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Davis Submerged Escape Apparatus
The Davis Submerged Escape Apparatus (also referred to as DSEA), was an early type of oxygen rebreather invented in 1910 by Sir Robert Davis, head of Siebe Gorman and Co. Ltd., inspired by the earlier Fleuss system, and adopted by the Royal Navy after further development by Davis in 1927. While intended primarily as an emergency escape apparatus for submarine crews, it was soon also used for diving, being a handy shallow water diving apparatus with a thirty-minute endurance, and as an industrial breathing set. Design The DSEA rig chiefly addressed the problem of anoxia threatening a person ascending through water, by providing oxygen; and the associated risk of lung over-pressure injury as underwater pressure reduces with reducing depth, which it addressed by managing oxygen pressures. It also provided assistance with buoyancy, both in the ascent and after reaching the surface. The risk of decompression illness due to ascending too fast could be addressed by associated e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is Earth's most abundant element, and after hydrogen and helium, it is the third-most abundant element in the universe. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula . Diatomic oxygen gas currently constitutes 20.95% of the Earth's atmosphere, though this has changed considerably over long periods of time. Oxygen makes up almost half of the Earth's crust in the form of oxides.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. Many major classes of organic molecules in living organisms contain oxygen atoms, such as proteins, nucleic acids, carbohydrates, and fats, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Dioxide
Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. It is a trace gas in Earth's atmosphere at 421 parts per million (ppm), or about 0.04% by volume (as of May 2022), having risen from pre-industrial levels of 280 ppm. Burning fossil fuels is the primary cause of these increased CO2 concentrations and also the primary cause of climate change.IPCC (2022Summary for policy makersiClimate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lionel Crabb
Lieutenant-Commander Lionel Kenneth Phillip Crabb, (28 January 1909 – presumed dead 19 April 1956), known as Buster Crabb, was a Royal Navy frogman and diver who vanished during a reconnaissance mission for MI6 around a Soviet cruiser berthed at Portsmouth Dockyard in 1956. Early life Lionel Crabb was born in 1909 to Hugh Alexander Crabb and Beatrice (née Goodall) of Streatham, south-west London. They were a poor family; Hugh Crabb was a commercial traveller for a firm of photographic merchants. In his youth Crabb held many jobs but after two years training for a career at sea in the school ship HMS ''Conway'' he joined the merchant navy and the Royal Naval Volunteer Reserve before the Second World War. Second World War At the outbreak of the Second World War, Crabb was first an army gunner. Then, in 1941, he joined the Royal Navy. The next year he was sent to Gibraltar where he worked in a mine and bomb disposal unit to remove the Italian limpet mines that enemy di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scuba Diving
Scuba diving is a mode of underwater diving whereby divers use breathing equipment that is completely independent of a surface air supply. The name "scuba", an acronym for "Self-Contained Underwater Breathing Apparatus", was coined by Christian J. Lambertsen in a patent submitted in 1952. Scuba divers carry their own source of breathing gas, usually compressed air, affording them greater independence and movement than surface-supplied divers, and more time underwater than free divers. Although the use of compressed air is common, a gas blend with a higher oxygen content, known as enriched air or nitrox, has become popular due to the reduced nitrogen intake during long and/or repetitive dives. Also, breathing gas diluted with helium may be used to reduce the likelihood and effects of nitrogen narcosis during deeper dives. Open circuit scuba systems discharge the breathing gas into the environment as it is exhaled, and consist of one or more diving cylinders containing breat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Normandy Landings
The Normandy landings were the landing operations and associated airborne operations on Tuesday, 6 June 1944 of the Allied invasion of Normandy in Operation Overlord during World War II. Codenamed Operation Neptune and often referred to as D-Day, it was the largest seaborne invasion in history. The operation began the liberation of France (and later western Europe) and laid the foundations of the Allied victory on the Western Front. Planning for the operation began in 1943. In the months leading up to the invasion, the Allies conducted a substantial military deception, codenamed Operation Bodyguard, to mislead the Germans as to the date and location of the main Allied landings. The weather on D-Day was far from ideal, and the operation had to be delayed 24 hours; a further postponement would have meant a delay of at least two weeks, as the invasion planners had requirements for the phase of the moon, the tides, and the time of day that meant only a few days each month were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DD Tank
DD or Duplex Drive tanks, nicknamed "Donald Duck tanks", were a type of amphibious swimming tank developed by the British during the Second World War. The phrase is mostly used for the Duplex Drive variant of the M4 Sherman medium tank, that was used by the Western Allies during and after the Normandy Landings in June 1944. DD tanks worked by erecting a 'flotation screen' around the tank, which enabled it to float, and had two propellers powered by the tank's engine to drive them in the water. The DD tanks were one of the many specialized assault vehicles, collectively known as Hobart's Funnies, devised to support the planned invasion of Europe. History Early development Amphibious tanks were devised during the First World War; a floating version of the British Mark IX tank was being tested in November 1918, just as the war ended. Development continued during the interwar period. As tanks are heavy for their size, providing them with enough buoyancy was a difficult enginee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphibious Tank Escape Apparatus
Amphibious means able to use either land or water. In particular it may refer to: Animals * Amphibian, a vertebrate animal of the class Amphibia (many of which live on land and breed in water) * Amphibious caterpillar * Amphibious fish, a fish that is able to leave water for extended periods of time * Amphibious insect, an insect which lives in the air or on land and breeds in water * Amphibious rat (other) * ''Scolopendra cataracta'', a species of amphibious centipede Arts and media * ''Amphibious'' (2010 film), a thriller film * ''Amphibious'' (2020 film), a drama film * Amphibius (comics), a minor comic book character Technology * Amphibious aircraft, an aircraft capable of landing on either water or land * Amphibious vehicle, a vehicle capable of being driven on both land and water * Amphibious warfare Amphibious warfare is a type of offensive military operation that today uses naval ships to project ground and air power onto a hostile or potentially host ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HMS Perseus (1929)
HMS ''Perseus'' was a British built in 1929 and lost in 1941 during the Second World War. This class were the first to be fitted with Mark VIII torpedoes. At the start of the war she was operating under the command of Commander Peter Bartlett on the China Station as part of the 4th Submarine Flotilla, together with the other members of her class. This continued until August 1940 when they were reassigned to the Mediterranean, where part of their duties were the ferrying of supplies between Alexandria and the besieged island of Malta. ''Perseus'' underwent a refit at Malta from October until April 1941. Attached to the 1st Submarine Flotilla based in Alexandria, and under the command of Lieutenant-Commander Edward Christian Frederick Nicolay DSO RN (see Nicolay (family)), she sank the 3,867-ton Italian tanker ''Maya'' south of Tenedos on 5 September 1941, and on 2 October, the 2,086-ton merchant ship ''Castellon'' west of Benghazi. It was as a result of these actions th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HMS Thetis (N25)
HMS ''Thetis'' (N25) was a Group 1 T-class submarine of the Royal Navy which sank during sea trials in Liverpool Bay, England on 1 June 1939. After being salvaged and repaired, the boat was recommissioned as HMS ''Thunderbolt'' in 1940. It served during the Second World War until being lost with all hands in the Mediterranean on 14 March 1943. The ''Thetis'' accident happened after the inner hatch on a torpedo tube was opened while the outer hatch to the sea was also open. Four men successfully used the sub's one-man escape chamber before a fifth panicked and jammed it. A total of 99 men died as a result. The sinking led to the redesign of all torpedo tubes on British and Australian submarines. A latch, known as the "''Thetis'' clip", was added to the inner torpedo tube door so it could be fractionally opened to check the tube was not open to the sea before being fully opened. As HMS ''Thetis'' ''Thetis'' was built by Cammell Laird in Birkenhead, England and launched on 29 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HMS Poseidon (1929)
HMS ''Poseidon'' (P99) was a designed and built by Vickers Shipbuilding and Engineering in Barrow-in-Furness, England for the Royal Navy, launched on 22 August 1929. She spent most of her short career assigned to the Yellow Sea region, based at the Royal Navy's Weihai naval base in mainland China. In 1931, the submarine sank after a collision with the steamship ''Yuta'' north of Weihai. The submarine was later secretly salvaged by the Chinese in 1972. Service history At about 12:12 on 9 June 1931, while exercising on the surface with the submarine tender north of the vessels' base at Weihai, and despite excellent visibility, ''Poseidon'' collided with the Chinese merchant vessel SS ''Yuta''. Thirty-one of the submarine's crew managed to scramble into the water before the submarine sank to the seabed below within a few minutes. The aircraft carrier , heavy cruiser and sister submarine led the rescue operations. ''Poseidon'' was equipped with Davis Submerged Escape Appar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lionel Crabb
Lieutenant-Commander Lionel Kenneth Phillip Crabb, (28 January 1909 – presumed dead 19 April 1956), known as Buster Crabb, was a Royal Navy frogman and diver who vanished during a reconnaissance mission for MI6 around a Soviet cruiser berthed at Portsmouth Dockyard in 1956. Early life Lionel Crabb was born in 1909 to Hugh Alexander Crabb and Beatrice (née Goodall) of Streatham, south-west London. They were a poor family; Hugh Crabb was a commercial traveller for a firm of photographic merchants. In his youth Crabb held many jobs but after two years training for a career at sea in the school ship HMS ''Conway'' he joined the merchant navy and the Royal Naval Volunteer Reserve before the Second World War. Second World War At the outbreak of the Second World War, Crabb was first an army gunner. Then, in 1941, he joined the Royal Navy. The next year he was sent to Gibraltar where he worked in a mine and bomb disposal unit to remove the Italian limpet mines that enemy di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
