Light Tank M3 – British Army Use

The first to use the American-designed and built a M3 series of light tanks in combat was the British Army in North Africa. The M3 pictured is from the 8th King’s Royal Irish Hussars, 4th Armoured Brigade, 7th Armoured Division, in November 1941. Over the base olive drab, the British have applied a multicolored paint scheme using three different colors. These included the new base color of BSC No. 64 Portland Stone, with overlays of BSC No. 28 Silver Grey, and BSC No. 34 Slate. Khaki Green 3 was also later authorized as an alternative to the slate color. The vehicle’s American registration number is in white on the original base olive drab. On the turret and hull of the tank is a national symbol consisting of a white background with a vertical red bar bisecting a yellow rectangle. In British Army service the M3 was referred to as the “Stuart I.”

British industry was unable to meet the production numbers required to replace the large number of tanks lost early in World War II. The British government turned to the United States in May 1941 to see what could be had quickly and in sufficient numbers under Lend-Lease to aid in the re-equipping of their tank units fighting in North Africa. What was available at the time was the relatively new light tank M3, which the British Army officially called the “Stuart,” after the famous American Civil War General J. E. B. Stuart.

The first batch of 84 M3s arrived in the Middle East in July 1941. By October 1941 almost 300 were on hand. Suitably modified by their shop personnel to meet the needs of British Army tankers serving in North Africa, which included the addition of sand shields and smoke grenade launchers, these M3s entered combat for the first time on November 19, 1941. Things did not go well for the British Army-manned M3s and the British Army as a whole against their German opponents. Of the 165 M3s committed to battle that month, there were only 35 left at the conclusion of the series of engagements referred to by the British Army as Operation Crusader, although the losses were more reflective of poor British performance on the battlefield rather than deficiencies of the light tank M3.

Combat experience showed that the light tank M3 was both under-gunned and under-armored compared with the German medium tanks it was meeting in battle. As the first of the American-supplied M3 series medium tanks began arriving in the Middle East in spring 1942, and the M4 medium tanks in summer 1942, the M3 light tanks were quickly reassigned to other duties as reconnaissance vehicles.

Early-production M3s went into battle with the same 37mm gun M5 that was mounted in the M2A4. Late-production units of the M3 were armed with an improved version of the 37mm gun M5 that featured a semi-automatic breech and was designated the 37mm antitank gun M6. The vehicle commander doubled as the loader on the M3, as he had on the M2A4.

The M3 inherited from the M2A4 the fixed forward-firing .30 caliber machine guns mounted on either side of the vehicle’s upper hull. They could only be aimed by turning the tank in the direction of the intended target or targets. British Army tankers in North Africa who manned the M3 quickly deduced the uselessness of the two fixed forward-firing machine guns and removed them to provide additional storage within the vehicle.


There were a couple of external features on the M3 that distinguished it from its earlier brethren besides the rear trailing idler. These included an improved cast-armor gun shield, designated the combination gun mount M22. Unlike the cast-armor combination gun mount M20 on the M2A4, the cast-armor gun mount on the M3 had a redesigned and shortened recoil mechanism that did not extend out from the bottom of the gun shield as it did so prominently on the M2A4 with its armor protected sleeve. Also, instead of the seven pistol ports on the turret of the M2A4, the M3 had only three.

Power for the four-man M3 came from a seven-cylinder Continental W-670 gasoline-powered, air-cooled radial engine that produced 250 net horsepower at 2,400rpm. It was this radial engine that most impressed the British tankers about their M3s due to its outstanding reliability compared with the engines that powered British tanks. So enamored were the British tank crews with the radial engines in their M3s that they began referring to the American-supplied tanks by the unofficial nickname “Honey.”


Due to a constant shortage of gasoline-powered, air-cooled radial engines, the American Car and Foundry Company built 1,285 units of the M3 powered by the Guiberson T-1020 diesel engine between June 1941 and January 1943. With the diesel engine fitted, the M3 was designated the light tank M3 (diesel). The gasoline-powered M3s employed by the British Army became the “Stuart I,” and the diesel-powered version the “Stuart II.” The maximum speed of the vehicle on a level road with a governed gasoline or diesel engine was 36mph.

With the gasoline-powered engine, the M3 had a maximum cruising range on roads of 70 miles; with the diesel-powered engine that went up to 90 miles. To increase the limited operational range of the M3, the Ordnance Committee directed that jettisonable fuel tanks be developed for the M3. What sprang forth from this project was an arrangement of two 25-gallon drums that sat on top of the tank’s upper hull and bracketed the rear portion of the vehicle’s turret.

The British Army also sought out ways to improve the operational range of the M3s that arrived in North Africa under Lend-Lease. Rather than have two external fuel tanks mounted on the top of the upper hull in a vulnerable location and preventing the turret from being rotated 360 degrees, the British Army attached a single external fuel tank at the rear of the tank’s upper hull on the armor fixture that slanted back over the rear hull engine access doors.

The only way to distinguish between a gasoline-powered M3 and a diesel-powered M3 is the arrangement of the flexible intake pipes from the two external air cleaners located on either side of the vehicle’s rear upper hull. On the gasoline-powered M3, the flexible intake pipes curve directly from the air cleaners into the top of the rear-hull engine deck. With the diesel-powered M3, the flexible intake pipes extend out of the air cleaners across the top of the rear engine deck and enter the engine compartment through an overhead metal screen.


British Army M3s also saw action in the Far East when an armored brigade, withdrawn from the fighting in North Africa, was hastily dispatched in January 1942 to Burma (now known as Myanmar) to stem the Japanese military invasion of that country. Outnumbered and outgunned, the British Army M3s fought a series of costly rearguard actions that cost them all their tanks except one as they were forced to cross back into India in May 1942.

The first American-designed and built tanks the Australian Army received under Lend-Lease were M3s in fall 1941. These vehicles were used successfully by the Australian Army during their campaign to rid the island of New Guinea of Japanese forces between September 1942 and January 1943. As the Japanese Army was short of dedicated antitank weapons, they often relied on close-in attacks by Japanese infantrymen using everything from iron bars to jam the turret ring of tanks to magnetic mines. For protection from the former threat, the Australian Army fitted a fairly wide piece of circular armor around the bottom of the M3’s turret, which is noticeable in pictures.

According to Paul Handel of the Australian Army Tank Museum, the Australian Army placed an extra crewman in the very small and cramped turret of their M3s to relieve the vehicle commander from the job of loading the 37mm main gun, allowing him to concentrate on managing the vehicle in action.