By the summer of 1918, the United States had embarked on a tank production programme based on the heavy Tank, Mark VIII, which was of British design, and a light tank which was an adaptation of the French Renault FT-17. In addition to these there was a requirement for an ultra-light vehicle to act as a machinegun or ammunition carrier for the infantry. As no suitable design for the infantry carrier existed, the U.S. Ordnance Department commenced work on this project in mid-1918. It was intended that the vehicle should be mass-produced by the Ford Motor Company (an output of 100 a day was planned) and so standard Ford automobile components were, as far as possible, introduced into the design.
A prototype was completed and tested in France in October with satisfactory results, because American G.H.Q. cabled from France to order 15,000 tanks! But one should note, that Pershing said that the vehicle was to be used as a light artillery tractor, as it did not have "sufficient value as a Tank to justify its production for that purpose except as an emergency substitute". So various uses were proposed besides the original role of machinegun carrier, including cargo carrier with 1500 lbs. capacity, self-propelled infantry howitzer and tractor, in emergency, for the 75-mm. field gun. The Armistice followed shortly afterwards, however, the big order was cancelled and only fifteen vehicles were completed.
The Ford 3-ton tank, as these little vehicles generally came to be known (it weighed just under 3 tons, 3.1 short tons), was 13 ft 8 in. long, 5 ft 6 in, wide and 5 ft 3 in. high. It owed some of its design layout to the Renault tank but it had no turret and the transmission system was entirely different from that of the French vehicle. Two Ford Model T engines were employed, each complete with its own electric starter, Ford planetary transmission (two speeds forward, one speed reverse), cardan shaft and worm driven half-axle. By varying the gear ratios for each engine, supplemented by the foot brakes when necessary, slow, fast or skid turns in either direction could be achieved. This system, a variant of which was used on the British "Whippet", permitted easy manoeuvring, although controlling the two engines was not a simple task. The combined horse power of the two four cylinder water-cooled engines was 45 h.p and the maximum speed of the Ford 3-ton tank was 8 mph.
The interior was cramped: the engines at the back, the driver sitting in the centre with the gunner in front of him. The armament as shown in the drawings consisted of one 0.3 inch machinegun, which had only limited movement: 21 degrees traverse and 38 degrees in the vertical plane. A simple ball mounting was at first provided for the gun but this was later changed to an armoured tube mounting resembling a gun of heavier calibre. A larger three man tank with a turret was also built by the Ford Motor Co. This appeared in 1918 but this was unsatisfactory in several ways and went no further than the prototype.
The Ford 3-ton tank was not a perfect tank, not by a long stretch, and would with all probability had suffered tactical problems if ever used in combat. Still, it demonstrates something that was the most important factor when the US put their weight in, during WW2: production and numbers. Instead of searching for a perfect tank, they went for a tank that could be produced cheaply and in huge numbers. The FT-17 was designed to overwhelm the German defenders, the Ford 3-tonner would surely have done just that.
The photos of the Ford 3-tonner below have been taken by Mike Casale, of NJ, USA, an expert in ferreting out old relics from the Great War in the US - there are probably more there than in Europe - and a valued contributor to this site. The 3-tonner in question can be seen in the Museum at Fort Knox. The present location of the surviving 3-ton tank is unknown - the armour collection at Fort Knox is scheduled to be moved to Fort Benning, Georgia.
The video shows an engine start and run of the surviving original 3-ton tank.