Jacob's Ladder (nautical)
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Jacob's Ladder (nautical)
The term Jacob's ladder, used on a ship, applies to two kinds of rope ladders. The first is a flexible hanging ladder. It consists of vertical ropes or chains supporting horizontal, historically round and wooden, rungs. Today, flat runged flexible ladders are also called Jacob's ladders. The name is commonly used without the apostrophe (Jacobs ladder). They are used to allow access over the side of ships and as a result Pilot ladders are often incorrectly referred to as Jacob's ladders. A pilot ladder has specific regulations on step size, spacing and the use of spreaders. It is the use of spreaders in a pilot ladder that distinguishes it from a Jacob's ladder. Spreaders are long treads that extend well past the vertical ropes to stop the ladder from twisting about its long axis (possible when a ship rolls and the ladder is no longer in contact with the ship's side) with the person possibly becoming trapped between the ship's side and the ladder. When not being used, the ladd ...
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Pilot Ladder
A pilot ladder is a highly specialized form of rope ladder, typically used on board cargo vessels for the purposes of embarking and disembarking pilots. The design and construction of the ladders is tightly specified by international regulation under the SOLAS regime. Construction The ladders are made by threading and fixing a series of hardwood, machined steps, each not more than , onto two pairs of minimum diameter manila ropes, and binding each step to the ropes at (+- ) intervals. At a maximum interval of eight steps, the standard step is replaced by a ''spreader'', which is an elongated version of the standard machined step, with a minimum length of . The spreader's function is to prevent the ladder from twisting in the prevailing weather conditions when in use. The lowest four steps of the ladder are normally made from a synthetic or composite resin, which is more resistant than hardwood, to the interaction between the host vessel and the pilot boat coming alongside. ...
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Fragmentation (weaponry)
Fragmentation is the process by which the casing, shot, or other components of an anti-personnel weapon, bomb, barrel bomb, land mine, IED, artillery, mortar, tank gun, or autocannon shell, rocket, missile, grenade, etc. are dispersed and/or shattered by the detonation of the explosive filler. The correct term for these pieces is "fragmentation"; "shards" or "splinters" can be used for non-preformed fragments. Preformed fragments can be of various shapes (spheres, cubes, rods, etc.) and sizes, and are normally held rigidly within some form of matrix or body until the high explosive (HE) filling is detonated. The resulting high-velocity fragments produced by either method are the main lethal mechanisms of these weapons, rather than the heat or overpressure caused by detonation, although offensive grenades are often constructed without a frag matrix. These casing pieces are often incorrectly referred to as "shrapnel", particularly by non-military media sources. History The ...
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Ladder
A ladder is a vertical or inclined set of rungs or steps used for climbing or descending. There are two types: rigid ladders that are self-supporting or that may be leaned against a vertical surface such as a wall, and rollable ladders, such as those made of rope or aluminium, that may be hung from the top. The vertical members of a rigid ladder are called stringers or rails (US) or stiles (UK). Rigid ladders are usually portable, but some types are permanently fixed to a structure, building, or equipment. They are commonly made of metal, wood, or fiberglass, but they have been known to be made of tough plastic. Historical usages Ladders are ancient tools and technology. A ladder is featured in a Mesolithic rock painting that is at least 10,000 years old, depicted in the Spider Caves in Valencia, Spain. The painting depicts two humans using a ladder to reach a wild honeybee nest to harvest honey. The ladder is depicted as long and flexible, possibly made out of some sort of gr ...
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Square Rigged
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. The square rig is aerodynamically the most efficient running rig (i.e., sailing downwind), and stayed popular on ocean-going sailing ships until the end of the Age of Sail. The last commercial sailing ships, windjammers, were usually square-rigged four-masted barques. History The oldest archaeological evidence of use of a square-rig on a vessel is an image on a clay disk from Mesopotamia from 5000 BC. Single sail square rigs were used by the ancient Egyptians, the Phoenicians, the Greeks, the Romans, and the Celts. Later the Scandinavians, the Germanic peoples, and the Slavs adopted the single square-rigged sail, with it be ...
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Topmast
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. The topmast is semi-permanently attached to the upper front of the lower mast, at the top. Its shrouds run to the edges of the top, rather than to the sides of the hull, though long shrouds leading well aft to the hull, more in the manner of backstays, are sometimes seen. In accordance with the standard square rig sail plan, the topmast carries the topsail. In the late 19th century, however, topsails became so big that merchant ships began to divide them into two separate sails for easier handling; since these were still on the topmast they were known as upper and lower topsails to preserve the consistency of the naming scheme. The majority of large square-riggers today carry separate upper and lower topsails. The main topmast carries the upper end of the main-topmast-staysail; a mizzen-topmast may carry the e ...
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Top (sailing Ship)
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 fore 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 r ...
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Futtock Shrouds
{{for, 1970 British television comedy, Futtocks End 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. Climbing a ship's rigging In the most traditional ships, the futtock shrouds can be used to gain access to the tops. Sailors ascend ratlines on the ordinary shrouds until nearly at the top, then transfer to the futtock shrouds which will be reaching upwards and outwards above them. Using the futtock shrouds involves climbing the underside of an overhanging rope at about 45 degrees. Futtock shrouds may or may not have ratlines. As well as climbing the futtock shrouds, most ships also allowed access to the top through the " lubber's hole" at the tip of the ordinary ratlines. However, this ...
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Tall Ship
A tall ship is a large, traditionally- rigged sailing vessel. Popular modern tall ship rigs include topsail schooners, brigantines, brigs and barques. "Tall ship" can also be defined more specifically by an organization, such as for a race or festival. History Traditional rigging may include square rigs and gaff rigs, usually with separate topmasts and topsails. It is generally more complex than modern rigging, which utilizes newer materials such as aluminum and steel to construct taller, lightweight masts with fewer, more versatile sails. Most smaller, modern vessels use the Bermuda rig. Though it did not become popular elsewhere until the twentieth century, this rig was developed in Bermuda in the seventeenth century, and had historically been used on its small ships, the Bermuda sloops. Author and master mariner Joseph Conrad (who spent 1874 to 1894 at sea in tall ships and was quite particular about naval terminology) used the term "tall ship" in his works; for example, ...
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Ratlines
Ratlines () are lengths of thin line tied between the shrouds of a sailing ship to form a ladder. Found on all square-rigged ships, whose crews must go aloft to stow the square sails, they also appear on larger fore-and-aft rigged vessels to aid in repairs aloft or conduct a lookout from above. Rat-boards Rat-boards are lower courses in a ratline, often made of slats of wood (battens) for support where the distance between shrouds is greatest. In some instances holes in these slats guide and organise low-tension lines between the deck and the rig. Knotting See also * Footrope Each yard on a square or gaff rigged sailing ship is equipped with a footrope for sailors to stand on while setting or stowing the sails. Formerly, the footrope was the rope sewn along the lower edge of a square sail, and the rope below the ya ... References {{Sail Types Sailing rigs and rigging ...
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Wooden Ship
A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished from boats, based on size, shape, load capacity, and purpose. Ships have supported exploration, trade, warfare, migration, colonization, and science. After the 15th century, new crops that had come from and to the Americas via the European seafarers significantly contributed to world population growth. Ship transport is responsible for the largest portion of world commerce. The word ''ship'' has meant, depending on the era and the context, either just a large vessel or specifically a ship-rigged sailing ship with three or more masts, each of which is square-rigged. As of 2016, there were more than 49,000 merchant ships, totaling almost 1.8 billion dead weight tons. Of these 28% were oil tankers, 43% were bulk carriers, and 13% were cont ...
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