|
Zabra
A zabra (zah-brə) was a small or midsized sailing vessel used off the coasts of Spain and Portugal to carry goods by sea from the 13th century until the mid-16th century; they were well-armed to defend themselves against pirates and corsairs. Early Iberian documentary sources, such as the ''Estoria de España'', refer to their use by the Moors and from about 1500 onwards a fleet of zabras developed in the coastal trade of Cantabria on the Cantabrian Sea, and fishermen began using them to exploit the fisheries of Ireland and North America. These zabras were fast, square-rigged row-sailers with two masts; they were rowed with 14 to 18 oars and had a tonnage of between 20 and 60 tons. Their ratio of beam to length was 1: 3.75–4.0. The smallest zabras had only a half deck or a poop deck, but the larger ones were covered with a flush deck. Because of their excellent handling qualities, and despite their modest size, they were frequently used by the Crown of Castile for the trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zabra Santiago
A zabra (zah-brə) was a small or midsized sailing vessel used off the coasts of Spain and Portugal to carry goods by sea from the 13th century until the mid-16th century; they were well-armed to defend themselves against pirates and corsairs. Early Iberian documentary sources, such as the ''Estoria de España'', refer to their use by the Moors and from about 1500 onwards a fleet of zabras developed in the coastal trade of Cantabria on the Cantabrian Sea, and fishermen began using them to exploit the fisheries of Ireland and North America. These zabras were fast, square-rigged row-sailers with two masts; they were rowed with 14 to 18 oars and had a tonnage of between 20 and 60 tons. Their ratio of beam to length was 1: 3.75–4.0. The smallest zabras had only a half deck or a poop deck, but the larger ones were covered with a flush deck. Because of their excellent handling qualities, and despite their modest size, they were frequently used by the Crown of Castile for the trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Square Rig
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waterline
The waterline is the line where the hull of a ship meets the surface of the water. Specifically, it is also the name of a special marking, also known as an international load line, Plimsoll line and water line (positioned amidships), that indicates the draft of the ship and the legal limit to which a ship may be loaded for specific water types and temperatures in order to safely maintain buoyancy, particularly with regard to the hazard of waves that may arise. Varying water temperatures will affect a ship's draft, because warm water is less dense than cold water, providing less buoyancy. In the same way, fresh water is less dense than salinated or seawater with a similar lessening effect upon buoyancy. For vessels with displacement hulls, the hull speed is defined by, among other things, the waterline length. In a sailing boat, the waterline length can change significantly as the boat heels, and can dynamically affect the speed of the boat. A waterline can also refer to any l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beam (nautical)
The beam of a ship is its width at its widest point. The maximum beam (BMAX) is the distance between planes passing through the outer extremities of the ship, beam of the hull (BH) only includes permanently fixed parts of the hull, and beam at waterline (BWL) is the maximum width where the hull intersects the surface of the water. Generally speaking, the wider the beam of a ship (or boat), the more initial stability it has, at the expense of secondary stability in the event of a capsize, where more energy is required to right the vessel from its inverted position. A ship that heels on her ''beam ends'' has her deck beams nearly vertical. Typical values Typical length-to-beam ratios ( aspect ratios) for small sailboats are from 2:1 (dinghies to trailerable sailboats around ) to 5:1 (racing sailboats over ). Large ships have widely varying beam ratios, some as large as 20:1. Rowing shells designed for flatwater racing may have length to beam ratios as high as 30:1, while a cor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumblehome
Tumblehome is a term describing a hull which grows narrower above the waterline than its beam. The opposite of tumblehome is flare. A small amount of tumblehome is normal in many naval architecture designs in order to allow any small projections at deck level to clear wharves. The term is also applied to automobile design, where a vehicle's sides taper inward as they go up. This includes a roof tapering in, and curved window glass. Origins Tumblehome was common on wooden warships for centuries. It allowed for maximizing a vessel's beam and creating a low center of gravity (by decreasing mass above the waterline), both tending to maximize stability. In the era of oared combat ships it was quite common, placing the oar ports as far abeam as possible, allowing maximum possible manpower to be brought to bear. Inward-sloping sides made it more difficult to board by a vessel by force, as the ships would come to contact at their widest points, with the decks some distance apart. W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gross Tonnage
Gross tonnage (GT, G.T. or gt) is a nonlinear measure of a ship's overall internal volume. Gross tonnage is different from gross register tonnage. Neither gross tonnage nor gross register tonnage should be confused with measures of mass or weight such as deadweight tonnage or Displacement (ship), displacement. Gross tonnage, along with net tonnage, was defined by the ''International Convention on Tonnage Measurement of Ships, 1969'', adopted by the International Maritime Organization (IMO) in 1969, and came into force on 18 July 1982. These two measurements replaced gross register tonnage (GRT) and net register tonnage (NRT). Gross tonnage is calculated based on "the moulded volume of all enclosed spaces of the ship" and is used to determine things such as a ship's manning regulations, safety rules, registration fees, and port dues, whereas the older gross register tonnage is a measure of the volume of only certain enclosed spaces. History The International Convention on Tonn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beakhead
A beakhead or beak is the protruding part of the foremost section of a sailing ship. It was fitted on sailing vessels from the 16th to the 18th century and served as a working platform by sailors working the sails of the bowsprit, the forward-pointing mast that carries the spritsails. The beakhead would be one of the most ornate sections of a ship, particularly in the extravagant Baroque-style ships of the 17th century. The sides were often decorated with carved statues and located directly underneath was the figurehead, usually in the form of animals, shields or mythological creatures. The beakhead also housed the crew's toilets (head A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may ...), which would drop refuse straight into the sea without sullying the ship's hull unnecessarily. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forecastle
The forecastle ( ; contracted as fo'c'sle or fo'c's'le) is the upper deck of a sailing ship forward of the foremast, or, historically, the forward part of a ship with the sailors' living quarters. Related to the latter meaning is the phrase " before the mast" which denotes anything related to ordinary sailors, as opposed to a ship's officers. History and design In medieval shipbuilding, a ship of war was usually equipped with a tall, multi-deck castle-like structure in the bow of the ship. It served as a platform for archers to shoot down on enemy ships, or as a defensive stronghold if the ship were boarded. A similar but usually much larger structure, called the aftcastle, was at the aft end of the ship, often stretching all the way from the main mast to the stern. Having such tall upper works on the ship was detrimental to sailing performance. As cannons were introduced and gunfire replaced boarding as the primary means of naval combat during the 16th century, the medieval ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bay Of Biscay
The Bay of Biscay (), known in Spain as the Gulf of Biscay ( es, Golfo de Vizcaya, eu, Bizkaiko Golkoa), and in France and some border regions as the Gulf of Gascony (french: Golfe de Gascogne, oc, Golf de Gasconha, br, Pleg-mor Gwaskogn), is a gulf of the northeast Atlantic Ocean located south of the Celtic Sea. It lies along the western coast of France from Point Penmarc'h to the Spanish border, and the northern coast of Spain west to Cape Ortegal. The south area of the Bay of Biscay that washes over the northern coast of Spain is known locally as the Cantabrian Sea. The average depth is and the greatest depth is . Name The Bay of Biscay is named (for English speakers) after Biscay on the northern Spanish coast, probably standing for the western Basque districts (''Biscay'' up to the early 19th century). Its name in other languages is: * ast, Mar Cantábricu * eu, Bizkaiko golkoa * br, pleg-mor Gwaskogn * french: golfe de Gascogne (named after Gascony, France) * gl, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Military Logistics
Military logistics is the discipline of planning and carrying out the movement, supply, and maintenance of military forces. In its most comprehensive sense, it is those aspects or military operations that deal with: * Design, development, acquisition, storage, distribution, maintenance, evacuation, and disposition of materiel. * Transport of personnel. * Acquisition or construction, maintenance, operation and disposition of facilities. * Acquisition or furnishing of services. * Medical and health service support. Etymology and definition The word "logistics" is derived from the Greek adjective ''logistikos'' meaning "skilled in calculating", and the corresponding Latin word ''logisticus''. In turn this comes from the Greek ''logos'', which refers to the principles of thought and action. Another Latin root, ''log-'', gave rise to ''logio'', meaning to lodge or dwell, around 1380, and became the French verb , meaning "to lodge". Around 1670, the French King Louis XIV created t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateen
A lateen (from French ''latine'', meaning "Latin") or latin-rig is a triangular sail set on a long yard mounted at an angle on the mast, and running in a fore-and-aft direction. The settee can be considered to be an associated type of the same overall category of sail. The lateen originated in the Mediterranean as early as the 2nd century CE, during Roman times, and became common there by the 5th century. The wider introduction of lateen rig at this time coincided with a reduction in the use of the Mediterranean square rig of the classical era. Since the performance of these two rigs is broadly similar, it is suggested that the change from one to the other was on cost grounds, since lateen used fewer components and had less cordage to be replaced when it wore out. Arab seafarers adopted the lateen rig at a later datethere is some limited archaeological evidence of lateen rig in the Indian Ocean in the 13th century CE and iconographic evidence from the 16th century. It has been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
