United States' M5 light tank¹²

M5 Light Tank:	M5 Light Tank:	M5 Light Tank on exercise in 1944.	M5 Light Tank with the 7th US Army entering Neustadt a.d. Aisch, Germany on April 6, 1945.
M5 Light Tank in Germany in 1945.	M5 Light Tank:	M5 Light Tank¹²: U.S. Ordnance Dept.	M5 Light Tank:
M5 Light Tank with the 761st Tank Battalion in Coburg, Germany, 21 April 1945	M5 Light Tank at the Patton Museum in Ft Knox, Kentucky Chris Bobo	M5 Light Tank gun mount¹²: U.S. Ordnance Dept.	M5 Light Tank traversing mechanism¹²: U.S. Ordnance Dept.
M5 Light Tank turret basket¹²: U.S. Ordnance Dept.

Design

In the fall of 1941 Cadillac suggested to the Ordnance Department that they should try the M3 with a twin Cadillac engine due to radial engine shortages that were used by the aircraft industry.^1,¹¹ It was also to have the Cadillac Hydra-matic transmission that was used in automobiles.¹²

In February 1942 an M3A1 had 2 Cadillac liquid cooled V-8 car engines installed which meant that the rear deck had to be raised.¹¹ Fuel tanks were put in the rear corners of the hull. Radiators were placed above the engines.

The flywheel in each engine was connected to the Hydra-Matic Transmission. Since the drive shaft from the Cadillac engines and the Hydra-Matic transmission, some of the traversing mechanisms and parts of the gun stabilizer were moved under the turret basket and this provided more room for the commander and gunner.¹² The turret was extended in back to accommodate the radio.

A single cylinder engine supplied auxiliary power and charged the batteries.

Crew

The seats for the driver and assistant driver could be locked in any position.¹² The seats went up under spring pressure and down under body weight.¹² The driver and assistant driver had 360° periscopes in the roof of the hull.

Four escape hatches were provided.¹²

New Designation

It was originally going to be designated the M4 Light Tank, but it was decided to use M5 to avoid confusion with the M4 Medium.¹¹

Armor

The M5's hull was welded armor plating with the front plate reinforced.¹² The turret was also welded.¹²

Armament

The M5's 37 mm M6 gun could fire an APC shell at a muzzle velocity of 2,900'/sec.¹² It's range was 12,850 yards.¹² At 1,000 yards the M6 gun could penetrate 1.8" of armor.¹²

There was a gyrostabilizer which helped keep the gun at a fixed elevation during movement.¹²

Prototype

The Ordnance Board was convinced that a car engine would work, so Cadillac converted a tank and drove it for 500 miles at a testing ground.¹ The test showed it to have a smooth ride and was easy to operate. The Ordnance Board was convinced and production commenced.¹

Production

Standardized in February 1942.¹ Production started in July 1942.
First production units were delivered at the end of March 1942.⁷

In July 1943, another Cadillac production facility in Southgate, California, and Massey-Harris in Racine, Wisconsin, also started production. When M3 production ceased in October 1943, American Car & Foundry started production of the M5.

M5 prototype: Cadillac Motor Car Division¹²
M5: 2,074⁷, 2,075¹
- Production: March 1942 - , May 1942 - December 1942¹
- Manufacturer: Cadillac¹, Massey Harris¹
M5A1: 6,810^1,7
- Production: November 1941 - June 1944¹, December 1942 - June 1944⁷:
- Manufacturer: Cadillac^1,9, Massey Harris^1,9, American Car & Foundry^1,9,10

Variants

M5:
M5A1:
M5 Command Tank: Turret removed and replaced by box structure.¹¹
M5 with T39 Rocket Launcher: T39 launcher mounted on turret top. Fired 20 7.2" rockets. Project only.
M5 Dozer: Turret removed and dozer blade added.¹¹ Made in 1944.¹¹ Few had turret remain.
M5 or M5A1 with Cullin Hedgerow Device: Prongs added to front of vehicle. Normandy, 1944.
M5 with Flame Thrower: Only a prototype.¹¹ Was fitted with the E8 and E9-9 flame guns.¹¹
M8 Howitzer Motor Carriage: Had enlarged turret with 75 mm howitzer.¹¹
T8 Reconnaissance Vehicle: Removed turret and added mounting for .50 cal MG.¹¹ Used in combat from 1944 - 1945.¹¹
T8E1 Reconnaissance Vehicle: Was fitted with racks to carry land mines.¹¹
T27, T27E1 81 mm Mortar Motor Carriage: The army wanted a mortar carrier based on the M5A1 chassis.¹¹ The T27 prototype had the turret removed and an armored superstructure installed. The mortar was to fire forward with a 35 degree traverse. A .50 cal MG was also installed. The T27E1 had the mortar lower in the hull so that it didn't stick above the superstructure. Project canceled in April 1944 due to inadequate crew and storage space.
T29 4.2" Mortar Motor Carriage: After the T27 was canceled a design that had more space internally and used a smaller mortar was devised, however, this too had too small of space.
T82 Howitzer Motor Carriage: Had 75 mm howitzer in a mount in the front of the hull.¹¹ It was intended for jungle warfare but the design was abandoned in May 1945.¹¹

British Use

Nicknamed "Honey" by British calvary regiments. 84 sent to 8th Army in July 1941.¹ Used in Burma⁷, New Guinea⁷, Iraq⁷, Britain, NW Europe⁷, Italy⁷, and North Africa⁷. Russia¹, China¹, New Zealand¹, and France received some as well.

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.

Stuart VI: M5 and M5A1.
Stuart Kangaroo: Removed turret and added seats.
Stuart Recce: As Kangaroo but with various MGs 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.

Usage

It was used as a training vehicle, and used as a scouting and reconnaissance vehicle in combat.

	M5 light tank¹², M5 (Stuart VI)
Crew	Commander, gunner, driver, co-driver.³ 4^1,3,4,12
Radio	SCR-508¹²
OR	SCR-528¹²
OR	SCR-538¹²
Radio - command tank	SCR-506¹²
Physical Characteristics
Weight	33,000 lb^3,12 14.7 tons^1,7, 15 tons⁴ 14,969 kg¹
Length w/gun	14' 2.75"^3,4,12, 14' 3"^1,7 4.34 m¹
Length w/o gun
Height	7' 6"⁷, 7' 6.5"^3,4,12, 7' 7"¹ 2.3 m¹
Width	7' 4"⁷, 7' 4.25"^3,4,12, 7' 5"¹ 2.25 m¹
Width over tracks
Ground clearance	13.75"¹²
Ground contact length	117"¹²
Ground pressure	12.4 psi¹²
Turret ring diameter	46.75"¹²
Armament
Main	37 mm M6^1,3,12 37 mm⁴
Secondary
MG	2: MG⁴ 3: 7.62 (.30 cal) MG¹ 2: .30 cal Browning MGs, most had additional MG as AA.³
MG - coaxial	1: .30 cal Browning M1919A5 MG¹²
MG - hull	1: .30 cal Browning M1919A4 MG¹²
MG - antiaircraft	1: .30 cal Browning M1919A4 MG¹²
Side arms	.30 cal M2 tripod mount¹² .45 cal submachine gun¹² Grenades
Quantity
Main	123^1,12, 133³ APC M51B1¹², APC M51B2¹², HE M63¹², Canister M2¹²
Secondary
MG	6,250^3,12
Side arms	.45: 420¹² 4: Fragmentation Mk II¹² 2: Offensive Mk III¹² 4: Smoke HC M8¹² 2: Thermite
Armor Thickness (mm)	12³, 67³ 12 - 67⁴
Hull Front, Upper	1 1/8"¹²
Hull Front, Lower	2 - 2.5"¹²
Hull Sides, Upper	1 - 1 1/8"¹²
Hull Sides, Lower
Hull Rear	1 - 1 1/8"¹²
Hull Top	0.5"¹²
Hull Bottom	3/8" - 0.5"¹²
Turret Front	1.75"¹²
Turret Sides	1.25"¹²
Turret Rear	1.25"¹²
Turret Top	0.5"¹²
Engine (Make / Model)	Cadillac Twin^1,3,4,7, Cadillac Series 42¹²
Bore / stroke
Cooling	Liquid¹²
Cylinders	2:V-8^7,12
Capacity	346 cu in¹²
Net HP	121⁴, 220@4,000 rpm¹²
Power to weight ratio	15 hp / ton⁷
Compression ratio
Transmission (Type)	Hydra-Matic¹² 6 forward, 1 reverse¹²; 4 forward, 1 reverse¹²
Gear ratio - first speed	3.26:1¹²
- second speed	2.26:1¹²
- third speed	1.44:1¹²
- fourth speed	1.00:1¹²
- reverse	3.81:1¹²
Steering
Steering ratio
Starter
Electrical system	12 volt¹²
Ignition
Fuel (Type)
Octane	70¹², 80¹²
Quantity	89 gallons¹²
Road consumption
Cross country consumption
Performance
Traverse	360°^3,12, hydraulic or hand¹²
Max speed	36 mph^3,7,12, 37 mph¹, 40 mph⁴ 58 kph¹
Cross country	24 mph³
Road radius	100 miles^1,3,7,12 161 km¹
Cross country radius
Turning radius	21'¹²
Elevation limits	-10° to +20°^3,12
Fording depth	3'^3,12
Trench crossing	5' 4"^3,12
Vertical obstacle	1' 6"^3,12
Climbing ability	60%¹²
Suspension (Type)	Vertical volute³, Vertical volute spring¹²
Wheels each side	4¹²
Wheel size	20"x6"¹²
Return rollers each side	3
Tracks (Type)	T16¹²
OR	T36E6¹²
OR	T55E1¹²
Length
Width	11 5/8"^3,12
Number of links	132¹²
Pitch	5.5"¹²
Tires
Track centers/tread	6' 1.5"^3,12

Sources:

The Encyclopedia of Tanks and Armored Fighting Vehicles - The Comprehensive Guide to Over 900 Armored Fighting Vehicles From 1915 to the Present Day, General Editor: Christopher F. Foss, 2002
Panzer Truppen The Complete Guide to the Creation and Combat Employment of Germany's Tank Force 1933-1942, Thomas L. Jentz, 1996
British and American Tanks of World War Two, The Complete Illustrated History of British, American, and Commonwealth Tanks 1933-1945, Peter Chamberlain and Chris Ellis, 1969
Tanks of the World, 1915-1945, Peter Chamberlain, Chris Ellis, 1972
The Encyclopedia of Weapons of World War II, Chris Bishop, 1998
-
Tanks of World War II, Duncan Crow, 1979
Battle Winning Tanks, Aircraft & Warships of World War II, David Miller, 2000
Tank Data, Aberdeen Proving Grounds Series, 1968?
Tank Data 2, Aberdeen Proving Grounds Series, E. J. Hoffschmidt and W. H. Tantum IV, 1969
Airfix Magazine Guide #26 American Tanks of World War 2, Terry Gander and Peter Chamberlain, 1977
The American Arsenal, 1996

United States' M5 light tank12