United States' M3 light tank, "General Stuart"

Photos

M3 light tank:	M3 Light Tank:	M3 Light Tank:	M3 Light Tank: Aberdeen Tank Museum
M3 Light Tank during war games in Tennessee: Mark Holloway	M3 Light Tank captured by the Germans in North Africa: U.S. Army in World War II - Pictorial Record, 1951, pg 56	M3 Light Tank purchased in July 1942, with war bonds by the community of Banning, California.	M44 gun mount6: U.S. Ordnance Dept.
M3 light tank with rounded homogeneous welded turret6: U.S. Ordnance Dept.	M3 light tank's pistol port and protectoscope6: U.S. Ordnance Dept.	M3 light tank with a seven sided welded turret and a riveted hull6: U.S. Ordnance Dept.	M3 light tank's rounded homogeneous turret6: U.S. Ordnance Dept.
M3 Light Tank in Casablanca: U.S. Army in World War II - Pictorial Record, 1951, pg 28	M3 Light Tank with a welded hull:	M3 Light Tank, M6 Heavy Tank, M3 Medium Tank:

Design

With events in Europe in 1940, the Army realized the M2 was inadequate and the decision was made to modernize it.¹¹ A new design with thicker armor was standardized on July 5, 1940.^6,7 Production started in March 1941 at the American Car & Foundry.⁷ It was based on the M2A4, but had thicker armor that was homogeneous rolled and the idler wheel was placed on the ground to act as another road wheel to help distribute the weight.^1,6,10

Initially the engine was the Continental but shortages caused it to be replaced by the Guiberson T-1020 diesel, and fitted into 500 M3s.⁸

Tracks could often last 1,000 miles, whereas other models required replacement at 500 miles.

During production the riveted turret was replaced by a welded one 7-sided one.⁶ Also in early 1942 an all welded hull was produced.

It had volute spring suspension with the rear idler on the ground. This reduced the ground pressure and gave support to the rear of the tank.

Layout

The engines were in the rear with the drive going to the front sprockets, which was controlled by differential steering.⁷ The rear idler was located on the ground which helped in supporting the rear of the M3.⁶

Crew

The driver was on the left and the hull gunner/assistant driver on the right.^6,7 They could see out through windshields in their hatches.⁶

The gunner and commander/loader were in seats that were in the M3's turret basket.⁶

Engine

Internally the M3 carried 56 gallons of fuel.⁶ Some tanks had two 25 gallon external tanks added, and these were jettisonable once combat started.⁶

Production

• M3: 5,811^5,7,10, ~6,000¹¹
  • Production: 1941 - ?¹¹, 1941 - August 1942⁵, March 1941 - August 1942⁷
  • Manufacturer: American Car Foundry
• M3A1: 4,621
  • Production: May 1942 - February 1943
  • Manufacturer: American Car Foundry
• M3A1 Diesel:
  • Manufacturer: American Car Foundary⁹
• M3A3: 3,427⁷
  • Production: December 1942 -⁷
  • Manufacturer: American Car Foundry
• Total: 13,859⁸
  • Production: - October 1943⁸

Variants

• M3: Production started in March 1941 right after the last M2 was produced.¹ In July 1943, the Ordnance Committee declared it obsolete. From mid-1941 a gyrostabilizer was installed with the gun. Had cupola on the left side of the turret. There was a sponson on each side of the vehicle which had a .30 caliber machine gun installed. The radios were in the left sponson and were usually the SCR508.
• M3A1:
• M3A1 Diesel:
• M3A2: Was going to be made welded like A1 but never produced.^6,10
• M3A3:
• M3 Command Tank: Removal of turret and putting welded box superstructure with .50 cal MG on mount.¹⁰
• M3 with Maxson Turret: In 1942 a quad Maxson .50 cal machine gun turret was put on in place of the turret. Rejected as similar equipment was on half-tracks.
• M3 and T2 Light Mine Exploder: In 1942 a T2 mine exploder on a boom was developed and rejected as too unwieldy.
• M3 or M3A1 with Satan Flame-gun: Produced in Hawaii for use by USMC. Gun was removed and flame thrower was installed.⁸ Capacity was 170 gallons and range of 40-60 yards. 20 converted in 1943. Used at Saipan, Tinian, and Guam.⁸
• M3A1 with E5R2-M3 Flame-gun: Flame thrower put in place of hull machine gun.⁸ 10 gallon capacity. Used at Saipan, Tinian, and Guam.⁸
• M3E2: Cadillac engines.¹⁰ Became the M5.¹⁰
• T18 75 mm Howitzer Motor Carriage: Design started in September 1941. It was to provide a close support vehicle for the M3. Two test vehicles with mild steel superstructures were sent to the Aberdeen Proving Ground. This project was abandoned in April 1942 as it was unsatisfactory with it's high profile and being nose heavy.
• T56 3" Gun Motor Carriage: Project started in September 1942 to mount a 3" in a modified M3A3 chassis. The gun was placed in the rear, and the engine was moved to the center. Had limited crew protection and was very heavy. Project dropped in February 1943.
• T57 3" Gun Motor Carriage: Same as the T56, but with an up-rated Continental engine from the M3 medium. Project dropped in February 1943.

Usage

Russia¹, China¹, New Zealand¹, and France received some as well.

United Kingdom Use

• Stuart I: M3 with Continental engine.^5,10
• Stuart II: 500 M3s with Guiberson diesel.^5,10
• Stuart III: M3A1 with Continental engine.¹⁰
• Stuart IV: M3A1 with Guiberson diesel.¹⁰
• Stuart V: M3A3.^5,10
• Stuart VI: M5 and M5A1.⁵
• Stuart Kangaroo: Removed turret and added seats.
• Stuart Recce: As Kangaroo but with various machine guns on pindle mounts.
• Stuart Command: As Kangaroo but with extra radios.
• Stuart 18 pdr. SP: At least one Stuart had it's turret replaced by an 18 pdr field gun.

Used in Burma⁷, New Guinea⁷, Iraq⁷, Britain, NW Europe⁷, Italy⁷, and North Africa⁷.

Experience in Africa

Some vehicles also had two 25 gallon jettisonable fuel tanks mounted on the side of the rear deck based on British experience in North Africa.

Sturdiness

During the retreat in Burma in 1942, Stuarts of the 2nd Royal Tanks went 2,400 miles in eleven weeks with very little maintenance.⁷

First Action

M3s were used by the 8th King Royal Irish Hussars in August 1941 in Egypt.⁷ Fought their first battle at Sidi Rezegh on November 19, 1941.⁷

Organization

There were 72 M3s in a Marine Light Tank Battalion.⁸

British Service:

Nicknamed "Honey" by British calvary regiments. 84 sent to 8th Army in July 1941.¹

The British were reported to like this tank at the time of its introduction. It could go about 10-20 mph faster than their own or enemy tanks, and required less maintenance.

Specifications

	M3 (Stuart I), M3 light tank	Stuart II
Crew	Commander, gunner, driver, co-driver3 42,3,4,6,8,11
Radio	SCR-2456
Physical Characteristics
Weight	27,400 lb3,6,8, 28,440 lb11 12.2 tons7, 12.3 tons4, 13 tons2 12,428 kg8, 12,927 kg11
Length	14.8'8, 14' 10"4,7, 14' 10 3/8"6, 14' 10.75"3,11 4.5 m8, 4.53 m2, 4.54 m11
Height	7' 6.5"11, 8' 3"3,4,6,7, 8.3'8 2.3 m11, 2.5 m8, 2.65 m2
Width	7.3'8, 7' 4"3,4,6,7,11 2.2 m8, 2.25 m11, 2.46 m2
Width over tracks
Ground clearance	16.5"6 0.42 m2
Ground contact length	117"6
Ground pressure	10.47 psi6, 10.5 psi8 0.7 (kg/cm2)8, 1 (kg/cm2)2
Turret ring diameter	46.75"6
Armament
Main	37 mm M5 or M6 L/561 37 mm L/562 37 mm M53,6,8 37 mm4,11
OR	37 mm M63,6,8
Secondary
MG	5: MG4 2: MG2 2: 7.7 mm MG11 3: .30 cal Browning MGs3
MG - coaxial	1: 0.3" M1919A48 1: .30 cal Browning M1919A4 1: .30 cal Browning MG6
MG - hull	1: 0.3" M1919A48 1: .30 cal Browning M1919A4 1: .30 cal Browning MG6
MG - antiaircraft	1: .30 cal Browning M1919A4 1: .30 cal Browning MG6 0.3" MG8
MG - sponsons	2: .30 cal Browning M1919A4 2: .30 cal Browning MG6 2: .30 cal Browning MG in sponsoons3
Side arms	1" .30 cal M2 tripod mount6 1: .45 cal submachine gun6 Hand grenades6
Quantity
Main	1033, 832 103: APC M51B1, APC M51B2, HE M63, Canister M26
Secondary
MG	6,400-8,2703, 5,4352, 8,2706
Side arms	.45: 5006, 500 - 540 Grenades: 12 (4: Fragmentation Mk II, 2: Offensive Mk IIIA2, 4: Smoke WP M15, 2: Thermite Incendiary)6
Armor Thickness (mm)	103, 513, 10 - 458, 15 - 4311
Hull Front, Upper	1.5"6, 1" - 1.5"4 38.12
Hull Front, Lower	5/8" - 1.75"6
Hull Sides, Upper	1"6, 1"@0° 25.42
Hull Sides, Lower
Hull Rear	1"6, 1"@0° 25.42
Hull Top	3/8"6 9.52
Hull Bottom	3/8" - 0.5"6 6.4 - 12.72
Turret Front	1.5"6 38.1 m2
Turret Sides	1.25"6, 1.25"@0° 25.42
Turret Rear	1.25"6, 1.25"@0° 25.42
Turret Top	0.5"6, 0.5"@90° 9.52
Engine (Make / Model)	Continental W-670-9A6,11, Continental Wright2, Continental W-6703,8, Continental4,5,7	Guiberson T-10205
OR	Guiberson7, Guiberson T10203, Guiberson T1020-46
Bore / stroke
Cooling	Air2,4,6,8
Cylinders	72,5,8,10 Continental: Radial 611, 76,7 , Radial4,5 Guiberson: 96,7
Capacity
Net HP	2504, 250@2,400 rpm2,8 Continental: 25011, 250@2,400 rpm6 Guiberson: 220@2,200 rpm6
Power to weight ratio	18 hp/ton7, 20.4 hp/ton8
Compression ratio
Transmission (Type)	Synchromesh 5 forward, 1 reverse2
Gear ratios - 1st gear	5.37:16
- 2nd gear	2.82:16
- 3rd gear	1.72:16
- 4th gear	1.09:16
- 5th gear	0.738:16
- reverse	6.19:16
Steering
Steering ratio
Starter
Electrical system	12 volt6
Ignition
Fuel (Type)	Gasoline2,8 Continental: Gasoline6,11 Guiberson: Diesel6
Octane	Continental: 806
Cetane	Guiberson: 506
Quantity	54 gallons, 56 gallons internal6, 50 gallons jettisonable tanks6 151 liters2
Road consumption
Cross country consumption
Performance
Traverse	360°3,6, hand6
Speed - Road	35 mph4, 36 mph3,6,7,8,11 57.9 kph2, 58 kph8,11
Speed - Cross Country	15 - 20 mph4, 20 mph3,8 32 kph8
Range - Road	70 miles3,6,7,8,11, 135 miles 112 km8, 112.6 km11, 120 km2
Range - Cross Country
Turning radius	21'6 13 m2
Elevation limits	-10° to +20°3,6
Fording depth	3'3,6,11 0.9 m2, 0.91 m11
Trench crossing	6'3,6,8,11 1.8 m8, 1.83'11
Vertical obstacle	2'3,11 0.61 m11
Climbing ability	60%6
Suspension (Type)	Vertical volute and trailing idler3 Volute Springs2,6
Wheels each side	42
Wheel size	20x66
Return rollers each side	3
Tracks (Type)	Rubber block6
Length
Width	11 5/8"6 295 mm2
Diameter
Number of links	132 or 1346
Pitch	5.5"6
Tire tread
Track centers/tread	6' 1"6