Scale: Unknown. A model of Sheer Legs as used in Royal dockyards, made in wood and metal and painted in realistic colours. The model shows a rectangular brick built structure, one portion of which can be removed. The crane structure consists of a tripod of three mast like poles, two of which are secured to the brick structure while the third middle pole is attached to a gearing mechanism partly embedded in the structure. The gearing mechanism consists of steel gear wheels attached to a brass framework which can be operated by a set of gears embedded on one side of the structure. The tops of the poles are secured together by brass caps. Between the three caps two blocks are rigged with chain. The chain is attached to two further blocks, one of which is attached to the structure while the second is used for lifting and moving equipment. The central pole has a simple scaling ladder. There is a small black painted wooden gun on a shaped wooden stand mounted at one end of the structure. Plaques are inscribed: 'Model of sheer-legs as erected in HM Dockyards for lifting masts, guns, boilers & c. Designed by Lieut-Col Andrew Clarke RE CB Admiralty.' and 'Designed at the Admiralty under the direction of Lt Col Andrew Clarke CB RE Assistants E J Woodhead, and A W Ackermann'. The model is displayed in a black polished Victorian display case with matching table.