M3 Light Tank

Development
Combat
Operation Torch and North Africa
Pacific
Export and Overseas Users of the M3
Variants
Stats

The M3 Light Tank was the most numerous light tank produced in the United States during the Second World War and saw combat in the Pacific, North Africa, Italy and the European theatre as well as with the British, where it was known as the 'General Stuart', and with the Red Army. It was already outclassed by the end of 1942 and was very vulnerable on the battlefield by the end of the war, but remained in use until 1944.

Development

The M3 was an example of a tank that was ordered 'from the drawing board', without any experimental T-series prototypes. This often caused great problems, but not in the case of the M3, which was developed from the Light Tank M2A4. Early examples of the M2 Light Tank had been armed with machine guns, but the M2A4 of 1939 saw the introduction of a single turret armed with a 37mm gun, at that stage the standard anti-tank gun of the US Army.

The M3 was designed at the Rock Island Arsenal early in 1940. It was quite similar to the M2A4, with the same basic layout (engine at the back, drive wheel at the front, centrally mounted turret), but with thicker armour. The thickest armour on the M2A4 had been 25mm thick, but on the M3 the frontal armour was 38mm thick with 51mm on the nose.

The superstructure of the M3 ran from the back of the tank to the front of the turret, with a sloping front deck between the turret and the front of the tank. One machine gun was mounted in this sloping deck and two more were carried in sponsons built over the tracks alongside the turret. These guns were remotely fired by the driver and were removed in later versions of the tank. The rear part of the superstructure was an armoured cover for the engine. On the M3 the top of the engine cover was level with the rest of the superstructure, but on the later M5 Light Tank the engine deck was raised up.

M3 Stuart Light Tank, North Africa, 1941
M3 Stuart Light Tank,
North Africa, 1941

The M3 used vertical volute spring suspension. There were four road wheels on each side of the tank, carried in pairs on two bogies. Each wheel was carried on a pivoting arm that was connected almost horizontally to a central mounting bracket. Shock absorption was provided by a vertical spring that connected the pivoting arm to the top of the bracket, protected from damage by the outer face of the bracket. On some tanks the return rollers were attached to the top of the suspension bogies, but that wasn't the case on the M3. The vertical volute system was simple to produce and maintain and if any part of a bogie was damaged the entire unit could easily be replaced. A similar system was used on most M4 Shermans. The M2A4 had used a similar suspension system, but with the rear trailing wheel lifted off the ground and the two bogies separated by a wide gap. On the M3 the two bogies were moved closer together and the trailing wheel was moved down to the ground to increase the length of track that was in contact with the ground and thus reduce the tank's ground pressure. This also helped compensate for the extra armour.

The M3 was approved in July 1940 and in March 1941 it replaced the M2A4 on the production line at American Car & Foundry. Between then and August 1942 a total of 5,811 M3 Light Tanks were built.

A number of changes were made during the production run, not all of which were reflected with new designations.

The first one hundred M3s used the D37812 turret. This was built from eight flat panels that were riveted together, and was the same shape as the turret of the M2A4. It had improved viewports and a six sided cupola. The gun was carried in an M22 mount, with the recuperator assembly inside the turret (the M2A4 had used an M20 mount which left part of the recuperator outside the turret and thus vulnerable to damage). Some early M3s had to use the older mount.

After the first hundred machines a new D38976 turret was adopted. This was the shame shape as the riveted turret, but was welded. The danger with rivets was that the inner part would fly off when the turret was hit by enemy fire and would bounce around the inside of the tank injuring the crew.

In March 1941 work began on a third turret, the D39273. The sides were constructed from a single piece of armour plate and the new turret had a curved appearance. From above it was shaped like a horse shoe. This turret retained the cupola and was introduced onto the production line with tank no.1946 in October 1941.

The final major change made to the basic M3 was the introduction of a gyro-stabilizer for the 37mm gun, designed to increase accuracy when the gun was being fired on the move. The first gyro-stabilizer wasn't very effective, but later models were a great improvement.

The M3A1 was introduced in 1942. The biggest changes came in the turret, where great efforts were made to improve the performance of the gyro-stabilizer. The M3 turret had manual traversing gear, but tests had shown that powered traverse gear improved the efficiency of the gyro-stabilizer. An oil gear traversing motor was added to the turret, but this increased the speed of rotation so much that the crew were unable to keep up. A turret basket had to be added so that the commander and gunner didn’t have to try and match the speed of the turret. A turret periscope was added and to make space the cupola was removed. The M3A1 entered production in July 1942, and production of the basic M3 ended in August.

The M3A3 was the final production version of the M3. In 1941 Cadillac developed the M5, a version of the M3 that was powered by twin Cadillac engines. This also had a modified superstructure which was extended towards the front of the tank, increasing the internal storage space. American Car and Foundry were then asked to produce a version of the M3 that included all of the improvements made to the M5, but powered by the Continental engine. This version also had a modified turret with a bustle added to the rear of the turret. This allowed the radio to be moved from the fuselage to the turret and proved to be so successful that the same turret was introduced on the M5A1. The M3A3 was standardised in August 1942 and entered production in January 1943.

Most of the 13,859 M3s, M3A1s and M3A3s were powered by the Continental W 670 petrol engine, but early in the war there was a real danger that the demands of the aircraft industry would lead to a shortage of this engine. A number of M3s were thus powered by a Guiberson diesel engine. Very few of these tanks saw combat with US forces, where diesel was rarely used. Some went to Lend Lease and others were used as training vehicles in the United States. 

Combat

When first introduced the M3 was used to equip separate tank battalions (often called GHQ tank battalions because they were under the control of the general headquarters, where they were used for infantry support) and the new armoured divisions. These had over 200 tanks and were designed for offensive operations, exploiting breakthroughs. They were formed from two armoured regiments, each with two battalions of M3 Medium Tanks and one of the M3 Light Tank.

The M3 first saw active service with the British, where it was known as the 'General Stuart'. Just as these tanks were getting their combat debut in Norh Africa the first two American units to use the M3 in combat were receiving their tanks. The 192nd and 194th Tank Battalions, with 108 M3 tanks, left San Francisco in September-November 1941, heading for the Philippines. They formed part of the Provisional Tank Group, commanded by Brigadier General James Weaver. They were used to provide a mobile rearguard during the retreat to Bataan, where the surviving tanks were eventually destroyed.

Operation Torch and North Africa

M3 Stuart light tank passes El Himeimat, 1942 M3 Stuart light tank passes El Himeimat, 1942

The 1st Armoured Division was the main US armoured force to take part in Operation Torch, the invasion of North Africa. It had two light tank battalions, both equipped with the M3 and M3A1. Despite the evidence provided by American liaison officers with the 8th Army, the M3 was still expected to be of use against German armour. This would quickly prove not to be the case. The Germans now had a significant number of 5.0cm anti-tank guns and Panzer IVs equipped with the long 7.5cm gun, both of which could easily penetrate the armour of the M3 and M3A1. In contract their 37mm gun struggled against the front armour of the American tanks and needed side or rear hits to penetrate.

The 1st and 2nd Armored Divisions were both allocated to Operation Torch, wit the 1st Armoured Division doing much of the early fighting. Both divisions had two tank regiments, each with one light tank battalion. The 1st Armored Division had the M3A1 while the 2nd Armored Division was equipped with the M5 Light Tank.

The light tanks of the 1st and 13th Armoured Regiments, 1st Armored Divsiion, were amongst the first to land at Oran on 8 November. They had one clash with French tanks on 9 November when a force of Chars leger 1935R attempted to interfere with the invasion. This was an easy introduction to combat for the Americans, and they destroyed 14 French tanks. The Americans suffered one man wounded and one M3A1 slightly damaged.

Things would chance once the Americans ran into the Germans in Tunisia. The first armoured clash in Tunisia was with Italian Semovente da 47/32 light tank destroyers, and was another easy success, but the first clash with German tanks, on 25 November, was rather more worrying. The 1st Battalion, 1st Armoured Regiment, came up against force that included three Panzer IIIs with 50mm guns and six Panzer IV ausf F2s, with 75mm guns. Company of the 1st Battalion attacked the Germans, but lost six tanks in a few minutes. Company B managed to get behind the Germans and destroyed six Panzer IVs and one Panzer III without loss, forcing the Germans to withdraw. Although this had been a tactical success, the performance of the M3 hadn't been encouraging, and as the Tunisian campaign developed the lessons would be repeated. The 37mm could only damage the Panzer III at under 500 yards and the front armour of the Panzer IV was almost impenetrable. The German tanks could destroy the M3s at much longer ranges.

By the spring of 1943 the commanders of the light tank battalions wanted both the M3 and M5 declared surplus and withdrawn from combat. Bradley and Patton recommended that it be removed from the main combat role and used for scouting and flank security roles only, and their recommendations would be followed. After the Tunisian campaign the M3 was replaced by the M5, and the US armoured forces were restructured. Most battalions became mixed forces, with three medium tank companies and one light tank company for reconnaissance.

Pacific

The M3 made its American combat debut in the Philippines in December 1941. In September-November 1941 the 192nd and 194th Tank Battalions, with 108 M3s, were shipped from San Francisco to the Philippines, and on 19 November they became part of the Provisional Tank Group, commanded by Brigadier James Weaver. These units had very little experience with their tanks and the vehicles themselves needed quite a bit of work to be fully combat ready, but on 8 December 1941 the Japanese invaded the Philippines, and the new units were thrown into the battle.

On 8 December Company D, 194th Tank Battalion, was guarding Clark Field. During the persistent Japanese attacks on the airfield they actually managed to shoot down one Japanese fighter aircraft, but the airfield was soon put out of action.

There were very few tank-vs-tank battles during the Japanese invasion of the Philippines. Instead the M3s were normally used to provide a mobile rearguard during the retreat into the Bataan peninsula. They were often misused by infantry officers who had little experience of armour, and many had to be abandoned (often when bridges were blown behind them).

There were a number of clashes between the M3 and the Japanese Type 95 Ha-Go light tank. The first of these came at Damortis on 22 December 1941. The 192nd Tank Battalion had been sent to attack the Japanese forces landing at Lingayen Gulf, but instead a patrol of five tanks ran into an ambush set by the 4th Sensha Rentai. The first M3 was destroyed and the remaining four all damaged but were able to escape. A second clash, outside Moncada on 27 December was no less successful, but on 31 December the American tanks finally had a success when they knocked out eight Ha-Gos at no cost to themselves during a battle in Baliuag. The final tank battle of the retreat came on 7 April 1942 when the 194th Tank Battalion destroyed two Japanese tanks.

At the end of the campaign every remaining M3 in Americans was destroyed, but the Japanese had captured 31 intact tanks. Some went to Japan, but most became part of the Japanese garrison on the Philippines. When the Americans returned in 1944-45 these tanks were used against them and a number were destroyed in battle in January and February 1945.

The M3 and M5 remained viable battle tanks for longer in the Pacific than in the European theatre. The Japanese light and medium tanks that were found in the Pacific were generally some way behind their German contemporaries, with thinner armour and less powerful guns, and the Japanese didn’t get good anti-tank guns until the last year of the war.

The M3A1 made its combat debut on Guadalcanal, where it was part of the equipment of the 1st Marine Tank Battalion. This battalion entered combat in August-September 1941 and was equipped with a mix of M2A4s, M3s and diesel powered M3A1s. There was little if any tank-vs-tank combat on Guadalcanal, and the M3s and M3A1s were used to destroy Japanese strong points during American offensives or defeat massed Japanese infantry attacks. Canister rounds became the most common ammo load for the M3 in the Pacific.

The US Marines used the M3A1 extensively and it wasn't replaced in the Marine Corps until 1944 when the M4 Sherman and M5A1 Light Tank began to take over.

In the summer of 1943 the Marine 9th, 10th and 11th Defense Battalions were each given the M3A1 for fire support. They took part in the fighting on New Georgia, and the 9th Defense Battalion was involved in the fighting at Munda (July-August 1943), while the 11th fought on nearby Arundel Island (August-September 1943), part of the mopping up operation on New Georgia.

The Marine 3rd Tank Battalion used the M3 at the start of the invasion of Bougainville (Operation Cherryblossom, November 1943-March 1944). They were still in use on Bougainville in March 1944 when the 754th Tank Battalion had some.

The M3A1 was used during the fighting on Tarawa in November 1943. By now the 37mm gun wasn't even powerful enough to deal with the reinforced log bunkers being used by the Japanese, although the M3 did play a useful part in the fighting on Betio, taking part in the initial invasion of 21-23 November and the mopping operations.

In November 1943 the US army used the M3A1 during the invasion of Makin in the Gilbert Islands. The 103rd Tank Battalion, which took part in the invasion, was mainly equipped with the M3 Medium Tank but also had a company of M3A1 Light Tanks.

The M3A1 was also used by the 767th Tank Battalion during the invasion of Enubuj, Kwajelin Atoll, in February 1944.

The M3 was used by the Marines when they landed on Emirau Island in the Bismarck Archipelago in March 1944.

During the fighting on Saipan the M3A1 was used as a flamethrower tank, with the M5A1 Light Tank guarding them. The Satan flamethrower was more effective against strong bunkers than the 37mm gun, but its uses felt that it was too short-ranged and the fuel supply was inadequate. After Saipan some of the flame thrower tanks moved to Tinian to take part in the final stages of the battle there.

Export and Overseas Users of the M3

The main overseas user of the M3 was Britain, where it was known as the 'General Stuart' or the 'Honey'. Some also went to South America, where they served in Brazil and Ecuador.

The M3A3 was provided to the Chinese Provisional Tank Group which was formed in India and fought in Burma. The group also used the M4A4 Sherman

The Germans captured a number of M3s from the 1st Armoured Division during the battle of the Kasserine Pass, and some were put back in use against the Americans.

Variants

M3

The M3 was the first production version of the tank and was produced in the largest numbers, with a total of 5,811 built. A series of improvements were introduced during the production run of the M3 without a new designation being allocated. Early tanks had a riveted hull and a riveted hexagonal turret made out of eight flat panels. The riveted turret was replaced with a hexagonal welded turret and this was eventually replaced with a composite welded/ cast turret with a rounded shape. An all-welded hull was also introduced, partly to save weight and partly to reduce the danger of rivets being blown into the fighting compartment in combat. Five hundred M3s were built with a Guiberson diesel engine when supplies of the Continental engine began to run short.

M3A1

The M3A1 entered production in July 1942. It saw the introduction of the fourth turret used on the M3, designed to improve the effectiveness of the gyro-stabilizer. Tests had shown that this was more effective in tanks with powered traverse on the turrets, but the standard M3 had a manually operated turret. An oil gear traversing motor was added to the new D58101 turret. To compensate for the increased speed of turning a turret basket was added so that the commander and gunner didn't have to try and move with the turret in the cramped interior of the tank. Production versions of the M3A1 also had a new gun mount, the M23, which had a turret periscope. To make room for this the cupola was removed and a second hatch was installed on the turret roof. A total of 4,621 M3A1s were produced, 211 with diesel engines, the rest with Continental petrol engines.

M3A2

The M3A2 designation was reserved for tanks that combined the layout of the M3 and M3A1 but with an all-welded hull. It was never used and instead production moved on to the M3A3.

M3A3

The M3A3 was the final production version of the tank. It had the modernized superstructure designed for the M5, with more space at the front of the tank and thus more internal storage space for 37mm shells. The M3A3 could carry 174 rounds compared to 116 on the M3A1. The M3A3 also had a turret bustle added so that the radio could be moved from the hull to the turret, and this was adopted on the M5A1. The M3A3 wasn't used in combat by the Americans, but instead went to Lend Lease. It was known as the Stuart V in British service and was the main reconnaissance tank during the campaign in north-western Europe. 

M3 Command Tank

The M3 Command Tank had the turret removed, a boxy armoured superstructure added and was used by senior officers.

M3 with Maxson Turret

The M3 with Maxson Turret was a 1942 project which saw the turret replaced with a quad .5in machine gun mount. It was designed for use as an anti-aircraft weapon but was rejected in favour of the same gun mounted on a half-track.

M3 and T2 Light Mine Exploder

This variant had the T2 Light Mine Exploder added on a boom in front of the vehicle. It was tested in 1942 but the M3 wasn't able to cope with the awkward mine exploder and the project was abandoned.

M3 or M3A1 with Satan Flame-gun

The Satan Flame-gun replaced the main 37mm turret gun on a number of tanks that were converted by the Marine Corps in the Pacific and used in combat on Saipan and Tinian.

M3A1 with E5E2-M3 Flame-gun

The E5E2-M3 Flame-gun replaced the hull machine gun. It could be used on the M3 and M5 Light Tanks, but there was only space for ten gallons of fuel.

T18 75mm Howitzer Motor Carriage

The T18 75mm Howitzer Motor Carriage carried a 75mm Howitzer in a similar mount to the one used for the main gun on the M3 Medium Tank. The M3 Light Tank couldn't cope with the extra weight and the project was abandoned.

T56 3in Gun Motor Carriage

The T56 3in Gun Motor Carriage was an attempt to produce a self-propelled gun using the M3 chassis. The gun was too heavy for the M3 and space was too limited

T57 3in Gun Motor Carriage

Work then moved on to the T57, which had a more powerful engine and removed the gun shield used on the T57. This was no more successful and both projects were dropped in February 1943.

Stats
Production: M3: 5,811; M3A1: 4,621; M3A3: 3,427; Total: 13,859
Hull Length: M3 and M3A1: 14ft 10 3/4in; M3A3: 16ft 1/2in
Hull Width: M3 and M3A1: 7ft 4in; M3A3: 8ft 3in
Height: M3: 7ft 6 1/2in; M3A1 and M3A3: 8ft 3in
Crew: 4 (commander, gunner, driver, co-driver)
Weight: M3: 27,400lb; M3A1: 28,500lb; M3A3: 31,752lb
Engine: Continental W-670 petrol engine (250hp) or Guiberson T1020 diesel engine
Max Speed: 36mph road, 20mph cross country
Max Range: 70 miles road radius
Armament: 37mm main gun; 5 .30in Browning machine guns on M3; 3 machine guns on other models
Armour: 10-51mm

WWII Home Page | WWII Subject Index | WWII Books | WWII Links | Day by Day

How to cite this article: Rickard, J (20 February 2014), M3 Light Tank , http://www.historyofwar.org/articles/weapons_light_tank_M3.html

Help - F.A.Q. - Contact Us - Search - Recent - About Us -  Subscribe in a reader - Join our Google Group - Cookies