Referred to as a 'land torpedo', 'exploding tankette', and 'mechanical robot', Jeffrey the robot was a remotely driven, fully-tracked vehicle made mostly from steel, powered by two electric motors and operated by a control box attached by cable.
Designed early in the Second World War to carry an explosive charge, the robot was intended to be used to destroy obstacles such as barbed wire entanglements, bunkers and other fortifications.
It was conceived by Corporal Harold Edward Jeffery of the Royal Australian Air Force, while at No. 1 Engineer School in Ascot Vale. Jeffery was a motor engineer who owned an engineer shop in Sydney. He had served with the 13th Light Horse Regiment during the First World War where he saw the barbed wire and bunker obstacles of the Western Front. Jeffery presented his idea to the Central Inventions Board, later to become the Army Inventions Directorate, in May 1941, which gave him funding to produce a prototype.
The prototype was a success, and the Army Inventions Directorate asked for three more to be built for testing. The army evaluated the prototypes but decided against adopting the design. It was believed that the robot would be too vulnerable to enemy fire and unable to fulfil its mission, a view that was proven accurate by a similar example, known as the Goliath, adopted by the German Army.
The robot was one of over 21,000 inventions submitted to the Army Inventions Directorate during the war; only 127 were accepted for development. The robot and a number of other invention prototypes were later donated to the Australian War Memorial.