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HMS Arethusa (1913)
HMS ''Arethusa'' was the name ship of her class of eight light cruisers built for the Royal Navy in the 1910s. She saw a considerable amount of action during the early years of the First World War, participating in the Battle of Heligoland Bight and the Battle of Dogger Bank. Design and description The ''Arethusa''-class cruisers were intended to lead destroyer flotillas and defend the fleet against attacks by enemy destroyers. The ships were long overall, with a beam of and a deep draught of . Displacement was at normalFriedman 2010, p. 384 and at full load. ''Arethusa'' was powered by four Brown-Curtis steam turbines, each driving one propeller shaft, which produced a total of . The turbines used steam generated by eight Yarrow boilers which gave her a speed of about .Gardiner & Gray, p. 55 She carried of fuel oil that gave a range of at . The main armament of the ''Arethusa''-class ships consisted of two BL Mk XII guns that were mounted on the centreline fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arethusa (mythology)
In Greek mythology, Arethusa (; grc-gre, Ἀρέθουσα) was a nymph who fled from her home in Arcadia beneath the sea and came up as a fresh water fountain on the island of Ortygia in Syracuse, Sicily. Mythology The myth of her transformation begins in Arcadia when she came across a clear stream and began bathing, not knowing it was the river god Alpheus, who flowed down from Arcadia through Elis to the sea. He fell in love during their encounter, but she fled after discovering his presence and intentions, as she wished to remain a chaste attendant of Artemis. After a long chase, she prayed to her goddess to ask for protection. Artemis hid her in a cloud, but Alpheus was persistent. She began to perspire profusely from fear, and soon transformed into a stream. Artemis then broke the ground allowing Arethusa another attempt to flee. Her stream traveled under the sea to the island of Ortygia, but Alpheus flowed through the sea to reach her and mingle with her waters. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Name Ship
The lead ship, name ship, or class leader is the first of a series or class of ships all constructed according to the same general design. The term is applicable to naval ships and large civilian vessels. Large ships are very complex and may take as many as five to ten years to build. Improvements based on experience with building and operating the lead ship are likely to be incorporated into the design or construction of later ships in the class, so it is rare to have vessels that are identical. The second and later ships are often started before the first one is completed, launched and tested. Nevertheless, building copies is still more efficient and cost-effective than building prototypes, and the lead ship will usually be followed by copies with some improvements rather than radically different versions. The improvements will sometimes be retrofitted to the lead ship. Occasionally, the lead ship will be launched and commissioned for shakedown testing before following ship ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propeller Shaft
A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power and torque and rotation, usually used to connect other components of a drivetrain that cannot be connected directly because of distance or the need to allow for relative movement between them. As torque carriers, drive shafts are subject to torsion and shear stress, equivalent to the difference between the input torque and the load. They must therefore be strong enough to bear the stress, while avoiding too much additional weight as that would in turn increase their inertia. To allow for variations in the alignment and distance between the driving and driven components, drive shafts frequently incorporate one or more universal joints, jaw couplings, or rag joints, and sometimes a splined joint or prismatic joint. History The term ''driveshaft'' first appeared during the mid-19th centu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Brown & Company
John Brown and Company of Clydebank was a Scottish Naval architecture, marine engineering and shipbuilding firm. It built many notable and world-famous ships including , , , , , and the ''Queen Elizabeth 2 (ship), Queen Elizabeth 2''. At its height, from 1900 to the 1950s, it was one of the most highly regarded, and internationally famous, shipbuilding companies in the world. However thereafter, along with other UK shipbuilders, John Brown's found it increasingly difficult to compete with the emerging shipyards in Eastern Europe and the far East. In 1968 John Brown's merged with other Clydeside shipyards to form the Upper Clyde Shipbuilders consortium, but that collapsed in 1971. The company then withdrew from shipbuilding but its engineering arm remained successful in the manufacture of industrial gas turbines. In 1986 it became a wholly owned subsidiary of Trafalgar House (company), Trafalgar House, which in 1996 was taken over by Kvaerner. The latter closed the Clydebank en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Displacement (ship)
The displacement or displacement tonnage of a ship is its weight. As the term indicates, it is measured indirectly, using Archimedes' principle, by first calculating the volume of water displaced by the ship, then converting that value into weight. Traditionally, various measurement rules have been in use, giving various measures in long tons. Today, tonnes are more commonly used. Ship displacement varies by a vessel's degree of load, from its empty weight as designed (known as "lightweight tonnage") to its maximum load. Numerous specific terms are used to describe varying levels of load and trim, detailed below. Ship displacement should not be confused with measurements of volume or capacity typically used for commercial vessels and measured by tonnage: net tonnage and gross tonnage. Calculation The process of determining a vessel's displacement begins with measuring its draft.George, 2005. p.5. This is accomplished by means of its "draft marks" (or "load lines"). A mer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Draft (ship)
The draft or draught of a ship's hull is the vertical distance between the waterline and the bottom of the hull (keel). The draught of the vessel is the maximum depth of any part of the vessel, including appendages such as rudders, propellers and drop keels if deployed. Draft determines the minimum depth of water a ship or boat can safely navigate. The related term air draft is the maximum height of any part of the vessel above the water. The more heavily a vessel is loaded, the deeper it sinks into the water, and the greater its draft. After construction, the shipyard creates a table showing how much water the vessel displaces based on its draft and the density of the water (salt or fresh). The draft can also be used to determine the weight of cargo on board by calculating the total displacement of water, accounting for the content of the ship's bunkers, and using Archimedes' principle. The closely related term "trim" is defined as the difference between the forward and aft ... [...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] |
Length Overall
__NOTOC__ Length overall (LOA, o/a, o.a. or oa) is the maximum length of a vessel's hull measured parallel to the waterline. This length is important while docking the ship. It is the most commonly used way of expressing the size of a ship, and is also used for calculating the cost of a marina berth (for example, £2.50 per metre LOA). LOA is usually measured on the hull alone. For sailing ships, this may ''exclude'' the bowsprit and other fittings added to the hull. This is how some racing boats and tall ships use the term LOA. However, other sources may include bowsprits in LOA. Confusingly, LOA has different meanings. "Sparred length", "Total length including bowsprit", "Mooring length" and "LOA including bowsprit" are other expressions that might indicate the full length of a sailing ship. LOD Often used to distinguish between the length of a vessel including projections (e.g. bow sprits, etc.) from the length of the hull itself, the Length on Deck or LOD is often repor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flotilla
A flotilla (from Spanish, meaning a small ''flota'' (fleet) of ships), or naval flotilla, is a formation of small warships that may be part of a larger fleet. Composition A flotilla is usually composed of a homogeneous group of the same class of warship, such as frigates, destroyers, torpedo boats, submarines, gunboats, or minesweepers. Groups of larger warships are usually called squadrons, but similar units of non-capital ships may be called squadrons in some instances, and flotillas in others. Formations including more than one capital ship, e.g. men-of-war, battleships, and aircraft carriers, typically alongside smaller ships and support craft, are typically called fleets, each portion led by a capital ship being a squadron or task force (see reference below). A flotilla is usually commanded by a rear admiral, a commodore or a captain, depending on the importance of the command (a vice admiral would normally command a squadron). A flotilla is often divided into two or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Destroyer
In naval terminology, a destroyer is a fast, manoeuvrable, long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against powerful short range attackers. They were originally developed in 1885 by Fernando Villaamil for the Spanish NavySmith, Charles Edgar: ''A short history of naval and marine engineering.'' Babcock & Wilcox, ltd. at the University Press, 1937, page 263 as a defense against torpedo boats, and by the time of the Russo-Japanese War in 1904, these "torpedo boat destroyers" (TBDs) were "large, swift, and powerfully armed torpedo boats designed to destroy other torpedo boats". Although the term "destroyer" had been used interchangeably with "TBD" and "torpedo boat destroyer" by navies since 1892, the term "torpedo boat destroyer" had been generally shortened to simply "destroyer" by nearly all navies by the First World War. Before World War II, destroyers were light vessels with little endurance for unattended o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battle Of Dogger Bank (1915)
The Battle of Dogger Bank was a naval engagement during the First World War that took place on 24 January 1915 near the Dogger Bank in the North Sea, between squadrons of the British Grand Fleet and the (High Seas Fleet). The British had intercepted and decoded German wireless transmissions, gaining advance knowledge that a German raiding squadron was heading for Dogger Bank and ships of the Grand Fleet sailed to intercept the raiders. The British surprised the smaller and slower German squadron, which fled for home. During a stern chase lasting several hours, the British caught up with the Germans and engaged them with long-range gunfire. The British disabled , the rearmost German ship, and the Germans put the British flagship out of action. Due to inadequate signalling, the remaining British ships stopped the pursuit to sink ''Blücher''; by the time the ship had been sunk, the rest of the German squadron had escaped. The German squadron returned to harbour, with some ship ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battle Of Heligoland Bight (1914)
The Battle of Heligoland Bight was the first Anglo-German naval battle of the First World War, fought on 28 August 1914, between ships of the United Kingdom and Germany. The battle took place in the south-eastern North Sea, when the British attacked German patrols off the north-west German coast. The German High Seas Fleet was in harbour on the north German coast while the British Grand Fleet was out in the northern North Sea. Both sides engaged in long-distance sorties with cruisers and battlecruisers, with close reconnaissance of the area of sea near the German coast—the Heligoland Bight—by destroyer. The British devised a plan to ambush German destroyers on their daily patrols. A British flotilla of 31 destroyers and two cruisers under Commodore Reginald Tyrwhitt, with submarines commanded by Commodore Roger Keyes, was dispatched. They were supported at longer range by an additional six light cruisers commanded by William Goodenough and five battlecruisers commanded b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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