M3 Lee

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 Its overall performance was not satisfactory and the tank was withdrawn from front line duty — except in the remote areas of the Asian Theater by British forces as late as mid-1944 or later — as soon as the M4 Sherman became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.

Variants

US variants

  • 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.

British variants

  • 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.

Australian Variants

  • 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.

Country Name Origin Year
United States of America 1941
Country Name Operational Year Retirement Year
United States of America View

In 1939, the U.S. Army possessed approximately 400 tanks, mostly M2 Light Tanks, with less than a hundred of the discontinued M2 Medium Tanks. The U.S. funded tank development poorly during the interwar years, and had no infrastructure for production, little experience in design, and poor doctrine to guide design efforts.

The M2 medium tank was typical of armored fighting vehicles (AFVs) many nations produced in 1939. When the U.S. entered the war, the M2 design was already obsolete with a 37 mm gun, 32 mm frontal armor, excessive machine gun secondary armament and a very high silhouette. The Panzer III and Panzer IV's success in the French campaign led the U.S. Army to order immediately a new medium tank armed with a 75 mm gun in a turret. This would be the M4 Sherman. Until the Sherman reached production, an interim design with a 75 mm gun was urgently needed.

The M3 was the solution. The design was unusual because the main weapon — a larger caliber, low-velocity 75 mm gun — was in an offset sponson mounted in the hull with limited traverse. (The sponson mount was necessary because at the time American tank plants were incapable of casting a turret big enough to hold the 75mm main gun). A small turret with a lighter, high-velocity 37 mm gun sat on the tall hull. A small cupola on top of the turret held a machine gun. The use of two main guns was seen on the French Char B, the Soviet T-35, and the Mark I version of the British Churchill tank. In each case, two weapons were mounted to give the tanks adequate capability in firing both anti-personnel high explosive ammunition and armor-piercing ammunition for anti-tank combat. The M3 differed slightly from this pattern having a main gun which could fire an armor-piercing projectile at a velocity high enough for efficiently piercing armor, as well as deliver a high-explosive shell that was large enough to be effective. Using a hull mounted gun, the M3 design could be produced faster than a tank featuring a turreted gun. It was understood that the M3 design was flawed, but Britain urgently needed tanks.

The M3 was tall and roomy: the power transmission ran through the crew compartment under the turret cage to the gearbox driving the front sprockets. Steering was by differential braking, with a turning circle of 37 ft (11 m). The vertical volute-sprung suspension (VVSS) units possessed a return roller mounted directly atop the main housing of each of the six suspension units (three per side), designed as self-contained and readily replaced modular units bolted to the hull sides. The turret was power-traversed by an electro-hydraulic system in the form of an electric motor providing the pressure for the hydraulic motor. This fully rotated the turret in 15 seconds. Control was from a spade grip on the gun. The same motor provided pressure for the gun stabilizing system.

The 75-mm was operated by a gunner and a loader. Sighting the 75-mm gun used an M1 periscope — with an integral telescope — on the top of the sponson. The periscope rotated with the gun. The sight was marked from zero to 3,000 yd (2,700 m)[6] with vertical markings to aid deflection shooting at a moving target. The gunner laid the gun on target through geared handwheels for traverse and elevation.

The 37-mm was aimed through the M2 periscope, though this was mounted in the mantlet to the side of the gun. It also sighted the coaxial machine gun. Two range scales were provided: 0-1,500 yd (1,400 m) for the 37-mm and 0-1,000 yd (910 m) for the machine gun.

Though not at war, the U.S. was willing to produce, sell and ship armored vehicles to Britain. The British had requested that their Matilda and Crusader tank designs be made by American factories, but this request was declined. With much of their equipment left on the beaches near Dunkirk, the equipment needs of the British were acute. Though not entirely satisfied with the design, they ordered the M3 in large numbers. British experts had viewed the mock-up in 1940 and identified features which they considered flaws — the high profile, the hull mounted main gun, the lack of a radio in the turret (though the tank did have a radio down in the hull), the riveted armor plating (whose rivets tended to pop off inside the interior in a deadly ricochet when the tank was hit by a non-penetrating round), the smooth track design, insufficient armor plating and lack of splash-proofing of the joints. The British desired modifications for the tank they were purchasing, including the turret being cast rather than riveted. A bustle was to be made at the back of the turret to house the Wireless Set No. 19 radio. The tank was to be given thicker armor plate than the original U.S. design, and the machine gun cupola was to be replaced with a simple hatch. With these modifications accepted the British ordered 1,250 M3s. The order was subsequently increased with the expectation that when the M4 Sherman was available it could replace part of the order. Contracts were arranged with three U.S. companies. The total cost of the order was approximately 240 million US dollars. This equaled the sum of all British funds in the US. It took the Lend-Lease act to solve the United Kingdom's shortfall.

The prototype was completed in March 1941 and production models followed with the first British specification tanks produced in July. Both U.S. and British tanks had thicker armor than first planned. The British design required one fewer crew member than the US version due to the radio in the turret. The U.S. eventually eliminated the full-time radio operator, assigning the task to the driver. After extensive losses in Africa and Greece the British realized that to meet their needs for tanks both the Lee and the Grant types would need to be accepted.

The U.S. military used the "M" (Model) letter to designate nearly all of their equipment. When the British Army received their new M3 medium tanks from the US, confusion immediately set in, as the M3 medium tank and the M3 light tank were identically named. The British Army began naming their American tanks after American military figures, although the U.S. Army never used those terms until after the war. M3 tanks with the cast turret and radio setup received the name "General Grant", while the original M3s were called "General Lee", or more usually just "Grant" and "Lee". The M3 brought much-needed firepower to British forces in the North African desert campaign.

The chassis and running gear of the M3 design was adapted by the Canadians for their Ram tank. The hull of the M3 was also used for self-propelled artillery and recovery vehicles.

Medium Tank M3 Lee was an armored vehicle (tank, AFV or armoured fighting vehicle) in combat use during the Second World War (World War II or WWII) in various theaters. The M3 was a fully tracked all-terrain vehicle designed for military operations. M3, also known as the Lee, was produced and deployed by the US Army of the United States of America (USA). The technical drawing (plan, layout or profile) shows the general appearance characteristics of the specified model (version) of the M3 tank for purposes of identification and reference. For more detailed information about this armored fighting vehicle, refer to M3 Lee.

GENERAL DATA
Other Designation(s)Medium Tank M3 Lee
Manufacturer(s)n.a.
Production Quantity4924Production PeriodJun. 1941-Aug. 1942
TypeMedium TankCrew6 or 7
Length /hull (m)6.12 or 5.64*/5.64Barrel Overhang (m)0.48 or 0*
Width (m)2.72Height (m)3.12
Combat Weight (kg)27900Radio EquipmentSCR508
FIREPOWER
Primary Armament75mm Gun M2 or M3 (hull mounted)Ammunition Carried75mm: 50
37mm Gun M5 or M6 (turret)37mm: 178
Traverse (degrees)75mm: 30° (15 L or R)Elevation (degrees)75mm: -9° to +20°
37mm: Hydraulic (360°)37mm: -7° to +60°
Traverse speed (360°)75mm: ManualSight75mm: n.a.
37mm: 18°/sec.37mm: n.a.
Secondary Armament3 x .30 caliber MG M1919A4 (turret, coaxial with 37mm, bow)Ammunition Carried9200


MOBILITY CHARACTERISTICS
Engine Make & ModelWright (Continental) R975 EC2Track Links79/track
Type & DisplacementR9, 15.9 litersTrack Width40.6 or 42.1 cm
Horsepower (max.)400hp@2400rpmTrack Ground Contact373.4 cm
Power/Weight Ratio14.3 hp/tonneGround Pressure12.6 psi
Gearbox5 forward, 1 reverseGround Clearance (m)0.43
FuelGasoline (Petrol)Turning Radius (m)18.9
Range on/off road (km)193Gradient (degrees)31°
Mileage (liters/100km)412 on roadVertical Obstacle (m)0.61
Fuel Capacity (liters)796Fording (m)1.0
Speed on/off road34 km/hTrench Crossing (m)2.3
ARMOR PROTECTION
Armor DetailFrontSideRearTop/Bottom
Hull51mm@45-90°38mm@90°38mm@80°-90°25mm@0°(front) 13mm@0°(rear)
Superstructure38mm@37°(lower) 51mm@60°(upper)38mm@90°-13mm@0-7°
Turret51mm@43°51mm@85°51mm@85°22mm@0°
Mantlet89mm@90°---

NOTES
*M3 or M2 gun respectively

End notes