By Mike Cecil
Head of Military Heraldry and Technology
Australian War Memorial

Harold Jeffery enlisted in the RAAF in June, 1940, as a Fitter Grade IIE. Always a ‘tinkerer’, during the latter part of 1940 he came up with the idea of a compact, remotely controlled tracked vehicle packed with explosive for destroying enemy installations.

It would be guided from cover to its target and then detonated. Harold Jeffery constructed a working prototype and submitted it to the Central Inventions Board in May, 1941. The board thought the idea worth developing and a workable prototype was ready by mid-November. Harold and the prototype proceeded to Melbourne for field testing in early December. 

Jeffery’s Robot Tank was 1480mm long by 770mm wide and just 585mm high. The early prototypes were powered by 6 volt DC batteries working through standard automotive starter motors. These motors were mounted inside the forward section of the sheet steel body, and independently drove tracks on each side of the tankette. The road wheels and large rear idler wheel were pressed sheet steel, and the track system was designed so that the return track was higher than the sides of the light-weight hull. With outriggers attached along each side, the robot tank could not topple onto its side, but would always roll right over onto its back, and hence could still move on its tracks.

Field testing in Melbourne during December was said to be ‘impressive’, and Harold was sent back to Sydney to construct three more improved prototypes. These were ready by May, 1942, and were sent for trials as far afield as 1st Australian Army Headquarters at Toowoomba, Queensland, SME at Liverpool, NSW and 2nd Australian Army Headquarters at Mt Martha in Victoria, usually accompanied by Harold. In all cases, the performance was said to be impressive.

However, reports from overseas about the limitations of such devices were not lost on the Inventions Board. Their review of the project, while noting that the robot performed very well, concluded that the robot was vulnerable to enemy fire and was easily stopped by wire entanglements. Based on these factors, and the relatively high cost of production, the Directorate decided to terminate the project. It was to prove a prudent decision. The German Army had persisted with the manufacture of hundreds of their remote controlled tankettes called ‘Goliath’, whose operational deployment late in the war was a dismal failure for precisely the reasons that the development of the Jeffery Robot Tank was discontinued.

Harold Jeffery was informed of the project’s termination in July, 1942, and subsequently released back to the RAAF, where he served until his discharge on 13 February, 1946. Post war, he went on to apply his engineering and inventive talents to the dairy industry and later to helping the disabled. He died on 5 June, 1968, aged 71.