A bunker is a defensive military fortification designed to protect people and valued materials from falling bombs or other attacks. Bunkers are underground, in contrast to blockhouses which are above ground, they were used extensively in World War I, World War II, the Cold War for weapons facilities and control centers, storage facilities. Bunkers can be used as protection from tornadoes. Trench bunkers are small concrete structures dug into the ground. Many artillery installations for coastal artillery, have been protected by extensive bunker systems. Typical industrial bunkers include mining sites, food storage areas, dumps for materials, data storage, sometimes living quarters; when a house is purpose-built with a bunker, the normal location is a reinforced below-ground bathroom with fibre-reinforced plastic shells. Bunkers deflect the blast wave from nearby explosions to prevent ear and internal injuries to people sheltering in the bunker. Nuclear bunkers must cope with the underpressure that lasts for several seconds after the shock wave passes, block radiation.
A bunker's door must be at least as strong as the walls. In bunkers inhabited for prolonged periods, large amounts of ventilation or air conditioning must be provided. Bunkers can be destroyed with bunker-busting warheads; the word bunker originates as a Scots word for "bench, seat" recorded 1758, alongside shortened bunk "sleeping berth". The word has a Scandinavian origin: Old Swedish bunke means "boards used to protect the cargo of a ship". In the 19th century the word came to describe a coal store below decks in a ship, it was used for a sand-filled depression installed on a golf course as a hazard. In the First World War as the belligerents built underground shelters called dugouts in English, while the Germans used the term bunker: By the Second World War the term came to be used by the Germans to describe permanent structures both large; the military sense of the word was imported into English during World War II, at first in reference to German dug-outs. All the early references to its usage in the Oxford English Dictionary are to German fortifications.
However in the Far East the term was applied to the earth and log positions built by the Japanese, the term appearing in a 1943 instruction manual issued by the British Indian Army and gaining wide currency. By 1947 the word was familiar enough in English that Hugh Trevor-Roper in The Last Days of Hitler was describing Hitler's underground complex near the Reich Chancellery as "Hitler's own bunker" without quotes around the word bunker; this type of bunker is a small concrete structure dug into the ground, a part of a trench system. Such bunkers give the defending soldiers better protection than the open trench and include top protection against aerial attack, they provide shelter against the weather. Some bunkers may have open tops to allow weapons to be discharged with the muzzle pointing upwards. Many artillery installations for coastal artillery, have been protected by extensive bunker systems; these housed the crews serving the weapons, protected the ammunition against counter-battery fire, in numerous examples protected the guns themselves, though this was a trade-off reducing their fields of fire.
Artillery bunkers are some of the largest individual pre-Cold War bunkers. The walls of the'Batterie Todt' gun installation in northern France were up to 3.5 metres thick, an underground bunker was constructed for the V-3 cannon. Typical industrial bunkers include mining sites, food storage areas, dumps for materials, data storage, sometimes living quarters, they were built by nations like Germany during World War II to protect important industries from aerial bombardment. Industrial bunkers are built for control rooms of dangerous activities, such as tests of rocket engines or explosive experiments, they are built in order to perform dangerous experiments in them or to store radioactive or explosive goods. Such bunkers exist on non-military facilities; when a house is purpose-built with a bunker, the normal location is a reinforced below-ground bathroom with large cabinets. One common design approach uses fibre-reinforced plastic shells. Compressive protection may be provided by inexpensive earth arching.
The overburden is designed to shield from radiation. To prevent the shelter from floating to the surface in high groundwater, some designs have a skirt held-down with the overburden, it may serve the purpose of a safe room. Munitions storage bunkers are designed to securely store explosive ordnance, contain any internal explosions; the most common configuration for high explosives storage is the igloo shaped bunker. They are built into a hillside in order to provide additional containment mass. A specialized version of the munitions bunker called a Gravel Gertie is designed to contain radioactive debris from an explosive accident while assembling or disassembling nuclear warheads, they are installed at all facilities in the United States and United Kingdom which do warhead assembly and disassembly, the largest being the Pantex plant in Amarillo, which has 12 Gravel Gerties. Bunkers deflect the blast wave from nearby explosions to prevent ear and internal injuri
A torpedo tube is a cylinder shaped device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, deck-mounted units installed aboard surface vessels. Deck-mounted torpedo launchers are designed for a specific type of torpedo, while submarine torpedo tubes are general-purpose launchers, are also capable of deploying mines and cruise missiles. Most modern launchers are standardised on a 12.75-inch diameter for light torpedoes or a 21-inch diameter for heavy torpedoes, although other sizes of torpedo tube have been used: see Torpedo classes and diameters. 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 the submarine into the sea at the ambient pressure of the water around the submarine, thus a submarine torpedo tube operates on the principle of an airlock. The diagram on the right illustrates the operation of a submarine torpedo tube.
The diagram does show the working of a submarine torpedo launch. A torpedo tube has a considerable number of interlocks for safety reasons. For example, an interlock prevents the breech muzzle door from opening at the same time; the submarine torpedo launch sequence is, in simplified form: Open the breech door in the torpedo room. Load the torpedo into the tube. Hook up the wire-guide connection and the torpedo power cable. Shut and lock the breech door. Turn on power to the torpedo. A minimum amount of time is required for torpedo warmup. Fire control programs are uploaded to the torpedo. Flood the torpedo tube; this may be done manually or automatically, from sea or from tanks, depending on the class of submarine. The tube must be vented during this process to allow for complete filling and eliminate air pockets which could escape to the surface or cause damage when firing. Open the equalizing valve to equalize pressure in the tube with ambient sea pressure. Open the muzzle door. If the tube is set up for Impulse Mode the slide valve will open with the muzzle door.
If Swim Out Mode is selected, the slide valve remains closed. The slide valve allows water from the ejection pump to enter the tube; when the launch command is given and all interlocks are satisfied, the water ram operates, thrusting a large volume of water into the tube at high pressure, which ejects the torpedo from the tube with considerable force. Modern torpedoes have a safety mechanism that prevents activation of the torpedo unless the torpedo senses the required amount of G-force; the power cable is severed at launch. However, if a guidance wire is used, it remains connected through a drum of wire in the tube. Torpedo propulsion systems vary but electric torpedoes swim out of the tube on their own and are of a smaller diameter. 21" weapons with fuel-burning engines start outside the tube. Once outside the tube the torpedo begins its run toward the target as programmed by the fire control system. Attack functions are programmed but with wire guided weapons, certain functions can be controlled from the ship.
For wire-guided torpedoes, the muzzle door must remain open because the guidance wire is still connected to the inside of the breech door to receive commands from the submarine's fire-control system. A wire cutter on the inside of the breech door is activated to release the wire and its protective cable; these are drawn clear of the ship prior to shutting the muzzle door. The drain cycle is a reverse of the flood cycle. Water can be moved as necessary; the tube must be vented to drain the tube since it is by gravity. Open the breech door and remove the remnants of the torpedo power cable and the guidance wire basket; the tube must be wiped dry to prevent a buildup of slime. This process is called "diving the tube" and tradition dictates that "ye who shoots, dives". Shut and lock the breech door. Spare torpedoes are stored behind the tube in racks. Speed is a desirable feature of a torpedo loading system. There are various manual and hydraulic handling systems for loading torpedoes into the tubes. Prior to the Ohio class, US SSBNs utilized manual block and tackle which took about 15 minutes to load a tube.
SSNs prior to the Seawolf class used a hydraulic system, much faster and safer in conditions where the ship needed to maneuver. The German Type 212 submarine uses a new development of the water ram expulsion system, which ejects the torpedo with water pressure to avoid acoustic detection. List of torpedoes by diameter The Fleet Type Submarine Online 21-Inch Submerged Torpedo Tubes United States Navy Restricted Ordnance Pamphlet 1085, June 1944 Torpedo tubes of German U-Boats
German frigate Lübeck (F224)
German frigate Lübeck was a Köln-class frigate which served in the Bundesmarine from 1963 through 1988. List of frigates List of German Federal Navy ships List of naval ships of Germany List of ship commissionings in 1963 List of ship decommissionings in 1988
The ships of the F120 Köln class of frigates were the first major warships built in Germany after World War II. They were the world's first ships to feature a combined gas propulsion system; the ships received numerous refits during their long careers with torpedo tubes. They were replaced by Type 122 frigates in the four ships were sold to the Turkish Navy. All ships were stationed as second frigate squadron in Wilhelmshaven. List of frigates List of German Federal Navy ships List of naval ships of Germany List of naval ship classes of Germany Lists of ship launches in: 1959, 1962 Lists of ship commissionings in: 1961, 1962, 1963, 1964 Lists of ship decommissionings in: 1982, 1983, 1988, 1989 Gardiner and Stephen Chumbley. Conway's All The World's Fighting Ships 1947–1995. Annapolis, Maryland, USA: Naval Institute Press, 1995. ISBN 1-55750-132-7. Prézelin, Bernard and A. D. Baker III; the Naval Institute Guide to Combat Fleets of the World 1990/1991. Annapolis, Maryland, USA: Naval Institute Press, 1990.
World War II
World War II known as the Second World War, was a global war that lasted from 1939 to 1945. The vast majority of the world's countries—including all the great powers—eventually formed two opposing military alliances: the Allies and the Axis. A state of total war emerged, directly involving more than 100 million people from over 30 countries; the major participants threw their entire economic and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. World War II was the deadliest conflict in human history, marked by 50 to 85 million fatalities, most of whom were civilians in the Soviet Union and China, it included massacres, the genocide of the Holocaust, strategic bombing, premeditated death from starvation and disease, the only use of nuclear weapons in war. Japan, which aimed to dominate Asia and the Pacific, was at war with China by 1937, though neither side had declared war on the other. World War II is said to have begun on 1 September 1939, with the invasion of Poland by Germany and subsequent declarations of war on Germany by France and the United Kingdom.
From late 1939 to early 1941, in a series of campaigns and treaties, Germany conquered or controlled much of continental Europe, formed the Axis alliance with Italy and Japan. Under the Molotov–Ribbentrop Pact of August 1939, Germany and the Soviet Union partitioned and annexed territories of their European neighbours, Finland and the Baltic states. Following the onset of campaigns in North Africa and East Africa, the fall of France in mid 1940, the war continued between the European Axis powers and the British Empire. War in the Balkans, the aerial Battle of Britain, the Blitz, the long Battle of the Atlantic followed. On 22 June 1941, the European Axis powers launched an invasion of the Soviet Union, opening the largest land theatre of war in history; this Eastern Front trapped most crucially the German Wehrmacht, into a war of attrition. In December 1941, Japan launched a surprise attack on the United States as well as European colonies in the Pacific. Following an immediate U. S. declaration of war against Japan, supported by one from Great Britain, the European Axis powers declared war on the U.
S. in solidarity with their Japanese ally. Rapid Japanese conquests over much of the Western Pacific ensued, perceived by many in Asia as liberation from Western dominance and resulting in the support of several armies from defeated territories; the Axis advance in the Pacific halted in 1942. Key setbacks in 1943, which included a series of German defeats on the Eastern Front, the Allied invasions of Sicily and Italy, Allied victories in the Pacific, cost the Axis its initiative and forced it into strategic retreat on all fronts. In 1944, the Western Allies invaded German-occupied France, while the Soviet Union regained its territorial losses and turned toward Germany and its allies. During 1944 and 1945 the Japanese suffered major reverses in mainland Asia in Central China, South China and Burma, while the Allies crippled the Japanese Navy and captured key Western Pacific islands; the war in Europe concluded with an invasion of Germany by the Western Allies and the Soviet Union, culminating in the capture of Berlin by Soviet troops, the suicide of Adolf Hitler and the German unconditional surrender on 8 May 1945.
Following the Potsdam Declaration by the Allies on 26 July 1945 and the refusal of Japan to surrender under its terms, the United States dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki on 6 and 9 August respectively. With an invasion of the Japanese archipelago imminent, the possibility of additional atomic bombings, the Soviet entry into the war against Japan and its invasion of Manchuria, Japan announced its intention to surrender on 15 August 1945, cementing total victory in Asia for the Allies. Tribunals were set up by fiat by the Allies and war crimes trials were conducted in the wake of the war both against the Germans and the Japanese. World War II changed the political social structure of the globe; the United Nations was established to foster international co-operation and prevent future conflicts. The Soviet Union and United States emerged as rival superpowers, setting the stage for the nearly half-century long Cold War. In the wake of European devastation, the influence of its great powers waned, triggering the decolonisation of Africa and Asia.
Most countries whose industries had been damaged moved towards economic expansion. Political integration in Europe, emerged as an effort to end pre-war enmities and create a common identity; the start of the war in Europe is held to be 1 September 1939, beginning with the German invasion of Poland. The dates for the beginning of war in the Pacific include the start of the Second Sino-Japanese War on 7 July 1937, or the Japanese invasion of Manchuria on 19 September 1931. Others follow the British historian A. J. P. Taylor, who held that the Sino-Japanese War and war in Europe and its colonies occurred and the two wars merged in 1941; this article uses the conventional dating. Other starting dates sometimes used for World War II include the Italian invasion of Abyssinia on 3 October 1935; the British historian Antony Beevor views the beginning of World War II as the Battles of Khalkhin Gol fought between Japan and the fo
French 100 mm naval gun
Modern French 100 mm naval guns are multipurpose artillery pieces, capable of a high rate of fire. Most modern French warships are/were equipped with one of its versions. At the end of the Second World War, the French Navy was equipped with guns of numerous calibres, most of which were obsolete. In 1953, the STCAN of Paris, under engineer Tonnelé, drafted the design of a multi-purpose 100 mm gun; the gun was designed to be effective for anti-aircraft defence anti-ship combat shore bombardmentThe first model of the family, "modèle 53", was tested at sea on the escort Le Brestois in 1958 and the escort aviso Victor Schoelcher in 1961. The most common version, modèle 68, features a automatic action and control; the ammunition is stored in a magazine underneath the turret, fed to the gun by a lift manned by two crewmen. A flexible pipe allows feeding the gun under any orientation. Rounds of ammunition are fed automatically. Cooling is provided by water circulating in layers of steel around the tube of the gun, by an injection of air and water after every shot.
The turret can be used in three modes: Remote control by the main weapon control system, from the Operation Center Remote control from a secondary weapon control system Manual control by the joystick at the left of the gun In manual mode, two crewmen serve the turret: the gunner, at the left of the gun, uses a joystick to point the gun, optic ranging and aiming instruments to direct the fire. Aiming is performed by one for the elevation and the other for the traverse. Two hydraulic systems feed the gun; the gun can be moved manually for maintenance. Since it is installed on the bow deck of warships, these turrets are exposed to breaking waves and humidity. To prevent corrosion and mechanical problems, the turret is made water-tight with rubber joints; the muzzle itself is sealed by a rubber tampion. The plexiglas viewbay used to manually aim the gun is protected by a steel cover. Over the years, the 100 mm turret went through several improvements, notably bringing more reliable operation and increased firing rate, new ammunition optimized to shoot down missiles, compatibility with modern firing computers.
Three main versions of French 100mm guns can be cited: modèle 53: the first shell had to be fed manually, with subsequent shots taking advantage of recoil to load automatically, firing at up to 60 rounds per minute. Employs electro-mechanical fire control, with two manual command stations on the front of the turret; the modèle 64 is a direct offspring of the 53, with a 78 round/min rate of fire. This version can be connected to modern firing computers. Modèle 68 In this model, the turret was lightened and can load the first round automatically, but rate of fire is reduced back to 60 rounds per minute; this version may operate unmanned with only one manual station remaining as a backup. This version was improved to the CADAM standard, restoring the 78 rounds/min rate of fire. A derivative is the modèle 100 TR, mechanically similar to the 68, but with a stealth armour; the manual control has been removed. Compact: This weapon has only been exported to China, Malaysia and Saudi Arabia, it is lighter than the modèle 68, at only 19 metric tons including gunhouse and magazine.
Mk 2 versions fire faster, at up to 90 rounds per minute. However, it is limited to firing short bursts of no more than 6 rounds; the 100 mm gun has been used in the French navy on most warships equal or greater than avisos. The aircraft carrier Charles de Gaulle, with her MBDA Aster-only defence, is the main exception; the future Horizon CNGF frigates are expected to be equipped with the 76 mm Oto-Breda gun. It is not yet known whether this is a general tendency to abandon the 100 mm gun, or only a special case for certain specialized vessels; the 100 mm has been sold abroad, is used by the navies of Argentina, China, Turkey, Saudi Arabia, Bulgaria & Germany, others. Belgian Wielingen-class frigates equipped with the system were sold to Bulgaria in 2004-2008. 4.5 inch Mark 8 naval gun: contemporary standard naval gun for British ships 5"/54 caliber Mark 45 gun: contemporary standard naval gun for US ships AK-130: contemporary 130 mm twin standard naval gun mounting for Russian ships Otobreda 127/54 Compact and Otobreda 127/64: contemporary 127 mm naval gun from Italian manufacturer Oto Melara NavWeaps French Naval Guns Le canon de 100mm
A gas turbine called a combustion turbine, is a type of continuous combustion, internal combustion engine. There are three main components: An upstream rotating gas compressor. Above. A fourth component is used to increase efficiency, to convert power into mechanical or electric form, or to achieve greater power to mass/volume ratio; the basic operation of the gas turbine is a Brayton cycle with air as the working fluid. Fresh atmospheric air flows through the compressor. Energy is added by spraying fuel into the air and igniting it so the combustion generates a high-temperature flow; this high-temperature high-pressure gas enters a turbine, where it expands down to the exhaust pressure, producing a shaft work output in the process. The turbine shaft work is used to drive the compressor; the purpose of the gas turbine determines the design so that the most desirable split of energy between the thrust and the shaft work is achieved. The fourth step of the Brayton cycle is omitted, as gas turbines are open systems that do not use the same air again.
Gas turbines are used to power aircraft, ships, electrical generators, gas compressors, tanks. 50: Earliest records of Hero's engine. It most served no practical purpose, was rather more of a curiosity. 1000: The "Trotting Horse Lamp" was used by the Chinese at lantern fairs as early as the Northern Song dynasty. When the lamp is lit, the heated airflow rises and drives an impeller with horse-riding figures attached on it, whose shadows are projected onto the outer screen of the lantern. 1500: The Chimney Jack was drawn by Leonardo da Vinci: Hot air from a fire rises through a single-stage axial turbine rotor mounted in the exhaust duct of the fireplace and turning the roasting spit by gear-chain connection. 1629: Jets of steam rotated an impulse turbine that drove a working stamping mill by means of a bevel gear, developed by Giovanni Branca. 1678: Ferdinand Verbiest built a model carriage relying on a steam jet for power. 1791: A patent was given to John Barber, an Englishman, for the first true gas turbine.
His invention had most of the elements present in the modern day gas turbines. The turbine was designed to power a horseless carriage. 1861: British patent no. 1633 was granted to Marc Antoine Francois Mennons for a "Caloric engine". The patent shows that it was a gas turbine and the drawings show it applied to a locomotive. Named in the patent was Nicolas de Telescheff, a Russian aviation pioneer. 1872: A gas turbine engine designed by Berlin engineer, Franz Stolze, is thought to be the first attempt at creating a working model, but the engine never ran under its own power. 1894: Sir Charles Parsons patented the idea of propelling a ship with a steam turbine, built a demonstration vessel, the Turbinia the fastest vessel afloat at the time. This principle of propulsion is still of some use. 1895: Three 4-ton 100 kW Parsons radial flow generators were installed in Cambridge Power Station, used to power the first electric street lighting scheme in the city. 1899: Charles Gordon Curtis patented the first gas turbine engine in the US.
1900: Sanford Alexander Moss submitted a thesis on gas turbines. In 1903, Moss became an engineer for General Electric's Steam Turbine Department in Lynn, Massachusetts. While there, he applied some of his concepts in the development of the turbosupercharger, his design used a small turbine wheel, driven by exhaust gases. 1903: A Norwegian, Ægidius Elling, built the first gas turbine, able to produce more power than needed to run its own components, considered an achievement in a time when knowledge about aerodynamics was limited. Using rotary compressors and turbines it produced 11 hp. 1906: The Armengaud-Lemale turbine engine in France with a water-cooled combustion chamber. 1910: Holzwarth impulse turbine achieved 150 kilowatts. 1913: Nikola Tesla patents the Tesla turbine based on the boundary layer effect. 1920s The practical theory of gas flow through passages was developed into the more formal theory of gas flow past airfoils by A. A. Griffith resulting in the publishing in 1926 of An Aerodynamic Theory of Turbine Design.
Working testbed designs of axial turbines suitable for driving a propellor were developed by the Royal Aeronautical Establishment proving the efficiency of aerodynamic shaping of the blades in 1929. 1930: Having found no interest from the RAF for his idea, Frank Whittle patented the design for a centrifugal gas turbine for jet propulsion. The first successful use of his engine occurred in England in April 1937. 1932: BBC Brown, Boveri & Cie of Switzerland] starts selling axial compressor and turbine turbosets as part of the turbocharged steam generating Velox boiler. Following the gas turbine principle, the steam evaporation tubes are arranged within the gas turbine combustion chamber. 1934: Raúl Pateras de Pescara patented the free-piston engine as a gas gener