M3 Lee: America’s Interim Medium Tank

1. Lead

The M3 Lee, known to the British as the Lee and the Grant, was the United States Army’s first mass-produced medium tank of the Second World War, an interim design that mounted a 75 mm gun in the hull and a 37 mm gun in the turret.

Introduced in 1941, the M3 was built because the American Army needed a tank with a 75 mm gun urgently, and because it did not yet have the industrial capacity to build a turret large enough to house the gun. The solution was to mount the 75 mm in a sponson on the right side of the hull, with a smaller 37 mm gun in the turret above.

Approximately 6,258 M3s were built, and the tank served with American, British and Soviet forces in North Africa, the Soviet Union, Burma and the Pacific. The M3’s 75 mm gun was a significant improvement over the 37 mm gun of earlier American tanks, and it gave Allied forces a weapon that could defeat the German Panzer III and Panzer IV in 1942.

The M3 was an interim tank in every sense: it was designed to fill a gap until the M4 Sherman, with its 75 mm gun in a fully traversing turret, was ready, and it was withdrawn from front-line service as soon as the Sherman became available in large numbers. Yet the M3’s service was significant.

In North Africa, the M3’s 75 mm gun was the first Allied tank gun that could defeat German armour at long range, and British crews valued the tank’s reliability and its firepower. In the Soviet Union, the M3 served on the Eastern Front, where Soviet crews nicknamed it the “coffin for seven brothers” for its height and its thin armour, but also valued its 75 mm gun.

In Burma, the M3 served with British and Indian forces, where its 75 mm gun was effective against Japanese fortifications. The M3’s high silhouette and its sponson-mounted gun were disadvantages, but the tank’s availability and its firepower made it a useful weapon in 1942, when the Allies needed tanks urgently.

The M3 is remembered today as a symbol of American industrial mobilisation and as the bridge between the light tanks of the 1930s and the Sherman, the great American tank of the war. Museums in the United States, Britain, Russia and Australia preserve examples, and the M3 remains a popular subject for modellers and historians.

For historians of armoured warfare, the M3 illustrates how an interim design, built to meet an urgent need, can shape the course of a war, and how the limitations of a stopgap vehicle can drive the development of its successor.

The M3’s service, from 1941 to 1945, and its production in large numbers, make it one of the most important American tanks of the Second World War, despite its brief front-line career.

2. Key Facts

Field	Value
Type	Medium tank
Origin	United States
Designed	1940–1941
In service	1941–1945 (front line to 1943; secondary roles to 1945)
Produced	Approximately 6,258 (Lee and Grant)
Manufacturers	Detroit Arsenal, American Locomotive, Baldwin Locomotive, Pullman, Pressed Steel Car
Crew	6–7 (Lee 7; Grant 6)
Weight	Approximately 27–28 tons
Length	Approximately 5.64 m (18 ft 6 in)
Width	Approximately 2.72 m (8 ft 11 in)
Height	Approximately 3.12 m (10 ft 3 in)
Armour	12–51 mm
Main armament	75 mm Gun M2/M3 (hull sponson); 37 mm Gun M5/M6 (turret)
Secondary armament	.30 calibre machine guns (hull, turret, cupola)
Engine	Continental R975 radial petrol, 340–400 hp
Speed	Approximately 42 km/h (26 mph) maximum on roads
Range	Approximately 190 km (120 miles) on roads
Notable variants	M3 Lee, M3 Grant, M3A1–M3A5, M7 Priest (based on M3 chassis)

3. Background and Development

An Interim Tank for an Emergency

The M3 was conceived as an interim tank, a temporary solution to an urgent problem. In 1940, after the fall of France, the United States Army recognised that its tanks, armed with 37 mm guns, were inadequate against German armour, and that it needed a tank with a 75 mm gun.

The Army’s Ordnance Department considered mounting the 75 mm gun in a turret, but American industry did not yet have the capacity to build a turret large enough, with a turret ring wide enough, to house the gun. The solution, proposed by the Ordnance Department, was to mount the 75 mm gun in a sponson on the side of the hull, as the French Char B1 had done, with a smaller 37 mm gun in the turret.

The design was accepted as an interim measure, with the understanding that a fully turreted 75 mm tank, which became the M4 Sherman, would follow. The M3 was ordered into production in 1940, and the first vehicles were delivered in 1941.

The M3’s interim nature shaped its design and its service. The tank was built quickly, using the chassis and components of the earlier M2 medium tank, and its production was shared between several firms, including the Detroit Arsenal, which had been built specifically for tank production.

The M3’s design was a compromise, and its limitations, particularly its high silhouette and its limited traverse for the 75 mm gun, were well understood. Yet the tank’s availability made it indispensable: in 1941 and 1942, the M3 was the only American tank with a 75 mm gun, and it was the only tank that could be supplied to Britain and the Soviet Union in large numbers.

The M3’s interim status did not prevent it from serving effectively, and its production was a key part of American industrial mobilisation.

From the T5 to the M3

The M3’s development began with the T5 medium tank, a prototype built in the late 1930s, which had a 37 mm gun in the turret and a hull-mounted machine gun. The T5 was developed into the M2 medium tank, which entered production in 1940, and the M2’s chassis became the basis for the M3.

The M3’s design retained the M2’s hull, suspension and engine, but added the sponson-mounted 75 mm gun and a larger turret for the 37 mm gun. The first prototype, the T5E2, was tested in 1940, and it was accepted for service as the M3 in 1941. The M3’s development was rapid, reflecting the urgency of the situation, and the tank entered production only months after its design was finalised.

The M3’s development from the T5 and M2 shows the evolutionary nature of American tank design in this period, in which each vehicle built on its predecessor, and in which the pressure of war accelerated the pace of development.

The M3’s development was also influenced by British requirements, as the British Purchasing Commission in the United States requested a version of the tank with a larger turret and no commander’s cupola, which became the Grant. The British version, named after the American general Ulysses S. Grant, had a lower silhouette and a more spacious turret, and it was preferred by British crews.

The American version was named the Lee, after the Confederate general Robert E. Lee, in accordance with the British practice of naming American tanks after Civil War generals. The M3’s development, with its two versions, reflected the close cooperation between the United States and Britain in tank production, and the British influence on the tank’s design was significant.

The Lee and Grant were functionally similar, but their differences in turret design were important to their crews.

Why the 75mm Went in the Hull

The decision to mount the 75 mm gun in the hull sponson, rather than in the turret, was a consequence of American industry’s limitations in 1940. The turret ring of the M2 medium tank was too small to accommodate a 75 mm gun, and enlarging it would have required a redesign of the hull and a new production line, which would have taken a year or more.

The Army needed a 75 mm tank urgently, and the sponson mounting allowed the gun to be fitted without redesigning the hull. The sponson gun had a limited traverse, approximately 15 degrees to either side, which meant that the tank had to be turned to aim the gun, and its elevation was also limited.

The sponson mounting was a compromise, and it was understood to be temporary, until the M4 Sherman’s turret could be built. The decision reflected the Army’s priorities: a tank with a 75 mm gun, even in a sponson, was better than no tank at all, and the M3’s availability justified its design.

Production at Detroit and Elsewhere

The M3 was produced at the Detroit Arsenal, the American Locomotive Company, the Baldwin Locomotive Works, the Pullman Company and the Pressed Steel Car Company, with a total production of approximately 6,258 vehicles. The Detroit Arsenal, built in 1940 specifically for tank production, was the largest producer, and its assembly line was a model of American industrial efficiency.

Production began in 1941, and the first M3s were delivered to the Army in the summer of that year. The production run was large, reflecting the Army’s commitment to the M3 as an interim tank, and the vehicle’s production was shared between the firms to maximise output.

The M3’s production was a success, and the tank was available in large numbers for the campaigns of 1942, when it was needed most. The production programme was coordinated by the Ordnance Department, which set standards for quality and interchangeability.

The M3’s production was also a key part of Lend-Lease, as large numbers of M3s were supplied to Britain and the Soviet Union. Britain received approximately 2,855 M3s, and the Soviet Union received approximately 1,386, under the Lend-Lease programme. The production for Lend-Lease was a significant part of the M3’s total, and it reflected the American commitment to supplying its allies with tanks.

The M3’s production ended in 1942, when the M4 Sherman entered production, and the Detroit Arsenal and other firms switched to building the Sherman. The M3’s production run, though brief, was one of the largest of any American tank up to that point, and it demonstrated the capacity of American industry to build tanks in quantity.

The M3’s production was a key factor in the Allied victory in North Africa in 1942.

4. Design

The Sponson 75mm and Turret 37mm

The M3’s armament was its most distinctive feature: a 75 mm Gun M2 or M3 mounted in a sponson on the right side of the hull, and a 37 mm Gun M5 or M6 mounted in the turret, with a coaxial .30 calibre machine gun. The 75 mm gun fired high-explosive and armour-piercing shells, and it was effective against the Panzer III and Panzer IV at normal combat ranges.

The gun’s traverse was limited to about 15 degrees, and the tank had to be turned to aim it, which was a significant disadvantage in combat. The 37 mm gun in the turret could traverse through 360 degrees, and it was used against light tanks, armoured cars and infantry.

The combination of the two guns gave the M3 a useful armament, but it also complicated the crew’s work, because the two guns had to be aimed independently, and the tank’s commander had to coordinate their fire. The M3’s armament was a compromise, and it reflected the tank’s interim nature.

The 75 mm gun’s performance was the M3’s greatest strength. The gun’s high-explosive shell was effective against infantry and fortifications, and its armour-piercing shell could penetrate the Panzer III and Panzer IV at ranges of up to 1,000 yards. The gun’s introduction in North Africa in 1942 was a significant moment, because it was the first Allied tank gun that could defeat German armour at long range.

The 37 mm gun, while less powerful, was useful against lighter targets, and its high rate of fire made it effective against infantry. The M3’s two guns, however, required a large crew, and the tank’s commander had to manage both weapons, which was a heavy workload.

The M3’s armament was a product of its interim design, and it was superseded by the Sherman’s single 75 mm gun in a fully traversing turret.

The High Silhouette Problem

The M3’s high silhouette, at approximately 3.12 metres, was its most serious design flaw, and it made the tank a conspicuous target. The height was a consequence of the sponson-mounted 75 mm gun, which required a tall hull, and of the turret mounted on top of the hull, which added further height. The M3’s height made it difficult to conceal, and German anti-tank gunners could spot it at long range.

The tank’s height also made it top-heavy, and its centre of gravity was high, which affected its stability on slopes. Soviet crews, who received the M3 under Lend-Lease, nicknamed it the “coffin for seven brothers”, a reference to its height, its thin armour, and its seven-man crew.

The high silhouette was a well-known disadvantage, and it was one of the reasons the M3 was replaced by the Sherman, which was lower and more compact. The M3’s height was the price of its sponson gun, and it was a reminder of the compromises inherent in an interim design.

Armour, Engine and Mobility

The M3’s armour was 12 to 51 mm thick, with the thickest plates on the front of the hull and turret. The armour was riveted, which meant that hits could drive rivets into the crew compartment, a danger known as spalling, and later production used welded armour to reduce this risk.

The M3’s armour was adequate against the 37 mm and 50 mm anti-tank guns of 1941, but it was vulnerable to the 75 mm and 88 mm guns that appeared in 1942. The tank’s engine, a Continental R975 radial petrol engine producing 340 to 400 horsepower, gave it a top speed of approximately 42 kilometres per hour on roads, and a range of approximately 190 kilometres.

The M3’s mobility was good, and its speed and reliability made it suitable for the desert warfare of North Africa. The tank’s suspension, with its vertical volute spring bogies, was the same as the Sherman’s, and it provided a stable ride.

The M3’s engine and transmission were reliable, and the tank’s mechanical soundness was one of the reasons it was valued by British crews in North Africa. The Continental radial engine was accessible for maintenance, and the tank’s parts were standardised, which simplified supply. The M3’s mobility, however, was limited by its height and its weight, which made it less agile than the Sherman.

The tank’s armour, while adequate in 1941, became obsolete as German guns became more powerful, and the M3’s vulnerability increased. The M3’s design reflected a trade-off between firepower, protection and mobility, and its service showed that firepower alone was not enough when the tank’s height and armour made it vulnerable.

The M3’s armour and mobility were adequate for its intended role as an interim tank, but they were insufficient for the long term.

The Seven-Man Crew

The M3 Lee carried a crew of seven: the commander, the 37 mm gunner, the 37 mm loader, the 75 mm gunner, the 75 mm loader, the driver, and the radio operator. The Grant carried a crew of six, because it had no commander’s cupola and its radio operator also served as a loader.

The large crew was a consequence of the M3’s two guns, each of which required a gunner and a loader, and of the need for a dedicated radio operator. The crew’s size made the tank crowded, and the internal layout was cramped, particularly in the turret, where the commander, gunner and loader worked in close quarters.

The 75 mm gun’s crew, in the hull, had more room, but their position was low and their visibility was limited. The M3’s crew was the largest of any American tank of the war, and its size reflected the complexity of operating two guns.

The seven-man crew was a significant burden, because it required more men to be trained and supplied, and because the loss of a tank meant the loss of seven men. The crew’s coordination was essential, because the two guns had to be aimed independently, and the commander had to direct both. The M3’s crew worked as a team, and the tank’s effectiveness depended on their training and discipline.

The large crew was also an advantage, because it allowed the tank to maintain a high rate of fire, with dedicated loaders for each gun, and because it provided redundancy if a crew member was wounded. The M3’s crew size was a product of its interim design, and it was reduced to five in the Sherman, which had a single gun and a more efficient layout.

The M3’s seven-man crew is a reminder of the complexity of the interim design, and of the burden it placed on its crews.

5. Variants

M3 Lee and M3 Grant

The M3 was produced in two main versions, the Lee and the Grant, which differed in their turrets. The Lee, the American version, had a small turret with a commander’s cupola on top, and a crew of seven. The Grant, the British version, had a larger turret, designed by the British, with no cupola, and a crew of six.

The Grant’s turret was lower and more spacious, and it was preferred by British crews, who found the Lee’s cupola to be a weak point and a source of discomfort. The Lee and Grant were functionally similar, with the same 75 mm sponson gun and 37 mm turret gun, but their turret differences were important to their crews.

The Grant was produced in larger numbers for Britain, with approximately 1,534 built, while the Lee was produced for the American Army, with approximately 4,724 built. The two versions served alongside each other in North Africa, where British units used both, and their crews’ preferences were a matter of debate.

The Lee and Grant’s differences reflected the different requirements of the American and British armies. The American Army wanted a commander’s cupola, which gave the commander a good view, while the British Army wanted a lower silhouette and a more spacious turret. The Grant’s turret, with its larger size, allowed the gunner and loader more room, and its lack of a cupola reduced the tank’s height slightly.

The Lee’s cupola, while giving the commander a good view, was a prominent target and was vulnerable to fire. The two versions’ service in North Africa showed that both were effective, and that the differences were a matter of preference rather than of capability.

The Lee and Grant remain the best-known variants of the M3, and their names, after Civil War generals, are a reminder of the British practice of naming American tanks.

Later Production and Improvements

Later production of the M3 included the M3A1 to M3A5 variants, which incorporated improvements to the armour, the engine, and the turret. The M3A1 had a cast upper hull, the M3A2 had a welded hull, the M3A3 had a different engine and a modified hull, the M3A4 had a different engine, and the M3A5 had a riveted hull with a different engine.

These variants were produced in smaller numbers than the original M3, and they reflected the Army’s efforts to improve the tank’s production and its performance. The improvements were modest, and they did not address the M3’s fundamental limitations, its high silhouette and its sponson gun.

The later variants’ production was a consequence of the M3’s continued use, even as the Sherman entered production, and they ensured that the tank remained available for Lend-Lease and for secondary roles. The M3A1 to M3A5 variants are a footnote to the M3’s history, but they show the tank’s evolution in its final years of production.

The later variants’ improvements included welded armour, which reduced spalling, and more powerful engines, which improved the tank’s mobility. The M3A3, with its General Motors diesel engine, was used by the British, who preferred diesel for its lower flammability. The M3A5, with its riveted hull and Continental engine, was the last production version, and it served in North Africa and in the Soviet Union.

The later variants’ service was similar to that of the original M3, and their crews found little difference between them. The improvements were incremental, and they did not change the tank’s fundamental design. The M3’s later variants demonstrate the Army’s willingness to refine a proven design, even as it was being replaced, and they ensured that the M3 remained a useful tank in 1942 and 1943.

The M3 as a Basis: The M7 Priest and Kangaroo

The M3’s chassis was used as the basis for the M7 Priest self-propelled howitzer, which mounted the M2 105 mm howitzer on the M3 chassis, and for the Kangaroo armoured personnel carrier, which was a converted M3 with its turret removed. The M7 Priest, introduced in 1942, became the standard self-propelled howitzer of the American armoured divisions, and it served in North Africa, Italy and North-West Europe.

The Kangaroo, developed by the Canadians in 1944, was used to carry infantry in Normandy, and it demonstrated the M3 chassis’s adaptability to new roles. The M3’s chassis was also used for the M31 armoured recovery vehicle and for other specialised vehicles.

The chassis’s reuse was a testament to its reliability and to the soundness of its design, and it ensured that the M3’s production lines remained busy after the gun tank itself had been replaced. The M3’s legacy as a chassis was more important than its service as a gun tank, and it is a key part of the vehicle’s history.

Special Variants

The M3 was also produced in a number of special variants, including the M3 with a mine roller, the M3 with a flamethrower, and the M3 as a command tank. These variants were produced in small numbers, and they were used in secondary roles, including training and engineering. The M3’s special variants reflected the vehicle’s adaptability and the Army’s willingness to use a reliable chassis for new purposes.

The mine roller variant was used to clear mines in North Africa, and the flamethrower variant was tested but did not enter large-scale service. The command tank variant, with additional radio equipment, was used by armoured unit commanders who needed better communications. The M3’s special variants were limited in number, but they demonstrated the vehicle’s versatility and the Army’s ingenuity in adapting a proven design.

The special variants are a reminder that the M3’s chassis was more valuable than its gun tank configuration, and that its reuse extended the type’s service life.

The M3’s special variants also included the Grant CDL, a canal defence light, which mounted a powerful searchlight in the turret and was intended to illuminate the battlefield at night. The CDL was produced in small numbers and was used in North-West Europe, although its effectiveness was limited.

The M3’s variants, taken together, show a vehicle that was adaptable and that served in a variety of roles, although its primary role remained that of a medium tank. The special variants’ service was limited, but they are a testament to the M3’s design and to the Army’s willingness to experiment.

The M3’s variants, from the Lee and Grant to the Priest and Kangaroo, demonstrate the vehicle’s importance to the Allied war effort, beyond its service as a gun tank.

6. Operational History

Gazala and El Alamein

The M3’s combat debut came in North Africa, at the Battle of Gazala in May 1942, where British M3 Grants first engaged German armour. The M3’s 75 mm gun proved effective against the Panzer III and Panzer IV, and its high-explosive shell was valued against German infantry and anti-tank guns.

The M3’s debut at Gazala was promising, although the battle itself was a British defeat, and the M3’s high silhouette and thin armour made it vulnerable to German 88 mm guns. The M3’s service at El Alamein in October 1942 was more successful, as the tank’s 75 mm gun supported the British infantry in the breakthrough, and its reliability in the desert was valued.

The M3’s North African service was the tank’s most important combat role, and it established the vehicle’s reputation. The British Eighth Army’s use of the M3 at Gazala and El Alamein demonstrated the tank’s value, and its 75 mm gun was a significant improvement over the 2-pounder gun of earlier British tanks.

The M3’s North African service continued through the Tunisian campaign, where American M3 Lees first saw combat with the United States Army in November 1942. The American M3s served at Kasserine Pass and in the final advance on Tunis, where their 75 mm guns were effective against German armour.

The M3’s service in Tunisia was the American Army’s first tank combat of the war, and it provided valuable experience for the crews who would later fight in Shermans. The M3’s North African service was the tank’s finest hour, and it demonstrated that an interim design could perform effectively when used well.

The vehicle’s reliability in the desert, and its 75 mm gun’s power, made it a valued tank in 1942, when the Allies needed every tank they could get.

The M3 against the Panzer IV

The M3’s engagements with the German Panzer IV in North Africa were among the most important of its service. The Panzer IV, with its 75 mm gun, was the most capable German tank in North Africa in 1942, and the M3’s 75 mm gun could match it at normal combat ranges.

The M3’s high-explosive shell was effective against the Panzer IV’s armour, and the tank’s crews learned to engage German tanks at long range, where the 75 mm gun’s accuracy was an advantage. The Panzer IV’s later versions, with longer 75 mm guns, outmatched the M3, but in 1942 the two tanks were evenly matched.

The M3’s encounters with the Panzer IV demonstrated the value of the 75 mm gun, and they showed that the Allies had finally produced a tank that could fight the Germans on equal terms. The M3’s service against the Panzer IV was a turning point in the North African campaign, and it gave Allied tank crews confidence in their equipment.

The Soviet Union and Lend-Lease

The Soviet Union received approximately 1,386 M3s under Lend-Lease, and used them on the Eastern Front in 1942–1943. Soviet crews nicknamed the M3 the “coffin for seven brothers”, a reference to its height, its thin armour, and its seven-man crew, and they found the tank vulnerable to German anti-tank guns.

The M3’s 75 mm gun, however, was valued, and the tank served in the fighting around Moscow, Stalingrad and Kursk, where it was used in secondary roles and in training. The Soviet M3s were used in tank brigades, alongside the T-34, and their service was limited by the availability of spare parts and by the tank’s vulnerability.

The M3’s Soviet service was the tank’s least successful, because the Eastern Front’s conditions, with its long ranges and powerful German guns, exposed the M3’s weaknesses. The Soviet Union’s use of the M3 was a consequence of Lend-Lease, and the tank’s service there was a reminder of the Allies’ need for tanks in 1942.

The M3’s Lend-Lease service also included its supply to Britain, which received approximately 2,855 M3s, and used them in North Africa, Italy and Burma. The British M3s, mostly Grants, served with distinction in North Africa, and their 75 mm guns were a significant improvement over earlier British tanks.

The Lend-Lease programme’s supply of M3s to Britain and the Soviet Union was a key part of the Allied war effort, and it demonstrated American industrial power. The M3’s Lend-Lease service was extensive, and the tank’s distribution to three armies ensured that it would be remembered as an international vehicle.

The Soviet experience with the M3, though negative, was a valuable lesson in the limitations of the interim design, and it influenced Soviet tank development.

Burma and the Pacific

In Burma, the M3 served with British and Indian forces, where its 75 mm gun was effective against Japanese fortifications and bunkers. The M3’s service in Burma began in 1942, and the tank was used in the Arakan and in the advance on Rangoon, where its high-explosive shell was valued against Japanese positions.

The M3’s height was less of a disadvantage in the jungle, where engagements were at short range, and its reliability in the heat and humidity was good. The tank’s service in Burma continued until 1945, and it was one of the longest of the M3’s career.

In the Pacific, the M3 served with American forces in limited numbers, where it was used against Japanese fortifications on islands, although its role there was secondary to that of the Sherman. The M3’s Burmese service was the tank’s most sustained, and it demonstrated the vehicle’s adaptability to jungle warfare.

The M3’s service in Burma and the Pacific was a testament to its reliability and to its 75 mm gun’s effectiveness against fortifications. The tank’s crews in Burma valued the 75 mm gun’s high-explosive shell, which could destroy Japanese bunkers that the 37 mm gun could not.

The M3’s service in these theatres was less well known than its North African service, but it was equally important, and it showed that the tank could serve effectively in different climates and against different enemies. The M3’s Burmese service continued after the tank had been withdrawn from front-line service in Europe, and it was a reminder of the vehicle’s longevity.

The tank’s service in Burma and the Pacific was the final chapter in its combat career, and it ended with the war in 1945.

7. Performance and Specifications

Strengths: The 75mm Gun

The M3’s greatest strength was its 75 mm gun, which was the first Allied tank gun that could defeat German armour at long range. The gun’s high-explosive shell was effective against infantry, fortifications and anti-tank guns, and its armour-piercing shell could penetrate the Panzer III and Panzer IV at ranges of up to 1,000 yards.

The M3’s 75 mm gun gave Allied tank crews confidence in 1942, when they had previously been outgunned by German tanks, and its introduction in North Africa was a significant moment in the campaign. The gun’s performance was the M3’s principal asset, and it was the reason the tank was valued by British crews, who had previously relied on the 2-pounder gun.

The M3’s 75 mm gun was a product of American industrial power, and its availability in large numbers was a key factor in the Allied victory in North Africa.

The M3’s strengths also included its reliability and its mobility. The tank’s Continental engine was reliable, and its speed, approximately 42 kilometres per hour, was adequate for the desert warfare of North Africa. The M3’s production in large numbers meant that it was available when needed, and its crews valued its mechanical soundness.

The tank’s strengths made it an effective interim vehicle, and its service in 1942 demonstrated that an interim design could perform well when used in its intended role. The M3’s 75 mm gun was its defining feature, and it is the reason the tank is remembered as a significant step in American tank development.

The gun’s performance, and the tank’s reliability, were the M3’s principal strengths, and they compensated, in part, for its high silhouette and thin armour.

Weaknesses: Height and the Sponson

The M3’s greatest weaknesses were its high silhouette and its sponson-mounted gun. The tank’s height, approximately 3.12 metres, made it a conspicuous target, and its sponson gun’s limited traverse meant that the tank had to be turned to aim the 75 mm gun. The M3’s armour, 12 to 51 mm, was vulnerable to the 75 mm and 88 mm guns, and its riveted construction risked spalling.

The tank’s seven-man crew was large, and its internal layout was cramped. The M3’s weaknesses were a consequence of its interim design, and they were well understood by the Army, which replaced the tank with the Sherman as soon as possible. The M3’s height and sponson gun were the price of its rapid production, and they ensured that the tank’s front-line career would be brief.

The weaknesses were significant, but they did not prevent the M3 from serving effectively in 1942, when the Allies needed a 75 mm tank urgently.

The M3’s weaknesses were also apparent in its ergonomics. The tank’s commander had to coordinate two guns, and the crew’s workload was heavy. The 75 mm gun’s position, low in the hull, gave its gunner a limited view, and the 37 mm gun’s turret was cramped. The M3’s height made it difficult to conceal, and its silhouette was a liability in open country.

The tank’s weaknesses were the reason it was withdrawn from front-line service in 1943, and the reason its chassis was reused for other roles. The M3’s weaknesses were fundamental, and they could not be fixed by minor improvements. The tank’s design was a compromise, and its service showed both the strengths and the weaknesses of that compromise.

The M3’s weaknesses are a key part of its history, and they explain why the tank was replaced so quickly.

M3 versus the Panzer III

The comparison between the M3 and the German Panzer III illustrates the different approaches to medium tank design in 1941–1942. The Panzer III, with its 50 mm gun, was more heavily armoured than the M3 in its later versions, and its fully traversing turret gave it an advantage in manoeuvre.

The M3, however, had a more powerful 75 mm gun, with a better high-explosive shell, and its armour, while thinner, was adequate against the Panzer III’s 50 mm gun at long range. The two tanks were evenly matched in 1942, and their encounters in North Africa were often decided by crew skill and by tactics rather than by the vehicles themselves.

The comparison shows that the M3’s 75 mm gun gave it an edge in firepower, while the Panzer III’s turret gave it an edge in manoeuvrability. The M3’s service against the Panzer III demonstrated the value of the 75 mm gun, and it showed that the Allies had closed the gap in tank design.

8. Operators

The United States

The principal operator of the M3 was the United States Army, which used the tank in North Africa and in training. The M3 served with American armoured divisions in Tunisia in 1942–1943, where it was the Army’s first medium tank in combat, and it was used in training in the United States for the rest of the war.

The M3’s American service was brief as a front-line tank, because the Sherman replaced it in 1943, but it was significant, because it gave American crews their first experience of tank combat. The M3’s American operators valued its 75 mm gun and its reliability, and the tank’s service in Tunisia provided valuable lessons for the Sherman’s crews.

The M3’s American service was the beginning of the Army’s medium tank programme, and the tank’s production and use were a key part of American industrial mobilisation. The M3 was withdrawn from American front-line service in 1943, but it remained in use for training and for secondary roles until 1945.

The M3’s American service also included its use as the basis for the M7 Priest, which served with American armoured divisions throughout the war. The tank’s chassis, reused for the Priest, ensured that the M3’s design remained in American service long after the gun tank had been withdrawn.

The M3’s American operators included the Army’s training establishments, where the tank was used to train crews for the Sherman, and the tank’s service in training was extensive. The M3’s American history is one of brief front-line service and long secondary service, and it is closely tied to the story of the Sherman’s development.

The tank’s American operators were the first to use the 75 mm gun in combat, and their experience shaped the Army’s tank doctrine.

Britain, the Soviet Union and Others

The M3 was also used by Britain, the Soviet Union, and other Allied armies. Britain received approximately 2,855 M3s, mostly Grants, and used them in North Africa, Italy and Burma, where they served with distinction. The Soviet Union received approximately 1,386 M3s, and used them on the Eastern Front, where their service was less successful.

Other users included Canada, Australia, New Zealand, and the Free French forces, which used the M3 in North Africa and in Europe. The M3’s foreign service was extensive, and the tank’s distribution to three major Allies ensured that it would be remembered as an international vehicle.

The British use of the M3 was the most successful, as the Grant’s 75 mm gun was a significant improvement over earlier British tanks, and the tank’s service at El Alamein was a key moment in the North African campaign. The M3’s foreign operators valued its availability and its firepower, and their service ensured the tank’s place in history.

The M3’s foreign service continued after the war, as the tank was used by the armies of several countries for training and for secondary roles. The British M3s were used in Burma until 1945, and the Soviet M3s were used in training until the end of the war. The M3’s distribution under Lend-Lease was a key part of the Allied war effort, and it demonstrated American industrial power.

The tank’s foreign operators were an important part of its history, and their service, particularly in North Africa and Burma, was the M3’s most significant combat role. The M3’s global service is a measure of its importance, and it ensured that the vehicle would be preserved in museums in Britain, Russia and Australia.

9. Legacy and Influence

The Bridge to the Sherman

The M3’s most important legacy was as the bridge to the Sherman, the great American tank of the Second World War. The M3’s production gave American industry the experience it needed to build the Sherman, and the M3’s 75 mm gun, its engine, and its suspension were all carried over to the Sherman.

The M3’s service in North Africa demonstrated the value of the 75 mm gun, and its limitations, particularly its high silhouette and its sponson mounting, drove the development of the Sherman’s fully traversing turret. The M3 was an interim tank, but its production and service were essential to the Sherman’s success, and without the M3, the Sherman would not have been ready in 1942.

The M3’s legacy as the bridge to the Sherman is its most significant contribution, and it is the reason the tank is remembered as more than a stopgap. The M3’s production lines, its factories, and its crews all contributed to the Sherman programme, and the tank’s history is inseparable from that of its successor.

The M3’s legacy as a bridge was also industrial. The Detroit Arsenal, built for M3 production, became the Sherman’s main factory, and the firms that built the M3, including American Locomotive and Baldwin, also built the Sherman. The M3’s production methods, including the assembly line and the standardisation of parts, were applied to the Sherman, and the M3’s supply chain was the basis for the Sherman’s.

The M3’s legacy in industry was as important as its legacy in design, and it ensured that the Sherman could be produced in the large numbers needed for the Allied war effort. The M3’s role as a bridge, in both design and production, is the tank’s most enduring contribution, and it is the reason historians regard the M3 as a key vehicle in American tank development.

The M3 in Memory

The M3 is remembered today as a symbol of American industrial mobilisation and as the tank that gave the Allies a 75 mm gun in 1942. The vehicle’s distinctive profile, with its high silhouette and its sponson gun, is instantly recognisable, and it is a popular subject for modellers and historians.

The M3’s reputation among veterans was mixed: British crews valued its 75 mm gun and its reliability, while Soviet crews criticised its height and its thin armour. The tank’s place in popular memory reflects its service in North Africa, where it fought at Gazala and El Alamein, and its role as the predecessor of the Sherman.

The M3 remains one of the best-known American tanks of the Second World War, and its history is closely tied to the story of the Allied victory in North Africa. The tank’s distinctive appearance has made it a favourite of filmmakers, and it has appeared in numerous films about the North African campaign.

The M3’s cultural legacy extends beyond museums and histories. The vehicle has appeared in films, in television programmes, and in video games about the Second World War, where it is often depicted in the desert warfare of North Africa. The M3’s name, Lee and Grant, after Civil War generals, has entered popular culture, and the tank is often cited as an example of American ingenuity in the face of industrial limitations.

The vehicle’s place in memory is a testament to its service and to its distinctive design, and it ensures that the M3 will continue to be studied and remembered. The M3’s legacy in memory is a reminder of the tank’s importance in 1942, when the Allies needed a 75 mm tank urgently, and of its role as the bridge to the Sherman.

Reassessing the Interim Tank

Historians have reassessed the M3 in recent decades, moving away from the view of it as a failure and recognising its importance as an interim tank and as the bridge to the Sherman. Early histories often dismissed the M3 as a flawed design, citing its high silhouette and its sponson gun.

Later work, drawing on British and American records, has shown that the M3 was effective in its intended role, and that its 75 mm gun was a significant improvement over earlier Allied tanks. The reassessment has not made the M3 into a great tank, but it has established its historical importance, and its role in the North African campaign.

The M3’s reassessment is part of a broader re-evaluation of American tank development, and it reflects the growing appreciation of the interim design’s contribution to the Allied victory. The M3’s place in history is now secure, as a necessary step in the development of the Sherman.

10. Surviving Examples

Museums in the United States

A significant number of M3s survive in museums in the United States, reflecting the vehicle’s large production run. The National Armor and Cavalry Museum at Fort Benning holds an M3 Lee, and the American Heritage Museum in Massachusetts displays an M3 in its collection. The National WWII Museum in New Orleans holds an M3, and the Patton Museum at Fort Knox displays the vehicle.

These museum examples are valuable because they show the M3’s high silhouette and its sponson-mounted 75 mm gun, which are difficult to appreciate from photographs. The Fort Benning example is particularly well preserved, and it is displayed alongside the Sherman, which allows visitors to compare the interim tank with its successor.

The museum examples in the United States are among the best-preserved in the world, and they are a testament to the tank’s historical significance.

The museum examples in the United States include vehicles that saw service in North Africa, and some that were used in training. The American Heritage Museum’s M3 was used in Tunisia, and the National WWII Museum’s example was used in the United States for training. These examples are a reminder of the M3’s long service and of its importance to the American Army.

The vehicles’ survival in museums ensures that future generations can see the tank that gave the Allies a 75 mm gun in 1942, and can appreciate its design and its construction. The M3’s American museum examples are a fitting legacy for a tank that served from 1941 to 1945, and they ensure that the vehicle’s place in history will not be forgotten.

Survivors Abroad and Running Examples

Other surviving M3s include examples at the Tank Museum at Bovington in Britain, which holds an M3 Grant, and at the Kubinka Tank Museum in Russia, which holds an M3 Lee received under Lend-Lease. The Australian War Memorial in Canberra holds an M3, and the Canadian War Museum in Ottawa displays the vehicle.

Several M3s are in private hands, and at least one is maintained in running condition, appearing at military vehicle shows in the United States and Britain. The running examples are particularly valuable, because they demonstrate the M3’s mobility and its distinctive engine note, and they allow visitors to appreciate the cramped conditions in which its seven-man crew worked.

The M3’s survival in relatively large numbers reflects its production run and its distribution to many armies, and it ensures that future generations can see the tank that bridged the gap to the Sherman.

The surviving M3s abroad include Grants in Britain and Australia, and Lees in Russia and Canada, reflecting the tank’s distribution under Lend-Lease. The Bovington Grant is one of the best-preserved examples, and it is displayed with its 75 mm sponson gun. The Kubinka Lee is a reminder of the tank’s Soviet service, and the Australian War Memorial’s M3 was used in Burma.

These examples are a testament to the M3’s global service, and they ensure that the vehicle will continue to be studied and appreciated around the world. The M3’s survival in museums and in running condition is a fitting legacy for an interim tank that served in North Africa, Russia and Burma, and that paved the way for the Sherman.

Frequently Asked Questions

Why did the M3 have two guns?
The M3 had a 75 mm gun in the hull sponson and a 37 mm gun in the turret because American industry could not yet build a turret large enough for the 75 mm gun. The sponson mounting was an interim solution until the Sherman’s turret was ready.

What is the difference between the Lee and the Grant?
The Lee was the American version, with a small turret and a commander’s cupola, and a crew of seven. The Grant was the British version, with a larger turret, no cupola, and a crew of six. Both had the same 75 mm sponson gun.

How many M3s were built?
Approximately 6,258 M3 Lees and Grants were built. Britain received about 2,855 and the Soviet Union about 1,386 under Lend-Lease. Production ended in 1942 when the Sherman entered production.

Why did Soviet crews call the M3 a coffin?
Soviet crews nicknamed the M3 the “coffin for seven brothers” because of its high silhouette, thin armour and seven-man crew. The tank was vulnerable to German anti-tank guns on the Eastern Front.

Was the M3 a good tank?
The M3 was effective in 1942, when its 75 mm gun was the best Allied tank gun available, but its high silhouette and sponson gun were serious disadvantages. It was an interim tank, replaced by the Sherman as soon as possible.

What replaced the M3?
The M3 was replaced by the M4 Sherman, which mounted the 75 mm gun in a fully traversing turret. The M3’s chassis was reused for the M7 Priest self-propelled howitzer and the Kangaroo personnel carrier.

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Sources

• Steven J. Zaloga, M3 Lee/Grant Medium Tank 1941–45 (Osprey Publishing, New Vanguard series).
• Peter Chamberlain and Chris Ellis, British and American Tanks of World War II (Arms and Armour Press).
• Bryan Perrett, The M3 Lee/Grant (Ian Allan).
• The Tank Museum, Bovington, M3 Grant collection records.
• National Armor and Cavalry Museum, Fort Benning, M3 Lee collection records.
• United States War Department, TM 9-750, Medium Tank M3 (wartime technical manual).
• Wikipedia, "M3 Lee"