Australian Dictionary of Biography

Lancelot Eldin de Mole (1880-1950), engineer and inventor, was born on 13 March 1880 in Adelaide, son of William Frederick de Mole, architect and surveyor, and his wife Emily, née Moulden. He was reputedly a great-grandson of Henry Maudslay (1771-1831), the noted British engineer and inventor. When he was 7 the family moved to Victoria where Lancelot attended Melbourne Church of England Grammar School until 1891 and completed his education at Berwick Grammar School. He became a draftsman and before World War I worked on mining, surveying and engineering projects in several States. His early inventions were claimed to include an automatic telephone, designed three years before a similar type was introduced into the United States of America, which the Australian Postal Department declined to test.

While surveying in difficult country near Geraldton, Western Australia, in 1911, de Mole hit upon an idea for a tracked armoured vehicle and next year sent sketches of his design to the British War Office. He described the principle of his vehicle as follows:

It can be steered to the right or left, when proceeding forwards, by altering the direction that the chain-rail is laid in by screwing the front portions to one side or the other …; or steered, when proceeding backwards, by pressing the bogie nearest the rear end of the tank to one side by means of the screw gear … or a hydraulic ram controlled by the steersman, thereby causing the body of the vehicle to be thrown to the right or left as required so that, as the vehicle proceeds, the links of the chain will be laid to the right or left of the line that the vehicle has been proceeding on and so form a curve, which as the vehicle proceeds will alter the direction of travel.

He was notified in June 1913 that his idea had been rejected, though only some of his drawings were returned. He resisted urging from friends to sell the design to the German consul in Perth.

On 21 July 1915, at St Matthew's Church, Kensington, Adelaide, de Mole married Harriett Josephine Walter; at the time he was employed as a draftsman in the Engineering Department of the South Australian Public Service. That year he resubmitted drawings of his design to the War Office but was told that a working model must be provided before the invention could be considered. He then attempted to interest the Australian Inventions Board, but failed. He had a model constructed and, being without means to travel to England, tried to enlist in the Australian Imperial Force but was rejected as medically unfit. When the first crude British tanks took the field in 1916, de Mole realized that his idea had been ignored and held that his design was superior. With the encouragement and assistance of (Sir) Harold Leslie Boyce, then a lieutenant in the 10th Battalion, he was accepted for active service on 26 September 1917. He embarked for England, taking his model with him, and was able to demonstrate it to the British Inventions Committee, which recommended it to the Tank Board. However, it was misplaced for six weeks, and before it could be demonstrated to the board Private de Mole was sent to France in March 1918 with reinforcements for the 10th Battalion. In January 1919 he was attached, as a temporary corporal, to the ammunition workers' depot at A.I.F. Headquarters, London.

In 1919 de Mole lodged claims with the British royal commission on awards to inventors, but the judgment handed down in November was unfavourable. The credit of designing the tanks actually used was attributed to two British inventors and while the commission noted that de Mole 'had made and reduced to practical shape, as far back as the year 1912, a brilliant invention which anticipated, and in some respects surpassed, that actually put into use in the year 1916' it found that 'a claimant must show a causal connection between the making of his invention and the user of any similar invention by the Government'. The commission considered that the designs which the War Office had kept since 1912 had in no way been employed. De Mole was, however, awarded £965 for expenses and made an honorary corporal; in 1920 he was appointed C.B.E.

De Mole returned to Australia in February 1920 and it is claimed that he later patented throughout the world a new style of motor-lorry chassis especially designed for heavy work. Records show only that he had made application for patents for several devices in the years before World War I, and that neither this nor his telephone was among them. The applications he did make—for improvements on chain-rail vehicles (1912), an apparatus for destroying prickly pear (1913), and improvements on rotary engines (1913-14)—were never seen through to acceptance; the prickly pear device was simply permitted to lapse, and only provisional specifications had been submitted for the others and completed designs were never presented.

After the war de Mole became an engineer in the design branch of the Sydney Water Board. In June 1940 he suggested to defence authorities a shell which would erect a fence or screen of suspended wires as a defence against enemy aircraft. The shell, which could be fired from the ground or from an aircraft, would release an encased charge on a steel wire 500-1000 ft (152-305 m) long attached to a parachute to slow its descent. The Army Headquarters Invention Board decided that the design had 'possibilities' and de Mole obtained a favourable hearing from Prime Minister (Sir) Robert Menzies for his device, but when relayed to London the British authorities responded that similar suggestions had already been examined and found 'impracticable'.

De Mole died, after a long illness, at the Liverpool State Hospital, Sydney, on 6 May 1950. He was cremated with Presbyterian forms. A model of his tank is on display at the Australian War Memorial, Canberra.