History
When the U.S. Army moved to Europe in 1917 during World War I, there was a shortage of almost all war equipment, including heavy artillery. One of the best of the day was the French made Canon de 155mm GPF heavy gun. At the end of the war, General Pershing brought some GFPs back to the United States for inspection and refinement for use by the U.S.
Army. U.S. Army engineers worked to modify the existing French system, and some prototypes were rolled out in 1926. Work continued back and forth (lack of Army funding) until the 1930s, culminating in pairing the original French GFP with a new British refraction system - the Asbury.
The T4 gun prototype was mounted on the T2 frame prototype and entered service as the 155mm M1 gun on the M1 frame. When this new weapon was introduced to the U.S. military, they affectionately called it the "Long Tom."
The Army places an initial quantity order of 20 Long Toms, and several arsenals begin production. The main improvement over the original French design is an improved L/45 barrel mounted on a new M1 heavy split rear frame, using an Asbury break. The front of the car is fitted with four twin-tire wheels, with two sets on each side of the car.
This placement acts as a stabilizing point between the gun's weight and the frame, making the gun more accurate. Additional upgrades to the weapon required a change to the model designation to "M1A1" (improved lockring) in 1941, and production changes that continued into 1944 eventually yielded the designation "M2" (again, improved lockring).
The M1A1E1 became the chrome prototype, while the M1A1E3 was another liquid-cooled prototype.
The M1 car has been refurbished and renamed the M1A1.
The M1/M2 grenade used is a 43.1 kg (95 lb) projectile which, if fired at a 45 degree angle, fires High Explosive (HE) at a distance of approximately 25,395 yards - up to 15 miles away - High Accuracy sex. The 15 skilled crew can fire more than 40 rounds per hour, including high-explosive, chemical, smoke or flares.
Gun elevation angles of up to 63 degrees provided the crew with a wide arc of fire.
The weapon proved reliable in practice and became a standard weapon in the U.S. Army's arsenal. Sales to allies around the world further fueled its success. This weapon was used extensively during World War II, the Korean War and the Vietnam conflict. Many countries have been using this weapon throughout the 1980s.
After World War II, the US Army gave the M1/M1A1/M2 a new designation "M59" during the reorganization.
The standard tractor used to tow the M1 during World War II was the M4 high-speed tractor, which also doubled as an ammunition carrier. By 1942, tracked tractors from manufacturer Allis Chalmers weighed 14.2 tons but lacked armor protection for the driver.
Waukesha 6-cylinder gas engines produce 210 hp and 14.7 hp per ton. This vehicle enables the heavy artillery to fight over 180 miles of territory at a top speed of 33 miles per hour. When the M4 arrived at the firing position with Long Tom, it took the crew about 30 minutes to fire the first round.
Long Toms were supplied on Lend-Lease to the British and French armies, totaling 184 and 25. They first fought in North Africa in 1943 as part of the 34th Field Artillery Battalion.
It saw further action in Europe and the Pacific, transported primarily by Mack NO 6x6 7 1/2 ton utility vehicles, until this mode of transport gave way to the aforementioned tracked M4.
She created "Steel Rain" on multiple fronts and continued to fight throughout the North African campaign, against the caves of Peleliu, into the ranks of Korea, and into the jungles of Vietnam.
The Long Tom is the main weapon of the 155 mm Gun Motor Carriage M40 self-propelled track cannon.
Specification
Basic
Roles
- fire support/attack/damage
Dimensions
13.71m
2.43m
3.04m
15 tons (13,880 kg; 30,600 lbs)
Performance
Performance
54 km/h
180 miles (290 km)
for everyone else in our database)
Armor
1 x 155mm gun on M1 mount
Depends on the ammunition carrier. Packing, bagging. The 95 lb projectile can be used for HE, smoke, gas and lighting.
Changes
M1920 - Prototype name
T4 - Prototype Designation
M1 - Released 1938; designated original production model; 20 copies made.
M1A1 - Released 1941; Modified locking ring.
M1A1E1 - One-off prototype with chrome holes.
M1A1E3 - One-off prototype with liquid cooling system.
M2 - Released 1942; Modified locking ring.
155mm Geschutzmotorwagen T83 / M40 - Modified M4 Sherman tank with M1/M2 main gun.
155mm gun T79 - 155mm gun mounted on the T23 tank chassis; proposed but never put into production.

