M41 Howitzer Motor Carriage

The 155 mm Howitzer Motor Carriage M41 (also known as the M41 Gorilla) was a United States self-propelled artillery vehicle built on a lengthened M24 Chaffee tank chassis that was introduced at the end of the Second World War. Out of a planned run of 250, only 85 were produced before cancellation of the order at the end of 1945. The M41 went on to serve extensively in the Korean War, its success influencing the design of later U.S. self-propelled artillery. The type was retired after the conclusion of that conflict, but went on to serve briefly in the French Army.

History
In December 1942, work began on a 155mm self-propelled howitzer based on the newly introduced M1 155mm howitzer and the chassis of an M5 Stuart light tank. This resulted in the production of a single prototype designated the T64. However, the approval of the superior M24 Chaffee light tank whose chassis was expected to be a standard used for other vehicles, such as self-propelled guns, and specialist vehicles (collectively known as "Light Combat Team") led to the scrapping of the T64 in favor of a new design - designated the T64E1 - using the Chaffee chassis.

Equipped with a M1 155mm howitzer with a heavy recoil-absorption spade at the back, the T64E1 was intended to the supplement the earlier M12 Gun Motor Carriage. It had two 110 hp Cadillac V8 engines centrally mounted and a crew of five, including a driver in the hull and gunners mounted in an open-top compartment in the back in an arrangement similar to the 155mm M12 Gun Motor Carriage already in service in the war. The howitzer had limited side-to-side traverse and up to 45 degrees vertical traverse, and a total of 22 rounds could be stored in the vehicle. Additional ammunition was carried by M39 Armored Utility Vehicles. The hull had only 13 mm of armor all around, sufficient to protect only against small arms, while the shielding around the gun compartment was only 6.5 mm thick.

After the T64E1 underwent trials at the Aberdeen Proving Ground in December, 1944, minor modifications were made and production began by the Massey Harris agricultural equipment company in May 1945. The type was re-designated the M41 in June, 1945. However, the M41 arrived too late to see action in World War II, and the initial order of 250 was reduced to 85. These M41s served in the peacetime army, where they received the appellation "Gorilla", and went on to serve in the Korean War before being retired. Some M41s were also passed on to the French Army, but they were soon replaced by other designs.

Operational service
M41s were used in action in the Korean War, where they were useful in providing support during the early mobile phase of the conflict. Once the war ground down to static engagements, the M41s employed their mobility to evade counter-battery fire. The 92nd Field Artillery Battalion and the 999th Armored Field Artillery Battalion were among units that employed M41s in Korea.

Ambush in the Battle of Imjin River
Another unit equipped with the M41 in Korea, the African-American 999th Armored Field Artillery Battalion, fought at the Battle of the Imjin River, where it provided artillery support for the 1st Republic of Korea Infantry Division. During the battle, Battery B was forced to evacuate its position after neighboring units withdrew. During the evacuation, it was ambushed by Chinese forces; during the battle the unit lost seven killed in action, and two M39 Armored Utility Vehicles and had two M41s damaged and 31 wounded. However, the unit broke through the ambush, inflicting an estimated 100 casualties on the ambushing forces, and promptly resumed providing artillery support afterwards.

Captured Chinese M41s
The Chinese People's Liberation Army captured two M41s during the Korean War, employing them against U.S. forces in the Battle of Maryang San. One of them can be seen on display at the Military Museum of the Chinese People's Revolution in Beijing.

Performance and legacy
Compared to the contemporary 155mm M40 Gun Motor Carriage, the M41 was lighter and faster, but had inferior range. Like other contemporary US Army self-propelled artillery, the open-topped gun compartment left the crew vulnerable to small arms fire and shrapnel, and the engines were sometimes criticized for being underpowered. Nonetheless, in a conflict in which enemy units frequently infiltrated or overran forward positions, the battlefield mobility and defensive firepower and armor of M41 units was seen as being greatly preferable to that of towed artillery units, and the performance of the 105mm M7 Howitzer Motor Carriage and M41 in the war influenced the U.S. Army to develop new self-propelled artillery in the 1960s such as the M109 Paladin that would almost entirely replace towed field howitzers.

Variants

 * T64 : Prototype based on M5A1 Stuart chassis. 1 Built.
 * T64E1 : Definitive prototype based on lengthened M24 Chaffee chassis. 1 Built.
 * M43 Gorilla : Final production model

Operators

 * US Army (85 Produced)
 * French Army
 * Chinese Army (2 captured)

Surviving vehicles

 * one at the US Army Artillery Museum at Fort Sill, Oklahoma, USA
 * one at the US Army Ordnance Museum at the Aberdeen Proving Ground, Maryland, USA
 * one in Military Museum of the Chinese People's Revolution, Beijing, China