The Medium Tank M3/ Grant/ Lee was the first American medium tank to carry a 75mm gun, and played a significant part in the fighting in North Africa in 1942, but it was always seen as a interim design as its main gun was carried in the right of the hull, and it had been rushed into production to fill a gap before the arrival of the Medium Tank M4 Sherman.
The events of May-June 1940 made it clear that the new Medium Tank M2, which carried a 37mm gun in its main turret and machine guns in four subsidiary turrets, was already obsolete. The most recent Panzer IIIs carried a 50mm anti-tank gun and the Panzer IV a short barrelled 75mm gun. The ideal solution was to fit a 75mm gun in the turret of a new medium tank, but no suitable turret existed. A detailed specification for what would become the Medium Tank M4 (Sherman) was issued on 31 August 1940, but it was clear that it would take some time to complete the new design.
Fortunately an intermediate layout had already been tested. The Medium Tank T5E2 was based on the T5 Phase III, one of the prototypes of the M2. The front-right machine gun sponson was removed and replaced with a 75mm Pack Howitzer M1A1. The normal M2 turret was replaced by a smaller turret that carried a 0.30in machine gun and an optical range finder. The other three sponson mounted machine guns were retained. The T5E2 underwent tests at the Aberdeen Proving Ground between 20 April 1939 and 8 February 1940 and the 75mm gun proved to be very effective.
The T5E2 became the basis of a set of requirements issued on 13 June 1940 and standardized as the M3 on 11 July 1940. The initial intention was to mount the 75mm gun in the front right sponson and add extra armour, but to keep the other three machine gun sponsons. An auxiliary machine gun turret was added at the left front of the hull. The turret carried a 37mm gun and coaxial machine gun, and yet another machine gun was carried in a smaller turret on top of the main turret.
A full size wooden mock-up of this design was inspected by the Tank Committee on 26 August 1940. The Armored Force wanted to order a small number of M3s, and wait for the arrival of the M4 before beginning large scale tank production. The Ordnance Board disagreed, and wanted full scale production of the M3 to begin as soon as possible, to be carried out alongside the development of the M4, which would use the same chassis. Ordnance got their way, and the M3 was ordered into production. The same meeting also modified the design of the M3, eliminating the sponson machine guns and the auxiliary turret and making a number of more minor changes.
On 28 August 1940 a contract for 1,000 M3s was issued to Chrysler, to be constructed at their new Detroit Arsenal Tank Plant. Work on the new Arsenal had only begun in June, and the contract for the M2 issued on 15 August, only thirteen days before it was cancelled in favour of the M3.
The M3 had two customers. The British Army lost most of its modern tanks at Dunkirk, and a British Tank Mission, headed by Michael Dewar, soon arrived in the United States. Permission to order US production of British designs was refused (luckily, given the limited performance of most British tank designs of this period), but the British were allowed to order production of a modified version of the M3. The biggest change was to the turret. The British felt that the standard M3 turret was too cramped, in particular because it lacked the space to carry the radio, and the machine gun turret on top made the tank far too high. A new turret was designed by L.E. Carr. This carried the same guns, but was larger, and had a bustle at the rear to carry the radio. The machine gun turret was removed and replaced with a circular hatch. The British gave the modified M3 the designation General Grant Mk I, and the standard US version became the General Lee Mk I.
Production of the M3 was split between several manufacturers alongside Chrysler's Detroit Arsenal. The British ordered 685 Grants from the Baldwin Locomotive Works, alongside a similar US order. Pullman Standard Manufacturing and the Pressed Steel Car Company both received an order for 500 tanks. The Lima Locomotive Company was given an order for 100, but production there began so slowly that the order was changed to one for the M4 Sherman.
Preliminary versions of both the US and UK turrets were ready by the end of 1940, and the US turret was installed on the chassis of an M2 by 20 December 1940.
The scale of production slowly increased. By the end of 1940 the plan was to produce 14.5 tanks per day, 8 for American orders and 6.5 for British, a total of around 450 tanks per month. Soon afterwards a Joint Tank Planning Committee was created to handle both countries orders, and by 1 April 1941 the target had doubled to 1,000 tanks per month, rising again to 2,000 by July. The aim was to maintain this rate across 1942 to produce 25,000 tanks, rising to 45,000 medium tanks in 1943.
The basic design of the M3 was completed by 1 February 1941. The pilot tank was built by the Rock Island Arsenal, and was able to move under its own power by 13 March, and was sent to the Aberdeen Proving Ground later in the month. The turret was installed at Aberdeen, and tests began. In the meantime the various manufacturers also began work on their pilot models, with the Detroit Tank Arsenal first to deliver, on 5 May 1941. This was soon followed by their first production pilot.
By the end of the summer of 1941 the M3 was under production at the American Locomotive Company, the Detroit Tank Arsenal, and for Britain at the Pressed Steel Car Company and the Pullman Standard Car Company.
The Pressed Steel Car Company completed their first Grant by 15 July 1941.
Pullman completed their first Grant by 25 July 1941.
By August 1942, when production ended, a total of 4,924 M3s, Lees and Grants had been built.
The first three M3s were delivered to their end users in August 1941, with one going to the US Armored Forces at Fort Benning and the other two to the UK. By September 1941 twenty had reached the UK, by now under the terms of the Lend Lease. By this point the danger of German invasion that had lend so much urgency to the original order was over, and the Germans were increasingly committed to a long war in the Soviet Union. This freed up the M3 for use in North Africa,
The M3 was a tall tank with an asymmetrical layout. The 75mm gun was carried in a sponson in the front right of the main fighting compartment. The turret was offset to the left, and filled about two thirds of the width of the tank. The machine gun turret was at the left-rear of the main turret.
Internally this split the fighting compartment into several sections. The large fighting compartment of the M2 was split in two, with the 75mm gun mount on a lower level on the right, and a step up into the turret cage on the left. The driver was in the front-left, to the left of the 75mm gun and in front of the turret.
The front plate sloped back from the nose to the top of the superstructure, just in front of the turret. The rear deck sloped back gently to the back of the tank.
The nose was made up of the three piece cast housing for the final drive and controlled differential steering, bolted together to give a distinctive appearance shared by many M4 Shermans.
The M3 used the same suspension system as the M2, the Vertical Volute Spring Suspension or VVSS system later used on the M4. This had three bogies on each side of the tank, each carrying two road wheels. The road wheels were attached to a central spur on pivoting arms, and the arms were suspended on volute springs that were attached to the top of the bogie. The volute springs were made by rolling up a flat strip of metal, and the coils could thus slide up and down inside each other, increasing the range of movement. The engine was at the rear of the tank and the final drive at the front, powering drive sprockets.
Early M3s were armed with the 75mm gun M2 and the 37mm M6, although a shortage of guns meant that some got the 37mm M5 instead. Later M3s got the 75mm gun M3, with a longer barrel that increased muzzle velocity to 2,030ft/ sec.
At first the M3 carried a crew of seven.
This was later reduced to six by having the driver also acting as the radio operator.
The M3 was used as the basis for a number of experiments.
A standard M3 was used to test the horizontal volute spring suspension system that was used late in the production run of the Medium Tank M4. The standard vertical volute spring system produced a very rough ride at high speeds, and the HVSS system was designed to deal with this. The springs were mounted horizontally, and the road wheels on each bogie pushed against each other. Shock absorbers were installed above the spring, also mounted horizontally.
The M3E1 was the designation given to one tank that was used to test a new Ford V-8 tank engine, produced by removing four cylinders from a V-12 aircraft engine. This engine was accepted for production, and was used to power the Medium Tank M4A3.
The M3A1E1 was used to test a Lycoming T1300 tank engine, which combined three Lycoming 6-cylinder air-cooled aircraft engines. This engine produced 560hp and the M3A1E1 reached 40mph, the fastest speed for any version of the M3. The engine was found to be reliable, but very difficult to maintain, and had to be removed from the engine compartment for many basic tasks (including changing a spark plug). The T1300 wasn't chosen for production.
The M3A5E1 was used to test out an automatic transmission system, using two Hydramatic transmissions linked to the twin diesel engine. This prototype was completed in January 1942, and the tests showed that the automatic transmission improved the performance of the tank.
The M3A5E2 was a second test vehicle for automatic transmission, and used a single heavy duty Hydramatic transmission in place of the two transmissions of the M3A5E2.
The first version of the M3 to enter combat was the Grant Mk I. This reached the British army in North Africa in the aftermath of the retreat to the Gazala line early in 1942. Although the layout of the tank wasn't ideal, it did give the British a 75mm tank gun for the first time, and the first tank gun capable of firing a useful high explosive shell (at least after problems with the fuse had been solved by installed First World War era French fuses on the US shells. At first the new APC M61 armour piercing capped projectile wasn't available, and the interim AP M72 monobloc shell wasn't very effective. This problem was solved by fitting captured German APCBC rounds for the Panzer IV into American cartridge cases to produce the 75mpp AP-Composite.
By the end of March 1942 666 Grant Is had been built, and by late May 167 of them had reached the British 1st and 7th Armoured Divisions in North Africa. This wasn't enough to fully equip every tank regiment, and so most had a mix of Grants and Light Tank M3 General Stuarts. 4th Armoured Brigade of the 7th Armoured Division would be the first unit to use the Grant in combat (by a narrow margin), when it was attacked during Rommel's attack on the Gazala line at the end of May 1942 (Operation Venezia). At the start of the battle 8th Army had 167 Grants, 149 Stuarts and 257 Crusaders, so the Grant made up a significant part of its armour.
On 27 May the leading elements of 4th Armoured Brigade ran into the advancing Panzer IIIs and Panzer IVs of the 15th Panzer Division, taking part in Rommel's attempt to outflank the Gazala line to the south. For once the British had the better tank gun, and in a defensive battle the 75mm gun of the Grants of 3rd RTR inflicted heavy damage on the Germans. However the British were badly outnumbered, and eventually had to retreat with seven tanks intact and three sent to the rear to have their guns repaired from the original force of nineteen. By the end of the day that total had been reduced to only five. The 8th Hussars were less fortunate, and were caught before they were fully organised. Only two of their Grants were still intact at the end of the day, although they did claim 30 German tanks. The Hussars had been caught by surprise, and had suffered heavily from the fire of anti-tank guns. Other parts of the army also fought hard on the 27th, and although they were generally forced to retreat, the hard hitting Grant disrupted Rommel's plans. The Germans lost one third of their tanks during the day.
The first American crews to use the M3 in combat were three that had been attached to the Eighth Army for combat trials. Early in June they were rushed forward to support the 1st RTR in the battles to keep open the lines of retreat from Gazala. During their time in combat the three American crews claimed nine German tanks, and all three survived intact.
The British ended up back at El Alamein, where a stalemate developed while both sides developed their strength. Rommel received reinforcements, including a handful of Panzer IVs with a long 75mm gun superior to the gun in the Grant. On the British side there were 164 Grants, and also a new commander, Montgomery having taken over. In August Rommel attacked the new British line (battle of Alam Halfa), but he ran into a strong defensive line. His advance was slowed down by 7th Light Armoured Division, with a mix of Stuart and Crusader tanks, and then ran into 22nd Armoured Brigade, which had four regiments, each with two squadrons of Grants. The Germans attacked the 22nd Armoured Brigade and inflicted heavy losses, but suffered almost as badly themselves, and were forced to retreat. Rommel's last chance to reach the Nile was over.
The M3 was very much an interim design, and it was soon joined in the desert by the M4 Sherman. At the start of the Battle of Alamein the British had 170 M3s, a mix of Grants and Lees, and a larger force of Shermans. The Grant and Lee remained in British service throughout the North African campaign, with many serving as command tanks. Their large interior made them more suited to this role than the Sherman, and so many had false superstructures added to give them a similar appearance to the M4.
After the end of the campaign in North Africa the British stopped using the M3 in Europe. However it remained in use in the Far East until the end of the war, serving with the British Fourteenth Army in Burma and the Australian army in the south-west Pacific. These tanks were generally known as the Lee-Grant. Most used the smaller US turret, but with the machine gun cupola removed, giving it a similar appearance to the British turret (and perhaps explaining why the M3A5, which was delivered to the British with the US turret, was designated as the Grant II instead of as the Lee). In both theatres the Japanese had little armour, and what few tanks they did have were outdated (the best Japanese tanks were reserved for the defence of the Home Islands, and never saw combat). The Grant-Lee thus operated as an infantry support weapon, often operating in difficult jungle conditions.
The Lee's limits didn't matter too much in the jungle. The limited traverse of the 75mm gun matched the limited visibility, while the 37mm gun now had a canister shot that was ideal for infantry support. During this battle the Lee-Grant crews worked out an effective method of bunker busting, using their HE shells to clear away any camouflage and their AP shells to break up the bunkers.
The Lee-Grant first saw combat in Burma during the Second Battle of Arakan, early in 1944. After an initial British attack, the Japanese launched a counterattack, triggering the famous battle of the Admin Box. A number of Lees took part in this battle, and played a part in breaking up the Japanese attacks.
The Lee went on to fight in the battles of Imphal and Kohima, once again helping to fight off Japanese attacks on besieged Allied forces. During these battles there were some armoured clashes. On 20 March a troop of Lees was ambushed by six Type 95 light tanks, and were in some danger until they were able to turn around and get their 75mm guns into action. After that the Japanese attack was doomed. Five of their tanks were destroyed and the sixth captured and sent back to Imphal as a trophy. This was the only deliberate tank attack carried out by the Japanese, and afterwards the Lees found themselves being used to support attacks on Japanese bunkers and defensive fighting in the hills.
The Lee-Grant turned out to be an excellent hill climber, and was able to get into positions where the Japanese had never expected to face tanks. One of the most famous of these battles took place on Nunshigum, a hill near to Imphal, where a force of Lees helped expel the Japanese, although only after losing most of the tank commanders.
The Lee-Grant fought at the highest altitude of any tanks during the Second World War, taking the 9,000ft Kennedy Peak during the fighting around Tiddim.
The Lee-Grant was then used during the reconquest of Burma, taking part in the liberation of Mandalay and the advance on Rangoon.
A total of 752 Lee-Grants went to Australia, where they became the most important equipment for the 1st, 2nd and 3rd Armoured Divisions.
The M3 entered US service during 1941, and played a vital part in the expansion of the US armoured force. Most early US armoured divisions trained with the M3, but many then converted to the M4 before entering combat.
One exception was the 1st Armored Division, which moved to Northern Ireland in May 1942 with its M3s. The 2nd Battalion, 13th Armored Regiment, was the only M3 battalion to take part in the first stage of Operation Torch, the invasion of North Africa, as the available tank landing ships couldn't cope with the tall M3. This battalion travelled to North Africa, but wasn't needed during the initial fighting against the Vichy French. Its combat debut thus came during the first advance into Tunisia. The 2nd Battalion formed part of Combat Command B, which was chosen to support the British 6th Armoured Division as it advanced east. The battalion reached the combat zone on 24 November after a lengthy journey. The first clash with the Germans came on 28 November, when part of the battalion supported an advance by the Northamptonshire Regiment at Djedeida. The advancing tanks ran into a German ambush and came under heavy fire from hidden antitank guns. The battalion suffered its first losses in this clash and by the end of 6 December had been reduced to 22 M3s. The first attempt to capture Tunisia ended in failure.
The M3 was soon joined by the M4 Sherman as American reinforcements arrived in North Africa, but it continued in use with the 13th Armored Regiment to the end of the fighting in North Africa. The regiment helped repulse two German attacks late in the Battle of the Kasserine Pass, Rommel's last significant attack in North Africa. After the final German surrender in North Africa the M3 was withdrawn from front line service in the European theatre.
The M3 also saw limited use with American troops in the Pacific. The 193rd Tank Battalion was equipped with the M3 during the invasion of Makin Atoll late in 1943. The Japanese defenders of the island only had a handful of light tanks and limited anti-tank firepower, and the M3 was thus able to act as an infantry support tank.
By this point the M3 had already been declared Limited Standard (1 April 1943), and it was officially declared obsolete in US service in April 1944.
The M3 used rolled armour, riveted to form the hull. The turret and cupola were both cast. It was powered by a Wright R975 EC2 air cooled radial engine, rated at 340hp GG or 400hp. 4,924 were accepted.
The M3A1 used cast armour for the upper part of the hull, as well as the turret and cupola. The lower hull was riveted. The M3A1 used the same Wright engine as the M3. 300 were accepted
The M3A2 introduced a welded hull in place of the riveted hull of the M3. The welded hull was stronger and slightly lighter than the riveted hull. The M3A2 used the Wright Continental engine, and only 12 were built before production shifted to the diesel powered M3A3.
The M3A3 was similar to the welded M3A2, but used twin General Motors diesel engines, in order to overcome a shortage of the Wright Continental engine used in earlier versions. 322 M3A3s were built.
The M3A4 was also developed in order to overcome a shortage of engines. It used a 30-cylinder Chrysler engine that was produced by combined five normal six cylinder automobile engines in a star pattern. It used the riveted hull of the M3. Only 109 were built before the Detroit Tank Arsenal switched over to production of the Medium Tank M4 (Sherman).
The M3A5 combined the riveted hull of the M3 with the GM diesel engine of the M3A3. It was produced in larger numbers than the welded M3A3, with 591 built in total.
Grant Mk I
The Grant Mk I was the designation for the M3 with the wider but lower British turret. A total of 2,653 M3s were delivered to Britain, a mix of Grant Is and Lee Is.
Hull Length: 222in
Hull Width: 107in
Height: 119in (including turret periscope)
Crew: 6 or 7
Weight: 62,000lb combat loaded
Engine: Wright Continental R975 EC2 9 cylinder air cooled
Hp: 340hp at 2,400rpm
Max Speed: 21mph sustained, 24mph max
Max Range: 120 miles cruising radius (roads)
Armament: 75mm Gun M2 in right front of hull; 37mm Gun M5 or M6 in turret; two or three 0.30in machine guns, one coaxial in turret, one or two in hull front plate; 2in Mortar Mk 1 (smoke) in turret
Grant Mk II
The Grant Mk II was the designation rather confusingly given to the M3A5 in British use. Britain received 185 of these tanks, which were built with the standard US turret arrangement, but most were modified to lower the profile. In some cases the cupola was removed but the rest of the small turret retained, while in others a standard Grant turret may have been installed. The Grant II was often called the Lee by the troops operating it, but later in the war the distinction between the two types began to fade anyway, and in the Far East both types were known as the Lee-Grant tank.
Lee Mk I
The Lee Mk I was the designation given to the standard M3 with American turret in British use. Britain received a total of 2,653 M3s, a mix of Grant Is and Lee IIs. In British use the machine gun cupola was often removed, and a split hatch similar to that used on the Grant I was installed.
Lee Mk II
The Lee Mk II was the British designation for the M3A1, but none were delivered.
Lee Mk III
The Lee Mk III was the British designation for the M3A2, but none were delivered.
Lee Mk IV
The Lee Mk IV was a British designation for the M3A3 with Continental engine. In the event all A3s used diesel engines, and so no Mk IVs can have been delivered
Lee Mk V
The Lee Mk V was the British designation for the M3A3 with the diesel engine. A total of 49 M3A3s went to Britain.
Lee Mk VI
The Lee Mk VI was the British designation for the M3A4, but none came to Britain.
The M3 Canal Defence Light carried a high powered spotlight in place of the 37mm gun. The idea was to use the light to support a night attack. After early experiments based on the British Matilda II infantry tank, the M3 was chosen for large scale production of the CDL, as it could carry the light and its 75mm gun. A total of 497 were converted by the American Locomotive Company, enough to equip two US Armored Groups and two British Tank Brigades, but the equipment was so secret that it was never used in its intended role. A few were used during the crossing of the Rhine in 1945,
M31 Tank Recovery Vehicle
The M31 was a tank recovery vehicle produced by fitting a crane in place of the 37mm gun in the turret. The 75mm gun was also removed, and replaced with a dummy gun. A second dummy gun was installed on the back of the turret, and the tank was normally driven with the turret facing backwards. A total of 805 were produced between October 1942 and the end of the war.
M33 Prime Mover
The M33 Prime Move was produced by removing the recovery gear and 37mm turret from the M31, and was used to tow heavy artillery. 109 were produced.
M7 105mm Howitzer Motor Carriage 'Priest'
The M7 'Priest' was the most successful conversion of the M3. It used the chassis and power train of the M3, but with a new open topping fighting compartment that carried a 105mm howitzer. The Priest was produced in large numbers, and continued in production after the M3 was replaced by the M4 Sherman. Later 'Priests' used M4 components, and were given the designation M7B1.
M9 3in GMC
The M9 was a tank destroyer that carried a 3in gun in an open topped fighting compartment. The Tank Destroyer Board didn't approve of the design, and this combined with a shortage of the chosen 3in gun to end the project.
M3/ Lee Mk I/ Grant Mk I (with British turret) - normal bogie gap, rear armour level with bottom of sponsons
M3A4/ Lee Mk VI (Chrysler engine) - increased space between bogies
M3A5/ Grant II (GM Diesel engine) - normal bogie gap, rear armour down to top of tracks
M3A1/ Lee Mk II
M3A2 (only a tiny number built)
M3A3/ Lee Mk V