World War I

As the American army did not have tanks of its own, the French two-man Renault FT light tank was used by US in the later stages of World War I. It was cheap and well-suited for mass production, and in addition to its traversable turret another innovative feature of the FT was its engine located at the rear. This pattern, with the gun located in a mounted turret and rear engine, became the standard for most succeeding tanks across the world even to this day.

The M1917 was a US tank accepted by the army in October 1918 and is primarily based on the plans of the French Renault FT. The crew, a driver and gunner, were separated from the engine by a bulkhead. Steel idler wheels replaced the wooden idlers fitted to French examples. Approximately 64 of the M1917 were built before the end of World War I and 10 were sent to Europe, but too late to be used in combat. After the war Van Dorn Iron Works, the Maxwell Motor Company, and the C.L. Best Tractor Company created 950 more. 374 had cannons and 526 had machine guns and 50 were signal (radio) tanks. A later modification, the M1917A1, was a lengthened, rebuilt, updated version compared to the French one, having a 100 hp Franklin engine and an electric self-starter rather than a crank starter.The Renault FT Light Tank; S. ZalogaTreat 'Em Rough! Capt. Dale E. Wilson

U.S. troops also used the British Heavy Tanks Mk V and Mk V* (pronounced "Mark Five" and "Mark Five Star"). A battalion trained in England and saw action in France in the last six weeks of the War. On a small number of occasions, U.S. troops were supported by tank units of the French Army operating Schneider and Saint-Chamond machines.

Light tanks

CTLS-4TA

World War II Marmon-Herrington tanks that could not be delivered because of the fall of the Dutch East Indies were taken over by the US. The CTLS-4TAC and -4TAY tanks were redesignated light tank T14 and T16 respectively. They were used for training, some were used in Alaska and by the US Marines. The CTLS-4TAC has the turret offset to the left, the CTLS-4TAY to the right.

M3/5 Stuart

World War II

The Stuart was an upgrade of the M2 light tank.

The initial upgrade was designated the M3 Stuart and had thicker armor, modified suspension and a 37mm gun. Production of the M3 and later the M5 Stuart started in March 1941 and continued until October 1943 with a total of 25,000 produced.

An upgrade of the M3, which was initially called M4 but later redesignated the M5, was developed with improved engines and produced through 1942. The M5 featured a redesigned hull and driver's hatches moved to the top. The M5 gradually replaced the M3 in production from 1942 and was in turn succeeded by the light tank M24 in 1944.

The British Army was the first to use the M3 in combat. In November 1941, some 170 Stuarts took part in Operation Crusader, with poor results.

Although the high losses suffered by Stuart-equipped units during the operation had more to do with better tactics and training of the enemy than superiority of enemy tanks in the North African campaign, the operation revealed that the M3 had several technical faults. Mentioned in the British complaints were the 37mm gun, a limited range and poor internal layout. The two-man turret crew was a significant weakness, and some British units tried to fight with three-man turret crews. However, crews liked its high speed and mechanical reliability.

From the summer of 1942, when enough US medium tanks had been received, the British usually kept Stuarts out of tank-to-tank combat. M3s, M3A3s, and M5s continued in British service until the end of the war, but British armor units had a smaller proportion of these light tanks than US units.

The other major Lend-Lease recipient of the M3, the Soviet Union, was even less happy with the tank, considering it undergunned, underarmored, likely to catch fire, and too sensitive to fuel quality. The narrow tracks were highly unsuited to operation in winter conditions, as they resulted in high ground pressures that sunk the tank. However, the Stuart was superior to early-war Soviet light tanks such as the T-60, which were often underpowered and possessed even lighter armament than the Stuart. In 1943, the Red Army tried out the M5 and decided that the upgraded design wasn't much better than the M3. Being less desperate than in 1941, the Soviets turned down an American offer to supply the M5. M3s continued in Red Army service at least until 1944.

In US Army service, the M3 first saw combat in the Philippines. Two battalions, comprising the Provisional Tank Group fought in the Bataan peninsula campaign. When the American army joined the North African Campaign in late 1942, Stuart units still formed a large part of its armor strength.

After the disastrous Battle of the Kasserine Pass the US quickly disbanding most of their light tank battalions and subordinating the Stuarts to medium tank battalions performing the traditional cavalry missions of scouting and screening. For the rest of the war, most US tank battalions had three companies of M4 Shermans and one company of M3s or M5/M5A1s.

In the European theater, Allied light tanks had to be given cavalry and infantry fire support roles since their main cannon armament could not compete with heavier enemy AFVs. However, the Stuart was still effective in combat in the Pacific Theater, as Japanese tanks were both relatively rare and were generally much weaker than even Allied light tanks. Japanese infantrymen were poorly equipped with anti-tank weapons and tended to attack tanks using close-assault tactics. In this environment, the Stuart was only moderately more vulnerable than medium tanks. In addition, the poor terrain and roads common to the theatre were unsuitable for the much heavier M4 medium tanks, and so initially, only light armor could be deployed. Heavier M4s were eventually brought to overcome heavily entrenched positions, though the Stuart continued to serve in a combat capacity until the end of the war.

The US liquidated its Stuarts when it got sufficient numbers of M24 Chaffees but the tank remained in service until the end of the war and well after. In addition to the United States, United Kingdom and Soviet Union, who were the primary users, it was also used by France and China.

M24 Chaffee

World War II

In April 1943 the government started work on the M24 Chaffee, designated light tank T24 as a replacement for the M3/M5 Stuart after the original replacement, the M7, was rejected in March. Every effort was made to keep the weight of the vehicle under 20 tons. The armor was kept light, and a lightweight 75 mm gun was developed. The design also featured wider tracks and torsion bar suspension. It had relatively low silhouette and a three-man turret. In mid-October the first pilot vehicle was delivered and production began in 1944 under the designation light tank M24; 4,730 were produced by the time production was stopped in August 1945.

The first thirty-four M24s reached Europe in November 1944 and were issued to the U.S. 2nd Cavalry Group (Mechanized) in France. These were then issued to F Company, 2nd Cavalry Reconnaissance Battalion and F Company, 42nd Cavalry Reconnaissance Battalion which each received seventeen M24s. During the Battle of the Bulge in December 1944, these units and their new tanks were rushed to the southern sector; two of the M24s were detached to serve with the 740th Tank Battalion of the U.S. First Army.

The M24 started to enter widespread issue in December 1944 but they were slow in reaching the front-line combat units. By the end of the war many armored divisions were still mainly equipped with the M5. Some armored divisions did not receive their first M24s until the war was over.

Reports were generally positive. Crews liked the improved off-road performance and reliability, but were most appreciative of the 75 mm main gun, as a vast improvement over the 37 mm. The M24 was still not up to the challenge of fighting tanks, however, the bigger gun at least gave it a chance to defend itself. Its light armor made it vulnerable in tank vs. tank actions.

The M24s contribution to winning the war was insignificant, as too few arrived too late to replace the M5s of the armored divisions.

Medium tanks

M4 Sherman

World War II The U.S. Army designed the M4 as a replacement for the M3 medium. The designated goals were to produce a fast, dependable medium tank able to support infantry, provide breakthrough striking capacity, and defeat any tank currently in use by the Axis nations. In April 1941 the U.S. Armored Force Board chose the simplest of five designs. Known as the T6, the design was a modified M3 hull and chassis, carrying a newly designed turret mounting the Lee's main gun. This became the Sherman.AFV database

The prototype M4 was completed in September 1941. The T6 became standardized as the M4, and production after modifications began in October 1941.Opening Salvo: M4A1 Sherman Tank by Michael J. Canavan

The U.S. Army had seven main sub-designations for M4 variants during the production period: M4, M4A1, M4A2, M4A3, M4A4, M4A5, and M4A6. These designations were manufactured concurrently at different locations.

While most Shermans ran on gasoline, the M4A2 and M4A6 had diesel engines: the M4A2 with a pair of GMC 6-71 straight six engines,Berndt, Thomas. Standard Catalog of U.S. Military Vehicles (Krause Publications, 1993), pp.192-3. the M4A6 a Caterpillar RD1820 radial.Berndt, pp.192-3. These, plus the M4A4 which used the Chrysler A57 multibank engine, were mostly supplied to Allied countries under Lend-Lease.Berndt, pp.190 & 192-3. "M4" can refer specifically to the initial sub-type with its Continental radial engine, or generically, to the entire family of seven Sherman sub-types, depending on context. Many details of production, shape, strength, and performance improved throughout production without a change to the tank's basic model number; more durable suspension units, safer "wet" (W) ammunition stowage, and stronger armor arrangements, such as the M4 Composite, which had a cast front hull section mated to a welded rear hull. British nomenclature differed from that employed by the U.S.

Early Shermans mounted a 75 mm medium-velocity general-purpose gun. Although Ordnance began work on the medium tank T20 as a Sherman replacement, ultimately the Army decided to minimize production disruption by incorporating elements of other tank designs into Sherman production. Later M4A1, M4A2, and M4A3 models received the larger T23 turret, with a high-velocity 76 mm gun M1, which reduced the number of HE and smoke rounds carried and increased the number of anti-tank rounds. Later, the M4 and M4A3 were factory-produced with a 105 mm howitzer and a new distinctive mantlet in the original turret. The first standard-production 76 mm gun Sherman was an M4A1, accepted in January 1944, and the first standard-production 105 mm howitzer Sherman was an M4 accepted in February 1944.