Abstract: A safety device for load lifting and lowering apparatus of the kind comprising a pair of parallel spaced apart upright guide members of hollow section along each of which travels a runner mounted on a load carrier, a cable being connected to each runner to pull it upwardly along the guide member or lower it down the guide member, comprises pawls rotatably mounted on the runner and a block slidable relative to the pawl to which the cable is connected. Levers are pivotally mounted one on each pawl and one end of each lever is pivotally and slidably connected to the block. Springs urge the block towards the runner. Each pawl has a tapered edge and a roller which rests in normal use in a recess. In normal operation tension in the cable separates the block from the runner but when the tension is released, the springs urge the block towards the runner thereby rotating the levers and thereby moving the roller upwardly so that the pawls are jammed against the walls of the guide member.