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Convoy ONS 5
ONS 5 was the 5th of the numbered ONS series of Slow trade convoys Outbound from the British Isles to North America. The North Atlantic battle surrounding it in May 1943 is regarded as the turning point of the Battle of the Atlantic in World War II. The battle ebbed and flowed over a period of a week, and involved more than 50 Allied ships and their escorts, and over 30 U-boats. It saw heavy losses on both sides. However it was almost the last Allied convoy to do so, while losses inflicted on attacking U-boats and U-boat groups became a besetting feature of the campaign; As such it is seen as the point when the tactical and strategic advantage passed to the Allies, and ushered in the period known to Nazi Germany's ''Kriegsmarine'' as Black May. Background ONS 5 consisted of 43 ships bound from Liverpool to Halifax. The ships were either in ballast or carrying trade and export goods. The convoy departed Liverpool on 21 April 1943, and would arrive in Halifax three weeks later ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks in World War II, Tanks and Air warfare of World War II, aircraft played major roles, enabling the strategic bombing of cities and delivery of the Atomic bombings of Hiroshima and Nagasaki, first and only nuclear weapons ever used in war. World War II is the List of wars by death toll, deadliest conflict in history, causing World War II casualties, the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Allied-occupied Germany, Germany, Allied-occupied Austria, Austria, Occupation of Japan, Japan, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Destroyer
In naval terminology, a destroyer is a fast, maneuverable, long-endurance warship intended to escort larger vessels in a fleet, convoy, or carrier battle group and defend them against a wide range of general threats. They were conceived in 1885 by Fernando Villaamil for the Spanish NavySmith, Charles Edgar: ''A short history of naval and marine engineering.'' Babcock & Wilcox, ltd. at the University Press, 1937, page 263 as a defense against torpedo boats, and by the time of the Russo-Japanese War in 1904, these "torpedo boat destroyers" (TBDs) were "large, swift, and powerfully armed torpedo boats designed to destroy other torpedo boats". Although the term "destroyer" had been used interchangeably with "TBD" and "torpedo boat destroyer" by navies since 1892, the term "torpedo boat destroyer" had been generally shortened to simply "destroyer" by nearly all navies by the First World War. Before World War II, destroyers were light vessels with little endurance for unatte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
ASDIC
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] [Amazon] |
Radar
Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track aircraft, ships, spacecraft, guided missiles, motor vehicles, map weather formations, and terrain. The term ''RADAR'' was coined in 1940 by the United States Navy as an acronym for "radio detection and ranging". The term ''radar'' has since entered English and other languages as an anacronym, a common noun, losing all capitalization. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwave domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Enigma Machine
The Enigma machine is a cipher device developed and used in the early- to mid-20th century to protect commercial, diplomatic, and military communication. It was employed extensively by Nazi Germany during World War II, in all branches of the Wehrmacht, German military. The Enigma machine was considered so secure that it was used to encipher the most top-secret messages. The Enigma has an electromechanical Rotor machine, rotor mechanism that scrambles the 26 letters of the alphabet. In typical use, one person enters text on the Enigma's keyboard and another person writes down which of the 26 lights above the keyboard illuminated at each key press. If plaintext is entered, the illuminated letters are the ciphertext. Entering ciphertext transforms it back into readable plaintext. The rotor mechanism changes the electrical connections between the keys and the lights with each keypress. The security of the system depends on machine settings that were generally changed daily, based ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Reykjavík
Reykjavík is the Capital city, capital and largest city in Iceland. It is located in southwestern Iceland on the southern shore of Faxaflói, the Faxaflói Bay. With a latitude of 64°08′ N, the city is List of northernmost items, the world's northernmost capital of a sovereign state. Reykjavík has a population of around 139,000 as of 2025. The surrounding Capital Region (Iceland), Capital Region has a population of around 249,000, constituting around 64% of the country's population. Reykjavík is believed to be the location of the first permanent settlement in Iceland, which, according to , was established by Ingólfr Arnarson, Ingólfur Arnarson in 874 Anno Domini, AD. Until the 18th century, there was no urban development in the city location. The city was officially founded in 1786 as a trading town and grew steadily over the following decades, as it transformed into a regional and later Country, national centre of commerce, population, and governmental activities. Re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Iceland
Iceland is a Nordic countries, Nordic island country between the Atlantic Ocean, North Atlantic and Arctic Oceans, on the Mid-Atlantic Ridge between North America and Europe. It is culturally and politically linked with Europe and is the region's westernmost and most list of countries and dependencies by population density, sparsely populated country. Its Capital city, capital and largest city is Reykjavík, which is home to about 36% of the country's roughly 380,000 residents (excluding nearby towns/suburbs, which are separate municipalities). The official language of the country is Icelandic language, Icelandic. Iceland is on a rift between Plate tectonics, tectonic plates, and its geologic activity includes geysers and frequent Types of volcanic eruptions, volcanic eruptions. The interior consists of a volcanic plateau with sand and lava fields, mountains and glaciers, and many Glacial stream, glacial rivers flow to the sea through the Upland and lowland, lowlands. Iceland i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Benbecula
Benbecula ( ; or ) is an island of the Outer Hebrides in the Atlantic Ocean off the west coast of Scotland. In the 2011 census, it had a resident population of 1,283 with a sizable percentage of Roman Catholics. It is in a zone administered by or the Western Isles Council. The island is about from west to east and a similar distance from north to south. It lies between the islands of North Uist and South Uist and is connected to both by road causeways. Benbecula's main settlement and administrative centre is Balivanich (Scottish Gaelic: ''Baile a' Mhanaich'', meaning "Town of the Monk"). In 1746, Bonnie Prince Charlie was caught in a storm and forced to land on Benbecula. The population of Benbecula were sympathetic to the Jacobite rising of 1745, Jacobite cause, and smuggled him off the island to safety, as the The Skye Boat Song, song has it: "over the sea to Skye". In 2006, local residents took control of parts of the island in a community buy-out. The previous landowners ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
206 Squadron RAF
No. 206 Squadron is a Test and Evaluation Squadron of the Royal Air Force. Until 2005 it was employed in the maritime patrol role with the Nimrod MR.2 at RAF Kinloss, Moray. It was announced in December 2004 that 206 Squadron would disband on 1 April 2005, with half of its crews being redistributed to Nos. 120 and 201 Squadrons, also stationed at Kinloss. This was a part of the UK Defence Review called ''Delivering Security in a Changing World''; the Nimrod MR.2 fleet was reduced in number from 21 to 16 as a consequence. History Formation and early years No. 206 Squadron was formed on 31 December 1916 as No. 6 Squadron, Royal Naval Air Service, a fighter unit operating Nieuport 17s and later Sopwith Camels over the Western Front before disbanding on 27 August 1917.Lewis 1959, p. 71. The squadron was reformed on 1 January 1918 as a bomber and reconnaissance unit, operating Airco DH9s. With the establishment of the RAF in 1918 the squadron was renumbered No. 206 Squadron, RAF, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
B-17
The Boeing B-17 Flying Fortress is an American four-engined heavy bomber aircraft developed in the 1930s for the United States Army Air Corps (USAAC). A fast and high-flying bomber, the B-17 dropped more bombs than any other aircraft during World War II, used primarily in the European Theater of Operations. It is the third-most produced bomber in history, behind the American four-engined Consolidated B-24 Liberator and the German multirole, twin-engined Junkers Ju 88. The B-17 was also employed in transport, anti-submarine warfare, and search and rescue roles. In a USAAC competition, Boeing's prototype Model 299/XB-17 outperformed two other entries but crashed, losing the initial 200-bomber contract to the Douglas B-18 Bolo. Still, the Air Corps ordered 13 more B-17s for further evaluation, which were introduced into service in 1938. The B-17 evolved through numerous design advances but from its inception, the USAAC (from 1941 the United States Army Air Forces, USAAF) pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
B-Dienst
The ''B-Dienst'' (, observation service), also called x''B-Dienst'', X-''B-Dienst'' and χ''B-Dienst'', was a Department of the German Naval Intelligence Service (, MND III) of the Oberkommando der Marine, OKM that dealt with the interception and recording, decoding and analysis of the enemy. In particular, it focused on British radio communications before and during World War II. B-Dienst worked on cryptanalysis and deciphering (decrypting) of enemy and neutral states' message traffic and security control of ''Kriegsmarine'' key processes and machinery. :"The ultimate goal of all evaluation was recognizing the opponent's goal by pro-active identification of data." B-Dienst was instrumental in moulding Wehrmacht operations during the Norwegian Campaign, Battles of Norway and Battle of France, France in spring 1940, primarily due to the cryptanalysis successes it had achieved against early and less secure British Naval ciphers. B-Dienst broke British Naval Combined Cypher No. 3 i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Air Gap (Battle Of The Atlantic)
An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosphere is the outer region of a star, which includes the layers above the opacity (optics), opaque photosphere; stars of low temperature might have outer atmospheres containing compound molecules. The atmosphere of Earth is composed of nitrogen (78%), oxygen (21%), argon (0.9%), Carbon dioxide in Earth's atmosphere, carbon dioxide (0.04%) and trace gases. Most organisms use oxygen for respiration (physiology), respiration; lightning and bacteria perform nitrogen fixation which produces ammonia that is used to make nucleotides and amino acids; plants, algae, and cyanobacteria use carbon dioxide for photosynthesis. The layered composition of the atmosphere minimises the harmful effects of sunlight, ultraviolet radiation, solar wind, and cosmic rays ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
