Abstract: A safety device specially suitable for preventing the further movement of power operated parts such as doors of trams or garage doors on contact with an obstacle for example a human being. A resilient member is attached to the edge of the door and is provided with two electrodes so that a constant small current flows between the electrodes to indicate that the safety device is operational and wherein, on contact with the edge of the door, the resilient member deforms and gives rise to an increased current between the electrodes which is used as a control signal to inhibit further movement of the door. The increased current is achieved either by allowing the two electrodes to contact each other directly thus short circuiting a resistor or by making the resilient member conductive so that its resistance decreases during compression. The resilient member is located within an elongate slot in a rubber moulding having additional airfilled elongate slots for cushioning the edge of the door.