Holt gas–electric tank
| Holt gas–electric tank | |
|---|---|
| Place of origin | |
| Production history | |
| Manufacturer | Holt Manufacturing Company and General Electric Company |
| Produced | 1917-1918 |
| Specifications | |
| Mass | 25.4 t (25.0 long tons; 28.0 short tons) |
| Length | 5.03 m (16 ft 6 in) |
| Width | 2.76 m (9 ft 1 in) |
| Height | 2.37 m (7 ft 9 in) |
| Crew | 6 |
| Armor | 6–15 mm |
Main armament | Vickers 75 mm mountain howitzer |
Secondary armament | two 7.62 mm (0.300 in) M1917 Browning machine guns |
| Engine | 4-cylinder Holt gasoline 90 hp (67 kW) |
| Power/weight | 3.5 hp/tonne |
| Transmission | G.E.C. generator powering one electric motor per track |
| Suspension | vertical coil springs |
Operational range | 50 km (31 mi) |
| Maximum speed | 10 km/h (6.2 mph) |
The Holt gas–electric tank was the first prototype tank built in the United States[1] in a collaboration between the Holt Manufacturing Company[a] and the General Electric Company. The transmission was petrol-electric with gasoline engine coupled to generator driving electric motors connected to the tracks. Only a single example was built during 1917–1918, 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.
Construction
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 7 feet 9.5 inches (2.375 m) tall, 16 feet 6 inches (5.03 m) long, and 9 feet 1 inch (2.77 m) wide.[3][page needed] The vehicle had a Holt 90 horsepower (67 kW), 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.[4].
Armament
Like the French tank, the Holt gas–electric had a British designed 75 mm mountain gun placed low in the V-shaped nose; two removable 7.62mm Browning machine guns in sponsons one 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 at about 25 short tons (23 t).[5]
Evaluation
The Hold proved to be a disappointing design, crawling along at a top speed of 6 mph and a range of only 31 miles. The cooling system added to the already too-heavy weight of the tank, which meant that it really struggled to climb even mild slopes. The project was abandon after the one prototype had been completed and underwent trials.[4]
References
- ^ Holt Manufacturing merged with the rival C. L. Best company for form Caterpillar Tractor Company in 1925
- ^ "The Holt Gas-Electric Tank – The first American tank". Landships. Archived from the original on May 1, 2008. Retrieved 3 April 2010.
- ^ "Holt Caterpillar". Archived from the original on 2009-12-04. Retrieved 2010-02-27.
- ^ Zaloga, Steven J. (2017). Early US Armor: Tanks 1916–40. New Vanguard No. 245. Oxford: Osprey Publishing. ISBN 978-1-4728-1807-2..
- ^ a b "Model 1917 Holt Gas-Electric Prototype Military Vehicle". www.militaryfactory.com.
- ^ Foss, Christopher F. (2003). The Encyclopedia of Tanks and Armoured Fighting Vehicles. Staplehurst: Spellmount. p. 18. ISBN 1-86227-188-7.