only 19 mm. A new lightweight 75 mm gun was developed, a derivative of the gun used in the B-25H Mitchell bomber. The gun had the same ballistics as the 75 mm M3 in use by American tanks but used a thinly walled barrel and different recoil mechanism. The design featured tracks and torsion bar suspension, similar to the slightly earlier M18 Hellcat tank destroyer, which itself started in production in July 1943. The torsion bar system was to give a smoother ride than the vertical volute suspension used on most US armored vehicles. At the same time, the chassis was expected to be a standard used for other vehicles, such as self-propelled guns, and specialist vehicles; known together as the "Light Combat Team". It had a relatively low silhouette and a three-man turret. On October 15, 1943, the first pilot vehicle was delivered. The design was judged a success and a contract for 1,000 was immediately raised by the Ordnance Department. This was subsequently increased to 5,000. Production began in 1944 under the designation Light Tank M24. It was produced at two sites; from April at Cadillac and from July at Massey-Harris. By the time production was stopped in August 1945, 4,731 M24s had been produced. Service history The M24 Chaffee was intended to replace the ageing and obsolete Light Tank M5 (Stuart), which was used in supplementary roles. World War II European theater The first 34 M24s reached Europe in November 1944 and were issued to the US 2nd Cavalry Group (Mechanized) in France. These were then issued to Troop F, 2nd Cavalry Reconnaissance Squadron and Troop F, 42nd Cavalry Reconnaissance Squadron, 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 use in December 1944, but they were slow in reaching the front-line combat units. By the end of the war, the light tank companies of many armored divisions were still mainly equipped with the M3/M5 Stuart. Some armored divisions did not receive their first M24s until the war was over. Aside from the US Army, the British Army was another main user of the Chaffee during the war, with at least several hundred obtained through the