I recently came across some archival footage which gives some glimpses of some quite rare US medium tanks developed in the 1920s. The footage features the M1921, the T2 Medium Tank and a Christie Tank.
The US tank arm subsequently abandoned the various medium tank designs they’d been working on and shifted towards cheaper light tanks. Always special finding archival footage, hope you enjoy the video.
More of a gun carrier than a tank, as the vehicle was open topped, it was, however, equipped with a 75mm field gun. During the footage it not only seamlessly operates on both land and water, it also fires four rounds as it crosses a body of water at the Aberdeen Proving Ground.
Very little is known about the vehicle but it is believed to be the second of three amphibious vehicles developed by Christie during the 1920s. None of the vehicles were purchased by the US military and no major international orders were made either.
The vehicle itself is manned by two people during the demonstration, presumably one steering while the other mans the gun. It appears to have narrow tracks over its four sets of wheels and a pair of propellers at the rear.
Demonstration of Ordnance Materiel at Aberdeen Proving Grounds, 1920-1926, US National Archives, (source)