“A stopgap solution meant to counter German armour until more advanced designs could be fielded.”

THE M3 Lee tank may not have been the most famous or beloved armoured vehicle of World War II, but it played a critical role during a time when the Allies desperately needed tanks.

Developed by the United States in the early years of the war, the M3 Lee was a stopgap solution meant to counter German armor until more advanced designs could be fielded.

Let’s dive into nine intriguing facts about this unique wartime workhorse.

A Rush Job

The M3, named after the Confederate general Robert E. Lee, was a product of wartime urgency.

In 1940, the Fall of France highlighted the Allies’ desperate need for tanks capable of defeating the heavily armoured German Panzer divisions. The United States, still ramping up its industrial war effort, needed a design that could be quickly produced.

The result was the M3, a tank that combined an older 37mm gun in a rotating turret with a more powerful 75mm gun mounted in a fixed sponson. This arrangement was unusual but allowed for faster production since it utilized existing manufacturing capabilities.

Packed Like Sardines

The M3 Lee wasn’t just unusual in design; it was also remarkable for its large crew. A full complement included seven men, each assigned to specific tasks:

• A commander in the turret.
• A gunner and loader for the 37mm gun.
• A driver in the front hull.
• A co-driver/radio operator seated next to the driver.
• Two additional crew members to man the 75mm gun in the sponson, one as a gunner and the other as a loader.

This crowded arrangement made the interior cramped, but it ensured the tank’s complex weapon systems could be operated efficiently. However, coordination among the crew was challenging, especially in the heat of battle.

Rolling Powerhouse

The M3 Lee was well-armed for its time. Its main weapon was the 75mm M2/M3 gun, mounted in a fixed sponson on the right side of the hull. This gun provided excellent firepower against enemy fortifications and lightly armoured vehicles but struggled against later German tanks like the Panther or Tiger. It could however only traverse 15 degrees in either direction. This limitation required the entire tank to be maneuvered to aim at targets outside of this narrow field of fire.

The secondary 37mm gun in the rotating turret allowed the Lee to engage faster-moving or more lightly armoured targets. Additionally, the tank was equipped with up to four M1919 Browning machine guns for anti-infantry defence.

The M3 Lee was powered by a Continental R975 radial engine, an air-cooled aircraft engine repurposed for tank use. This engine delivered 400 horsepower, giving the tank a top speed of about 26 miles per hour (42 km/h) on roads and slightly less off-road.

It had a range of 120 miles (190 km), which was respectable for its size, and its suspension system provided decent mobility over rough terrain. However, at 31 tons, the M3 Lee was cumbersome and often struggled to keep up with lighter, faster vehicles in fluid battlefield conditions.

Armour: Behind the Curve

While the M3 Lee offered significant firepower early in the war, it quickly became outdated, particularly when matched against more advanced German tanks like the Panzer IV.

One of the most glaring drawbacks of the M3 was its high silhouette, standing about 10 feet (3 meters) tall. This made the tank an easy target for enemy gunners, especially in open terrain like the deserts of North Africa.

The M3’s armour ranged in thickness from 13 mm to 51 mm (0.5–2 inches), depending on the section. This was enough to stop smaller-caliber rounds and protect against light machine-gun fire, but was largely ineffective against high-velocity weapons like the German 50 mm KwK 38 and 75 mm Pak 40 anti-tank guns. Vulnerable spots included the side and rear armor, which were thinner and often targeted by enemy flanking maneuvers.

What’s more, the M3’s armour was predominantly flat and vertical, which reduced its ability to deflect incoming rounds. Tanks like the Soviet T-34 used sloped armour to maximize effective thickness and increase the chance of deflecting enemy projectiles. The M3’s vertical plates were more likely to absorb the full impact of a shell, making it vulnerable to German anti-tank weapons. It was a drawback that became even more fatal as enemy firepower advanced.

Britain’s M3 “Grant”

The export version of the M3, known as the Grant, was a modified variant tailored to meet the specific needs of the British Army. Named after Union General Ulysses S. Grant, it differed from the American Lee in a several ways.

One of the most notable differences was the redesigned turret. The Grant featured a lower-profile turret that removed the commander’s cupola found on the Lee. This modification made the Grant less conspicuous on the battlefield, reducing its already significant silhouette. Additionally, the Grant’s turret was more spacious, allowing the radio equipment—critical for British armoured warfare doctrine—to be housed within the turret itself. In contrast, the Lee had its radio mounted in the hull, complicating communication for the tank commander during combat.

The Grant also differed in terms of internal crew layout and roles. While both tanks shared the awkward arrangement of a sponson-mounted 75 mm gun and a smaller turret-mounted 37 mm gun, the British configuration emphasized efficiency. This was partly due to the British doctrine of dividing responsibilities among crew members and partly a result of the turret modifications.

Despite these adjustments, the tank retained many of the fundamental design challenges of the original M3, such as the limited traverse of the 75 mm gun and the vulnerability of its high profile. In fact, British tank crews dubbed the Grant the “Queen Mary” after the giant ocean liner.

Combat Record

The M3 Lee saw extensive action in the North African Campaign, where it was first introduced in 1942.

Ironically, it would be the British Grants that would first see action during the Battle of Gazala in May as well as the pivotal Second Battle of El Alamein later in 1942. The 75mm gun proved valuable against German fortifications, and the tank’s reliability in harsh desert conditions was an asset.

American Lee tanks saw their first combat with U.S. forces during the North African Campaign in late 1942, notably during the Battle of Kasserine Pass and subsequent engagements. While their powerful 75 mm gun proved effective against German Panzer III and Panzer IV tanks at long range, their high silhouette and fixed sponson-mounted main gun made them vulnerable in close-quarters fighting and less versatile compared to German designs. The Lee’s thin side armour and lack of sloped protection further exposed it to flanking maneuvers and anti-tank weapons.

Service Across the World

Beyond North Africa, the M3 Lee was deployed in various theatres, including the Pacific, where it served in the jungle campaigns of Burma. The tank also saw service with the Soviet Red Army under the Lend-Lease program, though its performance on the Eastern Front was lacklustre against heavily armoured German tanks.

In total, over 6,000 M3 Lees were produced, with many variants tailored to specific battlefield needs. The tank’s wide distribution reflected its importance as a stopgap solution during a critical period of the war.

Replaced

Though the M3 performed adequately, its limitations highlighted the need for the more advanced and versatile tanks like M4 Sherman, which began to replace the Lee in frontline roles by mid-1943. The Sherman corrected many of the Lee’s flaws, featuring a fully rotating turret with a 75mm gun, sloped armour, and a lower profile.

Despite its relatively short service life, the M3 Lee played a crucial role during the early years of the war. Its impact extended beyond its battlefield contributions, as it paved the way for the development of more effective Allied armour.