http://en.wikipedia.org/wiki/Goliath_tracked_mine
Interesting read..I have seen the one in the Canadian War Museum and it is complete with cables and controls..
In late 1940, after recovering the prototype of a miniature tracked vehicle developed by the French vehicle designer Adolphe Kégresse from the Seine River, the Wehrmacht's ordnance office directed the Carl F.W. Borgward automotive company of Bremen, Germany to develop a similar vehicle for the purpose of carrying a minimum of 50 kg of explosives. The result was the SdKfz. 302 (Sonderkraftfahrzeug, ‘special-purpose vehicle’), called the Leichter Ladungsträger (‘light charge carrier’), or Goliath, which carried 60 kg of explosives. The vehicle was steered remotely via a joystick control box. The control box was attached to the Goliath by a triple-strand cable connected to the rear of the vehicle, for transmitting power to the electric driven version. Two of the strands were used to move and steer the Goliath, the third was used for detonation. The Goliath had 650 m of cable. Each Goliath was disposable, being intended to be blown up with its target. Early model Goliaths used an electric motor but, as these were costly to make (3000 Reichsmarks) and difficult to repair in a combat environment, later models (known as the SdKfz. 303) used a simpler, more reliable gasoline engine.