For heavy weights, the legs and also the jib can be of two or three poles tied together.
Gin.—The gyn, or gin, consists of three legs usually from 12 to 13 feet long. They are set up and joined together at the top, thus forming a triangulated frame. A pulley wheel or block is fastened at the apex, and extra power can be gained if they are furnished with a crab winch standing between two of the legs. They are useful in lifting or in lowering material through a well or opening in the working platform, as shown in [fig. 125].
Fig. 125
Fig. 126
Rails.—Scaffolds of a particularly strong construction have, when necessary, rails laid upon them, in order that light trucks may be moved freely from place to place.
Sack trucks are also used on platforms to carry cement, &c., where required.
Other accessories for carrying purposes, the uses of which are obvious, are described in the chapter on Scaffolding Accessories.
The attachment of material to the transporting power is within the province of the scaffolder. To take each class of material separately:—