Holt tractor
The Holt tractors were a range of continuous track haulers built by the Holt Manufacturing Company, which was named after Benjamin Holt.
Between 1908 and 1913, twenty-seven of the first 100 Holt caterpillar track-type tractors were used on the Los Angeles Aqueduct project, which provided a good proving ground for these machines.[1]
Military Use
They were most famously used by the British, French and American armies in World War I for hauling heavy artillery: including BL 9.2-inch howitzers and the BL 8-inch howitzer. By 1916 more than 1000 were in use by British and by the end of the war around 10,000 had been used.[2]
Specification
There were at least three civilian models used for military purposes: the Holt 45, Holt 75 and the Holt 120. The Holt 45 had a conventional clutch and brake steering system. The Holt 75 and 120 horsepower (89 kW) model had a tiller-type steering wheel at the front that was often covered. The primary difference between the larger models was the 4-cylinder engine in the 75 and 6-cylinder in 120. It weighed about 18,000 pounds (8,200 kg).[3] It had a maximum speed of 15 miles per hour (24 km/h) and had a gasoline engine.[4]. A number of the Holt 45 tractors were taken into service with the US Army and the French Army but they were not entirely satisfactory for towing artillery pieces. In 1917 the Holt company proposed the design of purpose built artillery tractors with towing capacities of 5 and 10 tons. These were capable of towing all but the heaviest pieces and were much lighter and more mobile than the heavy civilian tractors. The Holt 75 and 120 were adopted as the 15-ton and 20-ton tractors for the US Army. In addition, the work by the French Army to tow light artillery pieces with tracked vehicles lead to Holt designing the 2½ ton artillery tractor to fulfil this role. This used a Cadillac engine and a copy of the Renault FT suspension but proved to be unsatisfactory due to engine overheating and was not widely deployed. As well as the towing vehicles Holt also designed "tractor caissons" which could tow artillery pieces but also had some capability to transport stores as well. Neither of the Mark VII or Mark VIII tractor caissons progressed past the prototype stage when the end of WW1 ended any need for these vehicles.
Literature
- Holt Tractors Photo Archive: An Album of Steam and Early Gas Tractors, ISBN 978-1-882256-10-5
References
External links
Media related to Lua error in package.lua at line 80: module 'strict' not found. at Wikimedia Commons
