Hornsby Tractor

Back to search results

The oldest item in The Tank Museum is the Hornsby tracklayer or tractor, Little Caterpillar – a steam-powered tracked vehicle, trialled by the War Office for potential use in a combat situation.  

In 1904 David Roberts, Managing director of the firm Richard Hornsby & Sons of Grantham, patented a new form of crawler track which was applied to various prototype vehicles. One of these was tested by the War Office in 1907 and in 1909 this machine was ordered from Hornsbys for military use. It is said that the term Caterpillar was coined by soldiers who watched it moving along although the name was later adopted by an American company and is now world famous.

In 1907 Hornsbys had fitted tracks to the 1905 military tractor that had proved so successful in the War Office trials as a wheeled vehicle. This makes it the first tracked vehicle to enter service with the British Army. It was powered by a two-cylinder Ackroyd heavy oil engine rated at 80hp and was also one of the largest vehicles built for military service at the time. Steering was by braked differential assisted by compressed air at 80 psi although the compressor had to be hand charged with a manually operated pump. Trials were conducted with the Hornsby tracklayer pulling what appears to be a sixty pounder gun.

Despite the fact that it was still being used by the Army in 1914 the Little Caterpillar played virtually no part in the evolution of the tank which evolved in 1915 through Diplock’s Pedrail system and the Bullock Creeping Grip Tractor company of Chicago, neither of which had anything to do with Hornsbys at all.

The Tank Museum’s Hornsby Tractor

This tractor was one of four delivered to the War Office on 5th May 1910. It had a 60 hp six-cylinder engine, the other three, which were wheeled vehicles, had 50 hp four-cylinder engines. It was driven by road from Grantham to Aldershot in 1910 and then took part in extensive trials. It was converted to petrol fuel in 1911, raising the horsepower to 105. It was restored by 18 Command REME Workshops during the 1950s.


Tank facts

Country of use
Full Name
Hornsby Chain Track Tractor or Little Caterpillar
7.5 mph
8.5 tons
Number produced
Produced by
Warhorse to Horsepower


pre-wartowards the tank
Back to search results
Skip to content