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HDMS Helgoland (1878)
HDMS ''Helgoland'' was a coast defence barbette ironclad bult for the Royal Danish Navy in the late 1870s. The ship was decommissioned in 1907 and subsequently scrapped. Design and description ''Helgoland'' was long overall, had a beam of and a draft of .Gardiner, p. 365 She displaced Balsved and was fitted with a ram bow. Her crew consisted of 350 officers and enlisted men.Silverstone, p. 56 The ship was fitted with a pair of Burmeister & Wain compound-expansion steam engines, each engine driving one propeller shaft using steam provided by eight cylindrical boilers. The engines were rated at a total of and gave the ship a speed of . ''Helgoland'' carried a maximum of of coal that gave her a range of at a speed of . The ironclad's main battery consisted of a single 22-caliber rifled breech-loading (RBL) gun mounted in the barbette. She was also armed with four single 22-caliber RBL guns in the corners of the armored citadel in the hull. For defense against torpedo bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kingdom Of Denmark
The Danish Realm ( da, Danmarks Rige; fo, Danmarkar Ríki; kl, Danmarkip Naalagaaffik), officially the Kingdom of Denmark (; ; ), is a sovereign state located in Northern Europe and Northern North America. It consists of Denmark, metropolitan Denmark, the kingdom's territory in continental Europe and sometimes called "Denmark proper" ( da, egentlige Danmark, links=no), and the realm's two autonomous regions: the Faroe Islands and Greenland.Administrative divisions – Denmark The World Factbook. Access date: 14 April 2012 The relationship between the three parts of the Kingdom is also known as The unity of the Realm (; fo, ríkisfelagsskapurin, links=no; kl, naalagaaffeqatigiinneq, links=no). The Kingdom of Denmark is not a f ... [...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] |
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 ... [...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] |
Torpedo
A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, such a device was called an automotive, automobile, locomotive, or fish torpedo; colloquially a ''fish''. The term ''torpedo'' originally applied to a variety of devices, most of which would today be called naval mine, mines. From about 1900, ''torpedo'' has been used strictly to designate a self-propelled underwater explosive device. While the 19th-century battleship had evolved primarily with a view to engagements between armored warships with naval artillery, large-caliber guns, the invention and refinement of torpedoes from the 1860s onwards allowed small torpedo boats and other lighter surface combatant , surface vessels, submarines/submersibles, even improvised fishing boats or frogmen, and later light aircraft, to destroy large shi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torpedo Boat
A torpedo boat is a relatively small and fast naval ship designed to carry torpedoes into battle. The first designs were steam-powered craft dedicated to ramming enemy ships with explosive spar torpedoes. Later evolutions launched variants of self-propelled Whitehead torpedoes. These were inshore craft created to counter both the threat of battleships and other slow and heavily armed ships by using speed, agility, and powerful torpedoes, and the overwhelming expense of building a like number of capital ships to counter an enemy's. A swarm of expendable torpedo boats attacking en masse could overwhelm a larger ship's ability to fight them off using its large but cumbersome guns. A fleet of torpedo boats could pose a similar threat to an adversary's capital ships, albeit only in the coastal areas to which their small size and limited fuel load restricted them. The introduction of fast torpedo boats in the late 19th century was a serious concern to the era's naval strategists, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Armored Citadel
In a warship an armored citadel is an armored box enclosing the machinery and magazine spaces formed by the armored deck, the waterline belt, and the transverse bulkheads. In many post-World War I warships, armor was concentrated in a very strong citadel, with the rest of the ship virtually unprotected, which was found to be the most effective defence; this is referred to as all or nothing armor. In a non-military ship a citadel is a secure space equipped with means of communication and emergency supplies, used typically in case of piracy Piracy is an act of robbery or criminal violence by ship or boat-borne attackers upon another ship or a coastal area, typically with the goal of stealing cargo and other valuable goods. Those who conduct acts of piracy are called pirates, v .... Citations Bibliography * {{cite book, last1=Raven, first1=Alan, last2=Roberts, first2=John, title=British Cruisers of World War Two, year=1980, publisher=Naval Institute Press, location= ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rifled Breech Loader
A rifled breech loader (RBL) is an artillery piece which, unlike the smoothbore cannon and rifled muzzle loader (RML) which preceded it, has rifling in the barrel and is loaded from the breech at the rear of the gun. The spin imparted by the gun's rifling gives projectiles directional stability and increased range. Loading from the rear of the gun leaves the crew less exposed to enemy fire, allows smaller gun emplacements or turrets, and allows a faster rate of fire. Overview The major problem to be solved with breechloading artillery was obturation: the sealing of the breech after firing to ensure that none of the gases generated by the burning of the propellant (initially gunpowder) escaped rearwards through the breech. This was both a safety issue and one of gun performance – all the propellant gas was needed to accelerate the projectile along the barrel. The second problem was speed of operation – how to close the breech before firing and open it after firing as quickly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caliber (artillery)
In artillery, caliber or calibredifference in British English and American English spelling is the internal diameter of a gun barrel, or - by extension - a relative measure of the barrel length. Rifled barrels Rifled barrels introduce ambiguity to measurement of caliber. A rifled bore consists of alternating grooves and lands. The distance across the bore from groove to groove is greater than the distance from land to land. Projectiles fired from rifled barrels must be of the full groove to groove diameter to be effectively rotated by the rifling, but the caliber has sometimes been specified as the land to land diameter before rifling grooves were cut. The depth of rifling grooves (and the consequent ambiguity) increases in larger calibers. Steel artillery projectiles may have a forward bourrelet section machined to a diameter slightly smaller than the original land to land dimension of the barrel and a copper driving band somewhat larger than the groove to groove diameter t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Main Battery
A main battery is the primary weapon or group of weapons around which a warship is designed. As such, a main battery was historically a gun or group of guns, as in the broadsides of cannon on a ship of the line. Later, this came to be turreted groups of similar large-caliber naval rifles. With the evolution of technology the term has come to encompass guided missiles as a vessel's principal offensive weapon, deployed both on surface ships and submarines. A main battery features common parts, ammunition, and fire control across the weapons which it comprises. Description In the age of cannon at sea, the main battery was the principal group of weapons around which a ship was designed, usually its heavies. With the coming of naval rifles and subsequent revolving gun turrets, the main battery became the principal group of heaviest guns, regardless of how many turrets they were placed in. As missiles displaced guns both above and below the water their principal group became a ve ... [...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] |
Burmeister & Wain
Burmeister & Wain was a large established Danish shipyard and leading diesel engine producer headquartered in Copenhagen, Denmark. Founded by two Danes and an Englishman, its earliest roots stretch back to 1846. Over its 150-year history, it grew successfully into a strong company through the end of the 1960s. In the 1970s, global competitive pressures, particularly from the far east, began to take their toll. In 1980, B&W became MAN B&W Diesel A/S, part of MAN B&W Diesel Group, a subsidiary of the German corporation MAN AG, with operations worldwide. The company still maintains operations at three main sites in Denmark for manufacturing, servicing, and licensing of its two-stroke engines and complete propulsion systems. History Origins Hans Heinrich Baumgarten (1806–1875) was from the town of Halstenbek near Pinneberg, in the Duchy of Holstein, an area of Germany that was then under the rule of the king of Denmark. He was apprenticed as a coffin maker by a farmer who ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
