A lashing is an arrangement of rope wire or webbing with linking device used to secure and fasten two or more items together in a somewhat rigid manner. Lashings are most commonly applied to timber poles, and are commonly associated with cargo, containerisation, the Scouting movement, and sailors.
This word usage derives from using whipcord to tie things together.
It has been imagined that the first lashing made by humans was wrapping a few strips of bark around a stone to hold it to a tree branch to make an ax to hunt and build with. In modern times, the same methods are used, but strips of bark and vines have been replaced with natural and synthetic fiber ropes. Scouts and campers use lashings to build camp gadgets and improve their campsites for comfort and convenience. Lashings are also used in pioneering, the art of creating structures such as bridges and towers, using ropes and wooden spars.
There are still areas in the world where lashing spars (or poles) is the basic means of building.
Square lashing is a type of lashing used to bind spars together. There are different types, but all consist of a series of wraps around the spars, and fraps around the wraps between the spars.
Diagonal lashing is a type of lashing used to bind spars or poles together, to prevent racking. It gets its name from the fact that the wrapping turns cross the poles diagonally and is used to spring poles together where they do not touch as in the X-brace of a trestle.
Shear lashing (two-spar shear lashing) also spelled "sheer lashing" is used for lashing together two parallel spars which will be opened out of the parallel to form sheer legs as in the formation of an A-frame. The clove hitch is tied around one leg only and frapping turns are taken between the poles.
The round lashing is most frequently used to join two poles together to extend their length. In the simple version, a clove hitch is tied around both poles and there are no frapping turns.
The tripod lashing (also known as gyn lashing, figure of eight lashing, and three-spar shear lashing) is used to join three spars together to form a tripod.