| Holt Gas-Electric Tank | |
| Origin: |  |
| Is Vehicle: | yes |
| Length: | 5.03m (16.5feet) |
| Width: | 2.76m (09.06feet) |
| Height: | 2.37m (07.78feet) |
| Weight: | 25.4t |
| Suspension: | vertical coil springs |
| Speed: | 10km/h |
| Vehicle Range: | 50km (30miles) |
| Primary Armament: | 75 mm Vickers mountain howitzer |
| Secondary Armament: | two 7.62mm M1917 Browning machine guns |
| Armour: | 6–15 mm |
| Transmission: | G.E.C. generator powering one electric motor per track |
| Engine Power: | 90 hp (67 kW) |
| Pw Ratio: | 3.5 hp/tonne |
| Crew: | 6 |
The Holt Gas-Electric Tank was the first prototype tank built in the United States[1] in a collaboration between the Holt Manufacturing Company (now Caterpillar Inc.) and the General Electric Company. The tank, built during 1917-1918, was the only one of its kind built, as testing proved it lacked the agility and maneuverability required.[2] The crew number is often given as six, on the assumption there would be two machine gunners, a gunner and loader for the main gun, a driver and a commander.
The tank was based on a lengthened and modified version of the suspension of the Holt Model 75, with pivoting track frames. There were ten road wheels at each side. The tank was 7inchesft9.5inchesin (ftin) tall, 16inchesft6inchesin (ftin) long, and 9inchesft1inchesin (ftin) wide.[3] The vehicle had a Holt, 4-cylinder engine fitted with a General Electric generator driving an electric motor for each track; a comparable petro-electric system had earlier been used for the French Saint-Chamond that also was fitted with a lengthened Holt suspension. To prevent overheating the transmission—a constant problem with electrical types—a complicated water cooling system had been installed.
Like the French tank, the Holt Gas-Electric had a 75 mm gun placed low in the V-shaped nose; two removable Browning 7.62 mm machine guns in sponsons on each side. The engine and transmission were in the rear, next to a corridor leading to the only door. Only one was built as tests showed its climbing performance was unsatisfactory, and it was much heavier than planned, about .[4]