62 mm machine guns in coaxial, rear, and anti-aircraft mounts. This increased firepower was intended to aid crews in defeating dedicated anti-tank teams, as the original machine gun armament had been found insufficient.

 The turret rear ball mounting for the additional DT tank machine gun was installed on the T-26 tanks from the end of 1935 until 1939.

Specifications (T-26 mod. 1933)
Weight	9.6 tonnes (10.6 short tons)
Length	4.65 m (15 ft 3 in)
Width	2.44 m (8 ft)
Height	2.24 m (7 ft 4 in)
Crew	3 (commander, gunner, driver)
Armour	Bottom: 6 mm (0.24 in) Roof: 6–10 mm (0.24–0.39 in) Hull and Turret: 15 mm (0.59 in) (front, rear, sides)
Main armament	45 mm 20K mod. 1932–34 tank gun (122 rds.)
Secondary armament	7.62 mm DT tank machine gun(2,961 rds.)
Engine	4-cylinder gasoline flat air-cooledT-26 (Armstrong Siddeley type); engine volume 6,600 cc 90 hp (67 kW) at 2,100 rpm
Power/weight	9.38 hp/t
Transmission	single-disc main dry clutch, drive shaft, gearbox with five gears, steering clutches, final drives
Suspension	leaf quarter-elliptic springs
Ground clearance	380 mm (1 ft 3 in)
Fuel capacity	290 L (64 imp gal; 77 U.S. gal) [with additional 110-L fuel tank]
Operational range	Road: 220–240 km (140–150 mi) Off-road: 130–140 km (81–87 mi)
Speed	Paved: 31.1 km/h (19.3 mph) Gravel: 22 km/h (14 mph) Off-road: 16 km/h (9.9 mph)

Source : Wikipedia

MS-1 (T-18 Light Tank)

The T-18 light tank (also called MS-1, Russian: Maliy Soprovozhdeniya-Perviy, "First Small [Vehicle for] Support") was the first Soviet-designed tank. Produced from 1928–31, it was based on theRenault FT, with the addition of a vertically sprung suspension.

The T-18 and its derivatives were essentially unsuccessful designs, but they gave Soviet industry its first experiences in designing armoured vehicles, and in the meantime a number of foreign tank designs were available for production.

Development

A "Tank Bureau" was formed in May 1924 for the development of Soviet tanks. A specification was issued for a 3-tonne two-man light tank capable of 7.5 mph (12.1 km/h). It would be protected by 16 mm of armour and equipped with a 37 mm (1.5 in) gun. By 1925 the allowable weight had increased to 5 tonnes.

The tank was designed by Professor V. Zaslavsky at a new Tank Bureau set up under the Central Directorate of Military Industries. The 35-horsepower truck engine (a copy of the Italian FIAT 15 ter) was supplied by the Moscow AMO Factory, and the gun was a modified copy of the French 37 mm Puteaux SA 18 cannon. The sprung suspension which would allow a tank to travel faster over rough ground was the biggest improvement over the Renault. A prototype called the T-16 was tested in June 1927.

The T-16 was deemed a failure, as it had problems with its transmission failing too often and its inability to cross trenches more than 1.5 m wide.^[1] The T-16's maneuverability was only marginally better than that of the Renault. Meanwhile the КБ ОАТ drew up plans for an improved version of the T-16 which was accepted for production in July as the T-18, with the tank additionally noted as an MS-1 ("Support vehicle, small, type 1").

The T-18's chassis and suspension was improved from the T-16 by the addition of an extra support roller and an independent vertical spring suspension. The 300 mm track of the T-16 was transferred over to the T-18, with some improvements. The engine, a vertical, four-cylinder MS engine, was designed and improved upon by Alexander Mikulin. The engine was capable of a maximum of 35 horsepower. The MS engine was combined with the PSC transmission in one unit rather than being in two separate housings. The PSC transmission gave the tank four forward speeds and one reverse speed. The engine-transmission compartment in the back let air in via holes drilled in the rear plate. This improved protection, but also led to the engine overheating. Electrical equipment included a 6-volt battery, magneto and dynamo, which fed the lamp, horn, rear light, light distribution panel and two portable lamps.

Armor for the T-18 consisted of six 8 mm curved plates for the turret (covered with a mushroom-style cap of 3 mm thickness), 16 mm plates for the hull, and the bottom plates were 3 mm thick. An emergency exit was installed in the underside. A small circular or rectangle hatch was placed in the turret for ventilation.

The T-18s armament stayed the same as that found on the FR-17 and T-16, the French 37 mm Model 28, mounted in a Hotchkiss-system mantle. This gave the gun a range movement of 35 degrees horizontal, and +30 to -8 degrees vertical. This was coupled by a simple system of diopter sights. The 37 mm Model 28 was nearly obsolete by this time. That, coupled with a lack of optical sights, gave the T-18 little chance of taking out larger, better armoured opponents. However, with its 10–12 rounds per minute rate of fire and with the use of shrapnel projectiles it proved capable of combating infantry and soft vehicles. A double-barrelled 6.5 mm Fyodorov machine gun was mounted in a ball mount. Total ammunition carried was 104 37 mm shells and 2,016 6.5 mm cartridges. In later models the Fydorov was replaced by the 7.62 mm DT machine-gun.

Demonstration of the T-18 took place in mid-May 1927, but in combat tests its ability to move over rough terrain and fight effectively were not immediately apparent. A special commission comprising representatives of the Supreme Economic Council Mobupravleniya, OAT factory "Bolshevik", Artupravleniya, and the headquarters of the Red Army were on hand for the tests. During trials to overcome obstacles the T-18 behaved no better than the FT-17, with its biggest problem being trenches or ditches wider than 2 m and deeper than approximately 1.2 m. The machines often became stuck trying to cross these obstacles and needed to be pulled out by a tractor or another tank. However, the T-18 proved to be more "nimble" than the FT-17 or T-16 and had a maximum road speed of 18 km/h. In addition, in comparison with foreign analogues, the T-18 had better armour and a little more room for ammunition reserves.

Despite its problems, the T-18 was an improvement over the FT-17 and T-16, so 108 tanks were ordered into production starting in February 1928. Production took place at the Leningrad Obukhov Factory (later renamed Bolshevik Factory). The first batch of 30 tanks were found to have serious technical problems. After several interruptions, and the inclusion of the Motovilikhinsky Machine-Building Plant (Former Perm Artillery) to increase production the two plants were able to deliver 96 of the promised 133 tanks in 1929.

Another round of trials was completed in Moscow to address the T-18s inability to cross 2-m-wide ditches. To solve this problem, a "tail" was added to the front. The tank could now overcome widths of 1.8 m, but it hindered the visibility of the driver and was thus abandoned. An improved T-18 with a better 40-horsepower engine, improved suspension and added turret bustle proceeded from 1929 to 1931, with a total of 960 tanks built. Plans were made to replace the main gun with new 37 mm B-3s, but were never implemented.

A number of experimental designs based on the T-16 and T-18 were tested at the Bolshevik Factory, leading to the T-19 tank with a 90 hp engine in 1931, and the T-20 with a 60 hp engine. The new T2K Tank Design Bureau (later renamed Morozov Design Bureau) at the Kharkov Locomotive Factory used the T-18 as the basis for the new T-24 tank.

Specifications
Weight	5.9 tonnes
Length	4.38 m (14 ft 4 in)
Width	1.76 m (5 ft 9 in)
Height	2.10 m (6 ft 11 in)
Crew	2
Armor	6-16 mm
Main armament	37mm Model 28
Secondary armament	1 Fyodorov machine gun
Engine	T-18 35 hp (26 kW)
Power/weight	5.9 hp/tonne
Suspension	vertically sprung
Operational range	50 km (31 mi)
Speed	17 km/h (10 mph)

Source : Wikipedia