M-24 Chaffee
The M-24 was designed as a replacement for the M-5 Stuart (p.W:DF78), using a modified M-18 Hellcat suspension and a 75mm gun based on that used in the B-25H (p.W:DF84). The first pilot models were ready in late 1943 and production started in spring of 1944. M-24’s saw action starting in December 1944, in Italy and at the Battle of the Bulge and were also used in the Pacific. Some 4,070 Chaffees were built by the end of the war.
Small arms for the crew included a 51mm mortar with 14 smoke bombs, four M-3 SMGs with 720 rounds, 8 grenades and a tripod for the M-2HB A/A gun.
The M-24 has a crew of five. The commander sits in the turret and mans the Browning M-2HB. He can also fire the 51mm smoke mortar. Also in the turret is the main gunner, who fires the 75mm M-6 and the coaxial Browning M-1919A4, and the loader. The driver sits in the body. Next to him is the radio operator, who also fires the hull Browning M-1919A4. The turret hydraulically traverses at 24 degrees per second. The M-24 uses 9.9 gallons per hour at routine usage. A full load of fuel and ammo costs $1,037.
Subassemblies: Medium Tank chassis with mild slope +3, full rotation
Large AFV turret with mild slope [Body:T] +2, full-rotation Mini Weapon
open mount [Tur:T] +0, tracks +3.
Powertrain: Two 110.5-kW HP gas engines w/ 221-kW tracked drive
train and 110 gallons fuel in standard fuel tank [body]; 4,000-kWs batteries.
Occupancy: 2 CS Body, 1 CS Turret, 2 CS both
Cargo: 1.1 Body, 4.4 Turret.
| Armor | F | RL | B | T | U |
| Body | 5/150 | 4/85 | 4/100 | 4/50 | 4/40 |
| Tracks | 4/40 | 4/40 | 4/40 | 4/40 | 4/40 |
| Turret | 5/185 | 4/80 | 4/80 | 4/80 | 0/0 |
Weaponry
75mm Medium TG/M-6 [Tur:F] (48).
51mm Vehicle Mortar/M-3 [Tur:F] (14 smoke).
Very Long Ground HMG/M-2HB [Mini:F] (440).
Ground LMG/M-1919A4 [Tur:F] (2500).
Ground LMG/M-1919A4 [Body:F] (1250).
Equipment
Body: Fire extinguisher, medium radio receiver and transmitter.
Statistics
| Size: 16'x10'x8' | Payload: 1.38 tons | Lwt: 19.6 tons |
| Volume: 110 | Maint.: 48 hours | Price: $17,400 |
HT: 12
HP: 1500 [Body], 200 [Turret], 540 [Each Track], 30 [Open Mount]
| gSpeed: 34 | gAccel: 3 | gDecel: 20 | gMR: 0.25 | gSR: 6 | GP: Very Low (4/5) |
Design Notes
The design purchased 111 gallons of fuel tanks and 4,000 rounds of
MG ammo. Historical values have been used instead.
The rear hull was slightly sloped; rather than giving the hull medium
sloping, DR was slightly increased. Side armor varied in thickness from
25mm front and 19mm back; an average of 22mm was used for the design.
Variants
It was intended to build a whole family of armored vehicles around
the basic M-24 chassis. However, the end of the war largely left this goal
unreached, although several vehicles entered production. Not until a few
years later with the M-41 “Walker Bulldog” light tank was the concept more
fully realized.
The M-19 (1945) moved the turret to the rear of the body and the engine to the front, with a slightly lengthened hull. It mounted two 40mm Bofors M-2 anti-aircraft guns (40mm Long Ground AC) with 336 rounds in the open-topped turret. The new turret had a rotation speed of 40 degrees per second (with the guns capable of elevating and depressing at 25 degrees per second) and carried the 40mm ammo in containers around the turret. Armor protection was PD/DR 5/75 F, PD/DR 4/50 R, L, T and U, and PD/DR 4/40 B on the body and PD/DR 4/40 F and PD/DR 4/30 R and L on the turret. Although intended for use against aircraft, the M-19 was also used against infantry and the cannons had a useful AP round available for action against lightly armored vehicles. The same turret was later used with the M-42 Duster, which was based on the M-41 light tank. Crew was six, weight 19.25 tons and top speed 35 mph. Some 285 were built. The M-19 could tow the M-28 trailer, which carried 320 rounds of 40mm ammo.
The M-37 (1944) was intended to replace the M-7 Priest (p.W:DF80), which was considered too large and heavy for the gun it carried. The M-37 removed the turret and substituted an open superstructure to the front mounting a 105mm M-4 howitzer (105mm Short Howitzer) with 90 rounds and an M-2HB (in a pulpit-like structure, as with the M-7) with 500 rounds. Despite using a smaller chassis, the M-37 was actually wider than the M-7, which gave more room for the gun crew to work. The M-37 had a crew of seven, weighed 23 tons and had a top speed of 30 mph. Some 316 were built.
The M-41 Gorilla (1945) used the same general layout as the M-19, but mounted the M1 155mm howitzer with 22 rounds. The gun was on a pedestal that gave nearly 40 degrees of traverse, with a thin (DR 20) gunshield being the gun crew’s only protection. Crew was five, weight was 21 tons and speed was 35 mph. Only 85 were built.
The T-22, T23, and T-33 were intended to be prime movers and cargo vehicles,
but were cancelled.
A 4.2” mortar was carried by the T-38, but development was terminated
in August 1945.
The T-77 was another anti-aircraft variant that was never produced, mounting six M-2HB’s in a fully enclosed turret.