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. 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 good tank and coupled with the United Kingdom's demand for 3,650 medium tanks immediately, 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 as it was well armed and provided good protection, but had certain serious drawbacks in its general design and shape, such as: a high silhouette, an archaic sponson mounting of the main gun, riveted construction, and poor off-road performance. Its overall performance was not satisfactory and the tank was withdrawn from front line duty — except in the remote areas of the Asian Theater by British forces as late as mid-1944 or later — as soon as the M4 Sherman became available in large numbers.
- M3 (Lee I/Grant I)
Riveted hull, high profile turret, gasoline engine. 4,724 built.
- M3A1 (Lee II)
Cast (rounded) upper hull. 300 built.
- M3A2 (Lee III)
Welded (sharp edged) hull. Only 12 vehicles produced.
- M3A3 (Lee IV/Lee V)
Twin GM 6-71 diesel variant of welded hull. Side doors welded shut or eliminated. 322 built.
- M3A4 (Lee VI)
Stretched riveted hull, 1 x Chrysler A-57 Multibank engine, made up of five 4.12 litre displacement, 6-cyl L-head car engines (block upwards) mated to a common crankshaft, displacement 21 litres, 470 hp at 2,700 rpm. Side doors eliminated. 109 built.
- M3A5 (Grant II)
Twin GM 6-71 diesel variant of riveted hull M3. Although it had the original Lee turret and not the Grant one, was referred by the British as Grant II. 591 built.
- M31 Tank Recovery Vehicle (Grant ARV I)
Based on M3 chassis, with dummy turret and dummy 75 gun. A 60,000 lb (27,000 kg) winch installed.
- M31B1 Tank Recovery Vehicle
Based on M3A3.
- M31B2 Tank Recovery Vehicle
Based on M3A5.
- M33 Prime Mover
M31 TRV converted to the artillery tractor role, with turret and crane removed. 109 vehicles were converted in 1943-44.
- 105 mm Howitzer Motor Carriage M7 (Priest)
105 mm M1/M2 howitzer installed in open superstructure. A gunless version was used as an OP (observation post vehicle)
- 155 mm Gun Motor Carriage M12
Designed as the T6. A 155 mm howitzer on M3 chassis. 100 built in 1942-1943. M30 Cargo Carrier on same chassis to transport gun crew and ammunition.
- Grant ARV
Grant I and Grant UK models with guns removed and replaced with armored recovery vehicle equipment.
- Grant Command
Grant fitted with map table and extra radio equipment and having guns removed or replaced with dummies.
- Grant Scorpion III
Grant with 75 mm gun removed, and fitted with Scorpion III mine flail, few made in early 1943 for use in North Africa.
- Grant Scorpion IV
Grant Scorpion III with additional motor to increase Scorpion flail power.
- Grant CDL
From "Canal Defence Light"; Grants with the 37 mm gun turret replaced by a new turret containing a powerful searchlight and a machine gun. 355 were also produced by the Americans, who designated it the Shop Tractor T10.
- M3 BARV
A single M3A5 Grant tank was converted into a "Beach Armoured Recovery Vehicle".
- Yeramba Self Propelled Gun.
Australian SP 25 pounder. 13 vehicles built in 1949 on M3A5 chassis in a conversion very similar to the Canadian Sexton.