|Opening Salvo: M3 Lee|
|by Michael J. Canavan, Sr|
Command Sergeant Major
US Army (retired)
Reports from the field in 1939 indicated that the 37 mm gun mounted on the US M2 tank was not powerful enough. Experiments began immediately to enable installation of a 75 mm pack howitzer on the M2 tank, resulting in the gun being mounted in a sponson on the right-hand side. M3 production began in August of 1941 and continued through December of 1942. The British Tank Commission arrived in the U.S. in 1940 with every intention of ordering British-designed tanks from American manufacturers, but the U.S. National Defense Advisory Committee rejected their proposal, forcing the British tank commission to choose the M3 medium tank.
M3 Lee/Grant Medium Tank
Initially, the M3 was equipped with a Continental R-975-EC2 nine-cylinder, air-cooled, radial gasoline engine. This engine was capable of 340 horsepower at 2,400 rpm. The M3 had a road speed of 26 mph, a cross-country speed of 16 mph, and a range of 120 miles. It could climb a 60 percent gradient, cross a 6 foot 3 inch trench, and surmount a 2 foot vertical obstacle. It had a seven-man crew with a loader and gunner for each main weapon, commander, driver, and radio operator. The driver eventually took over radio operator duties, reducing the crew to six.
War shortages and the need for improvements motivated various modifications during production. The M3 had a riveted hull, while the M3A1 used a cast hull. The M3A2 had a welded hull to save weight. The M3A3 was equipped with two General Motors diesel bus engines coupled together, substituting for the Wright radial engine. Baldwin built 332 of these, which were otherwise identical to the M3A2. The M3, M3A1, and M3A2 could also be fitted with a Guiberson diesel engine, which changed their designation to M3 (Diesel). Chrysler, trying to overcome the radial engine shortages in 1941, combined five standard car engines into a configuration known as the "Eggbeater." This version, the M3A4, required modifications to the hull and suspension and used a riveted hull. Finally, twin GM diesel engines (previously used in the M3A3) installed in riveted hulls resulted in the M3A5.
The British named the M3 the Grant or Lee tank, depending on the version. The tanks purchased by the British from Press Steel and Pullman had a British-designed turret and were designated the Grant I. The name Lee was given to standard M3 variants. The M3 was the Lee I, the standard M3A1 was the Lee II, and so forth. The M3A5 was called the Grant II and supplied under the Lend Lease Act of 1941. The British made many variations and modifications to produce recovery vehicles, command vehicles, mine clearing vehicles, and even a canal defense light. This last variation replaced the gun in the top turret with a searchlight and was used in the Rhine crossings in March of 1945.
The armaments on the M3 were the 75 mm M2 or M3 gun in a hull sponson and a 37 mm M5 or M6 gun in a hand-rotated turret. The sponson had a limited traverse of 30 degrees, mostly to the vehicle's left side, and 29 degrees of elevation. The turret could complete a 360-degree rotation in 20 seconds. There were four .30 caliber Browning machine guns -- one mounted coaxially in the turret, one in the cupola on top of the turret, and two in the bow. The M3 weighed about 30 tons. It carried 46 rounds for the 75 mm gun, 178 rounds for the 37 mm gun, and could fire both HE and AP. There was also storage for 9,200 machine gun rounds.
This tank played a major role early in the war for the Allies, even though it was viewed as a stopgap measure. Grant Is first appeared on the battlefield during the Battle of Gazala in North Africa on 27 May 1942, where their heavy armor and powerful guns gave an ugly surprise to German tank crews. This was the first time the British 8th Army was able to match the 75 mm gun of the German PzKpfw IV. Grant tanks were instrumental to British success at El Alamein in November of 1942. The U.S. used the M3 in the Philippines as well as North Africa. Australia received more than 750 of the tanks and soon learned (as did the British in Burma) that the M3 worked well in jungle warfare because of the height of the turret -- whereas the tank's high silhouette had been a distinct disadvantage in North Africa. The Soviet Union received over 1,400 M3s, though they considered it inferior to their own T34. Germans also used captured M3 tanks against the Soviets.
The M3 was declared obsolete in March of 1944 but lived on in variants such as the M7 "Priest" and M31 Track Recovery Vehicle. The last Grant-based armor recovery vehicle was retired in 1972.