The chains, also called the chain-wales or channels, [1] 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.
The chains provided a platform for a 'leadsman', the sailor assigned to swing the sounding line, or 'lead' into the water. [2] The term originated from the practice of the sailor standing between the shrouds when casting the line, which were attached to the hull by chainplates, 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 stanchions above the chains, as an added safety measure. [2] 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, and ships are rarely now equipped with chains. [2]
A hull is the watertight body of a ship, boat, submarine, or flying boat. The hull may open at the top, or it may be fully or partially covered with a deck. Atop the deck may be a deckhouse and other superstructures, such as a funnel, derrick, or mast. The line where the hull meets the water surface is called the waterline.
Sailing employs the wind—acting on sails, wingsails or kites—to propel a craft on the surface of the water, on ice (iceboat) or on land over a chosen course, which is often part of a larger plan of navigation.
Rigging comprises the system of ropes, cables and chains, which support and control a sailing ship or sail boat's masts and sails. Standing rigging is the fixed rigging that supports masts including shrouds and stays. Running rigging is rigging which adjusts the position of the vessel's sails and spars including halyards, braces, sheets and vangs.
A sailing ship is a sea-going vessel that uses sails mounted on masts to harness the power of wind and propel the vessel. There is a variety of sail plans that propel sailing ships, employing square-rigged or fore-and-aft sails. Some ships carry square sails on each mast—the brig and full-rigged ship, said to be "ship-rigged" when there are three or more masts. Others carry only fore-and-aft sails on each mast, for instance some schooners. Still others employ a combination of square and fore-and-aft sails, including the barque, barquentine, and brigantine.
A dinghy is a type of small boat, often carried or towed by a larger vessel for use as a tender. Utility dinghies are usually rowboats or have an outboard motor. Some are rigged for sailing but they differ from sailing dinghies, which are designed first and foremost for sailing. A dinghy's main use is for transfers from larger boats, especially when the larger boat cannot dock at a suitably-sized port or marina.
A fathom is a unit of length in the imperial and the U.S. customary systems equal to 6 feet (1.8288 m), used especially for measuring the depth of water. The fathom is neither an international standard (SI) unit, nor an internationally accepted non-SI unit. Historically it was the maritime measure of depth in the English-speaking world but, apart from within the US, charts now use metres.
The knot is a unit of speed equal to one nautical mile per hour, exactly 1.852 km/h. The ISO standard symbol for the knot is kn. The same symbol is preferred by the Institute of Electrical and Electronics Engineers (IEEE), while kt is also common, especially in aviation, where it is the form recommended by the International Civil Aviation Organization (ICAO). The knot is a non-SI unit. The knot is used in meteorology, and in maritime and air navigation. A vessel travelling at 1 knot along a meridian travels approximately one minute of geographic latitude in one hour.
A spar is a pole of wood, metal or lightweight materials such as carbon fibre used in the rigging of a sailing vessel to carry or support its sail. These include yards, booms, and masts, which serve both to deploy sail and resist compressive and bending forces, as well as the bowsprit and spinnaker pole.
This glossary of nautical terms is an alphabetical listing of terms and expressions connected with ships, shipping, seamanship and navigation on water. Some remain current, while many date from the 17th to 19th centuries. The word nautical derives from the Latin nauticus, from Greek nautikos, from nautēs: "sailor", from naus: "ship".
A chip log, also called common log, ship log, or just log, is a navigation tool mariners use to estimate the speed of a vessel through water. The word knot, to mean nautical mile per hour, derives from this measurement method.
Futtock shrouds are rope, wire or chain links in the rigging of a traditional square rigged ship. They run from the outer edges of a top downwards and inwards to a point on the mast or lower shrouds, and carry the load of the shrouds that rise from the edge of the top. This prevents any tendency of the top itself to tilt relative to the mast.
The top on a traditional square rigged ship is the platform at the upper end of each (lower) mast. This is not the masthead "crow's nest" of the popular imagination – above the mainmast is the main-topmast, main-topgallant-mast and main-royal-mast, so that the top is actually about 1/4 to 1/3 of the way up the mast as a whole.
Careening is a method of gaining access to the hull of a sailing vessel without the use of a dry dock. It is used for cleaning or repairing the hull. Before ship's hulls were protected from marine growth by fastening copper sheets over the surface of the hull, fouling by this growth would seriously affect the sailing qualities of a ship, causing a large amount of drag. As this growth was underwater, removing it was difficult. Beaching the vessel at high tide allowed the lower hull to be exposed for cleaning or repairs.
Builder's Old Measurement is the method used in England from approximately 1650 to 1849 for calculating the cargo capacity of a ship. It is a volumetric measurement of cubic capacity. It estimated the tonnage of a ship based on length and maximum beam. It is expressed in "tons burden", and abbreviated "tons bm".
The angle of list is the degree to which a vessel heels to either port or starboard at equilibrium—with no external forces acting upon it. If a listing ship goes beyond the point where a righting moment will keep it afloat, it will capsize and potentially sink.
Foul is a nautical term meaning to entangle or entwine, and more generally that something is wrong or difficult. The term dates back to usage with wind-driven sailing ships.
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.
A windjammer is a commercial sailing ship with multiple masts that may be square rigged, or fore-and-aft rigged, or a combination of the two. The informal term "windjammer" arose during the transition from the Age of Sail to the Age of Steam during the 19th century. The Oxford English Dictionary records the word "windjamming" from 1886 and "windjammer" with reference to a ship from 1892. The term has evolved to include such a vessel, carrying passengers on overnight cruises in the Caribbean, the U.S. state of Maine and elsewhere.
This glossary of nautical terms is an alphabetical listing of terms and expressions connected with ships, shipping, seamanship and navigation on water. Some remain current, while many date from the 17th to 19th centuries. The word nautical derives from the Latin nauticus, from Greek nautikos, from nautēs: "sailor", from naus: "ship".
The Kelvite sounding machine was a small motor- or hand-operated windlass mounted on the deck of a ship. It was used to deploy and retrieve a wire sounding line to determine the depth of water in which the vessel was operating. It was invented by William Thomson, 1st Baron Kelvin, in 1872.
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