In the early 1900's, Sir William Tritton was the inventive Managing Director of Foster & Co, Lincoln. As such, he attended the 1909 military tractor trials. The result of which was the Foster-Daimler tractor, first produced in 1912.

The winner of the £750 first prize for tractors in the 1909 trial was the Thornycroft. Tritton had been impressed with the Thornycroft's performance and determined to combine Foster's existing steam expertise with an internal combustion engine.

Convinced that a heavy tractor would benefit from more power than the 50hp provided by Thornycroft, Tritton turned to Daimler in Coventry. Daimler had a 6-cylinder, sleeve-valve, 105hp petrol engine of 14.6 litres and this was the engine that Tritton used for the tractor. The same engine was later used in the first tanks.

The tractor followed traction engine principles with a sturdy channel plate chassis and large, 8ft diameter sprung traction engine rear wheels. Weighing 11.5 tons, it proved too large for domestic use, and few were built prior to 1914. When tested by the War Office at Boulogne in February 1915, it proved capable of towing 35 tons at 2mph while using 1.5 gallons of petrol every 2 miles.

The Coventry Ordnance Works had long supplied the Admiralty with 15-inch naval guns. When WW1 was declared the head of the company, Admiral Sir Reginald Bacon, approached Winston Churchill who was First Lord of the Admiralty, with the idea of 15-inch howitzers. These were to be used for heavy bombardment in France and this approach resulted in an initial order for 10 guns and presented the immediate problem of transportation.

The howitzers were extremely heavy and though they could be broken down into component parts for transportation, still presented a major challenge. Bacon decided on the Foster-Daimler as the most suitable gun-tractor. With the ammunition trailers included, a total of 8 tractors were required for each gun. The guns were broken down into barrel, cradle and carriage for transportation and reassembled when in position.

Responsibility for manning and transporting these huge guns was that of The Royal Marines Artillery, using Army Service Corps drivers. Soon after arriving in France in 1915, the howitzers were transferred to the army. At the time, the Ordnance Board noted that these ‘unwanted gifts’ had been developed for the Admiralty with no input from the Ordnance and had poor range, were too heavy and were a waste of money.

Repair and maintenance was carried out at the 3^rd Heavy Repair Shop (358 Coy ASC) at St Omer in Northern France. Spares and stores supplies were provided through No2 Base MT Depot at Calais, just a few miles north of St Omer. In total, around 110 Foster-Daimlers were supplied to the army, which were all scrapped when the howitzers became obsolete after the war and were disposed of in 1920.

An important aspect of the design of the Foster-Daimler was its ability to be converted for use on railway lines by simply changing the traction engine wheels for flanged wheels.