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HMS Hydra (1871)
HMS ''Hydra'' was the second ship completed of the four breastwork monitors built for the Royal Navy during the 1870s. The ships were ordered to satisfy demands for local defence during the war scare of 1870, but the pace of construction slowed tremendously as the perceived threat of war declined. The ship spent most of her career in Wikt:mothball, reserve; her only sustained period in commission was four months during the Russo-Turkish War (1877–1878), Russo-Turkish War in 1878 when the British were trying to force the Russians to end the war without seizing Constantinople. ''Hydra'' was sold for ship breaking, scrap in 1903. Design and description The ships had a length between perpendiculars of , a beam (nautical), beam of , and a draft (ship), draught of at deep load. They displaced . Their crew consisted of 156 officers and men.Parkes, p. 213 The ''Cyclops''-class ships and other ships of her type were described by Admiral George Alexander Ballard as being like "full ...
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Brassey's Naval Annual
''The Naval Annual'' was a periodical that provided considerable text and graphic information (largely concerning the British Royal Navy) which had previously been obtainable only by consulting a wide range of often foreign language publications. During its life it underwent a number of title changes. The ''Annual'' was started by Thomas Brassey, 1st Earl Brassey, in 1886. Though often compared with ''Jane's Fighting Ships'', the two British annuals were, in fact quite different. The Brassey series began a dozen years earlier, and its special strength was the dozen or more detailed articles on naval (plus, from 1920 through 1935, merchant marine) matters, authored by experts. They covered British and other nations' naval developments ranging from the latest ships to overall policy. The first five or six Brassey volumes used a second printing colour (a light blue green) to highlight armored portions of naval vessels' hulls. Through 1949, the series was also known for its ex ...
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Mothball
Mothballs are small balls of chemical pesticide and deodorant, sometimes used when storing clothing and other materials susceptible to damage from mold or moth larvae (especially clothes moths like ''Tineola bisselliella''). Composition Older mothballs consisted primarily of naphthalene, but due to naphthalene's flammability, many modern mothball formulations instead use 1,4-dichlorobenzene. The latter formulation may be somewhat less flammable, although both chemicals have the same NFPA 704 rating for flammability. The latter chemical is also variously labeled as para-dichlorobenzene, p-dichlorobenzene, pDCB, or PDB, making it harder to identify unless all these acronyms are known to a potential purchaser. Both of these formulations have the strong, pungent, sickly-sweet odor often associated with mothballs. Both naphthalene and 1,4-dichlorobenzene undergo sublimation, meaning that they transition from a solid state directly into a gas; this gas is toxic to moths and moth lar ...
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Jack (device)
A jack is a mechanical lifting device used to apply great forces or lift heavy loads. A mechanical jack employs a screw thread for lifting heavy equipment. A hydraulic jack uses hydraulic power. The most common form is a car jack, floor jack or garage jack, which lifts vehicles so that maintenance can be performed. Jacks are usually rated for a maximum lifting capacity (for example, 1.5 tons or 3 tons). Industrial jacks can be rated for many tons of load. Etymology The personal name ''Jack'', which came into English usage around the thirteenth century as a nickname form of ''John'', came in the sixteenth century to be used as a colloquial word for 'a man (of low status)' (much as in the modern usage 'jack of all trades, master of none'). From here, the word was 'applied to things which in some way take the place of a lad or man, or save human labour'. The first attestation in the ''Oxford English Dictionary'' of ''jack'' in the sense 'a machine, usually portable, for lifting ...
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Shell (projectile)
A shell, in a military context, is a projectile whose payload contains an explosive, incendiary, or other chemical filling. Originally it was called a bombshell, but "shell" has come to be unambiguous in a military context. Modern usage sometimes includes large solid kinetic projectiles that is properly termed shot. Solid shot may contain a pyrotechnic compound if a tracer or spotting charge is used. All explosive- and incendiary-filled projectiles, particularly for mortars, were originally called ''grenades'', derived from the French word for pomegranate, so called because of the similarity of shape and that the multi-seeded fruit resembles the powder-filled, fragmentizing bomb. Words cognate with ''grenade'' are still used for an artillery or mortar projectile in some European languages. Shells are usually large-caliber projectiles fired by artillery, armored fighting vehicles (e.g. tanks, assault guns, and mortar carriers), warships, and autocannons. The shape ...
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Round Shot
A round shot (also called solid shot or simply ball) is a solid spherical projectile without explosive charge, launched from a gun. Its diameter is slightly less than the bore of the barrel from which it is shot. A round shot fired from a large-caliber gun is also called a cannonball. The cast iron cannonball was introduced by a French artillery engineer Samuel J. Besh after 1450; it had the capacity to reduce traditional English castle wall fortifications to rubble. French armories would cast a tubular cannon body in a single piece, and cannonballs took the shape of a sphere initially made from stone material. Advances in gunpowder manufacturing soon led the replacement of stone cannonballs with cast iron ones. Round shot was made in early times from dressed stone, referred to as gunstone (Middle English: ''gunneston''), but by the 17th century, from iron. It was used as the most accurate projectile that could be fired by a smoothbore cannon, used to batter the ...
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Wrought Iron
Wrought iron is an iron alloy with a very low carbon content (less than 0.08%) in contrast to that of cast iron (2.1% to 4%). It is a semi-fused mass of iron with fibrous slag Inclusion (mineral), inclusions (up to 2% by weight), which give it a wood-like "grain" that is visible when it is etched, rusted, or bent to structural failure, failure. Wrought iron is tough, malleable, ductile, corrosion resistant, and easily forge welding, forge welded, but is more difficult to welding, weld electrically. Before the development of effective methods of steelmaking and the availability of large quantities of steel, wrought iron was the most common form of malleable iron. It was given the name ''wrought'' because it was hammered, rolled, or otherwise worked while hot enough to expel molten slag. The modern functional equivalent of wrought iron is Carbon steel#Mild or low-carbon steel, mild steel, also called low-carbon steel. Neither wrought iron nor mild steel contain enough carbon to be ...
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Muzzle Velocity
Muzzle velocity is the speed of a projectile (bullet, pellet, slug, ball/shots or shell) with respect to the muzzle at the moment it leaves the end of a gun's barrel (i.e. the muzzle). Firearm muzzle velocities range from approximately to in black powder muskets, to more than in modern rifles with high-velocity cartridges such as the .220 Swift and .204 Ruger, all the way to for tank guns firing kinetic energy penetrator ammunition. To simulate orbital debris impacts on spacecraft, NASA launches projectiles through light-gas guns at speeds up to . Projectile velocity For projectiles in unpowered flight, its velocity is highest at leaving the muzzle and drops off steadily because of air resistance. Projectiles traveling less than the speed of sound (about in dry air at sea level) are ''subsonic'', while those traveling faster are ''supersonic'' and thus can travel a substantial distance and even hit a target before a nearby observer hears the "bang" of the shot. Projec ...
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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 ...
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Boiler (steam Generator)
A boiler is a closed vessel in which fluid (generally water) is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications, including water heating, central heating, boiler-based power generation, cooking, and sanitation. Heat sources In a fossil fuel power plant using a steam cycle for power generation, the primary heat source will be combustion of coal, oil, or natural gas. In some cases byproduct fuel such as the carbon monoxide rich offgasses of a coke battery can be burned to heat a boiler; biofuels such as bagasse, where economically available, can also be used. In a nuclear power plant, boilers called steam generators are heated by the heat produced by nuclear fission. Where a large volume of hot gas is available from some process, a heat recovery steam generator or recovery boiler can use the heat to produce steam, with little or no extra fuel consumed; such a configuration is com ...
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George Alexander Ballard
Admiral George Alexander Ballard (7 March 1862 – 16 September 1948) was an officer of the Royal Navy and a historian. Biography Ballard was the eldest son of General John Archibald Ballard (1829–1880), and his wife Joanna, the daughter of Robert Scott-Moncrieff, and was born at Malabar Hill, Bombay on 7 March 1862. He joined the Royal Navy as a sub-lieutenant, was promoted lieutenant 15 March 1884, and commander 31 December 1897. In February 1902 he was ordered to six months' service at the Admiralty. He was further promoted captain 31 December 1903. In May 1913, Ballard was appointed a naval aide-de-camp to King George V, and in the King´s Birthday Honours 3 June 1913 he was appointed a Companion of the Order of the Bath. The following year he was appointed rear admiral 27 August 1914. He became Admiral Superintendent Malta Dockyard in September 1916. After a long and active career in the Navy he retired as vice-admiral in 1921 and was advanced to the rank of admiral o ...
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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 ...
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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 ...
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