XM734 Mounted Infantry Combat Vehicle (MICV)

The XM734 Mechanized Infantry Combat Vehicle (MICV) was an experimental M113 with gun ports in the sides. It was developed in response to the early 1964 Department of the Army development effort for mechanized infantry combat vehicles (MICV), to include an interim vehicle, the MICV-65 (Mechanised Infantry Combat Vehicle-1965), to be based on existing components. The capability for mounted combat by all of the onboard infantrymen was fundamental to the Infantry Fighint Vehicle [IFV] concept as developed by Russia, Germany, and the United States, for it allowed the infantrymen in the M2 Bradley (and M2A1) to fight from within the vehicle, under armor. While the troops in the standar M113 sat on benches along the walls facing inward, on the XM734 sat on a central bench facing outwards. Four gun ports and vision blocks were added on each side and two on the rear. The design failed in part because the heat inside the cabin was realy bad, and the humidity made the rubber firing port seals rot and fall apart.

The regular infantry, equipped with the M113, would have the mobility to get to the battlefield, but would fight dismounted. The M113 Armored Personnel Carrier entered service in 1959 after three years of development. In 1964 a more powerful diesel engine was added making it the M113A1. This APC was produced in large numbers and used by armies around the world. It saw service in Vietnam. It could carry a commander, a driver and eleven men for 480 km at about 34 kph. It mounted a Browning .50 caliber machine gun on its turret.

The M113 armored personnel carrier, dating back to the early 1960s, was really little more than a battle taxi. The 1973 Arab-Israeli War demonstrated that infantry should accompany tanks, but it was increasingly clear that the M113 could not perform that function because it was far slower than the new M1 Main Battle Tank and much more poorly armored.

Although tanks were invented and employed by some of the combatants in the Great War, armored transport for foot soldiers did not become a reality until the eve of the Second World War. At that time, the German Wehrmacht and the US Army simultaneously developed the concept of mechanized infantry, and created the armored personnel carrier (APC) to equip their high-mobility units. Like its German counterpart, the M3 “half-track” was a thinly-armored, open-topped vehicle that provided some protection from small arms fire and shrapnel, but left the infantry squad vulnerable to air-bursts of artillery shells. Because of the limitations inherent to its design, doctrine intended that the APC would be employed as a “battle taxi”; that is, it would give the troops a degree of protection en route to the objective, but the infantry would dismount to make the attack while the vehicle remained at a safe distance. In actual use, half-tracks were often driven right onto the objective, thereby enabling the onboard infantry-men to fight while mounted, firing their individual weapons over the sides of the squad compartment. When the half-track was employed in this manner, the vehicle’s armament — typically a single,pintle-mounted, M2 .50-caliber heavy machine gun (HMG) — added greatly to the firepower of the squad. After World War II, there was a succession of full-tracked, armored personnel carriers — the M39, M44, M75, and M59 — none of which satisfactorily met Armyrequirements.3 Finally, in 1960, the M113 APC arrived on the scene. With a hull made of a special aluminum alloy, the “one-one-three” was light enough for parachute delivery, buoyant enough to swim without preparation, yet tough enough to protect the occupants from artillery fragments and rifle bullets. Also, the troops inside are shielded from artillery air-bursts (a significant weakness ofthe WWII half-track) when the cargo hatch is shut on the fully-enclosed design, but they are unable to use their weapons until after they exit the vehicle. This is in keeping with the “battle taxi” concept, but — once again — wartime practice overturned peacetime doctrine. When the M113 was used in the Vietnam War, it did not take long for mechanized soldiers to realize that the APC was quite usable for mounted warfare; with the cargo hatch locked open, as many as four men can stand up in the opening to fire their rifles during amounted attack. Although they were then partially exposed to enemy fire, the risk proved to be well worth the benefits, and the idea was soon taken a step further. By installing a pintle-mounted, 7.62mm machine gun on each side of the cargo hatch, the fightability of the vehicle was essentially triple that of an issue M113, which only had the standard APC armament of a single .50-caliber HMG. With armor shields added to each of the three machine guns, the gunners were fairly well protected from small arms fire, and the configuration became known as the armored cavalry assault vehicle (ACAV).

In theory, mechanized infantry, self-propelled artillery, and armored forces are mutually supporting. Artillery rains destruction onto the front and flanks as infantry personnel carriers and dismounted infantry protect tanks from enemy antitank systems and enemy infantry. Simultaneously, tanks protect the personnel carriers and dismounted infantry from enemy tanks and strongpoints. In practice, personnel carriers have problems keeping upwith fast-moving tanks, and their armor protection is too thin to survive at the point of the attack. The proliferation of rocket-propelled grenade (RPG)-7 anti-tank grenade launchers and antitank missiles have complicatedthe task of tanks and mechanized infantry working together.

In 1959, the Soviets decided to develop two types of infantry personnel carriers: tracked infantry fighting vehicles that would serve in tank divisions and cheaper wheeled armored infantry personnel carriers that would serve in the more numerous motorized rifle divisions. The tracked chassis of the BMP [Beovaya mashina podderzhki] offered better mobility and a better chance to keep up with the tanks. However, the tracked vehicles were more expensive to produce, operate, and maintain. The BMP was designed to serve as more than a mere battle taxi. Its armor protected the crew and infantry from bullets and radiation and its armaments and firing ports allowed the vehicle to engage the enemyeffectively without dismounting the in-fantry squad.9 The BMP allowed the tanks and mechanized infantry to func-tion as a mutually supporting team.

The IFV equipped armored infantry, in their tank supporting role, would fight dismounted by exception. In the mechanized combat team, which is supported by main battle tanks (MBTs), it is the Infantry Combat Vehicle's mobility that must be maintained. The infantry squad contributes to this either by firing its weapons through its weapons ports or by dismounting and clearing forward.

The first real efforts at armored mechanization for infantry included the venerable International M2 Half Track in 1941. Although comparatively less mobile cross-country than the German three-quarter trackeds dkfz 251, the M3 saw action throughout World War II. Following World War II, a number of vehicles succeeded the M3. The most notable of these was the M113 armored personnel carrier (APC). The preliminary concept drawings for the M113 were completed in 1956, with approval in late 1956 to seek competitive proposals forthe engineering development. In only 43 months, the winner, FMC, delivered the first production vehicle.

Soviets did not like dismounting their infantrymen. Within the armored combat team, a premium on speed and momentum precludes the use of deliberate dismounted infcantry support unless it is absolutely necessary. The development of the Soviet BMP and the German Maxder caused the US to seek an alternative to the M113 "battle taxi". The Mechanized Infantry Combat Vehicle (MICV)-1965 program was in response to the search for a US IFV. The Vietnam war and the resulting shortage of funds caused the cancellation of the MICV-65 program. Continued pressure from Soviet mechanization and the proliferation of the BMP caused the US to resume its IFV program in 1968.

European practice influenced American plans for a new vehicle. German infantry used the well-armored Marder, a vehicle that carried seven infantrymen in addition to its crew of three, was armed with a 20-mm. gun and coaxial 7.62-mm. machine gun in a turret, and allowed the infantrymen to fight from within the vehicle. The French Army fielded a similar infantry vehicle in the AMX–10P in 1973. The Soviets had their BMP family of armored vehicles, which had a 73-mm. smoothbore cannon and an anti-tank guided missile as early as the late 1960s. Variations of the BMP were generally considered the best infantry fighting vehicles in the world during the 1980s. The United States had fallen at least a decade behind in the development of infantry vehicles. General DePuy at TRADOC and General Starry at the U.S. Army Armor Center and School at Fort Knox, Kentucky, agreed the Army needed a new infantry vehicle and began studies in that direction.

After some false starts, budgetary difficulties, and program delays, the M2 Bradley infantry fighting vehicle (IFV) was born. In a move that is both curious and interesting, the Army later abandoned the concept of fighting mounted when itadded, on the newer M2A2 and M3A2 vehicles, steel applique armor on the turret and hull, with extended side skirts that block the firing ports on the left and right sides. Apparently, the increased level of protection was deemed more important than the infantryman’s ability to fight from within the vehicle.