Historical information

A sailing or rope block has single or multiple pulleys with one or more sheaves enclosed in an assembly between cheeks or chocks.

In use, a block is fixed to the end of the line, spar or load to be lifted such as at a transport dock. A rope line is reeved through the sheaves, and through one or more matching blocks at the far end, to make up what's known as a tackle. Generally, the more sheaves in the blocks that make up a tackle, the higher its mechanical advantage.

Various types of blocks are used in sailing. Some blocks are used to increase mechanical advantage and others to change the direction of a line. A ratchet block turns freely when a line is pulled in one direction but does not turn in the other direction, although the line may slip past the sheave. This kind of block makes a loaded line easier to hold by hand.

Significance

This rope block is an example of rope and tackle systems used in maritime settings to lift and move cargo and machinery, often with the help of a crane. It is also used on sailing vessels as part of the rigging, help to raise and lower the ropes and sails.

Physical description

Block; two sheave wooden rope block with ring and becket. It features a Closed Spelter Socket (CSS). Rings are galvanised metal. There is a compliance plate attached with an inscription. It was once owned by a government body, as indicated by the 'up-arrow" symbol.

Inscriptions & markings

Compliance plate: stamped twice "CS" [Closed Spelter] and "↑"