I-201 Class Submarine
The were submarines of the Imperial Japanese Navy during World War II. These submarines were of advanced design, built for high underwater speed, and were known as or . The type name, was shortened to . They were one of the fastest submarine class built during World War II, second only to Walter Type XVII closed-cycle powered submarines. Twenty-three units were ordered from the Kure Naval Arsenal under the 1943 construction program. Due to the deteriorating war situation, only eight boats were laid down, and only three, numbered ''I-201'', ''I-202'' and ''I-203'', were completed before the end of the war. None of them saw operational use. Background In 1938 the Imperial Japanese Navy constructed an experimental high-speed submarine for evaluation purposes, which was designated for security purposes. Based on previous experience with high-speed, short-range midget submarines, Number 71 displaced only 230 tons surfaced with a length of . She could attain a submerged speed of ove ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Anti-submarine Warfare
Anti-submarine warfare (ASW, or in older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations are typically carried out to protect friendly shipping and coastal facilities from submarine attacks and to overcome blockades. Successful ASW operations typically involved a combination of sensor and weapon technologies, along with effective deployment strategies and sufficiently trained personnel. Typically, sophisticated sonar equipment is used for first detecting, then classifying, locating, and tracking a target submarine. Sensors are therefore a key element of ASW. Common weapons for attacking submarines include torpedoes and naval mines, which can both be launched from an array of air, surface, and underwater platforms. ASW capabilities are often considered of significant strategic importance, particularly following provocative instan ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state geographically located within the tropics. Hawaii comprises nearly the entire Hawaiian archipelago, 137 volcanic islands spanning that are physiographically and ethnologically part of the Polynesian subregion of Oceania. The state's ocean coastline is consequently the fourth-longest in the U.S., at about . The eight main islands, from northwest to southeast, are Niihau, Kauai, Oahu, Molokai, Lānai, Kahoolawe, Maui, and Hawaii—the last of these, after which the state is named, is often called the "Big Island" or "Hawaii Island" to avoid confusion with the state or archipelago. The uninhabited Northwestern Hawaiian Islands make up most of the Papahānaumokuākea Marine National Monument, the United States' largest protected ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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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Submarine Snorkel
A submarine snorkel is a device which allows a submarine to operate 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 ''Schnorchel''. History Until the advent of 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 German 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 few knots and very limited range. An early submar ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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I-51-class Submarine
The was a type of first-class submarine operated by the Imperial Japanese Navy (IJN) before and during World War II. The type name was shortened to Navy Large Type Submarine. All ''Kaidai''-class submarines originally had a two-digit boat name, from ''I-51'' onwards. On 20 May 1942, all Kaidai submarines added a '1' to their names. For example, ''I-52'' became ''I-152''. Ships are listed by the three-digit boat name if they had one, two-digit if they were not granted one or left service before 20 May 1942. Class variants The ''Kaidai''-type submarines were divided into seven classes and two subclasses: * * * * * * * * * Kaidai I (''I-51'' class) Project number S22. The prototype for the class. The sole Kaidai I, ''I-51'', was based on World War I-era German submarines. She was completed in 1924, refitted with new engines in 1932 and scrapped in 1941. ''I-51'' never saw combat. *Boat in class Kaidai II (''I-152'' class) Project number S25. There was only 1 Kaidai ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Submarine Snorkel
A submarine snorkel is a device which allows a submarine to operate 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 ''Schnorchel''. History Until the advent of 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 German 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 few knots and very limited range. An early submar ... [...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 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]   |
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Center Of Gravity
In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weight function, weighted relative position (vector), position of the distributed mass sums to zero. This is the point to which a force may be applied to cause a linear acceleration without an angular acceleration. Calculations in mechanics are often simplified when formulated with respect to the center of mass. It is a hypothetical point where the entire mass of an object may be assumed to be concentrated to visualise its motion. In other words, the center of mass is the particle equivalent of a given object for application of Newton's laws of motion. In the case of a single rigid body, the center of mass is fixed in relation to the body, and if the body has uniform density, it will be located at the centroid. The center of mass may be located outside the physical body, as is sometimes the case for wikt:hollow, hollow or open-shaped object ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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 and 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, ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Depth Charge
A depth charge is an anti-submarine warfare (ASW) weapon. It is intended to destroy a submarine by being dropped into the water nearby and detonating, subjecting the target to a powerful and destructive Shock factor, hydraulic shock. Most depth charges use explosive, high explosive charges and a fuze set to detonate the charge, typically at a specific depth. Depth charges can be dropped by ships, patrol aircraft, and helicopters. Depth charges were developed during World War I, and were one of the first viable methods of attacking a submarine underwater. They were widely used in World War I and World War II, and remained part of the anti-submarine arsenals of many navies during the Cold War, during which they were supplemented, and later largely replaced, by anti-submarine homing torpedoes. A depth charge fitted with a nuclear warhead is also known as a "nuclear depth bomb". These were designed to be dropped from a patrol plane or deployed by an anti-submarine missile from a s ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |