military knowledge: What is Light tank?

An example of a modern light tank, the Polish PL-01

A light tank is a tank variant initially designed for rapid movement, and now primarily employed in the reconnaissance role, or in support of expeditionary forces where main battle tanks cannot be made available. Early light tanks were generally armed and armored similar to an armored car, but used tracks in order to provide better cross-country mobility.

The fast light tank was a major feature of the pre-World War II buildup, where it was expected they would be used to exploit breakthroughs in enemy lines created by slower, heavier tanks. Numerous small tank designs and "tankettes" were developed during this period and known under a variety of names, including the "combat car".

The light tank has been one of the few tank variants to survive the development of the main battle tank, and has seen use in a variety of roles including the support of light airborne or amphibious forces and reconnaissance. Modified IFVs are assuming these roles in many militaries due to their immediate availability, and as a cheaper alternative to developing and fielding a pure light tank.

Modern light tank design

Countermeasures

Typically, the armor in contemporary light tanks is modular, sometimes up to three configurations.
The flat hull necessary for amphibious light tanks to plane across the surface of the water is not nearly as blast-resistant as the V-shaped 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

A gun capable of defeating modern tanks at reasonable ranges requires a large vehicle to carry it. 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 are effective against close-quarter targets but lack the power and/or accuracy to effectively engage heavier vehicles at a distance.

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.

Strategic mobility

Some light tanks, such as the M551 Sheridan armored reconnaissance vehicle, could be rigged for low-velocity airdrops 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.
RoleThe modern light tank supplements the main battle tank in expeditionary roles and situations where all major threats have been neutralized and excessive weight in armor and armament would only hinder mobility and cost more money to operate. They have also been used for reconnaissance and in some cases, infantry support.

Type of the tank