Chapter Six

American Tanks in British Service

In May 1940, following the successful evacuation of the British Expeditionary Force (BEF) from the beaches of northern France and Belgium, huge quantities of equipment, including tanks, wheeled vehicles and self-propelled guns, were abandoned. Although much was deliberately destroyed, some of this equipment fell into German hands.

The evacuation, Operation Dynamo, started on 27 May and by 4 June 338,226 British and French soldiers had been rescued by a fleet of 850 boats. When the operation ended the army was forced to leave 2,472 guns, almost 65,000 vehicles–including more than 400 tanks and 20,000 motorcycles–416,000 tons of stores, more than 75,000 tons of ammunition, and 162,000 tons of petrol behind. If the nation was to fight on, some way had to be found to make good these huge losses and, clearly it could not be done by British industry alone. The government turned to the Commonwealth and to the USA for help.

At that time, the US Army had just 464 tanks, most of which were of the light pattern. Perhaps with one nervous eye on the events that had unfolded in Europe during May and June 1940, the American National Munitions Program had standardised on the M2A4 light tank and the M2A1 medium, with 365 units of the light tank ordered, and 2,000 of the medium. At the same time, representatives of the British Tank Commission arrived in the USA in June 1940 with the intention of buying medium tanks and, by April 1941, American Locomotive, General Motors and Baldwin Locomotive had all produced pilot models for the M3 medium tank and production was in full swing by August.

In early 1941, a small batch of M2 light tanks came to Britain for training and, by July of that year, the first examples of the improved M3 light tank arrived and were promptly shipped to Egypt. The first M3 medium tanks, known both as the General Lee and the General Grant, according to configuration, followed in 1942. By the time the war was over, the US government had supplied tanks and tank parts worth a total of $3.55 billion to the Allies under the Lend-Lease Act of 1941. Britain’s share of this huge figure consisted of 25,554 tanks–made up of 5,473 M3/M5 Stuart light tanks, 2,900 M3 Lee/Grant medium tanks, and 17,181 M4 Sherman medium tanks.

M3/M5 Light Tank–Stuart

Before the Second World War, the US Army shared the British view that tanks should be classified as light, medium and heavy. In the light category, the Ordnance Board had standardised on the M2, which had been developed by the Tank Design Department at Rock Island Arsenal. It went into production as the M2A4 in April 1940, with just 375 vehicles constructed. However, having seen the German tanks in operation in Poland, it was apparent that the M2 was scarcely adequate, and work was instigated to improve the armour. Unfortunately, the increased weight compromised the ride quality and the engineers were forced to redesign the suspension system, repositioning the rear track idler to increase the effective track length. The design of what had now become the M3 was standardised in July 1940 and went into production in March 1941. Although scarcely at the cutting edge of tank design, the 37mm gun was at least a nominal match for the original 37mm KwK L/46.5 weapon of the German Panzer III, and the tank was relatively fast, being capable of 36mph on roads and around 20mph across country.

The compact, high-sided boxy hull was of riveted construction, measuring 179in in length and 88in in width; with a 51mm maximum thickness of armour. This gave a combat weight of 12.25 tons. The seven-sided turret had a separate commander’s cupola, and was also of riveted construction, mounting the American 37mm M5 or M6 gun. Three .30in Browning machine guns were also mounted in the turret, with two more in side sponsons. A small number of machines were fitted with a 220bhp Guiberson Buda Model T-1020-4 nine-cylinder radial air-cooled diesel engine of 16,731cc, but most were powered by a Continental W670-9A seven-cylinder radial petrol engine producing 242bhp from 10,946cc. Drive was conveyed to the front sprockets via a five-speed manual transmission.

In August 1941, the M3A1 variant was standardised, dispensing with the cupola in favour of a turret basket, with the original turret replaced by a welded design with power traverse and a gyrostabiliser. Improvements were also made to the gun mount, which included fitting two periscopes, and the sponson-mounted machine guns were omitted. The weight was increased to 12.75 tons. The British referred to this variant as the Stuart III or Stuart IV, according to the type of engine.

Production of the original M3 ended in February 1943, after a total of 4,621 had been built, with both versions being declared obsolete in July.

A temporary shortage of radial engines led to the development of the M3E2 and M3E3 pilot models, powered by twin Cadillac Series 42 V8 petrol engines, producing 125bhp each from 5,670cc. The engines were coupled to a GM Hydramatic automatic transmission with six forward speeds and two reverse. Other improvements included changes to the hull, which was now of welded construction with a cast, rounded front, providing more space in the four-man crew compartment.

It had also been planned that there would be a welded-hull variant of the M3A1, which would have been designated M3A2, but there was no series production, and the next round of modifications resulted in the M3A3, known as the Stuart V by the British. This was standardised in August 1942. Weighing 14 tons, the M3A3 included a radio bustle at the back of the turret and had three additional periscopes; the gun mount was redesigned to incorporate a telescope; and there was better armoured protection for the driver. The sponsons were extended to house additional fuel-storage tanks and provide ammunition stowage, and sand shields were fitted over the suspension units. Improvements were also made to the crew’s facilities, including redesigned steering gear, a detachable windshield, and better fire protection. The M3A3 was produced only with the Continental engine, and was reclassified ‘limited standard’ in April 1943, meaning that it met certain criteria set by the US Ordnance Department but did not reach the required standard to be issued to combat units.

M3 light tanks were constructed by American Car and Foundry, with 5,811 vehicles built. Production ceased in August 1942.

At the end of 1941 Cadillac started to build tanks at plants in Detroit, Michigan and Southgate, California and one of the first vehicles on the assembly lines was a production version of the M3E2/M3E3, intended to replace the M3. To avoid confusion with the M4 medium tanks, the new model was redesignated M5. It was similar in design to the M3E2/M3E3 but had a maximum armour thickness of 67mm, putting the weight up to 14.75 tons, and incorporated a six-speed automatic transmission with a two-speed auxiliary unit. The M5 was standardised in February 1942, but was reclassified ‘limited standard’ in April 1943.

In September 1942, the M5 was replaced by the M5A1, with a lengthened turret similar to that fitted to the earlier M3A3, a new gun mount and a driver’s escape hatch. The anti-aircraft gun mount was repositioned to the right, and the internal arrangements of the hull and turret were rearranged to provide more space for the crew. The battle weight was now 15.15 tons. The M5A1 was downgraded to ‘substitute standard’ in July 1944, meaning that it was authorised for issue in lieu of a ‘standard’ item of like nature and quality.

The M5, or Stuart VI, was not supplied in large numbers to Britain, but a few served in northwest Europe in 1944. Production of the M5 was undertaken by American Car and Foundry, Cadillac and Massey-Harris. Between them these manufacturers constructed 8,884 vehicles, of which 2,074 were M5s and 6,810 were M5A1s. Production was terminated in October 1944.

M3 Medium Tank–Lee/Grant

The M3 medium tank was a logical development of the T5, which had appeared in mock-up form in 1937. A year later, a fully armoured prototype had been constructed, mounting a 37mm gun, and was put through its paces at Aberdeen Proving Ground. With minor refinements the T5 was standardised as the M2 medium tank and was put into production at the Rock Island Arsenal in Illinois but, after just eighteen units had been built, it was superseded by the up-armoured and improved M2A1. The original plan had been to build 1,000 M2A1s, but the production facilities at Rock Island were modest and by 15 August 1940 Chrysler had agreed to build the M2A1 in a new government-financed, purpose-built tank arsenal in Detroit.

However, the 37mm gun of the M2A1 was insufficiently powerful to take on the more modern German tanks and, after just ninety-four had been built, the production contract was cancelled. Almost immediately, Rock Island Arsenal started work on designing a new medium tank, designated M3, which would be armed with a 75mm gun. With just sixty days for the design work, there was little choice but to produce an up-armoured, up-gunned version of the M2A1, though the basic hull and the Wright Continental air-cooled radial engine and running gear were retained, as was the vertical volute spring suspension (VVSS). The major challenge was how to accommodate the big 75mm M2/M3 howitzer–with no access to a suitable turret ring, the gun ended up mounted in a sponson on the right-hand side of the hull. There was also a revolving turret mounting a 37mm M5/M6 gun, and on top of this was the commander’s cupola, mounting a .30in machine gun–looking for all the world like another turret.

The original M3, M3A4 and M3A5 variants had a riveted hull designed for a crew of six; the hull of the M3A1 variant was of cast construction, whilst the M3A2 and M3A3 were welded. For most variants, the hull width was 123in and the length 222in; the M3A4 was 236in long. The maximum thickness of armour was 57mm on the turret and 50mm on the hull, and the combat weight varied between 26.75 and 28.6 tons according to the method of manufacture and the power unit.

In its original guise, and in the subsequent M3A1 and M3A2 versions, the M3 was powered by a rear-mounted Wright Continental R-975-C1 or EC2 nine-cylinder air-cooled radial petrol engine producing 340bhp from a capacity of 15,945cc. The M3A3 and M3A5 variants were fitted with twin General Motors 6-71 diesel engines, each producing 205bhp from 13,930cc, whilst the Chrysler WC multi-bank unit went into the M3A4, incorporating five six-cylinder blocks disposed around a single crankcase to give 425bhp from 20,533cc. A shortage of Wright radial engines also led to the limited production of the M3(D) and M3A1(D) variants, which were fitted with a 220bhp Guiberson Buda Model T-1020-4 nine-cylinder radial air-cooled diesel engine of 16,731cc. In all cases, the tracks were driven by the front sprockets through a five-speed manual transmission.

Production started in April 1941 and, alongside the initial 1,000 tanks constructed for the US Army, the British Purchasing Committee placed orders for a further 1,686 units–500 from the Pullman Standard Car Company, 501 from either the Lima Locomotive Works or the Pressed Steel Car Company, and 685 from Baldwin Locomotive. The US Lend-Lease Act had yet to be passed and these tanks were supplied on a ‘cash and carry’ basis. The British were not entirely happy with some features of the design, and the British version was fitted with a larger cast turret, lacking the cupola but designed to accommodate a Number 19 radio set in a bustle. The British dubbed ‘their’ version ‘General Grant’ and the US Army version ‘General Lee’, although the word ‘General’ was soon dropped. The original M3 was described as Grant I, and the M3A5 was Grant II; the US pattern M3 was known as Lee I, the M3A1 was Lee II, the M3A2 was Lee III (although none of these was supplied to the British), the M3A3 was Lee IV, the M3A1(D) was Lee V and the M3A4 was known as Lee VI.

Obsolete M3s were also converted for a variety of roles including artillery prime mover, mine-clearance vehicle, searchlight carrier, flame-thrower, armoured recovery vehicle, command vehicle, etc. The chassis was also used as for the T24 3in gun motor carriage, and the M7 105mm howitzer motor carriage; when these became redundant some were converted to Kangaroo armoured personnel carriers.

With its 75mm main gun, heavy armour and excellent reliability, the M3 outclassed most of the British tanks of the period and was able to engage the early German tanks and anti-tank guns on a relatively equal basis. Top speed was around 26mph on roads, reducing to 16mph across country.

M4 Medium Tank–Sherman

The M4 Sherman medium tank is probably the best known Allied tank of the Second World War. It served with the US Army and Marine Corps, the British Army, the British Commonwealth Armies, the Soviet Union, the Free French, the Polish government-in-exile, Brazil and China.

Work on the M4 medium tank–it was the British who dubbed it the ‘General Sherman’, or more usually just Sherman–started almost as soon as the M3 medium had gone into production. Although far from perfect, the design was enormously successful and remained in production from late 1941 to the end of the war. Whilst not the best protected tank of the conflict, nor the hardest hitting (particularly with the original 75mm gun), it was simple to build, reliable and easy to maintain–and, above all, it was available in large numbers.

The drawings and specification of what was at first known as the T6 medium tank were signed off at Aberdeen Proving Ground on 18 April 1941, with five different schemes suggested. The simplest of these utilised the lower hull of the M3 along with the engine, transmission and running gear. Both cast and welded upper hulls were proposed, designed for a crew of five, and mounting a new cast turret with the 75mm M3 gun. A wooden mock-up was produced in May 1941 for the approval of the Armored Force Board, and a pilot model, with a cast distinctively rounded hull was completed in September 1941. As with the earlier M3, the engine was the Wright Continental R-975-C1 nine-cylinder air-cooled radial unit, producing 400bhp from 15,945cc, and coupled to a five-speed manual gearbox driving the front sprockets.

In October 1941, the M4 was standardised, with production planned at eleven plants, including those already producing the M3. The first production units were of the cast-hull M4A1 configuration starting in February 1942 at the Lima Locomotive Works in Lima, Ohio, under British Ministry of Supply contract. Known by the British as the Sherman I, this tank saw its first action with the 8th Army at El Alamein in October 1942.

The Sherman was constantly under development, often more to expedite production rather than to improve the breed. For example, whilst the hull of the original M4 and of the A2, A3, A4, A5 and A6 was of welded construction, the M4A1 had a cast hull, which tended to make the interior rather cramped. Similarly, although the Wright Continental was fitted into the M4 and the M4A1, there were also other engine configurations: twin GM 6-71 diesel engines, each of 13,930cc, with a combined power output of 410bhp, were fitted to the M4A2; a 500bhp Ford V8 GAA petrol engine of 18,026cc was used in the M4A3; the Chrysler WC multi-bank unit, incorporating five six-cylinder blocks disposed around a single crankcase to give 425bhp from 20,533cc, was fitted into the M4A4; and a 450bhp Caterpillar RD-1820 radial diesel was installed in the M4A6.

The suspension, initially employing vertical volute springs, was redesigned, with the springs placed horizontally. This horizontal volute spring suspension (HVSS) resulted in an improved ride and extended the life of the suspension units. It also meant that the suspension was better able to accommodate the increasing weight of later vehicle designs.

Compared to other tank designs of the period, the M4 presented a rather high profile, with a maximum height of 117in, although this was a considerable improvement on the M3 Lee/Grant. The hull was 232–288in long, according to the variant, and 103–106in wide, with the later horizontal volute spring suspension increasing this latter figure to 120in. The maximum thickness of armour was 75mm on the turret and 50–62mm on the hull, again depending on the variant, giving an all-up battle weight in the order of 29.7 to 32.5 tons. Maximum speed was in the order of 24–29mph on the road and 15–20mph across country, although it was a bumpy ride and the tank also exhibited an unpleasant tendency to catch fire when hit, giving rise to its ‘Ronson’ nickname.

The most serious drawback of the Sherman was the main gun and, as the war progressed, it was increasingly outclassed. With the original 75mm M3 gun, the Sherman could not defeat either a Panther or a Tiger on equal terms. In 1944, the 75mm weapon was replaced by the 76mm M1 anti-tank gun. This offered some improvements in performance but the more powerful German guns could still penetrate the Sherman’s frontal armour, whilst the Sherman had little chance of defeating a Panther or a Tiger unless it could shoot it from the side or the rear, where the armour was thinner. When the British 17-pounder (76.2mm) gun was fitted into the Sherman Firefly in 1943/44, the M4 was finally almost a match for the heavier German tanks.

A total of 17,181 Shermans were supplied to Britain. The original M4 was designated Sherman I, whilst subsequent variants were identified as Sherman II through Sherman VII, with the Firefly being designated Sherman VC.

The M4 chassis was also used for the M7 105mm gun motor carriage, and was widely adapted by both the British and US armies to a wide range of specialised roles, including flame-thrower, armoured recovery vehicle, tank ‘dozer, rocket launcher and a range of mine-clearance devices.


The first examples of the M3 entered Britain in July 1941. Officially named General Stuart by the British Army, and simply referred to as the Stuart, it saw its first action in Libya in November 1941. (IWM, H17289)


The British Army referred to the petrol-engined version as Stuart I, whilst the diesel was Stuart II; both shared the same riveted form of construction. (Tank Museum)


In recognition of its excellent reliability and general ease of operation, the British crews dubbed the M3 ‘Honey’. This example wears sand skirts over the tracks. (Warehouse Collection)


The Lee/Grant was an ungainly machine, 123in high, which meant that it tended to stick out like the proverbial sore thumb–by contrast the German Panzer III was just 96in high. The designers were also well aware that the sponson-mounted gun was a compromise that would often require the tank to be manoeuvred into the right position to achieve the required aim. (Warehouse Collection)


The M3 first saw action at the Battle of Gazala in North Africa against Rommel on 27 May 1941. When the M3 was superseded by the M4 Sherman, British M3s were shipped to Burma and to Australia. The photograph shows the US Army’s M3 Lee with the commander’s cupola. (Warehouse Collection)


The major disadvantage of the Lee/Grant was its height, though the riveted hull of the early versions was also a drawback, since the rivets had a nasty habit of breaking loose under fire and ricocheting around the crew compartment–but this was equally true of many contemporary British tanks. (Warehouse Collection)


The British version, known as the Grant, was fitted with a larger cast turret, lacking the cupola but designed to accommodate a Number 19 radio set in a bustle. (Tank Museum)


External rear stowage diagram for the British Grant. (Warehouse Collection)


A total of 6,258 M3 tanks were produced, most of them (4,924) of the original M3 pattern. Of these, 2,855 were supplied to the British Army, and 1,368 went to the Soviet Union. (IWM, H21027)


Stowage diagram for the Grant fighting compartment. (Warehouse Collection)


The M3 was never intended to be anything more than a compromise, whilst the designers tried to find a way to mount the 75mm gun in a proper revolving turret. (Warehouse Collection)


Despite its shortcomings, the M3 went into production at the Detroit Tank Arsenal, and at the American Locomotive Company (ALCO) and the Baldwin Locomotive Works during April 1941 just three weeks after the final drawings were produced. Tanks intended for Britain were produced by Baldwin Locomotive Works, as well as by Pressed Steel, Pullman Standard, and Lima Locomotive Works. (Warehouse Collection)


The detailed design characteristics for the M4 Sherman had been prepared by the US Army Ordnance Department by the end of August 1940 with the intention of producing a fast, dependable tank that would improve on the stop-gap M3, and which would be capable of defeating any of the Axis tanks–effectively meaning the later incarnations of the Panzer III. (Warehouse Collection)


During the conflict, US factories produced a total of almost 50,000 Shermans, compared to a grand total of 48,456 German tanks of all types produced during 1939–45. (Warehouse Collection)


The Sherman driving compartment. (Warehouse Collection)


This unusual low-level view shows the cast hull and the massive three-piece bolted nose of the M4A4. (Warehouse Collection)


British tank crew in Normandy effecting repairs to a Sherman which has been damaged by a German 88mm shell. (IWM, B5423)


M4, M4A1 and M4A5 Shermans were all fitted with a Wright or Continental radial engine. This example belongs to the US Army. (Tank Museum)


Late production M4A2 with one-piece cast nose and M34A1 mount for the 75mm gun. (Warehouse Collection)


It was not until the British quick-firing 17-pounder (76.2mm) was fitted into the Sherman Firefly in 1943/44 that the M4 was able to take on the heavier German tanks on a more equal basis. (Warehouse Collection)


The Sherman was certainly the most significant tank operated by the British Army and saw more widespread use than any of the comparable British designs during the conflict. This is the Firefly VC. (Tank Museum)


Simultaneous facing and drilling of the cast turret for the M4 at the Detroit Tank Arsenal. (Warehouse Collection)


The M4A2 was fitted with twin GM 6-71 diesel engines, and most vehicles were supplied for Lend-Lease. (Warehouse Collection)


Produced by the Dunlop Rubber Company and RFD of Godalming, this inflatable dummy Sherman tank was designed to deceive enemy aircraft regarding the numbers and deployment of Allied tanks. (IWM, H42532)

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