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 (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 running sideways out from the mast to spread the topmasts shrouds. These crosstrees rests on two trestle trees running for and aft, which themself 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.
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 mizen-top would be a platform on the mizenmast.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 be manned by sailors or marines armed with muskets or rifles; Horatio Nelson was killed 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 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—schooners. Still others employ a combination of square and fore-and aft sails, including the barque, barquentine, and brigantine. Sailing ships developed differently in Asia, which produced the junk and dhow—vessels that incorporated innovations absent in European ships of the time. Technically in the Age of Sail a ship was a specific type of vessel, with a bowsprit and three masts, each of which consists of a lower, top, and topgallant mast.
A sail plan is a description of the specific ways that a sailing craft is rigged, as discussed below. 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 brig is a sailing vessel with two square-rigged masts. During the Age of Sail, brigs were seen as fast and maneuverable and were used as both naval warships and merchant vessels. They were especially popular in the 18th and early 19th centuries. Brigs fell out of use with the arrival of the steam ship because they required a relatively large crew for their small size and were difficult to sail into the wind. Their rigging differs from that of a brigantine which has a gaff-rigged mainsail, while a brig has a square mainsail with an additional gaff-rigged spanker behind the mainsail.
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, and 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 is a partial glossary of nautical terms; some remain current, while many date from the 17th to 19th centuries. See also Wiktionary's nautical terms, Category:Nautical terms, and Nautical metaphors in English. See the Further reading section for additional words and references.
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, beyond the last stay, 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 a 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.
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, used to anchor the shrouds from the topgallant mast. Similarly, they may be mounted at the upper end of the topgallant to anchor the shrouds from the royal mast. Similar transverse spars remain on steam ship 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.