Cranes, which describe a family of

Cranes, which describe a family of vehicles used to
lift materials.
• Towlines, which are continuous cables that can move
trailers around a fixed path, rather like ski lifts.
• Conveyors, which are used to move large quantities
of goods along fixed paths.
• Tractors or trains, which are power units that pull
loads that have been put onto trailer units. The
tractor delivers trailers to the place needed, rather
like small articulated trucks or tugs and barges.
• Carousels, which are basically a series of bins going
round a fixed track.