M22 Light Tank mounted under plane wing. US Ordnance Dept.
M22 Light Tank. Looking inside turret basket with turret removed. US Ordnance Dept.
M22 Light Tank's top view of the hatches and combination gun mount. US Ordnance Dept.
M22 Light Tank: US Ordnance Dept.
M22's Tracks and Tools: US Ordnance Dept.
Based on the development of airborne forces by the Germans and Russians, the US Army decided in February 1941 that it should have airborne forces with armor support. General Motors, Christie, and Marmon-Herrington were asked to submit designs in May 1941.1,4 Marmon-Herrington Corp. was selected and worked with the U.S. Army Ordnance Department Tank Engineering Division.4
It was built with a welded hull and cast turret. The engine was located on the right side in the rear of the hull. The power train was located in the front and consisted of a fixed-ratio transfer case, a 4-speed transmission, and controlled differential.
To save on weight there was no power traverse or a gyrostabilizer.8
The turret could be moved and four brackets were mounted above the suspension on the hull to allow for the tank to be attached to a C-54 Skymaster cargo airplane.4,7
The driver's hatch could be fastened open for driving in non-combat areas.8 A detachable windshield with cover was also provided. Two hatches in the roof of the turret and and escape hatch in the hull provided exit points.
The gun was mounted in a Combination Gun Mount, M53.
The 37 mm gun can fire a 1.9 lb AP shell with a muzzle velocity of 2,600'/sec.6
There were two bogie assemblies that contained two wheels each side that used volute springs with two support rollers.5 The idler trailed on the ground in the rear.8
The armor on the M22 wasn't thick enough to protect against .50 caliber guns.4
The first prototype, the T9, was delivered in late 1941 and designated the Light Tank T9 (Airborne).4
In January 1942, two pilot models designated T9E1 were ordered.4 The shape of the turret was altered, the power traverse, gyrostabilizers and bow machine guns were not installed to save weight.4 These were tested by the 28th Airborne Tank Battalion. One of the prototypes was sent to England for testing.4
Tests were conducted even after production was ordered in 1943 to 1944.4 These were conducted by the Ordnance Department at the Aberdeen and General Motors Proving Grounds.4 The Armored Board conducted their tests at Fort Knox.4
The Army Air Corps conducted tests with a C-54.4 Brackets were added to the hull sides to allow for lifting hooks to be used to attach the tank to the aircraft.4 However, it was found the turret had to be removed first.4
500 were ordered in April 1942 before service tests had begun.4 Eventually 1,900 were ordered but due to design changes and manufacturing problems only 830 were delivered.4,5
Standardized as the M22 in early 1943.7
The Ordnance Committee redesignated it Limited Standard in September 1944.8
Production: November 19424
M22: >8009, 8301,4,5
Production: April 1942 - March 19451, April 1943 - February 19444,5, ? - February 19447
T9: Prototype.4,7 Had 37 mm main gun.4,7
T9E1: Prototype.4,7 Hull shape changed.4,7 Powered traverse for the turret and the gyrostabilizer for the main armament was removed to save weight.4,7 Hull machine guns were removed to save weight.4
T9E2: Design.4 Was to carry an 81 mm breech loading mortar.4
M22: Production model.4
T18 Light Tractor: M22 with no turret.4 Could carry the five member crew of a 105mm airborne howitzer that it towed.4 Only one converted and project cancelled in late 1943.4
Never used in combat by US forces.4,5,9 No suitable glider or aircraft to transport it.
Some had a Littlejohn adaptor installed which increased the barrel length.1,4
British used them in the Normandy landings.6
British forces did not use them in Normandy despite advertising by Marmon-Herington.4
The British named it Locust and used it in the 6th Airborne Division in the Rhine crossing on March 22, 1945 / March 24, 19454.1,7,9 Were carried in the Hamilcar glider.9 Used with the Tetrarch during the crossing on March 24, 1945.5
In July 1945, the M22 was declared obsolete as it was no longer going to be used.4
Some of the surviving M22s were sold to Belgian scrap dealers and some of those may have ended up in Egypt.4
Some were supplied to Egypt after the war.1