The T22 Light Armored Car was a prototype of a design for a six wheeled armoured car which entered production as the M8, the main American armoured car of the Second World War.
Work on a new armoured car began in July 1941. The new vehicle was to be armed with the 37mm Gun M6, which potentially made it useful as both an armoured car and a tank destroyer, and it was also to be adaptable to other uses, such as cargo carrier, multiple gun motor carriage or mortar carrier. The original design also called for a hull mounted machine gun, but in March 1942 this was changed to a coaxial machine gun in the turret.
On 9 October 1941 the Ordnance Committee recommended the purchase of two pilot armoured cars, one from Ford and one from Fargo. Both were to be 6x6 vehicles (six wheels, all powered). The Ford vehicle was designated as the 37mm Gun Motor Carriage T22 and the Fargo vehicle as the 37mm Gun Motor Carriage T23.
On 10 December two more pilot vehicles were ordered, this time 4x4s. Once again Ford and Fargo were both given orders, for the Ford 37mm Gun Motor Carriage T22E1 and Fargo 37mm Gun Motor Carriage T23E1. A third company entered the field when Studebaker offered to build a pilot at their own expense, and this became the Light Armoured Car T21.
Although it wasn’t obvious in the later M8 because of its sizable fenders, the T22 and M8 had a long fuselage with tapered sides, which made it quite narrow at the base. The top of the fuselage was flat, with raised air intakes for the engine at the rear, the open topped turret in front of the half way point, and an armoured shield for the driver’s compartment in front of the turret. It was powered by a Hercules JXD six-cylinder inline engine which provided 112hp.
The panels of the armoured shield were on hinges and could be lowered. The front of the vehicle was protected by a long sloped glacis, which ended just below the top of the wheels. A second armoured panel then sloped back under the fuselage, giving the vehicle a ‘V’ shaped front. The T22 and T22E1 could both carry a ball mounted machine gun in the glacis. The largely circular turret had sloped sides and an open top.
Fenders were built onto the sides of the fuselage to protect the wheels. On the T22 and T22E these were simple metal panels, mounted above the wheels, sloping down between the first and second set of wheels to create room for a step (and some external storage), but with open sides (somewhat resembling the fenders over the front wheels of the Willys Jeep. Some photographs of the T22E show it running with the fenders removed, but so far I haven’t found one showing the T22 in that configuration.
The T22 was the first of the pilot models to be completed. It began company tests at Dearborn, Michigan, on 5 March 1942, and was then sent to the Aberdeen Proving Ground, Maryland, on 12 March. It was displayed in an Ordnance demonstration at Aberdeen on 16 March, and on 17 March was driven by representatives from the Armoured Force. They were impressed enough to ask for it to be driven to the Armoured Force base at Fort Knox on 19-20 March, where it underwent three days of tests.
As a result of these tests, the T22 was judged to be suitable for use as a reconnaissance vehicle for the Armored Force and Cavalry and as a 37mm GMC for Tank Destroyer Command. Some changes were requested, although they were fairly minor – a 12 volt electrical system, an auxiliary generator, improvements to the driver’s position, and a mount for a .50in anti-aircraft gun at the back of the turret.
On 23 April the T22E1, T23 and T23E1 projects were terminated. The existing pilots were to be completed for testing but no more would be built. The Studebaker T21 was delivered on 22 May, but production ended with the prototype.
On 19 May the Ordnance Committee recommended standardizing the T22 as the Light Armored Car M8, and this was approved on 25 June 1942. A number of changes were made between to the T22 before it entered production, and the modified version was designated as the T22E2 before becoming the M8. This included changes to the driver’s armour, the fenders and the engine deck, but the basic design stayed the same.