M24 Chaffee

Light Tank M24
A preserved M24
Type	Light tank
Place of origin	United States
Service history
In service	1944–1953 (U.S Army)
Used by	USA and 28 others; see Operators
Wars	World War II, Korean War, First Indochina War, Ifni War, Vietnam War, Algerian War, Indo-Pakistani War of 1971
Production history
Manufacturer	Cadillac, Massey-Harris
Produced	1944 – August 1945
Number built	4,731
Specifications
Weight	18.4 tonnes (40,500 lb)
Length	5.56 m (18 ft 3 in) including gun 5.03 m (16 ft 6 in) excluding gun
Width	3 m (9 ft 10 in)
Height	2.77 m (9 ft 1 in)
Crew	5 (Commander, gunner, loader, driver, co-driver/radio operator)
Armor	15–38 mm (0.60–1.50 in)
Main armament	1 × 75 mm Gun M6 L / 39 48 rounds
Secondary armament	1 × .50 cal Browning M2HB machine gun 440 rounds 2 × .30-06 Browning M1919A4 machine gun 3,750 rounds
Engine	2 × Cadillac Series 44T24, 8 Cylinder 110 bhp each (220/164 kW total)
Power/weight	16.09 hp/tonne
Transmission	GM Hydraumatic 4F
Suspension	Torsion Bar
Fuel capacity	110 US gal
Operational range	161 km (100 mi)
Speed	56 km/h (35 mph) road 40 km/h (25 mph) off-road

The Light Tank M24 is an American light tank used during the latter part of World War II and in postwar conflicts including the Korean War and, with the French, in the War in Algeria and the First Indochina War. In British service it was given the service name Chaffee, after the United States Army General Adna R. Chaffee, Jr., who helped develop the use of tanks in the United States armed forces. While long removed from American and British service, it is still found in service as a light tank in third-world countries, along with other hardware from that era.

Development and production history

British combat experience in the North African campaign identified several shortcomings of the M3 Stuart light tank, especially the performance of its 37mm cannon. A 75mm gun was experimentally fitted to an M8 Howitzer Motor Carriage - an M3 tank with a larger turret - and trials indicated that a 75 mm gun on the M5 light tank development of the M3 was possible. The M3/M5 design was dated though, the 75 mm gun reduced stowage space, and the armor was insufficient.

The T7 light tank design, which was initially seen as a replacement, grew in weight to more than 25 short tons taking it out of the light tank classification, and so was designated as the Medium Tank M7. The weight increase without increased power gave it unsatisfactory performance; the program was stopped in March 1943 to allow standardization on a single medium tank - the M4 medium. This prompted the Ordnance Committee to issue a specification for a new light tank, with the same powertrain as the M5A1 but armed with a 75 mm gun.

In April 1943, the Ordnance Corps, together with Cadillac (who manufactured the M5), started work on the new project, designated Light Tank T24. The powerplant and transmission of the M5 was used together with some aspects of the T7. Every effort was made to keep the weight of the vehicle under 20 tons. The armor was kept light, with the glacis plate only 25 mm thick but sloped to maximize effectiveness. 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 also featured wider - 16 in (41 cm) - tracks and torsion bar suspension, similar to the slightly earlier M18 Hellcat tank destroyer. 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 left the assembly lines. Some of them were supplied to the British forces.

Combat history

M24 Chaffee moves on the outskirts of Salzburg, May 1945

The M24 Chaffee was intended to replace the aging and obsolete Light Tank M5 (Stuart), which was used in supplementary roles. 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 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 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 M3/M5 Stuart. Some armored divisions did not receive their first M24s until the war was over.

Reports from the armored divisions that received them prior to the end of hostilities were generally positive. Crews liked the improved off-road performance and reliability, but were most appreciative of the 75 mm main gun, which was a vast improvement over the 37 mm. The M24 was not up to the challenge of fighting German tanks, but the bigger gun at least gave its crews a much better chance to fight back when it was required. The M24's light armor made it vulnerable to virtually all German tanks, anti-tank guns, and hand-held anti-tank weapons. The contribution of the M24 to winning the war in Europe was insignificant, as too few arrived too late to replace the worn-out M5s of the armored divisions.

M24 Chaffee light tanks of the 25th Infantry Division, U.S. Army, wait for an assault of North Korean T34/85 tanks at Masan.

In the Korean War, M24s were the initial U.S. tanks directed to combat the North Korean T-34-85s. The occupation troops in Japan from which the tanks were drawn were inexperienced and under-equipped due to rapid demobilization after World War II. The M24 fared poorly against these better armed, better armored, and better crewed medium tanks, losing most of their number while inflicting only minor damage on the T-34 units. Managing a fighting withdrawal, they ended up as artillery in the Pusan Perimeter; in August reinforcements from the US and the Commonwealth brought heavier tanks that could easily dispatch the T-34s. M24s were more successful later in the war in their reconnaissance role, supported by heavier, more capable tanks such as the M4 Sherman, M26 Pershing, and M46 Patton.

The French deployed several M24 tanks during the Battle of Dien Bien Phu.

Like other successful World War II designs, the M24 was supplied to many armies around the globe and was used in local conflicts long after it had been replaced in the U.S. Army by the M41 Walker Bulldog. France employed its M24s in Indo-China in infantry support missions, with good results. They employed ten M24s in the Battle of Dien Bien Phu. In December 1953, ten disassembled Chaffees were transported by air to provide fire support to the garrison. They fired about 15,000 shells in the long siege that followed before the Viet Minh forces finally overcame the camp in May 1954. France also deployed the M24 in Algeria. Some Chaffees are known to have been passed down to the Army of South Vietnam, where they saw service at least until the Battle of Huế. The last time the M24 is known to have been in action was in the Indo-Pakistani War of 1971, where 66 Pakistani Chaffees stationed in East Pakistan were lost to Indian Army T-55s, PT-76s, and anti-tank teams. Although both Iran and Iraq had M24s prior to the Iran–Iraq War, there is no report of their use in that conflict. South Korean Chaffees saw service in the Korean War, often performing hit-and-run raids on communist forces.

Variants

M19 Twin 40 mm Gun Motor Carriage

Spanish Army M37 105 mm howitzer.

M41 155 mm howitzer in the US Army Ordnance Museum.

• Light Tank T24 – prototype, was standardized as Light Tank M24.
• Light Tank T24E1 – prototype with Continental R-975-C4 engine and Spicer torque converter transmission. One vehicle was converted from the original T24 prototype and tested in October 1944. The vehicle had superior performance compared to the M24, but suffered from transmission reliability problems.
• M19 Multiple Gun Motor Carriage

Developed from T65 40mm GMC (anti-aircraft gun on extended M5 chassis). Lengthened M24 hull with engine moved to center, twin 40mm Bofors anti-aircraft guns mounted at hull rear (336 rounds). 904 were ordered in August 1944, but only 285 were completed by the end of the war.

• M37 105 mm Howitzer Motor Carriage

Developed in 1945. Carried a 105 mm howitzer M4 (126 rounds). Was intended to replace the 105mm Howitzer Motor Carriage M7. 448 ordered, 316 delivered. Saw service in the Korean War.

• M41 155 mm Howitzer Motor Carriage (Gorilla)

Engine moved to the center of hull, 155 mm howitzer M1 mounted at rear. 250 ordered, 60 delivered. Saw service in the Korean War, with some exported to France

• T77 Multiple Gun Motor Carriage.

Had six .50 (12.7 mm) caliber machine guns mounted in a new designed turret.

• T9, T13 Utility vehicles.
• T22E1, T23E1, T33 Cargo carriers.
• T42, T43 Cargo tractors.

Based on the T33, the T42 had a torque converter transmission from the M18 Hellcat. The M43 was a lightened version of the T42.

• T9.

Had bulldozer kit installed.

• T6E1 Tank recovery vehicle.

Additionally the M38 Wolfhound prototype armored car was experimentally fitted with an M24 turret.

Additional Equipment

• M4

Earth Moving Tank Mounting Bulldozer. Bulldozer kit for the M24 series.

Foreign variants

NM-116

In 1972, the Norwegian Army decided to retain 54 of their 123 M24 light tanks as reconnaissance vehicles after they were substantially rebuilt under the designation NM-116. It was calculated that the NM-116 rebuilding program cost only about a third as much as contemporary light tanks.

This program was managed by the firm Thune-Eureka. The American firm NAPCO developed an improved power-pack based around the 6V53T diesel engine used in the M113 armored personnel carrier mated to an Allison MT-653 transmission. The original 75 mm Gun M6 L/39 was replaced with a French D-925 90 mm low pressure gun, with a co-axial 0.50-inch (12.7 mm) M2 heavy machine gun. The bow gunner position was eliminated in favor of ammunition stowage. A new fire-control system was installed, complete with a Simrad LV3 laser rangefinder. Norwegian firms also converted eight M24 light tanks into light armored recovery vehicles to support the NM-116. The NM-116 were retired from service in 1993.

Other

The Chilean Army up-gunned their M24s in the mid-1980s to the IMI-OTO 60 mm Hyper Velocity Medium Support (HVMS) gun, with roughly comparable performance to a standard 90 mm gun. Chile operated this version until 1999.

Uruguay continues to use the M24, modernized with new engines and 76mm guns which can fire armor-piercing, fin stabilised, discarding sabot (APFSDS) rounds.

In mid-1950s, in an attempt to improve the anti-tank performance of the vehicle, some French M24s had their turrets replaced with those of the AMX-13 light tank. AMX-13 variants with Chaffee turret also existed.

Operators

Operators of the M24

• Austria – 46 M24's in active service from 1956 till 1966. Turrets of retired M24 tanks were fixed in Austrian bunker systems.
• Belgium
• Cambodia
• Chile
• Denmark
• Ethiopia
• France
• Greece
• Iran
• Iraq
• Italy
• Japan – entered service in 1952; last ones taken out of service by 1974.
• Laos
• Netherlands – 50 entered service after World War II, taken out of service around 1962.
• Norway – 123 entered service in the 1950s, last Chaffees were taken out of service in 1993.
• Pakistan – (citation needed)
• Philippines – 7 Chaffees assigned to the Recon Company of the 10th BCT, PEFTOK during the Korean War. Two known were on static display in Lingayen, Pangasinan.
• Portugal
• Republic of China
• Republic of Korea – 30 Chaffees were used for training in the early 1950s for a short period of time, later delivered to Taiwan.
• Saudi Arabia
• South Vietnam
• Spain - Used during Ifni War.
• Thailand
• Turkey
• United Kingdom
• United States
• Uruguay – 17 upgraded
• Vietnam

See also

• List of "M" series military vehicles
• G-numbers

References

Bibliography

• Icks, Robert Light Tanks M22 Locust and M24 Chaffee AFV Profile No. 46 Profile Publishing

Further reading

• Schulimson, Jack, LtCol. Leonard Blasiol, Charles R. Smith, and Capt. David A. Dawson. U.S. Marines in Vietnam: 1968, the Defining Year. Washington, D.C.: History and Museums Division, United States Marine Corps, 1997. ISBN 0-16-049125-8

External links

• Light Tank M24 Chaffee at AFV Database
• Twin 40mm Gun Motor Carriage M19
• World War II Vehicles
• M24 Chaffee Photos and Walk Arounds on Prime Portal
• NM-116 – 31-photo walk around of a Norwegian NM-116 at Primeportal.net
• M24 Recognition Features