A load-hauling device includes a pair of karabiners, each having an array of pulleys, a pulley rope fixed at one end to one of the karabiners below its respective pulley array, to anchor that end of the rope, the pulley rope passing sequentially between the pulleys of each pulley array to provide a mechanical advantage at the free end of the pulley rope when pulled, a rotatable locking cam mounted between a cam yoke fixed around an end pulley of one of the pulley arrays, wherein the cam includes a cam spring to bias the cam to engage with the rope and permit movement of the rope in one direction while preventing movement of the rope in the other direction, the cam including an integral trigger and locking mechanism to selectively disengage the cam from the rope and allow the device to release a load carried thereby.