The Steam Wheel Tank was a U.S.-produced, prototype
armoured fighting vehicle
An armoured fighting vehicle (AFV) is an armed combat vehicle protected by armour, generally combining operational mobility with offensive and defensive capabilities. AFVs can be wheeled or tracked. Examples of AFVs are tanks, armoured cars, ...
built by the
Holt Manufacturing Company
The Holt Manufacturing Company began with the 1883 founding of Stockton Wheel Service in Stockton, California, United States. Benjamin Holt, later credited with patenting the first workable crawler ("caterpillar") tractor design, incorporated ...
(now
Caterpillar Inc.
Caterpillar Inc. (stock symbol CAT) is an American ''Fortune'' 500 corporation and the world's largest construction-equipment manufacturer.
In 2018, Caterpillar was ranked number 65 on the ''Fortune'' 500 list and number 238 on the Global ''Fo ...
). Developed sometime between late 1916 and early 1917, it was the third tank to be designed in the U.S. The prototype was completed in February 1918 and was evaluated between March and May 1918 at
Aberdeen Proving Ground
Aberdeen Proving Ground (APG) (sometimes erroneously called Aberdeen Proving ''Grounds'') is a U.S. Army facility located adjacent to Aberdeen, Harford County, Maryland, United States. More than 7,500 civilians and 5,000 military personnel work a ...
. It performed poorly and was not developed further.
Design
Although it is often assumed that the vehicle was a
tadpole configuration (with two driving wheels at the front), a senior Holt executive and the Aberdeen Proving Ground's report state that it was a
delta configuration (with the large wheels at the rear), and that the vehicle drove like a conventional agricultural tractor.
[Crismon, p. 84]
The two driving wheels were in diameter with treads, and a diameter roller, used for steering, was sited at the front. The rear wheels were made from pressed-steel sheet, the same as those used on Holt agricultural machinery of the period. A small plate was attached to the roller to assist in crossing trenches. Each rear wheel was driven by a
Doble two-cylinder steam engine and a Doble kerosene-fired boiler.
The vehicle's armament comprised 2 6-pounder (57 mm) cannons, mounted in
sponsons
Sponsons are projections extending from the sides of land vehicles, aircraft or watercraft to provide protection, stability, storage locations, mounting points for weapons or other devices, or equipment housing.
Watercraft
On watercraft, a spon ...
, and two machine guns. Its riveted armour plating was between six and fifteen millimetres thick.
See also
*
Steam powered tracked tank
References
*
*Crismon, F.W. (1992) U.S. Military Tracked Vehicles. Motorbooks International
*Automotive Historical Records: Volume III, Tanks and Combat Cars, (Automotive Division, Aberdeen Proving Ground, Maryland 1945)
External links
United States Heavy Tanks
{{US WWI Vehicles
World War I tanks of the United States
Abandoned military projects of the United States
History of the tank
Steam road vehicles
Trial and research tanks of the United States