German Type XXI Submarine
Type XXI submarines were a class of German diesel–electric '' Elektroboot'' (German: "electric boat") submarines designed during the Second World War. One hundred eighteen were completed, with four being combat-ready. During the war only two were put into active service and went on patrols, but these were not used in combat. They were the first submarines designed to operate primarily submerged, rather than spending most of their time as surface ships that could submerge for brief periods as a means of escaping detection. They incorporated many batteries to increase the time they could spend submerged, to as much as several days, and they only needed to surface to periscope depth for recharging via a snorkel. The design included many general improvements as well: much greater underwater speed by an improved hull design, greatly improved diving times, power-assisted torpedo reloading and greatly improved crew accommodations. However, the design was also flawed in many ways, wi ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Blohm+Voss
Blohm is a surname. Notable people with the surname include: *Hans Blohm C.M. (born 1927), photographer and author *Hermann Blohm (1848–1930), German businessman and co-founder of German company Blohm+Voss *Irma Blohm (1909–1997), German politician *Linn Blohm (born 1992), Swedish handball player for IK Sävehof and the Swedish national team *Robert Blohm (born 1948), American and Canadian investment banker, economist and statistician, professor in China's Central University of Finance and Economics *Tom Blohm (1920–2000), Norwegian football player See also *Blohm + Voss, a German shipbuilding and engineering works *Blom *Bohm (other) Bohm may refer to: Physics * David Bohm, 20th century theoretical physicist who lent his name to several concepts in physics: ** Aharonov–Bohm effect of electromagnetic potential on a particle ** Debye sheath#The Bohm sheath criterion, Bohm sheat ... {{surname de:Blohm ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Submarine Snorkel
A submarine snorkel is a device which allows the engine of a submarine to operate Underwater, submerged while still taking in air from above the surface. British Royal Navy personnel often refer to it as the snort. A concept devised by Dutch engineers, it was widely used on German U-boats during the last year of World War II and known to them as a . History Until the advent of Nuclear submarine, nuclear power, submarines were designed to operate on the surface most of the time and submerge only for evasion or for daylight attacks. Until the widespread use of radar after 1940, at night a submarine was safer on the surface than submerged, because sonar could detect boats underwater but was almost useless against a surface vessel. However, with continued radar improvement as the war progressed, submarines (notably, the Germany, German U-boat, U-boats in the Battle of the Atlantic) were forced to spend more time underwater, running on electric motors that gave speeds of only a fe ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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United States Navy
The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 million tons in 2021. It has the world's largest aircraft carrier fleet, with List of aircraft carriers in service, eleven in service, one undergoing trials, two new carriers under construction, and six other carriers planned as of 2024. With 336,978 personnel on active duty and 101,583 in the Ready Reserve, the U.S. Navy is the third largest of the United States military service branches in terms of personnel. It has 299 deployable combat vessels and about 4,012 operational aircraft as of 18 July 2023. The U.S. Navy is one of six United States Armed Forces, armed forces of the United States and one of eight uniformed services of the United States. The United States Navy traces its origins to the Continental Navy, which was established during ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Freezer
A refrigerator, commonly shortened to fridge, is a commercial and home appliance consisting of a thermally insulated compartment and a heat pump (mechanical, electronic or chemical) that transfers heat from its inside to its external environment so that its inside is cooled to a temperature below the room temperature. Refrigeration is an essential food storage technique around the world. The low temperature reduces the reproduction rate of bacteria, so the refrigerator lowers the rate of spoilage. A refrigerator maintains a temperature a few degrees above the freezing point of water. The optimal temperature range for perishable food storage is .Keep your fridge-freezer clean and ice-free ''BBC''. 30 April 2008 A freezer is a specialized refrigerator, or portion of a refrigerator, that maintains its contents’ temperature below the freezing point of water. The refrigerator replaced the icebox, which had been a common household appliance for almost a century and a half. The ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Sonar
Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances ( ranging), communicate with or detect objects on or under the surface of the water, such as other vessels. "Sonar" can refer to one of two types of technology: ''passive'' sonar means listening for the sound made by vessels; ''active'' sonar means emitting pulses of sounds and listening for echoes. Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of "targets" in the water. Acoustic location in air was used before the introduction of radar. Sonar may also be used for robot navigation, and sodar (an upward-looking in-air sonar) is used for atmospheric investigations. The term ''sonar'' is also used for the equipment used to generate and receive the sound. The acoustic frequencies used in sonar systems vary from very low ( infrasonic) to e ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Torpedo
A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, 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 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 large-caliber guns, the invention and refinement of torpedoes from the 1860s onwards allowed small torpedo boats and other lighter surface vessels, submarines/submersibles, even improvised fishing boats or frogmen, and later light aircraft, to destroy large ships without the need of large guns, though somet ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Type VII Submarine
Type VII U-boats were the most common type of Nazi Germany, German World War II U-boat. 704 boats were built by the end of the war. The type had several modifications. The Type VII was the most numerous U-boat type to be involved in the Battle of the Atlantic. The lone surviving example, , is on display at the Laboe Naval Memorial located in Laboe, Schleswig-Holstein, Germany. At the start of the Second World War the ''Type VII'' class wastogether with the British British U-class submarine, ''U'', British S-class submarine (1931), ''S'' and British T-class submarine, ''T'' class and Dutch O 21-class submarine, ''O 21'' classone of the most advanced submarine classes in service. Design After the defeat in World War I, the Treaty of Versailles forbade Germany to build submarines. Germany circumvented the treaty by setting up the Netherlands, Dutch dummy company ''NV Ingenieurskantoor voor Scheepsbouw Den Haag'' (I.v.S) which continued to design submarines. Based on the World Wa ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Conning Tower
A conning tower is a raised platform on a ship or submarine, often armoured, from which an officer in charge can conn (nautical), conn (conduct or control) 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 is 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 cruiser, armoured 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 j ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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British Porpoise-class Submarine
The ''Porpoise'' class was an eight-boat class of diesel-electric submarines operated by the Royal Navy. This class was originally designated patrol submarines, then attack. They were the first conventional British submarines to be built after the end of World War II. Their design was, in many ways, influenced by the German World War II-era Type XXI U-boats. Design The ''Porpoise''-class submarines were larger but shorter than their T-class predecessors and used a much improved steel known as UXW.''Rebuilding the Royal Navy : Warship Design Since 1945'', D. K. Brown and George Moore, Chatham Publishing, 2003, pp.114–115 This, and improved design and construction techniques allowed much deeper diving. It was found in tests that the unusually long engine room was liable to collapse, so there were extra large frames in this section, which proved to be something of an operational inconvenience. Designed with a top speed of , the boats were capable of , or once fitted with sile ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Submarine Snorkel
A submarine snorkel is a device which allows the engine of a submarine to operate Underwater, submerged while still taking in air from above the surface. British Royal Navy personnel often refer to it as the snort. A concept devised by Dutch engineers, it was widely used on German U-boats during the last year of World War II and known to them as a . History Until the advent of Nuclear submarine, nuclear power, submarines were designed to operate on the surface most of the time and submerge only for evasion or for daylight attacks. Until the widespread use of radar after 1940, at night a submarine was safer on the surface than submerged, because sonar could detect boats underwater but was almost useless against a surface vessel. However, with continued radar improvement as the war progressed, submarines (notably, the Germany, German U-boat, U-boats in the Battle of the Atlantic) were forced to spend more time underwater, running on electric motors that gave speeds of only a fe ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Surface Ship
Surface combatants (or surface ships or surface vessels) are a subset of naval warships which are designed for warfare on the surface of the water, with their own weapons and armed forces. They are generally ships built to fight other ships, submarines, aircraft or land targets, and can carry out several other missions including counter-narcotics operations and maritime interdiction. Their primary purpose is to engage space, air, surface, and submerged targets with weapons deployed from the ship itself, rather than by crewed carried craft.Naval Transformational Roadmap . Retrieved 2009-08-29. Surface ships include [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |