The chains were small platforms, built on either side of the hull of a ship, used to provide a wide purchase for the shrouds, and to assist in the practice of

depth sounding Depth sounding, often simply called sounding, is measuring the depth of a body of water. Data taken from soundings are used in bathymetry to make maps of the floor of a body of water, such as the seabed topography. Soundings were traditionally ...

. The chains provided a platform for a 'leadsman', the sailor assigned to swing the sounding line, or 'lead' into the water. The term originated from the practice of the sailor standing between the

shrouds Shroud usually refers to an item, such as a cloth, that covers or protects some other object. The term is most often used in reference to '' burial sheets'', mound shroud, grave clothes, winding-cloths or winding-sheets, such as the famous S ...

when casting the line, which were attached to the hull by

chainplate A chainplate is a metal plate used to fasten a shroud or stay to the hull of a sailboat A sailboat or sailing boat is a boat propelled partly or entirely by sails and is smaller than a sailing ship. Distinctions in what constitutes a sailing ...

s, or, in earlier sailing ships, to lengths of chain along the ship's side. A length of chain was usually fixed at waist height to the

stanchion A stanchion () is a sturdy upright fixture that provides support for some other object. It can be a permanent fixture. Types In architecture stanchions are the upright iron bars in windows that pass through the eyes of the saddle bars or horizo ...

s above the chains, as an added safety measure. The chains were common on large sailing vessels, but the role of leadsman and swinging the lead to obtain depth soundings declined with developments in

echo sounding Echo sounding or depth sounding is the use of sonar for ranging, normally to determine the depth of water (bathymetry). It involves transmitting acoustic waves into water and recording the time interval between emission and return of a pulse; ...

, and ships are rarely now equipped with chains.

Notes

References

* {{Sailing ship elements Sailing ship components Nautical terminology