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HMS Achates (H12)
HMS ''Achates'' was an destroyer built for the Royal Navy during the late 1920s. Completed in 1930, she initially served with the Mediterranean Fleet. She was sunk on 31 December 1942 during the Battle of the Barents Sea. Design and description In the mid-1920s, the Royal Navy ordered two destroyers from two different builders, , built by Yarrow Shipbuilders, Yarrow, and , built by John I. Thornycroft & Company, Thornycroft, incorporating the lessons learned from World War I, as prototypes for future classes. The A-class destroyers were based on ''Amazon'', slightly enlarged and carrying two more torpedo tubes. They displaced at Displacement (ship), standard load and at deep load. The ships had an length overall, overall length of , a beam (nautical), beam of and a draft (hull), draught of .Whitley, p. 97 ''Acasta'' was powered by a pair of Brown-Curtis geared steam turbines, each driving one shaft, using steam provided by three Admiralty 3-drum boilers. The turbines deve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hedgehog (weapon)
The Hedgehog (also known as an ''Anti-Submarine Projector'') was a forward-throwing anti-submarine weapon that was used primarily during the Second World War. The device, which was developed by the Royal Navy, fired up to 24 spigot mortars ahead of a ship when attacking a U-boat. It was deployed on convoy escort warships such as destroyers and corvettes to supplement the depth charges. As the mortar projectiles employed contact fuzes rather than time or barometric (depth) fuzes, detonation occurred directly against a hard surface such as the hull of a submarine making it more deadly than depth charges, which relied on damage caused by hydrostatic shockwaves. During WWII out of 5,174 British depth charge attacks there were 85.5 kills, a ratio of 60.5 to 1. In comparison, the Hedgehog made 268 attacks for 47 kills, a ratio of 5.7 to 1. Development The "Hedgehog", so named because the empty rows of its launcher spigots resembled the spines on the back of a hedgehog, was a repla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against France. The modern Royal Navy traces its origins to the early 16th century; the oldest of the UK's armed services, it is consequently known as the Senior Service. From the middle decades of the 17th century, and through the 18th century, the Royal Navy vied with the Dutch Navy and later with the French Navy for maritime supremacy. From the mid 18th century, it was the world's most powerful navy until the Second World War. The Royal Navy played a key part in establishing and defending the British Empire, and four Imperial fortress colonies and a string of imperial bases and coaling stations secured the Royal Navy's ability to assert naval superiority globally. Owing to this historical prominence, it is common, even among non-Britons, to ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superfiring
Superfiring armament is a naval military building technique in which two (or more) turrets are located in a line, one behind the other, with the second turret located above ("super") the one in front so that the second turret can fire over the first. This configuration meant that both forward or aft turrets could fire at any target within their sector, even when the target was in the same vertical plane as the turrets. History The history of large surface warships follow generic labels as battleships, and a further distinction between pre-dreadnoughts and dreadnoughts. The era of technical evolution occurred roughly from 1900 to 1945. Part of the technical evolution was driven by the need to compress as much large-gun firepower into the smallest space possible. In early designs, the large-caliber turrets were all located on the same plane firing to one side or the other. In firing ahead or to the rear, usually only the forward-most or rearmost turret could fire, especially a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fuel Oil
Fuel oil is any of various fractions obtained from the distillation of petroleum (crude oil). Such oils include distillates (the lighter fractions) and residues (the heavier fractions). Fuel oils include heavy fuel oil, marine fuel oil (MFO), bunker fuel, furnace oil (FO), gas oil (gasoil), heating oils (such as home heating oil), diesel fuel and others. The term ''fuel oil'' generally includes any liquid fuel that is burned in a furnace or boiler to generate heat ( heating oils), or used in an engine to generate power (as motor fuels). However, it does not usually include other liquid oils, such as those with a flash point of approximately , or oils burned in cotton- or wool-wick burners. In a stricter sense, ''fuel oil'' refers only to the heaviest commercial fuels that crude oil can yield, that is, those fuels heavier than gasoline (petrol) and naphtha. Fuel oil consists of long-chain hydrocarbons, particularly alkanes, cycloalkanes, and aromatics. Small molecules, such as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Trial
A sea trial is the testing phase of a watercraft (including boats, ships, and submarines). It is also referred to as a " shakedown cruise" by many naval personnel. It is usually the last phase of construction and takes place on open water, and it can last from a few hours to many days. Sea trials are conducted to measure a vessel's performance and general seaworthiness. Testing of a vessel's speed, maneuverability, equipment and safety features are usually conducted. Usually in attendance are technical representatives from the builder (and from builders of major systems), governing and certification officials, and representatives of the owners. Successful sea trials subsequently lead to a vessel's certification for commissioning and acceptance by its owner. Although sea trials are commonly thought to be conducted only on new-built vessels (referred by shipbuilders as 'builders trials'), they are regularly conducted on commissioned vessels as well. In new vessels, they are used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Draft (hull)
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] |
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] |
Torpedo Tube
A torpedo tube is a cylindrical device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units (also referred to as torpedo launchers) installed aboard surface vessels. Deck-mounted torpedo launchers are usually designed for a specific type of torpedo, while submarine torpedo tubes are general-purpose launchers, and are often also capable of deploying naval mine, mines and cruise missiles. Most modern launchers are standardized on a diameter for light torpedoes (deck mounted aboard ship) or a diameter for heavy torpedoes (underwater tubes), although other sizes of torpedo tube have been used: see Torpedo#Classes and diameters, Torpedo classes and diameters. Submarine torpedo tube A submarine torpedo tube is a more complex mechanism than a torpedo tube on a surface ship, because the tube has to accomplish the function of moving the torpedo from the normal atmospheric pressure within t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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