The top on a traditional square rigged ship is the platform at the upper end of each (lower) mast. [1] This is not the masthead "crow's nest" of the popular imagination – above the mainmast (for example) 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.
The main purpose of the top is to anchor the shrouds of the topmast that extends above it. Shrouds down to the side of the hull would be at too acute an angle from the mast, so crosstrees run sideways out from the mast to spread the topmast shrouds. These crosstrees rest on two trestle trees running fore and aft, which themselves are placed on top of the cheeks of hounds, bolted to the sides of the mast. Placing a few timbers onto the crosstrees produces a useful platform, the top. The futtock shrouds carry the load of the upper shrouds into the mast below. [2]
At the upper end of the topmast and topgallant, there is a similar situation regarding the next mast up (topgallant and royal respectively). At these points a smaller top might be constructed, but it is more usual simply to leave the shroud-bearing struts open, in which case they are known as crosstrees.
Access for sailors to the top may be by a Jacob's ladder, lubber's hole, or the futtock shrouds.
A foremast might be stepped into a similar fore-top platform on the foremast. A mizzen-top would be a platform on the mizzenmast. [3] Similar main-top and fore-top platforms have been retained on steam ships and motor vessels as preferred locations for installing rotating radar antennae.
A fighting top was an enlarged top with swivel guns, designed to fire down at the deck of enemy ships. They could also hold sailors or marines armed with muskets or rifles; Horatio Nelson was mortally wounded at the Battle of Trafalgar by a sniper firing from a fighting top of the Redoutable.
Rigging comprises the system of ropes, cables and chains, which support a sailing ship or sail boat's masts—standing rigging, including shrouds and stays—and which adjust the position of the vessel's sails and spars to which they are attached—the running rigging, including halyards, braces, sheets and vangs.
A sail plan is a description of the specific ways that a sailing craft is rigged. Also, the term "sail plan" is a graphic depiction of the arrangement of the sails for a given sailing craft.
A brigantine is a two-masted sailing vessel with a fully square-rigged foremast and at least two sails on the main mast: a square topsail and a gaff sail mainsail. The main mast is the second and taller of the two masts.
A jib is a triangular sail that sets ahead of the foremast of a sailing vessel. Its tack is fixed to the bowsprit, to the bows, or to the deck between the bowsprit and the foremost mast. Jibs and spinnakers are the two main types of headsails on a modern boat.
A topsail ("tops'l") is a sail set above another sail; on square-rigged vessels further sails may be set above topsails.
On a sailing boat, the shrouds are pieces of standing rigging which hold the mast up from side to side. There is frequently more than one shroud on each side of the boat.
Standing rigging comprises the fixed lines, wires, or rods, which support each mast or bowsprit on a sailing vessel and reinforce those spars against wind loads transferred from the sails. This term is used in contrast to running rigging, which represents the moveable elements of rigging which adjust the position and shape of the sails.
The mast of a sailing vessel is a tall spar, or arrangement of spars, erected more or less vertically on the centre-line of a ship or boat. Its purposes include carrying sails, spars, and derricks, giving necessary height to a navigation light, look-out position, signal yard, control position, radio aerial or signal lamp. Large ships have several masts, with the size and configuration depending on the style of ship. Nearly all sailing masts are guyed.
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".
Square rig is a generic type of sail and rigging arrangement in which the primary driving sails are carried on horizontal spars which are perpendicular, or square, to the keel of the vessel and to the masts. These spars are called yards and their tips, outside the lifts, are called the yardarms. A ship mainly rigged so is called a square-rigger.
A full-rigged ship or fully rigged ship is a sailing vessel's sail plan with three or more masts, all of them square-rigged. A full-rigged ship is said to have a ship rig or be ship-rigged. Such vessels also have each mast stepped in three segments: lower mast, top mast, and topgallant mast. Other large, multi-masted sailing vessels may be regarded as ships while lacking one of the elements of a full-rigged ship, e.g. having one or more masts support only a fore-and-aft sail or having a mast that only has two segments.
Stays are ropes, wires, or rods on sailing vessels that run fore-and-aft along the centerline from the masts to the hull, deck, bowsprit, or to other masts which serve to stabilize the masts.
PNS Rah Naward is a sail training ship of the Pakistan Navy. She was commissioned in 2001 as Prince William for the Tall Ships Youth Trust and sold in 2010 to the Pakistan Navy and renamed Rah Naward.
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 term Jacob's ladder, used on a ship, applies to two kinds of rope ladders.
The masts of traditional sailing ships were not single spars, but were constructed of separate sections or masts, each with its own rigging. The topmast is one of these.
A jackass-barque, sometimes spelled jackass bark, is a sailing ship with three masts, of which the foremast is square-rigged and the main is partially square-rigged and partially fore-and-aft rigged (course). The mizzen mast is fore-and-aft rigged.
Crosstrees are the two horizontal spars at the upper ends of the topmasts of sailing ships that are used to anchor the shrouds from the topgallant mast. They may also be mounted at the upper end of the topgallant to anchor the shrouds from the royal mast. Similar transverse spars remain on steamship and motor vessel masts to secure wire antennae or signal flag halyards.
A sprit topmast is a small topmast that was sometimes carried on the end of the bowsprit of a large European warship during the Age of Sail. Its purpose as initially built was to assist the spritsail in bringing the bow around when tacking.
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".