While Lieutenant-Colonel Swinton and Captain Tulloch were urging their proposals, a third scheme was brought forward by Admiral Sir Reginald Bacon in connection with which the Secretary of State, in January 1915, ordered trials to be carried out with a 105 h.p. Foster-Daimler tractor fitted with a bridging apparatus for crossing trenches. At about the same time similar trials were made with a 120 h.p. Holt caterpillar tractor at Shoeburyness in connection with Captain Tulloch’s scheme. Both experiments proved a failure.
The position, therefore, in June, so far as the Army was concerned, was as follows: Proposals had been put forward by Lieutenant-Colonel Swinton, Admiral Bacon, and Captain Tulloch, and submitted to the War Office. Certain trials had been made, the result of which, in the view of the authorities, was to emphasise the engineering and other difficulties to be overcome. It was only in June 1915 that Major-General Sir George Scott-Moncrieff, Director of Fortifications and Works, War Office, who, throughout the initial period, had shown a strong interest in the development of the idea, ascertained that investigations on similar lines were being carried out by the Admiralty; he at once proposed that a “Joint Naval and Military Committee” should be formed for the purpose of dealing with the subject generally. This Committee was constituted on June 15.
The work done by the Admiralty had so far been independent. In February 1915, Mr. Churchill sent to Mr. E. H. T. (now Sir Eustace) D’Eyncourt, Director of Naval Construction, a copy of the notes embodying the proposals set forth by Major T. G. Hetherington (18th Hussars), R.N.A.S., for a new type of war machine. This machine may be described as a veritable Juggernaut, heavily armoured, highly offensive, and capable of moving across country.
It consisted of a platform mounted on three wheels, two driving wheels in front and the steering wheel behind. It was to be equipped with three turrets each containing two 4-in. guns and its motive power was to be derived from a 800 h.p. Sunbeam Diesel set of engines.
The problem of design was examined by the Air Department engineers and the following rough data, worked out at the time, are of interest: