United States Department of Defense - Infantry fighting vehicle

An infantry fighting vehicle (IFV, also known as (mechanized) infantry combat vehicle, (M)ICV) is a type of armoured fighting vehicle (AFV) used to carry infantry into battle and provide fire support for them.

IFVs are similar to armoured personnel carriers (APCs), designed to transport five to ten infantrymen and their equipment. They are differentiated from APCs ("battle taxis") by their enhanced armament (allowing them to give direct-fire support during an assault), firing ports (allowing the infantry to fire personal weapons while mounted), and usually improved armour. They are typically armed with an autocannon of 20 to 40mm caliber, 7.62mm machine guns and possibly with ATGMs and/or surface-to-air missiles. IFVs are usually tracked, but some wheeled vehicles fall into this category, too. IFVs are generally much less heavily-armed and -armoured than main battle tanks (MBTs), but they sometimes carry missiles, such as the NATO TOW missile and Soviet Spigot which offer a significant threat to tanks.

Although the M113 was designed as an APC, it was among the first to be used in the early 1960s as an IFV when South Vietnam ARVN troops fought while mounted against infantry which lacked effective antitank weapons. After the Battle of Ap Bac showed that the exposed machine gun was vulnerable to enemy fire, they were fitted with the ACAV armour kit which protected the main machine gun and added shields for two additional gunners. The M113 served in Vietnam as one of the most effective and widely used armored vehicles of that war, and remains in service today as a lighter and less expensive alternative to purpose built IFVs.

Western powers were surprised when the Soviet Union paraded the first purpose-designed IFV, the BMP-1, in 1967. The BMP possessed a very low profile and was armed with both a 73mm smoothbore gun and an AT-3 Sagger ATGM. Its steeply-sloped front armour offered partial protection against NATO's standard .50 calibre machine gun in a 60 degree frontal arc, while its smoothbore gun and ATGM were a threat to NATO APCs and even MBTs. It was not quite the breakthrough some would make it out to be, as in practice its performance was similar to the heavily-armed APCs which NATO countries had already begun to develop.

Since then, all major military powers have developed or adopted IFVs. Examples include the German Marder and Puma, the Canadian LAV III, the British Warrior, the American M2 Bradley and the M1126 Stryker variant, the Spanish Pizarro, the Italian Dardo, the South African Ratel, the French AMX-10P, the Swedish Combat Vehicle 90 and the Dutch YPR-765 AIFV.

To cope with urban combat and mine warfare, including the use of large improvised explosive devices, there have been a number of heavy IFVs (HIFV) with the high protection level of a tank developed, based largely on experience of the Israel Defense Force (although the Canadian Kangaroo of World War II could be called the first). The Israeli Merkava tank is capable of carrying 10 infantrymen or extra ammunition in the back , and the Achzarit is a T-55 tank modified to be heavily armoured personnel carrier. A newer example is the Russian BTR-T, also based on the T-55. The Ukrainian BMT-72 and BTMP-84 are based on lengthened T-72 and T-84 main battle tanks, respectively, and retain the tanks' 125mm main guns.

Main armament

The primary weapon on most IFVs is an autocannon, usually of a calibre between 20 and 40mm. It is effective against a wide range of targets such as unarmoured and lightly armoured vehicles, infantry, helicopters and low-flying aircraft. It can fire several types of munitions, including high explosive, incendiary, and kinetic penetrator rounds. Germany's Puma (IFV) can fire air burst munition (ABM), that contain hundreds of tungsten rods that are effective against vehicles, helicopters, and stationary strong points. IFV cannons can elevate their barrels by as much as 70 degrees to permit their crews to engage aircraft.

Machine guns

On all IFVs, a coaxial machine gun is mounted on the turret along with the main armament. The most common calibre is 7.62mm. Some vehicles mount more machine guns, for example on the German Marder, one machine gun fires from the rear of the vehicle.

Missiles

Some IFVs are equipped with anti-tank guided missiles. These missiles are mostly medium range (2000-4000 m). Others carry surface-to-air missiles or a combination of the two, such as the 2T Stalker.