M2 Light Tank - Development History

Development History

As the Light Tank T2E1, the M2 was developed in 1935 by Rock Island Arsenal for the infantry branch of the U.S. Army. The design coming from the earlier T1 and T2 was somewhat inspired by the famous Vickers 6-ton. Its main weapon was one .50-caliber machine gun, installed in a small one-man turret. After only 10 units were delivered, the Infantry branch decided to switch to a twin turret configuration, with a .30-caliber machine gun in the second turret. These early twin-turret tanks were given the nickname "Mae West" by the troops, after the popular busty movie star. The twin-turret layout was inefficient, but was a common feature of 1930s light tanks derived from the Vickers, such as the Soviet T-26 and Polish 7TP.

Following the Spanish Civil War, most armies, including the U.S. Army, realized that they needed "gun" armed tanks and not vehicles armed merely with machine guns. The cavalry branch had already opted for a single, larger turret on its nearly identical M1 Combat Car. By 1940 the twin machine gun turrets were replaced by one larger turret with a 37 mm gun, and armor reached 25 mm. Other upgrades included improved suspension, improved transmission, and better engine cooling.

The French Army had traditionally been highly regarded by the U.S. military as having the best and most modern military in Europe. The French army, in many cases, had more technologically advanced tanks than the Germans. The French tanks had better guns and armor protection. But what shocked the U.S. military into action was the amount of time that it took France to fall: only six weeks. The reason France fell so quickly was due to tactics, and not the quality of the German tanks themselves. German tanks were concentrated in a few formations and viewed as a decisive combat arm, while French tanks were distributed in small formations, most of which were devoted to infantry support. The fall of France gave momentum to the U.S. tank program, and in July 1940 the US Army Armored Force was created.

In December 1938, OCM #14844 directed that a single M2A3 be removed from the assembly line and modified with heavier armor and weapons, to meet the standards of the U.S. Infantry. This vehicle, after conversion, was re-designated as the M2A4. The new light tank was equipped with an M5 37 mm main gun, 1 inch (25 mm) thick armor, and a 7 cylinder gasoline engine. Production of the M2A4 began in May 1940, and continued through March 1941; an additional ten M2A4s were assembled in April 1942, for a total production run of 375 M2A4 light tanks. In addition the US Army sent out press photos still showing the M2A4 being assembled in July 1941 after the assembly line had been changed over to the M3.

In March 1941, the 1/2" thicker (1½" total thickness) armor, and Continental W-670 gasoline engined M3 Stuart light tanks replaced the M2A3 on the assembly lines. The original riveted M3s closely resembled the M2A4, and indeed the two types occasionally served in the same units; the easiest recognition feature is the aft (rear) idler wheel. On the M2A4, the idler is raised; on the M3 it trails on the ground, increasing the flotation of the heavier vehicle.

The M2's importance lies in the sound basis it provided for US M3-series light tanks early in World War II. The M3's high speed and mechanical reliability were legacies of the M2 program.