Two of the first three Chaffees facing the North Koreans in 1950 had faulty recoil mechanisms and both guns recoiled clear into the turret bustle, crashing through the radio and one breech almost penetrating the turret rear armor. In the official unit history, the tanks are recorded to have been put out of action by "mechanical failures". I wonder what the guilty crews thought as the barrel/breech proceeded to shoot out the back of the turret.
To the right of the main weapon was a coaxial .30cal Browning MG, the typical coax used in US tanks during the war. Further off to the right was a M3 smoke mortar discharger, adapted from the British weapon, at that time found in all their battle tanks. The M3 also shows up in US M4 Sherman tanks. Above the 75mm gun tube was a hinged travel lock for connecting the gun to the turret roof during road marches, and to the far left was the gunner's M71G direct telescopic sight with a head bump pad just above. The gunner was also provided with a M4A1 combination periscope/sight that was mounted in the roof over-head, just forward of his position. This was the same periscope/sight used in the Sherman and other US vehicles at this time. The commander also had a periscope on his side of the weapon, this time a M6, like the drivers'. It was mounted in a rotating fitting in his cupola hatch.
The gun tube of the M6 was lighter and thinner walled than the M3 75mm weapon originally envisioned for the Chaffee, but it also heated up quicker and therefore had a shorter life. In return, the weight of only slightly over 400lbs (compared with the M3 weapon's 893lbs) provided the kind of light weight the designers had been looking for. The coaxial .30cal MG was off to the right of the main gun. Both guns were fired electrically. The gunner traversed the turret by either a hydraulic powered stick control or manually, via a hand wheel. The gun's elevation was only manually controlled by a hand wheel. A US gun stabiliser system was installed and allowed some increased gun performance in elevation only, although most crews were not happy with the bouncing breech when the system was switched on and they were traveling over uneven ground. The breech was a horizontal semi-automatic type and in most vehicles the tube recoil housing and mount was painted the same gloss white as the turret interior, while the breech and ring were painted gloss black.
Twin Cadillac Series 44T24 engines provides power for the M24. These units are each 8 cylinder, 4 cycle, 90 degree V, liquid cooled gasoline engines and when combined, produce 220hp at 3400rpm maximum. The power provided a top speed of 35mph on roads and a cruising range of approximately 100 miles if you started off with full tanks of 110 gallons of 80 octane gas. The combined power of the two engines was handled by twin Hydromatic (automatic) transmissions, allowing 4 speeds forward. Combined into the Synchromesh transfer case, the tank then had a possibility of 8 speeds forward and 4 reverse, now capable of running 18mph in reverse, which was used on a number of occasions when out gunned and looking for a place to withdraw. In this TM photo the engines are shown mounted side by side in the engine compartment with the two access plates unbolted and removed. Air intake hoses, leading to the carburetors on top of each engine, originate inside the vehicle at the air cleaners mounted on the back wall. The shaft passing from carb to carb is the throttle cross shaft and the exhaust manifolds and pipes can be seen running from each engine to the muffler and exhaust pipe at the rear (close to us). Each engine also has a large generator attached at the back which is driven by pulleys, and each also is shown with a large light-colored oil filter, vertically attached next to the horizontal generators. Radiators and fans can not be seen here as they are mounted forward of the engines.
An over-head view of the standard production M24 shows numerous turret roof equipment details. This US Army (Aberdeen PG) photo illustrates the commander's cupola with rotating hatch (including 6 surrounding vision blocks) and a M6 periscope mount located in the forward half of his circular hatch. Forward, and to the left of his cupola, is a spotlight, the control handle and electrical wire would be seen inside the turret at this position. The spotlight could be removed from this mount and stored inside the vehicle, or used by hand, pulling a bit of the electrical cord out the mounting hole. Forward of the cupola is the armored protective cover for the gunner's M4A1 periscopic sight. Off to the right side of the turret front is the oblong opening for the M3 smoke discharger. The surface mount does not rotate- the entire turret must be turned in order to aim the smoke bomb's trajectory. The M3 projector was eliminated shortly after WWII, but at the time it was the primary method to provide smoke to obscure the tank. A turret roof ventilator, similar but smaller than the one we saw earlier between the driver's hatches, is positioned in front of the loader's wide hatch, and a .50cal M2 HB Browning MG tripod mount is welded behind this hatch, the MG included mainly for aircraft defense. Notice the antenna mount on the left side of the ample turret bustle and the use of an additional storage bin on the back of the turret.
