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Convoy PQ 1
Convoy PQ 1 was the first of the Arctic Convoys of the Second World War to have the code prefix PQ, which was chosen from the initials of Commander Phillip Quellyn Roberts, an operations officer in the Admiralty. The Western Allies used the Arctic route to supply the Soviet Union after the beginning of Operation Barbarossa, the German invasion, which began on 22 June 1941. The convoy sailed from Hvalfjörður, Hvalfiord in Iceland on 29 September 1941 and arrived at Archangelsk on 11 October 1941. To protect return convoys and sweep for mines, a British naval force of ocean-going Halcyon-class minesweepers, which accompanied the convoy, that had the speed, armament and anti-submarine capacity similar to that of Flower-class corvettes, to be established at the Kola naval base. The fleet oiler , which had accompanied the first Arctic convoy, Operation Dervish (1941), Operation Dervish (21–31 August 1941), was at Kola to refuel ships for the return journey. Soviet destroyers at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic Convoys
The Arctic convoys of World War II were oceangoing convoys which sailed from the United Kingdom, Iceland, and North America to northern ports in the Soviet Union – primarily Arkhangelsk (Archangel) and Murmansk in Russia. There were 78 convoys between August 1941 and May 1945, sailing via several seas of the Atlantic and Arctic oceans, with two gaps with no sailings between July and September 1942, and March and November 1943. About 1,400 merchant ships delivered essential supplies to the Soviet Union under the Anglo-Soviet agreement and US Lend-Lease program, escorted by ships of the Royal Navy, Royal Canadian Navy, and the U.S. Navy. Eighty-five merchant vessels and 16 Royal Navy warships (two cruisers, six destroyers, eight other escort ships) were lost. Nazi Germany's ''Kriegsmarine'' lost a number of vessels including one battleship, three destroyers, 30 U-boats, and many aircraft. The convoys demonstrated the Allies' commitment to helping the Soviet Union, prior to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halcyon-class Minesweeper
The ''Halcyon'' class was a class of 21 oil-fired minesweepers (officially, "fleet minesweeping sloops") built for the British Royal Navy between 1933 and 1939. They were given traditional small ship names used historically by the Royal Navy and served during World War II. Design There were 21 ships in the ''Halcyon'' class, built in two groups; the first using reciprocating steam engines, with steam turbines in the latter. They were generally smaller versions of the escort sloops. ''Niger'' and ''Salamander'' of the reciprocating group used vertical triple expansion engines, instead of the vertical compound engines of their sisters. As a result of the increased installed power they had a half knot speed advantage, even though they used slightly shorter hulls. The turbine ships used the same shorter hulls as ''Niger'' and ''Salamander'', but with lower installed power, speed dropped back to . ''Gleaner'', ''Franklin'', ''Jason'' and ''Scott'' were completed as unarmed surve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
German Naval Intelligence Service
The German Naval Intelligence Service (German: ''Marinenachrichtendienst'' (MND)) was the naval intelligence department of the Germany Navy and had a long history, going back to the naval aspirations of German emperor Wilhelm II in 1899. The department had various names throughout its existence. Between 1901 and 1919, the service was called the Nachrichten-Abteilung also known as N (English: Military intelligence department) and was the naval intelligence service of the Imperial German Navy. It focused its efforts on France, the United States and above all the United Kingdom, whose Royal Navy was Germany's principal rival for naval supremacy. Its activities had little practical impact on the course of the First World War and it was dissolved in 1919 after Germany's defeat in the war. After the war, saw the establishment of the observation service (B-Dienst) in 1918–1919. In spring 1925, the Naval Intelligence Division was disbanded and did not reform until October 1934 under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B-Dienst
The ''B-Dienst'' (german: Beobachtungsdienst, observation service), also called x''B-Dienst'', X-''B-Dienst'' and χ''B-Dienst'', was a Department of the German Naval Intelligence Service (german: Marinenachrichtendienst, MND III) of the OKM, that dealt with the interception and recording, decoding and analysis of the enemy, in particular 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 Battles of Norway and France in spring 1940, primarily due to the cryptanalysis successes it had achieved against early and less secure British Naval cyphers. B-Dienst broke British Naval Combined Cypher No. 3 in October 1941, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wireless Telegraphy
Wireless telegraphy or radiotelegraphy is transmission of text messages by radio waves, analogous to electrical telegraphy using cables. Before about 1910, the term ''wireless telegraphy'' was also used for other experimental technologies for transmitting telegraph signals without wires. In radiotelegraphy, information is transmitted by pulses of radio waves of two different lengths called "dots" and "dashes", which spell out text messages, usually in Morse code. In a manual system, the sending operator taps on a switch called a telegraph key which turns the transmitter on and off, producing the pulses of radio waves. At the receiver the pulses are audible in the receiver's speaker as beeps, which are translated back to text by an operator who knows Morse code. Radiotelegraphy was the first means of radio communication. The first practical radio transmitters and receivers invented in 1894–1895 by Guglielmo Marconi used radiotelegraphy. It continued to be the only type of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Y-stations
The "Y" service was a network of British signals intelligence collection sites, the Y-stations. The service was established during the First World War and used again during the Second World War. The sites were operated by a range of agencies including the Army, Navy and RAF plus the Foreign Office (MI6 and MI5), General Post Office and Marconi Company receiving stations ashore and afloat. There were more than 600 receiving sets in use at Y-stations during the Second World War. Background The "Y" stations tended to be of two types, for intercepting of the signals and for identifying where they were coming from. Sometimes both functions were operated at the same site, with the direction finding (D/F) hut being a few hundred metres from the main interception building, because of the need to minimise interference. The sites collected radio traffic which was then either analysed locally or if encrypted, passed for processing initially to the Admiralty Room 40 in London and during Worl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traffic Analysis
Traffic analysis is the process of intercepting and examining messages in order to deduce information from patterns in communication, it can be performed even when the messages are encrypted. In general, the greater the number of messages observed, the greater information be inferred. Traffic analysis can be performed in the context of military intelligence, counter-intelligence, or pattern-of-life analysis, and is also a concern in computer security. Traffic analysis tasks may be supported by dedicated computer software programs. Advanced traffic analysis techniques which may include various forms of social network analysis. Traffic analysis has historically been a vital technique in cryptanalysis, especially when the attempted crack depends on successfully seeding a known-plaintext attack, which often requires an inspired guess based on how specific the operational context might likely influence what an adversary communicates, which may be sufficient to establish a short crib. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bletchley Park
Bletchley Park is an English country house and estate in Bletchley, Milton Keynes ( Buckinghamshire) that became the principal centre of Allied code-breaking during the Second World War. The mansion was constructed during the years following 1883 for the financier and politician Sir Herbert Leon in the Victorian Gothic, Tudor, and Dutch Baroque styles, on the site of older buildings of the same name. During World War II, the estate housed the Government Code and Cypher School (GC&CS), which regularly penetrated the secret communications of the Axis Powersmost importantly the German Enigma and Lorenz ciphers. The GC&CS team of codebreakers included Alan Turing, Gordon Welchman, Hugh Alexander, Bill Tutte, and Stuart Milner-Barry. The nature of the work at Bletchley remained secret until many years after the war. According to the official historian of British Intelligence, the "Ultra" intelligence produced at Bletchley shortened the war by two to four years, and without it th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Government Communications Headquarters
Government Communications Headquarters, commonly known as GCHQ, is an intelligence and security organisation responsible for providing signals intelligence (SIGINT) and information assurance (IA) to the government and armed forces of the United Kingdom. Primarily based at "The Doughnut" in the suburbs of Cheltenham, GCHQ is the responsibility of the country's Secretary of State for Foreign and Commonwealth Affairs (Foreign Secretary), but it is not a part of the Foreign Office and its Director ranks as a Permanent Secretary. GCHQ was originally established after the First World War as the Government Code and Cypher School (GC&CS) and was known under that name until 1946. During the Second World War it was located at Bletchley Park, where it was responsible for breaking the German Enigma codes. There are two main components of the GCHQ, the Composite Signals Organisation (CSO), which is responsible for gathering information, and the National Cyber Security Centre (NCSC), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USSR
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national republics; in practice, both its government and its economy were highly centralized until its final years. It was a one-party state governed by the Communist Party of the Soviet Union, with the city of Moscow serving as its capital as well as that of its largest and most populous republic: the Russian SFSR. Other major cities included Leningrad (Russian SFSR), Kiev ( Ukrainian SSR), Minsk ( Byelorussian SSR), Tashkent (Uzbek SSR), Alma-Ata (Kazakh SSR), and Novosibirsk (Russian SFSR). It was the largest country in the world, covering over and spanning eleven time zones. The country's roots lay in the October Revolution of 1917, when the Bolsheviks, under the leadership of Vladimir Lenin, overthrew the Russian Provisional Gove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
