Tank

A tank is a track-laying, turreted, all-terrain AFV (armoured fighting vehicle). A modern main battle tank (MBT) is distinguished from other AFVs primarily by its heavy armour and armament.

The MBT is the most powerful direct fire[?] land based weapon. It is used mainly to combat other MBTs, but its weapons are effective against almost all targets. Although some MBTs can carry infantry, this is not its primary task.

The MBT is the most heavily armoured vehicle in the armies of today. Its armour is designed to protect the vehicle and crew against all known threats, including KE-penetrators fired from other tanks, ATGMs (guided missiles) fired from infantry or aircraft, and mines. The amount of armour needed to protect against all these threats from all angles would be far too heavy to be practical, so when designing an MBT much effort goes into finding the right balance between protection and weight.

The main weapon of any modern tank is its gun, the size of which is exceeded by only the largest howitzers. It is usually 120mm calibre for western-built tanks and 125mm for eastern-built. The gun fires KE-penetrator rounds as well as High Explosive (HE) ones. Some tanks have the ability to fire missiles through the main gun barrel. Usually, the vehicle has a machine-gun coaxially mounted with the main gun. This machine-gun is of relatively small calibre (7.62mm - 12.7mm) and used against soft targets such as infantry. Additionally, many tanks carry a roof-mounted machine-gun for anti-aircraft fire.

An MBT is designed to be very mobile and able to tackle most types of terrain. Its wide tracks disperse the heavy weight of the vehicle over a large area, resulting in a specific ground pressure that might be lower than that of a man's foot. The types of terrain that do pose a problem are usually extremely soft ground such as swamps, or rocky terrain scattered with large boulders. In "normal" terrain, a tank can be expected to travel at about 30-50 km/h, with a road speed of up to 70 km/h.

Armour piercing ammunition

There are several types of ammunition designed to defeat armour, including HESH (High Explosive Squash Head), HEAT (High Explosive Anti Tank), APDS/APFSDS (Armour Piercing Fin Stabilized Discarding Sabot) - the latter being a type of KE-penetrator.

See also: List of tanks, Tank history, Armour, Blitzkrieg, Armoured fighting vehicle, Anti tank missile

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Tank also means:

• a shallow man-made pond or lake
• to decline or crash as in a stock declining rapidly in price
• a container used to store liquid or compressed gas
• an aquarium or terrarium

The armoured vehicle got the name "tank" because in their early days they were referred to as "water reservoirs" for security reasons, which was soon shortened to "tank".