United States' M3 medium tank, Grant, Lee

Photos

Design

Model	US Turret	British Turret	Engine Type
M3	Lee I	Grant I	Gasoline
	Lee I Lee IV	Grant IV	Diesel
M3A1	Lee II	Grant II	Gasoline
	Lee II Lee V	Grant V	Diesel
M3A2	Lee III	Grant III	Gasoline
	Lee VI	Grant VI	Diesel
M3A3	Lee V		Gasoline
	Lee IV, Lee VII	Grant VII	Diesel
M3A4	Lee V, Lee VI, Lee VIII	Grant VIII	Gasoline
M3A5	Lee IX	Grant II Grant IX	Diesel

By the time 1,000 M2A1 Medium tanks were ordered in mid-1940, they were shown to have inadequate armor and armament by the events unfolding in Europe. To match the newest German tanks that had 75 mm guns, the Ordnance Department wanted to fit a 75 mm into a M2A1. However, there just wasn't enough space in the turret. Based on experiments with the T5E2 a 75 mm M2 was installed on the right side of a modified M2A1.

The order for 1,000 M2A1s was cancelled days after it was initially placed and on August 28, 1940, an order for 1,000 M3s was made. The Ordnance Department decided that 60 days was enough in which to design the M3.

A wooden mock-up for the M3 design was completed in August 1940. The Board had the remaining machine gun sponsons removed and the turret lowered.

It was intended only as a stopgap tank before the M4 Shermans arrived.

Chassis

The chassis of the M3 was based on the M2's.

Suspension

There were three sets of vertical volute bogies on each side with the idler at the rear and the drive sprocket in the front.

Crew

At the left front sat the driver with the gearbox beside him and the radio operator on the right. The driver also operated the twin machine guns in the hull. The 75 mm gunner sat on the left of the gun. The 37 mm gunner, gun loader and commander were in the turret. The driver's door and the pistol ports had protectoscopes for indirect vision.

Engine

The engine was in the rear with the fuel tanks on each side of the engine compartment. There were access doors in the rear armor plate. A drive shaft went down the center of the fighting compartment, under the floor, to the gearbox that was next to the driver.

The transmission was accessible by removing the three piece nose in the front.

Main Armament

The Watervliet Arsenal developed the 75 mm gun based on a French 75 mm design.

The 37 mm turret was offset to the left.

The turret could be rotated by hydraulics or by hand. The cupola normally rotated with the turret but could be rotated by hand.

The 37 mm and 75 mm guns had gyrostabilizers and periscopic sights. Some of the early M2 75 mm guns had counterweights installed so that they would emulate the longer M3 75 mm gun in that the settings for the gyrostabilizers would be the same to simplify maintenance in the field.

An auxiliary generator provided electricity when needed.

Weapon	Type of Ammunition	Weight (lb)	Velocity (ft/sec)	Range (yards)	Thickness (mm) of armor penetrated
				Shot	1000 yards
.30 MG			2,800
37 mm	AP	1.9	2,900
	APC		2,900	12,850	1.8"
		1.9	2,550
75 mm	APC		1,920	13,090	2.9"
	AP	14.4	1,290
		14.4	1,850

Prototype

The M3 was ordered straight from the drawing board in July 1940. Baldwin and the American Locomotive Company each made pilot models by April 1941.

Production

M3 Lend-Lease	United Kingdom	USSR	Brazil	Total
1941-42	2,643	1,386	75	4,104
1943	212		21	233
Total	2,855	1,386	96	4,337
Notes	M3A3: 49 M3A5: 185	410 sunk in transit

See M3 Medium Tank's production page.

The chairman of General Motors, William S. Knudsen, (also member of National Defense Advisory Committee) convinced the United States government that the auto industry should be used for massed tank production as the governments factory at Rock Island Arsenal wouldn't be able to keep up with demand. Chrysler leased a 113 acre site for a new factory in Warren, Michigan. The Government built the Detroit Tank Arsenal in Detroit that was run by K. T. Keller, president of Chrysler.

Production was initially slow as the Detroit manufacturing facility was tooled to produce the M2 Medium Tank.

In July 1940 the Watervliet Arsenal was given an order, off the drawing board, for the 75 mm guns and mountings. The first of these were delivered in April 1941. These became the M2 with an 84" long barrel. The M3, an improved model, had a barrel 110" long.

In October 1940 it was decided to add the American Locomotive Co and the Baldwin Locomotive Works to the production of the M3s.

Design work was finished in March 1941 and M3s started coming off the production line in April 1941. Some of the early M3s were almost hand made as the equipment in the factory hadn't been completely setup. This resulted in some of the early M3s to not have their main armament, but this was often satisfactory as they were used for training. Later their equipment was updated.

When the M4 started production the M3 was designated Substitute Standard in October 1941. In April 1943, they were classified as Limited Standard and in April 1944 were classified as obsolete.

Canadian Production

At the end of 1940, the Montreal Locomotive Works, a subsidiary of the American Locomotive Co, received an order for 1,157 M3s from the Canadian government. These only has small changes made to them, one being the installation of mud chutes between the bogies and jettisonable fuel tanks.

Variants

• M3 Medium Tank, Grant Mk I: Initial production type. Production of this model ceased August 1942. With riveted hull, cast turret, and side doors. All riveted construction.
• M3 Medium Tank; Lee Mk I: Had Guiberson diesel engine.
• M3A1 Medium Tank: Cast hull.
• M3A1 Medium Tank; Lee Mk II: Had Guiberson diesel engine.
• M3A2 Medium Tank; Lee Mk III: Welded hull.
• M3A3 Medium Tank; Lee Mk IV: Two General Motors 6-71 diesel engines. Welded hull.
• M3A3 Medium Tank; Lee Mk V: Had Wright R975 engine.
• M3A4 Medium Tank; Lee Mk VI: Chrysler Multibank engine. Riveted hull.
• M3A5 Medium Tank; Grant Mk II: Riveted hull. Used twin General Motors 6-71 diesel engines.
• M7 Priest: Had turret removed and box structure installed with 105 mm howitzer.
• 155mm Gun Motor Carriage T6 (M12): Used M3 Chassis. Engine placed in front of hull. 100 produced.
• Cargo Carrier M30: The same as the M12 but no gun.
• Tank Recovery Vehicle M31: Guns replaced by dummies. Boom and a 60,000 lb capacity winch added. Conversion of the M3.
• Tank Recovery Vehicle M31B1: Used M3A3 chassis.
• Tank Recovery Vehicle M31B2: Used the M3A5 chassis.
• Full Track Prime Mover M33: Towed 155 mm and 240 mm guns. M31s converted by removing turret and booms. 0.5" MG was placed where turret had been.
• 3" Gun Motor Carriage T4:
• Shop Tractor T10 (Canal Defense Light): Was intended to illuminate areas during night actions. The turret was replaced by an armored searchlight. Had British CDL turret. 355 produced by the United States, but they were not used in combat. British versions were used at the Rhine and Elbe crossings.
• Cargo Carrier T14:
• Heavy Tractor T16: Heavy gun tractor. Not sucessful.
• 3" Gun Motor Carriage T24: Developed in September 1941. 3" gun. Turret and sponson was removed. Was considered to complex and high.
• 105 mm Howitzer Gun Motor Carriage T25:
• 75 mm Gun Motor Carriage T26:
• 40 mm Gun Motor Carriage T36: Single Bofors 40 mm antiaircraft gun. Designed in October 1941 but was found to be too complex for the amount of firepower it had.
• 3" Gun Motor Carriage T40 (M9): Mounted a 40 mm Bofors antiaircraft gun.
• 25 pdr Gun Motor Carriage T51:
• Flamethrower Vehicles: Flamethrower vehicle. Used E5E2-M3 flamethrowers. Some trials were done with the E3 flame gun.
• Mine Exploder T1: Two rollers pushed in front and one pulled in back.
• ?: British conversion. Flail rotors attached for mine clearing. Used in Sicily and Italy.

Usage

The M3s were first used in the Philippines. They were then used in North Africa, including Kasserine Pass. In the Pacific they were used at Makin Island by the Marines.

Supplied to Britain and Russia (1,400) as Lend-Lease. 750 were sent to Australia.

Britain's Orders and Use

A British Tank Mission came to the United States in June 1940 looking to acquire tanks to replace their losses in France. The British wanted to have their own designs produced but the National Defense Advisory Committee advised that this would divide America's efforts to rearm, to have to produce separate vehicles, so the British were told they had to accept the current American designs. This limited the British choices to the M3 Light and M3 Medium.

In October 1940 contracts were placed with Baldwin, Lima Locomotive Works, and Pullman-Standard Car Co. for slightly modified M3 Mediums. They insisted that the turret had to have a bulge placed on the rear of the turret for a radio. It was felt that the M3 was too tall so the machine gun cupola on top of the 37 mm turret was removed. Modified M3s were called Grants and standard M3s were called Lees.

Used at the Battle of Gazala on May 27, 1942. Many were used at the Battle of Alamein that took place from October 23 to November 4, 1942.

Australia Gets Leftovers

Once the M4 Mediums started to replace the M3 Medium in British service these castoffs were then sent to Australia. These were very effective used against the lighter armed Japanese forces in Burma and the southwest Pacific.