United States' M3 medium tank, Grant, Lee

Photos

M3 Medium Tank in North Africa: U.S. Army in World War II - Pictorial Record, 1951, pg 49	M3 Medium Tank in North Africa: U.S. Army in World War II - Pictorial Record, 1951, pg 49	M3 Medium Tank in Tunisia: U.S. Army in World War II - Pictorial Record, 1951, pg 40	M3 Medium Tank: Aberdeen Tank Museum
M3 Medium Tank:	M3 Medium Tank production at Detroit Tank Arsenal in late 1941.	M3 Medium Tank at the Virginia Museum of Military Vehicles.
M3 Medium Tank, Lee:	M3 Medium Tank engine installation: Mark Holloway	M3 Medium Tank engines: Mark Holloway	M3 Medium Tank at Fort Knox, Kentucky: Mark Holloway
M3 Medium Tank at Fort Knox, Kentucky: Mark Holloway
1/72 Scale Armor
Forces of Valor
95211:

Design

Model	US Turret	British Turret	Engine Type
M3	Lee I6,10,14	Grant I6,10	Gasoline10
	Lee I10 Lee IV	Grant IV	Diesel10
M3A1	Lee II10,14	Grant II6	Gasoline
	Lee II10 Lee V	Grant V	Diesel10
M3A2	Lee III10	Grant III	Gasoline
	Lee VI	Grant VI	Diesel
M3A3	Lee V10		Gasoline
	Lee IV6,10,14, Lee VII	Grant VII	Diesel6,10
M3A4	Lee V6, Lee VI10,14, Lee VIII	Grant VIII	Gasoline10
M3A5	Lee IX	Grant II10 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.^1,16 To match the newest German tanks that had 75 mm guns, the Ordnance Department wanted to fit a 75 mm into a M2A1.^1,6,10 However, there just wasn't enough space in the turret.^6,10 Based on experiments with the T5E2 a 75 mm M2 was installed on the right side of a modified M2A1.^1,10

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.¹⁰ The Ordnance Department decided that 60 days was enough in which to design the M3.¹⁰

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.¹

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.¹⁰

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.¹⁰

Crew

At the left front sat the driver with the gearbox beside him and the radio operator on the right.^8,10 The driver also operated the twin machine guns in the hull.^8,10 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.^8,10 There were access doors in the rear armor plate.¹⁰ A drive shaft went down the center of the fighting compartment, under the floor, to the gearbox that was next to the driver.¹⁰

The transmission was accessible by removing the three piece nose in the front.¹⁰

Main Armament

The Watervliet Arsenal developed the 75 mm gun based on a French 75 mm design.¹⁰

The 37 mm turret was offset to the left.¹⁰

The turret could be rotated by hydraulics or by hand. The cupola normally rotated with the turret but could be rotated by hand.⁷

The 37 mm and 75 mm guns had gyrostabilizers and periscopic sights.^8,10 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.^10,14

An auxiliary generator provided electricity when needed.⁷

Weapon	Type of Ammunition	Weight (lb)	Velocity (ft/sec)	Range (yards)	Thickness (mm) of armor penetrated
				Shot	1000 yards
.30 MG			2,80012
37 mm	AP12	1.912	2,90012
	APC7		2,9007	12,8507	1.8"7
		1.911	2,55011
75 mm	APC7		1,9207	13,0907	2.9"7
	AP12	14.412	1,29012
		14.411	1,85011

Prototype

The M3 was ordered straight from the drawing board in July 1940.^9,14 Baldwin and the American Locomotive Company each made pilot models by April 1941⁹.^8,10

Production

M3 Lend-Lease	United Kingdom	USSR	Brazil	Total
1941-42	2,64313	1,38613	7513	4,10413
1943	21213		2113	23313
Total	2,85513	1,38613	9613	4,33713
Notes	M3A3: 4913 M3A5: 18513	410 sunk in transit13

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.^1,10 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.^1,8,10

Production was initially slow as the Detroit manufacturing facility was tooled to produce the M2 Medium Tank.^6,14

In July 1940 the Watervliet Arsenal was given an order, off the drawing board, for the 75 mm guns and mountings.¹⁰ The first of these were delivered in April 1941.¹⁰ These became the M2 with an 84" long barrel.¹⁰ The M3, an improved model, had a barrel 110" long.¹⁰

In October 1940 it was decided to add the American Locomotive Co and the Baldwin Locomotive Works to the production of the M3s.¹⁰

Design work was finished in March 1941 and M3s started coming off the production line in April 1941.¹⁴ Some of the early M3s were almost hand made as the equipment in the factory hadn't been completely setup.¹⁰ 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.¹⁰ Later their equipment was updated.¹⁰

When the M4 started production the M3 was designated Substitute Standard in October 1941.⁷ In April 1943, they were classified as Limited Standard and in April 1944 were classified as obsolete.⁷

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.¹⁰ These only has small changes made to them, one being the installation of mud chutes between the bogies and jettisonable fuel tanks.¹⁰

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.^10,14 All riveted construction.^8,15
• M3 Medium Tank; Lee Mk I: Had Guiberson diesel engine.^8,10
• M3A1 Medium Tank: Cast hull.^10,14,15
• M3A1 Medium Tank; Lee Mk II: Had Guiberson diesel engine.¹⁰
• M3A2 Medium Tank; Lee Mk III: Welded hull.^10,14,15
• M3A3 Medium Tank; Lee Mk IV: Two General Motors 6-71 diesel engines.^10,14,15 Welded hull.^7,10
• M3A3 Medium Tank; Lee Mk V: Had Wright R975 engine.¹⁰
• M3A4 Medium Tank; Lee Mk VI: Chrysler Multibank engine.^10,14,15 Riveted hull.⁷
• M3A5 Medium Tank; Grant Mk II: Riveted hull.^7,10 Used twin General Motors 6-71 diesel engines.⁷
• M7 Priest: Had turret removed and box structure installed with 105 mm howitzer.
• 155mm Gun Motor Carriage T6 (M12): Used M3 Chassis.¹⁴ Engine placed in front of hull.¹⁴ 100 produced.¹⁴
• Cargo Carrier M30: The same as the M12 but no gun.¹⁴
• Tank Recovery Vehicle M31: Guns replaced by dummies.¹⁴ Boom and a 60,000 lb capacity winch added.^10,14 Conversion of the M3.¹⁴
• Tank Recovery Vehicle M31B1: Used M3A3 chassis.¹⁴
• Tank Recovery Vehicle M31B2: Used the M3A5 chassis.¹⁴
• Full Track Prime Mover M33: Towed 155 mm and 240 mm guns.^10,14 M31s converted by removing turret and booms.¹⁴ 0.5" MG was placed where turret had been.¹⁴
• 3" Gun Motor Carriage T4:
• Shop Tractor T10 (Canal Defense Light): Was intended to illuminate areas during night actions.¹ The turret was replaced by an armored searchlight.^1,10 Had British CDL turret.^10,14 355 produced by the United States, but they were not used in combat.^10,14 British versions were used at the Rhine and Elbe crossings.¹⁰
• Cargo Carrier T14:
• Heavy Tractor T16: Heavy gun tractor.¹⁴ Not sucessful.¹⁴
• 3" Gun Motor Carriage T24: Developed in September 1941.¹⁰ 3" gun.^10,14 Turret and sponson was removed.¹⁴ Was considered to complex and high.¹⁴
• 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.¹⁰ Designed in October 1941 but was found to be too complex for the amount of firepower it had.¹⁰
• 3" Gun Motor Carriage T40 (M9): Mounted a 40 mm Bofors antiaircraft gun.¹⁴
• 25 pdr Gun Motor Carriage T51:
• Flamethrower Vehicles: Flamethrower vehicle.¹⁰ Used E5E2-M3 flamethrowers.¹⁴ Some trials were done with the E3 flame gun.¹⁴
• Mine Exploder T1: Two rollers pushed in front and one pulled in back.^10,14
• ?: British conversion.¹⁰ Flail rotors attached for mine clearing.¹⁰ Used in Sicily and Italy.¹⁰

Usage

The M3s were first used in the Philippines.¹ They were then used in North Africa, including Kasserine Pass.¹ In the Pacific they were used at Makin Island by the Marines.¹

Supplied to Britain and Russia (1,400¹) as Lend-Lease. 750 were sent to Australia.¹

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.^6,10,14 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.¹⁰ This limited the British choices to the M3 Light and M3 Medium.¹⁰

In October 1940 contracts were placed with Baldwin, Lima Locomotive Works, and Pullman-Standard Car Co. for slightly modified M3 Mediums.¹⁰ They insisted that the turret had to have a bulge placed on the rear of the turret for a radio.^6,10,14 It was felt that the M3 was too tall so the machine gun cupola on top of the 37 mm turret was removed.¹⁰ Modified M3s were called Grants and standard M3s were called Lees.¹⁰

Used at the Battle of Gazala on May 27, 1942.^6,9,10,14,16 Many were used at the Battle of Alamein that took place from October 23 to November 4, 1942.^9,10

Australia Gets Leftovers

Once the M4 Mediums started to replace the M3 Medium in British service these castoffs were then sent to Australia.¹⁰ These were very effective used against the lighter armed Japanese forces in Burma and the southwest Pacific.¹⁰

Specifications

	M3 medium tank, Lee I	M3 medium tank, Grant I
Crew	Commander, driver, loaders(2), gunners(2).4,9 61,2,3,4,5,8,9,10,11,12,14,15,16, 73	Commander, driver, loaders(2), gunners(2).4 63,4
Radio	SCR-5087,10
Radio - command tank	SCR-5067,10
Physical Characteristics
Weight	26.7 tons1, 28 tons2, 27.9 tons3, 30 tons8, 31.1 tons11 59,928 lb16, 60,000 lb4,5,9,10,14,15, 62,280 lb12 27,216 kg1,9, 27,240 kg14,16, 27,900 kg	28 tons3
Length w/gun	18.6'11, 18' 6"1,4,5,8,9,10,12,14,15,16 5.6 m9, 5.63 m3, 5.639 m14, 5.64 m1,16, 5.9 m2	18' 6"4 5.9 m3
Length w/o gun	5.64 m
Height	10' 3"1,4,5,8,10,12,14,15,16, 10.3'9,11 3.02 m2, 3.1 m9, 3.12 m1,3,16, 3.124 m14	9' 4"4, 10' 3"4 3.02 m3
Width	8.9'9,11, 8' 11"1,4,5,8,10,12,14,15,16 2.7 m9, 2.718 m14, 2.72 m1,3,16, 2.75 m2	8' 11"4 2.75 m3
Ground clearance	17 1/8"10,12,15 0.43 m2,3	0.43 m3
Ground contact length	147"10,11,12,15	147"
Ground pressure	12.6 psi, 12.9 psi, 13.2 psi11, 13.36 psi10,15, 13.4 psi9 0.9 (kg/cm2)9, 1.2 (kg/cm2)2,3	1.2 (kg/cm2)3
Turret ring diameter	57"15, 60"10
Armament
Main	75 mm M21,4,9, M1 mount, L/31 75 mm L/312,3 75 mm5,8,14,16 75 mm QF M2 L/3111 75 mm M210,12,15	75 mm M24 75 mm L/313
OR	75 mm M31,4,9,10,15	75 mm M34
Secondary	37 mm M51,4,9,10,15, M24 mount, L/56 37 mm L/562,3 37 mm5,8,14,16 37 mm QF M5, L/5011 37 mm M6, gyrostabilized12	37 mm M54 37 mm L/563
OR	37 mm M61,4,9,10,15	37 mm M64
MG	4: 7.62 mm MG1,16 1: MG2 3: MG3,5 3-4: .30 cal Browning MG4 3 or 4: .30" MG14	MG3 3-4: .30 cal Browning MGs4
MG - cupola	1: .30 cal MG8 1: .30 cal M1919A412 1: .30 cal Browning M1919A4 MG9,10,,15
MG - coaxial	1: .30 cal M1919A411,12 1: .30 cal Browning M1919A4 MG9,10,15
MG - hull	1: .30 cal M1919A411 2: .30 cal M1919A412 1: .30 cal Browning M1919A4 MG7,10 2: .30 cal Browning M1919A4 MG9
OR	2: .30 cal Browning M1919A4 MG10
Side arms	.45 cal submachine gun7,10 Hand grenades12	.45 cal submachine gun Hand grenades
Quantity
Main	419,11, 461,4,10,12,14,15, 502,3	464, 503
Secondary	1781,3,4,10,12,14,15, 17911, 1822	1784, 1823
MG	3,1002, 8,00011, 9,2001,3,4,10,12,14,15	3,1003, 9,2004
Side arms	.45: 1,2007,10 Grenades: 1212,15
Armor Thickness (mm)	12 - 379, 12 - 3816, 124, 374, 1.5" - 2"5 Front: 2"11,14, 5114 Side: 1.5"11,14, 3814 Rear: 1.514, 3814	124, 374, 12 - 506
Hull Front, Upper	2"7,10, 2"@0°12 38.1 - 50.82,3, 508, 38 - 51@0-45°	38.1-50.83
Hull Front, Lower	1.5"7,10 38@53° & 51@30°
Hull Sides, Upper	1.5"@0°12, 1.5"7,10 38@0°, 38.12,3	38.13
Hull Sides, Lower	1.5"7,10 38@0°
Hull Rear	1.5"@0°12, 1.5"7,10 38@0°, 38.12,3	38.13
Hull Top	0.5"7,10 13@83-90°, 12.72,3	12.73
Hull Bottom	0.5" - 1"7,10 12.7-25.42,3, 13@90° rear, 25@90° front	12.7-25.43
Turret Front	2"10,11, 2.25"@0°12, 2.25"14,15 51@47°, mantlet 89@0° 50.8-76.22, 508, 50.83, 5714, 76	50.8-76.23
Turret Sides	2.25"@0°12, 2.25"7,10 50.82,3, 51@5°	50.83
Turret Rear	2.25"7,10 50.82,3, 51@5°	50.83
Turret Top	7/8"7,10 31.82, 22.23, 22@90°	32 31.83
Engine (Make / Model)	Continental R-975-EC21,9,10,15,16, Continental R-975-E11,10, Continental Wright2,3, Continental R-9755, Wright Continental (Whirlwind) R-9758, Wright R-975-EC211, Continental R975-EC112, Guiberson T-140012	Continental Wright3
OR	Continental R-975-EC17
Cooling	Air2,3,8,9,10,11,12,15	Air3
Cylinders	Radial16, 92,3,5,8,9,10, R-911,12,15	93
Net HP	3405,14,16, 340@2,400rpm9,10,15, 400@2,400 rpm2,3,11 Continental: 34012 Guiberson: 34512	400@2,400 rpm3
Transmission (Type)	Synchromesh10,11 5 forward, 1 reverse2,3,10,11,15	Synchromesh 5 forward, 1 reverse3
Steering	Controlled differential10,11
Starter	Electric or hand11
Electrical system	24 volts10,11,15
Ignition	Magneto
Gear - 1st gear	7.56:17,10
- 2nd speed	3.11:17,10
- 3rd speed	1.78:17,10
- 4th speed	1.11:17,10
- 5th speed	0.73:17,10
- Reverse	5.65:17,10
Fuel (Type)	Gasoline2,3,9,10,11,15,16
Octane	8010,15, 9210,15
Capacity	174 gallons11, 175 gallons10,12,15 662 liters2,3, 796 liters	662 liters3 175 gallons
Fuel consumption - Road	0.837 mpg11
Fuel consumption - Cross country
Power to Weight Ratio	12.7 hp/ton9
Performance
Traverse	37 mm: 360°4,10,12,15, 18°/sec, hydraulic and hand10,11, power or manual12 75 mm: 15° each way8,1012,15	37 mm: 360°4 75 mm: 15° left, 15° right4
Speed - Road	22 mph11, 25 mph12, 26 mph1,4,5,8,9,10,14,15,3405,14,16, 340@2,400rpm9,10,15 42 kph1,9,14,3405,14,16, 340@2,400rpm9,10,15 , 40.2 kph3	26 mph4 40.2 kph3
Speed - Cross Country	4-20 mph11, 16 mph4,9,14 25 kph14, 26 kph9	16 mph4
Range - Road	120 miles1,4,9,10,14,15,16, 146 miles11 177 km2, 193 km1,2,9,14,16	120 miles4 177 km3
Range - Cross Country	120 miles11
Turning Radius	37'10,15 18.9 m, 19 m3, 21 m2	21 m3
Elevation Limits	75 mm: -9° to +20°4,10,12,15 37 mm: -7° to +60°4,12,15	75 mm: -9° to +20°4 37 mm: -7° to +60°4
Fording depth	3' 4"4,10,11,12,15,16 1 m2,3, 1.02 m16	1 m3 3' 4"4
Trench crossing	6.2'7, 6' 2"10,12, 6' 3"4,16, 6.3'9, 7.5'11 1.9 m9, 1.91 m16, 2.3 m	6' 3"4
Vertical Obstacle	2'4,10,11,12,15,16 0.61 m16	2'4
Climbing ability	30° slope12, 31° (60%) slope11, 60%7
Suspension (Type)	Volute Spring3,10,15 3: Vertical Volute bogies8 Vertical volute spring, 3 bogies of 2 wheels each11	Volute Spring3 3: Vertical Volute bogies8
Wheels each side	62	63
Wheel size	20" x 9"7,10
Wheel size - idler	22" x 9"7,10
Return rollers each side	311
Tracks (Type)	Dry pin, double pin per shoe, rubber cleat11 Rubber block7,10
Length
Width	16.5"4,14, 16 9/16"7,10 0.419 m14, 0.42 m3	16.5"4 420 mm3
Number of Links	7911,12,15
Pitch	6"10,11,12,15
Tire Tread	Rubber3	Rubber3
Track centers/tread	6' 9"12, 6' 11"4,10,14,15, 7'11 2.108 m14	6' 11"4