The trucker's hitch, also known as the power cinch, is a self-binding knot commonly used for securing loads on trucks or trailers.
There are several variations of the knot, all of which use a loop in the standing part of the rope as a make-shift pulley in order to obtain a 3 to 1 mechanical advantage. The version depicted here has the advantage that it can be tied anywhere in the rope (without access to an end). Once tight, the knot is secured with a half hitch, usually slipped for easy releasing.