In parallel to the development of the No 1 Lincoln Machine and Little Willie, Wilson had created a wooden mock-up of a larger, alternative design, roughly based on a rhomboid shape and with the tracks running around the complete outside of the vehicle.
It was first shown to the likes of D’Eyncourt, Hetherington and Swinton earlier in the month in Lincoln and then, on 29 September 1915, it was shown to a wider audience at the Trench Warfare Department’s experimental ground in Wembley Park. It was known as the Wilson machine and also as the Centipede.
The following day instructions were issued for Wilson and his team to produce a working prototype of the new design while at the same time continuing with their work on Little Willie
The solution eventually came to them. On 22 September 1915 Wilson and Tritton sent the now famous telegram to the Admiralty that said:
New arrival by Tritton out of pressed plate. STOP. Light in weight but very strong. STOP. All doing well Thank you. STOP. Proud parents.
Tritton was an engineer and he had used first principles to work out what design of track was required. The systems that they had been experimenting with up until now (Bullock, Holt, Hornsby) were fairly complicated systems. Tritton and Wilson came up with an unsprung system of interlocking links and a basic track tensioning system that they believed would stop the tracks from sagging and prevent them being thrown when driving over rough ground.
According to David Fletcher this new design of track was probably the single most important factor in the evolution of the British tank. A set was made for the No 1 Lincoln Machine and this new improved prototype became Little Willie.
Tritton and his colleague Wilson oversaw the building of what came to be known as the Number One Lincoln Machine.
Construction started on 11 August 1915 in a corner of the factory in Lincoln. The machine was little more than a boiler plate box body fitted with a dummy turret. The wheels were to both help with steering and to make the somewhat top-heavy machine more stable.
Number One Lincoln Machine
The machine moved for the first time, inside the factory, on 8 September 1915 ** and it started trials on the South Common, next to Cross O’Cliff Hill in Lincoln, on 10 September 1915. These trials were not successful because the tracks weren’t up to the job; they were fine for steady use on level ground but on anything more severe they had a tendency to sag and fall off the rollers.
Despite his continuing reservations about tracked vehicles, Tritton was determined to improve the design and he and Wilson spent many late nights in their office in the White Hart Hotel working on a solution.
The South Common (Courtesy of Richard Pullen)
The Last Standing Remnant of William Fosters Factory (Courtesy of Richard Pullen)
**B Liddell Hart, The History of the Royal Tank Regiment, p44.