Abstract: A railless vehicle for use underground is equipped with a three-phase asynchronous motor as the principal drive, and a power distributor with a plurality of power inputs as well as a magazine drum for the wind up or pay out of the power supply line. The drum 2 is connected to the distributor 8 through a hydrostatic drive 10. The control of hydrostatic drive 10 is a function of the slack of the free, not wound up portion of the supply line 3. This slack is detected by a contact lever 5, translated by a converter 14, and transmitted to a torque control 13, to vary the wind up or payout speed of the drum. Any undue horizontal and vertical deflections of the power supply line 3 are effective to switch off the principal drive 7.