Skidding

a lumbering operation that consists in the collection of trees from which the branches have been removed (trunks) and hauling them from the cutting area to loading areas on logging routes. The chief means of mechanization in skidding are skidding tractors and winches. Tractors are used on level ground and on mountain slopes with a grade not exceeding 22° (in winter, 14°); one end of the tree, trunk, or log is attached to the tractor, and the other end drags on the ground. In the case of trees, the butt usually rests on the tractor, and in the case of trunks, the top. Depending on the method of collecting the cut lumber, skidding may be done with or without chain or cable chokers. Felling and hauling machines may also be used.

Winch skidding, which involves the use of cable and block systems for semisuspended or suspended hauling of trees, trunks, or logs, is used mostly in mountains and in swampy areas. For example, in high-lead hauling, a carrier moves on a carrier cable stretched between two poles; on the rehaul the carrier brings cable chokers to the felling area, and on the return pass it pulls the logs, trunks, or trees to the loading area. The carrier is driven by traction ropes.