Light tank

A light tank is one of the classifications of tank design. Light tanks have in general been used for scouting and reconnaissance roles rather than combat.

World War I
In World War I Industrial initiative also led to swift advances. The car industry, already used to vehicle mass production and having much more experience in vehicle layout, in 1916 designed the first practical light tanks, a class largely neglected by the British. It would be Renault's small tank design the FT-17, incorporating a proper climbing face for the tracks, that was the first tank to incorporate a top-mounted turret with a full rotation. In fact the FT was in many respects the first truly 'modern' tank having a layout that has been followed by almost all designs ever since: driver at the front; main armament in a fully-rotating turret on top; engine at the rear. Previous models had been "box tanks", with a single crowded space combining the role of engine room, fighting compartment, ammunition stock and driver's cabin. The FT-17 would have the largest production run of any tank of the war - with over 3,700 built it was more numerous than all British tanks combined.

Interwar


In 1928, the British firm of Vickers produced their "6 Ton" tank. Not purchased by the British army, it was bought by some smaller nations. It formed the basis of the Soviet T-26 (around 10,000 built) and the Polish 7TP tank and influenced the Italian Fiat M11/39. The British Army used a different Vickers design which was the first of a series of Light tanks in service.

In general, French tanks of the 1930s were well-armored, innovative vehicles that owed little to foreign designs. However, the light tanks lacked firepower and almost all French tanks were handicapped by their one-man turrets, even the larger tanks such as the Char B overworked the commander who besides directing the vehicle, or even a troop, had to load and aim the turret gun. The lack of radios with the light tanks was not seen as a major drawback, since French doctrine called for slow-paced, deliberate maneuvers in close conformance to plans. The role of small unit leaders was to execute plans, not to take the initiative in combat. In 1939 a belated effort was made to improve flexibility and increase the number of radios.

Throughout the interwar period the US produced only a few hundred tanks. From the end of World War I to 1935, only 15 tanks were produced. Most were derivatives or foreign designs or very poor quality private designs. The Christie designs were among the few bright spots, but the US Army acquired only three Christies and did not pursue the idea any further. Budget limitations and the low priority given to the Army meant that there were few resources for building tanks. The US Army instead developed and tested tank components such as suspensions, tracks, and transmissions. This work paid off when production needed to be initiated upon the outbreak of war.

World War II


Germany's armored Panzer force was not especially impressive at the start of the war. In the invasions of Poland and of France the German forces were mostly made up of the Panzer I and Panzer II light tanks. The Panzer I was little more than a training vehicle armed only with machine guns, the Panzer II with a 20 mm cannon. The Panzer division also included some Czech designed light tanks - the Panzer 35(t). As the war proceeded, production of the heavier tanks increased.

On the American side, the M2 Light Tank series was the most important. These light tanks were mechanically very reliable, with good mobility. However, they had a high silhouette and only a few saw combat. The M3 Stuart series was an improvement of the M2, with better armor and a 37 mm gun. The new medium tank just entering production in 1940 was the M2A1. This was a poor design with thin armor and a high silhouette.

The M3 Stuart saw use in the North African Campaign but was relegated to reconnaissance as soon as US-built medium tanks became available. Further light tank development in the war included the M24 Chaffee and air-portable tanks such as the Tetrach.

The Japanese made extensive use of light tanks which were much better suited to jungle warfare than larger designs.

Cold War
Light tanks continued to be built, but for very limited roles such as amphibious reconnaissance, support of Airborne units, and in rapid intervention forces which were not expected to face enemy tanks. The Soviet PT-76 is a specialized light tank -amphibious with sufficient firepower to engage other reconnaissance vehicles, but very lightly armored. The US M551 Sheridan had similar strengths and weaknesses, but could also be airdropped, either by parachute or LAPES.

The British FV101 Scorpion, the fire support variant of the Combat Vehicle Reconnaissance (Tracked) series of vehicles that replaced armoured cars in British service has been described as a light tank and was sold to many smaller nations.

Post Cold War
Light tanks, such as the PT-76, continue to play a small role in tank warfare, although many are losing favor to cheaper, faster, lighter armoured cars. The light tank still fills an important niche in many armies, especially nations with airborne divisions, or those which do not have the resources and funding to maintain main battle tanks. They have important advantages over heavier tanks in Southeast Asia and other nations in the Equatorial region. Their size allows them to maneuver through thick rainforests and their weight reduces the risk of getting stuck in muddy terrain. This makes the light tank the preferred choice for infantry support in Equatorial nations.

Many armies are experimenting the feasibility of unmanned light tanks such as the Black Knight. Such vehicles are being deployed in reconnaissance roles.

Countermeasures
Typically, the armor in contemporary light tanks is modular, sometimes up to three configurations.

The flat hull, is necessary for amphibious light tanks to plane across the surface of the water is not nearly as blast-resistant as the V-shape hull. It has been suggested that underbelly armor appliqué could be applied after the light tanks come ashore and before they encounter explosive devices.

Weapons suite
Guns capable of defeating modern tanks at reasonable ranges requires a large vehicle to carry them. Gun weight is typically the product of caliber and muzzle velocity. Large caliber guns on light tanks often sacrifice muzzle velocity in interest of saving weight. These guns can make and disable close-quarter targets but lack the power to penetrate some tanks. Alternately, high muzzle velocity guns often sacrifice gun caliber in interest of saving weight. These guns can make and penetrate long-distance targets but lack the explosive power to disable some tanks.

Mobility

 * Tactical mobility

Some light tanks such as the PT-76 are amphibious, typically being propelled in the water by hydrojets or by their tracks. Most amphibious light tanks weigh little and often utilize aluminum armor. Some light tanks require no modifications for river crossings. Crews simply raise the easily accessible cloth sides around the hull, cover the hatches, turn on the bilge pump and shift the transmission to water operations. Often a fold down trim vane is erected to stop water from flooding into the hatch. Some amphibious tanks, such as the PT-76, are able to transition from land to water with little to no preparation and fire from the main gun while afloat.


 * Strategic mobility

Some light tanks, such as the M551 Sheridan Armored Reconnaissance vehicle, could be rigged for low-velocity airdrop from cargo aircraft. With this method the tank is pulled out of the aircraft by brake chutes and skids to a stop. The crew does not ride in the tank during extraction, but parachutes from another plane. Upon landing, they go to their tank, release the lines, and drive it away.

Role
The modern light tank supplements the Main battle tank in expeditionary roles and situations where all major treats have been neutralized and excess weight in armor and armament would only hinder mobility and cost more money to operate.