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HMS Australia (1886)
HMS ''Australia'' was one of seven armoured cruisers built for the Royal Navy in the mid-1880s. She was assigned to the Mediterranean Fleet in 1889 and remained there until 1893 when she returned home. The ship was assigned to the Coast Guard Squadron for the next decade before she was placed in reserve in 1903. ''Australia'' was sold for scrap in 1905. Design and description ''Australia'' had a length between perpendiculars of , a beam of and a draught of . Designed to displace , all of the ''Orlando''-class ships proved to be overweight and displaced approximately . The ship was powered by a pair of three-cylinder triple-expansion steam engines, each driving one shaft, which were designed to produce a total of and a maximum speed of using steam provided by four boilers with forced draught. During her sea trials, ''Australia'' reached . The ship carried a maximum of of coal which was designed to give her a range of at a speed of . The ship's complement was 484 offi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australia (continent)
The continent of Australia, sometimes known in technical contexts by the names Sahul (), Australia-New Guinea, Australinea, Meganesia, or Papualand to distinguish it from the country of Australia, is located within the Southern and Eastern hemispheres. The name "Sahul" takes its name from the Sahul Shelf, which is a part of the continental shelf of the Australian continent. The continent includes mainland Australia, Tasmania, the island of New Guinea (Papua New Guinea and Indonesian Western New Guinea), the Aru Islands, the Ashmore and Cartier Islands, most of the Coral Sea Islands, and some other nearby islands. Situated in the geographical region of Oceania, Australia is the smallest of the seven traditional continents. The continent includes a continental shelf overlain by shallow seas which divide it into several landmasses—the Arafura Sea and Torres Strait between mainland Australia and New Guinea, and Bass Strait between mainland Australia and Tasmania. Wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conning Tower
A conning tower is a raised platform on a ship or submarine, often armored, from which an officer in charge can conn the vessel, controlling movements of the ship by giving orders to those responsible for the ship's engine, rudder, lines, and ground tackle. It is usually located as high on the ship as practical, to give the conning team good visibility of the entirety of the ship, ocean conditions, and other vessels. The naval term "conn" may derive from the Middle English ''conne'' (study, become acquainted with) or French ''conduire'' from Latin ''conducere'' (conduct). Surface ships On surface ships, the conning tower was a feature of all battleships and armored cruisers from about 1860 to the early years of World War II. Located at the front end of the superstructure, the conning tower was a heavily armored cylinder, with tiny slit windows on three sides providing a reasonable field of view. Designed to shield just enough personnel and devices for navigation during battle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broadside (naval)
A broadside is the side of a ship, or more specifically the battery of cannon on one side of a warship or their coordinated fire in naval warfare, or a measurement of a warship's maximum simultaneous firepower which can be delivered upon a single target (because this concentration is usually obtained by firing a broadside). From the 16th century until the early decades of the steamship, vessels had rows of guns set in each side of the hull. Firing all guns on one side of the ship became known as a "broadside". The cannon of 18th-century men of war were accurate only at short range, and their penetrating power mediocre, which meant that the thick hulls of wooden ships could only be pierced at short ranges. These wooden ships sailed closer and closer towards each other until cannon fire would be effective. Each tried to be the first to fire a broadside, often giving one party a decisive headstart in the battle when it crippled the other ship.Platt (1993) p. 18 History Since anci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pivot Gun
A pivot gun was a type of cannon mounted on a fixed central emplacement which permitted it to be moved through a wide horizontal arc. They were a common weapon aboard ships and in land fortifications for several centuries but became obsolete after the invention of gun turrets. History By mounting a cannon on a pivot, a much wider arc of fire could be obtained than was possible with conventional carriage-mounted cannons. Unlike the latter, however, pivot guns were fixed in one place and could not easily be moved outside of their horizontal arc; they could thus only really be used in fixed positions such as in a fort or on a battleship. There was no standard size of pivot gun, though they tended to be fairly substantial weapons. Like other cannons, they were usually muzzleloaders and could fire either shells or grapeshot (or other types of shot). Their calibers ranged from a few inches to the giant 11-inch Dahlgren guns used by the United States Navy in the mid-19th century. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of British Ordnance Terms
This article explains terms used for the British Armed Forces' ordnance (i.e.: weapons) and also ammunition. The terms may have slightly different meanings in the military of other countries. BD Between decks: applies to a naval gun mounting in which part of the rotating mass is below the deck, and part of it is above the deck. This allows for a lower profile of turret, meaning that turrets need not be superfiring (i.e. they can be mounted on the same deck and not obstruct each other at high angles of elevation.) BL The term BL, in its general sense, stood for breech loading, and contrasted with muzzle loading. The shell was loaded via the breech (i.e. the gunner's end of the barrel, which opened) followed by the propellant charge, and the breech mechanism was closed to seal the chamber. Breech loading, in its formal British ordnance sense, served to identify the gun as the type of rifled breechloading gun for which the powder charge was loaded in a silk or cloth bag and the br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forced Draught
The difference between atmospheric pressure and the pressure existing in the furnace or flue gas passage of a boiler is termed as draft. Draft can also be referred to as the difference in pressure in the combustion chamber area which results in the motion of the flue gases and the air flow. Types of draft Drafts are produced by the rising combustion gases in the stack, flue, or by mechanical means. For example, a boiler can be put into four categories: natural, induced, balanced, and forced. *Natural draft: When air or flue gases flow due to the difference in density of the hot flue gases and cooler ambient gases. The difference in density creates a pressure differential that moves the hotter flue gases into the cooler surroundings. * Forced draft: When air or flue gases are maintained above atmospheric pressure. Normally it is done with the help of a forced draft fan. * Induced draft: When air or flue gases flow under the effect of a gradually decreasing pressure below atmospheric p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triple-expansion Steam Engine
A compound steam engine unit is a type of steam engine where steam is expanded in two or more stages. A typical arrangement for a compound engine is that the steam is first expanded in a high-pressure ''(HP)'' cylinder, then having given up heat and losing pressure, it exhausts directly into one or more larger-volume low-pressure ''(LP)'' cylinders. Multiple-expansion engines employ additional cylinders, of progressively lower pressure, to extract further energy from the steam. Invented in 1781, this technique was first employed on a Cornish beam engine in 1804. Around 1850, compound engines were first introduced into Lancashire textile mills. Compound systems There are many compound systems and configurations, but there are two basic types, according to how HP and LP piston strokes are phased and hence whether the HP exhaust is able to pass directly from HP to LP ( Woolf compounds) or whether pressure fluctuation necessitates an intermediate "buffer" space in the form of a st ... [...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 Between Perpendiculars
Length between perpendiculars (often abbreviated as p/p, p.p., pp, LPP, LBP or Length BPP) is the length of a ship along the summer load line from the forward surface of the stem, or main bow perpendicular member, to the after surface of the sternpost, or main stern perpendicular member. When there is no sternpost, the centerline axis of the rudder stock is used as the aft end of the length between perpendiculars. Measuring to the stern post or rudder stock was believed to give a reasonable idea of the ship's carrying capacity, as it excluded the small, often unusable volume contained in her overhanging ends. On some types of vessels this is, for all practical purposes, a waterline measurement. In a ship with raked stems, naturally that length changes as the draught of the ship changes, therefore it is measured from a defined loaded condition. See also * Length overall __NOTOC__ Length overall (LOA, o/a, o.a. or oa) is the maximum length of a vessel's hull measured para ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reserve Fleet
A reserve fleet is a collection of naval vessels of all types that are fully equipped for service but are not currently needed; they are partially or fully decommissioned. A reserve fleet is informally said to be "in mothballs" or "mothballed"; an equivalent expression in unofficial modern US naval usage is "ghost fleet". In earlier times, especially in British usage, the ships were said to be "laid up in ordinary". Overview Such ships are held in reserve against a time when it may be necessary to call them back into service. They are usually tied up in backwater areas near naval bases or shipyards in order to speed the reactivation process. They may be modified for storage during such a period, for instance by having rust-prone areas sealed off or wrapped in plastic or, in the case of sailing warships, the masts removed. While being held in the reserve fleet, ships typically have a minimal crew (known informally as a skeleton crew) to ensure that they stay in somewhat usable co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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