Historical information
A sailing block is single or multiple pulleys with one or more sheaves that are enclosed in an assembly between cheeks or chocks.
In use, a block is fixed to the end of a line, to a spar, or a surface. A rope line is reeved through the sheaves, and maybe through one or more matching blocks at the far end, to make up what's known as a tackle.
The purchase of a tackle refers to its mechanical advantage. In general, the more sheaves in the blocks that make up a tackle, the higher its mechanical advantage. The matter is slightly complicated by the fact that every tackle has a working end where the final run of rope leaves the last sheave. More mechanical advantage can be obtained if this end is attached to the moving load rather than the fixed end of the tackle.
Various types of blocks are used in sailing. Some blocks are used to increase mechanical advantage and others are used simply to change the direction of a line. A ratchet block turns freely when a line is pulled in one direction but does not turn the other direction, although the line may slip past the sheave. This kind of block makes a loaded line easier to hold by hand, and is sometimes used on smaller boats for lines like main and jib sheets that are frequently adjusted.
A single, large, sail-powered warship in the mid-19th century required more than 1,400 blocks of various kinds and sizes.
Significance
An item from an old sailing vessel from the late 19th to early 20th century, unfortunately, the item cannot be identified as to what vessel it belonged to. It does however give an insight into a piece of sailing equipment that's design is still in use today on pleasure sailing craft.
Physical description
Wooden closed spelter double rope block with two pully's between sheaves, block has metal frame around outside of the sheaves and 4 metal pins, 2 each side of the frame at top and 2 at bottom, joining the sheaves together. The shaft between the sheaves is also wooden. Remnants of orange and black paint on outside of block. Shafts are chipped, wood has borer holes. (NOTE: Block was rediscovered after relocating objects to new storage area)
Inscriptions & markings
None
