Orion Online

This is a QuickTime video showing how to tie a Harvester's Hitch, sometimes called a Waggoner's Hitch.

It is used when a rope needs to be tightened, for instance when securing a load on a vehicle or tightening a rope on a pioneering project. It acts a bit like a block and tackle. Truck drivers use a more secure (extra twists in places) version of this knot to secure their loads.