Christie suspension

Christie advocated the use of lightweight tanks with long range and high speed, designed to penetrate enemy lines and attack their infrastructure and logistics capabilities.

The modifications added coil suspension to the front wheels and removed the turret - the armament being moved to the nose of the vehicle.

The tank - now known as M1921 - was tested in 1922 and 1923 but considered lacking in maneuverability and internal space and so put into the Ordnance Museum at Aberdeen Proving Ground in 1924.

The road wheels were individually mounted on a pipe that could move vertically only, at the top of which the bell crank rotated the direction of motion to the rear.

Although there was interest by the Army in the design, negotiations over the requirements were drawn out and a single Christie M1931 was delivered in March 1931 followed by an order for 7 more in June.

The Army drew up a specification for an improved T3 but following disputes with Christie the order - for 5 of the "Convertible Medium Tank T3E2" was given to the American-La France company.

Because large road wheels and "slack track" are characteristic of the Christie suspension, other designs with these features are sometimes misidentified as such.