By 1942 it was evident that the day of the 37-mm (1.46-in) tank gun had passed, and requests were coming from the field for a light tank with a 75-mm (2.95-m) main gun. Attempts to fit such a gun into the Light Tank M5 were unsuccessful, so a new design was started by Cadillac. The first was ready by late 1943 and it carried over several features of the MS, including the twin engines, but the main change was to the turret and gun.
The new turret mounted the required 75-mm (2.95-in) gun, whose development was lengthy. Originally it had been the old French '75' field gun altered for use in tanks. Various efforts were made to lighten the gun to the extent that it could be mounted in B-25 bomber aircraft for anti-shipping use, and in this form the T13E1 was easily adapted as a light tank weapon.
The new light tank was initially known as the T24 but when accepted for service it became the Light Tank M24 and was later given the name Chaffee. It was not in full service until late 1944, and thus was able to take only a small part in the fighting in Europe during 1945. Perhaps its biggest contribution was not really felt until the war was over, for the M24 was designed to be only a part of what the designers called a 'combat team' of armoured vehicles. The idea was that a common chassis could be used to provide the basis for a whole family of armoured vehicles that included self propelled artillery, anti-aircraft tanks and so on. In fact this concept did not make the impresion that it might have done as the war ended before it could be put into full effect, and indeed the M24 did not make its full combat impact until the Korean War of the early 1950s.
The M24 was a good-looking little tank, well armed for its size and weight, but the armour (minimum 12 mm/0.47 in and maximum 38mm/ 1.5-in) had to be lighter than in heavier tanks to give the vehicle its agility. The M24 had a surprisingly large crew of five men (commander, gunner, loader, radio operator who sometimes acted as assistant driver, and driver). Apart from the main gun there were two 7.62 mm (0.3-m) machine-guns (one coaxial with the main gun and one in the front hull) and a 12.7-mm (0.5-in) gun on the turret mounted on a pintle. To add to this array there was a 51-mm (2-in) smoke mortar. All this was a considerable armament for a vehicle with a tactical responsibility that was limited mainly to reconnaissance, but by the time the M24 entered service it was a luxury that the Americans could well afford.
As mentioned above, the M24 went on to make its greatest impact after 1945 and many nations retain the M24 to this day, several of them going to the trouble of re-engining the vehicles and updating their fire-control systems. Armed with a 75-mm (2.95-in) gun, the M24 was introduced into service during late 1944 and post-war it formed the basis for a new family of armoured vehicles.
Performance: maximum road speed 56 km/h (35 mph); maximum road range 161 km (100 miles); fording 1,02 m (3 ft 4 in); gradient 60 per cent; vertical obstacle 0.91 m (3 ft); trench 2.44 m (8 ft)
Specification Light Tank M24 Crew: 5 Weight: in action 18.37 tonnes Powerplant: two Cadillac Model 44T24 V-8 petrol engines developing 82 kW (HOhp)each Dimensions: length, with gun 5.49 m (18 ft) andoverhull 4.99m (16 ft 4,5 in); width 2.95 m (9 ft 8 in); height 2.48 m (8 ft 1.5 in)