M3 Lee

Medium Tank M3
Medium Tank M3, Fort Knox, June 1942
Type	Medium tank
Place of origin	United States
Service history
Wars	World War II
Production history
Produced	August 1941–December 1942
No. built	6,258
Variants	numerous, see text
Specifications
Weight	30 short tons (27 t)
Length	18 ft 6 in (5.64 m)
Width	8 ft 11 in (2.72 m)
Height	10 ft 3 in (3.12 m) - Lee
Crew	7 (Lee) or 6 (Grant)
Armor	51 mm (hull front, turret front, sides, and rear) 38 mm (hull sides and rear)
Main armament	1 × 75 mm Gun M2/M3 in hull 46 rounds 1 × 37mm Gun M5/M6 in turret 178 rounds
Secondary armament	2-3–4 × .30-06 Browning M1919A4 machine guns 9,200 rounds
Engine	Wright (Continental) R975 EC2 400 hp (300 kW)/340 hp (250 kW)
Transmission	Mack Synchromesh, 5 speeds forward, 1 reverse
Suspension	vertical volute spring
Ground clearance	18 in (0.46 m)
Fuel capacity	662 liters (175 US gallons)
Operational range	193 km (119 mi)
Speed	26 mph (42 km/h) (road) 16 mph (26 km/h) (off-road)
Steering system	Controlled differential

The Medium Tank M3 was an American tank used during World War II. In Britain, the tank was called by two names based on the turret configuration and crew size. Tanks employing US pattern turrets were called the "Lee," named after Confederate general Robert E. Lee. Variants using British pattern turrets were known as "Grant," named after U.S. general Ulysses S. Grant.

Design commenced in July 1940, and the first M3s were operational in late 1941. The U.S. Army needed a medium tank armed with a 75mm gun and, coupled with the United Kingdom's immediate demand for 3,650 medium tanks, the Lee began production by late 1940. The design was a compromise meant to produce a tank as soon as possible. The M3 had considerable firepower and good armor, but had serious drawbacks in its general design and shape, including a high silhouette, an archaic sponson mounting of the main gun preventing the tank from taking a hull-down position, riveted construction, and poor off-road performance.

Its overall performance was not satisfactory and the tank was withdrawn from combat in most theaters as soon as the M4 Sherman tank became available in larger numbers. In spite of this, it was considered by Hans von Luck (an Oberst (Colonel) in the Wehrmacht Heer and the author of Panzer Commander) to be superior to the best German tank at the time of its introduction, the Panzer IV (at least until the F1 variant).

Despite being replaced elsewhere, the British continued to use M3s in combat against the Japanese in southeast Asia until 1945.

In 1939, the U.S. Army possessed approximately 400 tanks, mostly M2 Light Tanks, with 18 of the to-be-discontinued M2 Medium Tanks as the only ones considered "modern". The U.S. funded tank development poorly during the interwar years, and had little experience in design as well as poor doctrine to guide design efforts.