A diesel–electric transmission, or diesel–electric powertrain, is used by a number of vehicle and ship types for providing locomotion. A diesel–electric transmission system includes a diesel engine connected to an electrical generator, creating electricity that powers electric traction motors. No clutch is required. Before diesel engines came into widespread use, a similar system, using a petrol engine and called petrol–electric or gas–electric, was sometimes used. Diesel–electric transmission is used on railways by diesel electric locomotives and diesel electric multiple units, as electric motors are able to supply full torque at 0 RPM. Diesel–electric systems are used in submarines and surface ships and some land vehicles. In some high-efficiency applications, electrical energy may be stored in rechargeable batteries, in which case these vehicles can be considered as a class of hybrid electric vehicle; the first diesel motorship was the first diesel–electric ship, the Russian tanker Vandal from Branobel, launched in 1903.
Steam turbine–electric propulsion has been in use since the 1920s, using diesel–electric powerplants in surface ships has increased lately. The Finnish coastal defence ships Ilmarinen and Väinämöinen laid down in 1928–1929, were among the first surface ships to use diesel–electric transmission; the technology was used in diesel powered icebreakers. In World War II the United States built diesel–electric surface warships. Due to machinery shortages destroyer escorts of the Evarts and Cannon classes were diesel–electric, with half their designed horsepower; the Wind-class icebreakers, on the other hand, were designed for diesel–electric propulsion because of its flexibility and resistance to damage. Some modern diesel–electric ships, including cruise ships and icebreakers, use electric motors in pods called azimuth thrusters underneath to allow for 360° rotation, making the ships far more maneuverable. An example of this is Symphony of the Seas, the largest passenger ship as of 2019. Gas turbines are used for electrical power generation and some ships use a combination: Queen Mary 2 has a set of diesel engines in the bottom of the ship plus two gas turbines mounted near the main funnel.
This provides a simple way to use the high-speed, low-torque output of a turbine to drive a low-speed propeller, without the need for excessive reduction gearing. Early submarines used a direct mechanical connection between the engine and propeller, switching between diesel engines for surface running and electric motors for submerged propulsion; this was a "parallel" type of hybrid, since the motor and engine were coupled to the same shaft. On the surface, the motor was used as a generator to recharge the batteries and supply other electric loads; the engine would be disconnected for submerged operation, with batteries powering the electric motor and supplying all other power as well. True diesel–electric transmissions for submarines were first proposed by the United States Navy's Bureau of Engineering in 1928—instead of driving the propeller directly while running on the surface, the submarine's diesel would instead drive a generator that could either charge the submarine's batteries or drive the electric motor.
This meant that motor speed was independent of the diesel engine's speed, the diesel could run at an optimum and non-critical speed, while one or more of the diesel engines could be shut down for maintenance while the submarine continued to run using battery power. The concept was pioneered in 1929 in the S-class submarines S-3, S-6, S-7 to test the concept; the first production submarines with this system were the Porpoise-class, it was used on most subsequent US diesel submarines through the 1960s. The only other navy to adopt the system before 1945 was the British Royal Navy in the U-class submarines, although some submarines of the Imperial Japanese Navy used separate diesel generators for low-speed running. In a diesel–electric transmission arrangement, as used on 1930s and US Navy, German and other nations' diesel submarines, the propellers are driven directly or through reduction gears by an electric motor, while two or more diesel generators provide electric energy for charging the batteries and driving the electric motors.
This mechanically isolates the noisy engine compartment from the outer pressure hull and reduces the acoustic signature of the submarine when surfaced. Some nuclear submarines use a similar turbo-electric propulsion system, with propulsion turbo generators driven by reactor plant steam. During World War I, there was a strategic need for rail engines without plumes of smoke above them. Diesel technology was not yet sufficiently developed but a few precursor attempts were made for petrol–electric transmissions by the French and British. About 300 of these locomotives, only 96 being standard gauge, were in use at various points in the conflict. Before the war, the GE 57-ton gas-electric boxcab had been produced in the USA. In the 1920s, diesel–electric technology first saw limited use in switchers, locomotives used for moving trains around in railroad yards and assembling and disassembling them. An early company offering "Oil-Electric" locomotives was the American Locomotive Company; the ALCO HH series of diesel–electric switcher entered series production in 1931.
In the 1930s, the system was adapted for the fastest trains of their day. Diesel–electric powerplants became popular
In broadcasting and radio communications, a call sign is a unique designation for a transmitter station. In the United States of America, they are used for all FCC-licensed transmitters. A call sign can be formally assigned by a government agency, informally adopted by individuals or organizations, or cryptographically encoded to disguise a station's identity; the use of call signs as unique identifiers dates to the landline railroad telegraph system. Because there was only one telegraph line linking all railroad stations, there needed to be a way to address each one when sending a telegram. In order to save time, two-letter identifiers were adopted for this purpose; this pattern continued in radiotelegraph operation. These were not globally unique, so a one-letter company identifier was added. By 1912, the need to identify stations operated by multiple companies in multiple nations required an international standard. Merchant and naval vessels are assigned call signs by their national licensing authorities.
In the case of states such as Liberia or Panama, which are flags of convenience for ship registration, call signs for larger vessels consist of the national prefix plus three letters. United States merchant vessels are given call signs beginning with the letters "W" or "K" while US naval ships are assigned call signs beginning with "N". Both ships and broadcast stations were assigned call signs in this series consisting of three or four letters. Ships equipped with Morse code radiotelegraphy, or life boat radio sets, Aviation ground stations, broadcast stations were given four letter call signs. Maritime coast stations on high frequency were assigned three letter call signs; as demand for both marine radio and broadcast call signs grew American-flagged vessels with radiotelephony only were given longer call signs with mixed letters and numbers. Leisure craft with VHF radios may not be assigned call signs, in which case the name of the vessel is used instead. Ships in the US still wishing to have a radio license are under FCC class SA: "Ship recreational or voluntarily equipped."
Those calls follow the land mobile format of the initial letter K or W followed by 1 or 2 letters followed by 3 or 4 numbers. U. S. Coast Guard small boats have a number, shown on both bows in which the first two digits indicate the nominal length of the boat in feet. For example, Coast Guard 47021 refers to the 21st in the series of 47-foot motor lifeboats; the call sign might be abbreviated to the final two or three numbers during operations, for example: Coast Guard zero two one. Aviation mobile stations equipped with radiotelegraphy were assigned five letter call signs.. Land Stations in Aviation were assigned four letter call signs; these call signs were phased out in the 1960s when flight radio officers were no longer required on international flights. USSR kept FRO's for the Moscow-Havana run until around 2000. All signs in aviation are derived from several different policies, depending upon the type of flight operation and whether or not the caller is in an aircraft or at a ground facility.
In most countries, unscheduled general aviation flights identify themselves using the call sign corresponding to the aircraft's registration number. In this case, the call sign is spoken using the International Civil Aviation Organization phonetic alphabet. Aircraft registration numbers internationally follow the pattern of a country prefix, followed by a unique identifier made up of letters and numbers. For example, an aircraft registered as N978CP conducting a general aviation flight would use the call sign November-niner-seven-eight-Charlie-Papa. However, in the United States a pilot of an aircraft would omit saying November, instead use the name of the aircraft manufacturer or the specific model. At times, general aviation pilots might omit additional preceding numbers and use only the last three numbers and letters; this is true at uncontrolled fields when reporting traffic pattern positions or at towered airports after establishing two-way communication with the tower controller. For example, Skyhawk eight-Charlie-Papa, left base.
In most countries, the aircraft call sign or "tail number"/"tail letters" are linked to the international radio call sign allocation table and follow a convention that aircraft radio stations receive call signs consisting of five letters. For example, all British civil aircraft have a five-letter call sign beginning with the letter G. Canadian aircraft have a call sign beginning with C–F or C–G, such as C–FABC. Wing In Ground-effect vehicles in Canada are eligible to receive C–Hxxx call signs, ultralight aircraft receive C-Ixxx call signs. In days gone by American aircraft used five letter call signs, such as KH–ABC, but they were replaced prior to World War II by the current American system of civilian aircraft call signs. Radio call signs used for communication in manned spaceflight is not formalized or regulated to the same degree as for aircraft; the three nations curren
Germany the Federal Republic of Germany, is a country in Central and Western Europe, lying between the Baltic and North Seas to the north, the Alps to the south. It borders Denmark to the north and the Czech Republic to the east and Switzerland to the south, France to the southwest, Luxembourg and the Netherlands to the west. Germany includes 16 constituent states, covers an area of 357,386 square kilometres, has a temperate seasonal climate. With 83 million inhabitants, it is the second most populous state of Europe after Russia, the most populous state lying in Europe, as well as the most populous member state of the European Union. Germany is a decentralized country, its capital and largest metropolis is Berlin, while Frankfurt serves as its financial capital and has the country's busiest airport. Germany's largest urban area is the Ruhr, with its main centres of Essen; the country's other major cities are Hamburg, Cologne, Stuttgart, Düsseldorf, Dresden, Bremen and Nuremberg. Various Germanic tribes have inhabited the northern parts of modern Germany since classical antiquity.
A region named Germania was documented before 100 AD. During the Migration Period, the Germanic tribes expanded southward. Beginning in the 10th century, German territories formed a central part of the Holy Roman Empire. During the 16th century, northern German regions became the centre of the Protestant Reformation. After the collapse of the Holy Roman Empire, the German Confederation was formed in 1815; the German revolutions of 1848–49 resulted in the Frankfurt Parliament establishing major democratic rights. In 1871, Germany became a nation state when most of the German states unified into the Prussian-dominated German Empire. After World War I and the revolution of 1918–19, the Empire was replaced by the parliamentary Weimar Republic; the Nazi seizure of power in 1933 led to the establishment of a dictatorship, the annexation of Austria, World War II, the Holocaust. After the end of World War II in Europe and a period of Allied occupation, Austria was re-established as an independent country and two new German states were founded: West Germany, formed from the American and French occupation zones, East Germany, formed from the Soviet occupation zone.
Following the Revolutions of 1989 that ended communist rule in Central and Eastern Europe, the country was reunified on 3 October 1990. Today, the sovereign state of Germany is a federal parliamentary republic led by a chancellor, it is a great power with a strong economy. As a global leader in several industrial and technological sectors, it is both the world's third-largest exporter and importer of goods; as a developed country with a high standard of living, it upholds a social security and universal health care system, environmental protection, a tuition-free university education. The Federal Republic of Germany was a founding member of the European Economic Community in 1957 and the European Union in 1993, it is part of the Schengen Area and became a co-founder of the Eurozone in 1999. Germany is a member of the United Nations, NATO, the G7, the G20, the OECD. Known for its rich cultural history, Germany has been continuously the home of influential and successful artists, musicians, film people, entrepreneurs, scientists and inventors.
Germany has a large number of World Heritage sites and is among the top tourism destinations in the world. The English word Germany derives from the Latin Germania, which came into use after Julius Caesar adopted it for the peoples east of the Rhine; the German term Deutschland diutisciu land is derived from deutsch, descended from Old High German diutisc "popular" used to distinguish the language of the common people from Latin and its Romance descendants. This in turn descends from Proto-Germanic *þiudiskaz "popular", derived from *þeudō, descended from Proto-Indo-European *tewtéh₂- "people", from which the word Teutons originates; the discovery of the Mauer 1 mandible shows that ancient humans were present in Germany at least 600,000 years ago. The oldest complete hunting weapons found anywhere in the world were discovered in a coal mine in Schöningen between 1994 and 1998 where eight 380,000-year-old wooden javelins of 1.82 to 2.25 m length were unearthed. The Neander Valley was the location where the first non-modern human fossil was discovered.
The Neanderthal 1 fossils are known to be 40,000 years old. Evidence of modern humans dated, has been found in caves in the Swabian Jura near Ulm; the finds included 42,000-year-old bird bone and mammoth ivory flutes which are the oldest musical instruments found, the 40,000-year-old Ice Age Lion Man, the oldest uncontested figurative art discovered, the 35,000-year-old Venus of Hohle Fels, the oldest uncontested human figurative art discovered. The Nebra sky disk is a bronze artefact created during the European Bronze Age attributed to a site near Nebra, Saxony-Anhalt, it is part of UNESCO's Memory of the World Programme. The Germanic tribes are thought to date from the Pre-Roman Iron Age. From southern Scandinavia and north Germany, they expanded south and west from the 1st century BC, coming into contact with the Celtic tribes of Gaul as well
In electricity generation, a generator is a device that converts motive power into electrical power for use in an external circuit. Sources of mechanical energy include steam turbines, gas turbines, water turbines, internal combustion engines and hand cranks; the first electromagnetic generator, the Faraday disk, was invented in 1831 by British scientist Michael Faraday. Generators provide nearly all of the power for electric power grids; the reverse conversion of electrical energy into mechanical energy is done by an electric motor, motors and generators have many similarities. Many motors can be mechanically driven to generate electricity and make acceptable manual generators. Electromagnetic generators fall into one of two broad categories and alternators. Dynamos generate pulsing direct current through the use of a commutator. Alternators generate alternating current. Mechanically a generator consists of a rotating part and a stationary part: Rotor The rotating part of an electrical machine.
Stator The stationary part of an electrical machine, which surrounds the rotor. One of these parts generates a magnetic field, the other has a wire winding in which the changing field induces an electric current: Field winding or field magnets The magnetic field producing component of an electrical machine; the magnetic field of the dynamo or alternator can be provided by either wire windings called field coils or permanent magnets. Electrically-excited generators include an excitation system to produce the field flux. A generator using permanent magnets is sometimes called a magneto, or permanent magnet synchronous generators. Armature The power-producing component of an electrical machine. In a generator, alternator, or dynamo, the armature windings generate the electric current, which provides power to an external circuit; the armature can be on either the rotor or the stator, depending on the design, with the field coil or magnet on the other part. Before the connection between magnetism and electricity was discovered, electrostatic generators were invented.
They operated on electrostatic principles, by using moving electrically charged belts and disks that carried charge to a high potential electrode. The charge was generated using either of two mechanisms: electrostatic induction or the triboelectric effect; such generators generated high voltage and low current. Because of their inefficiency and the difficulty of insulating machines that produced high voltages, electrostatic generators had low power ratings, were never used for generation of commercially significant quantities of electric power, their only practical applications were to power early X-ray tubes, in some atomic particle accelerators. The operating principle of electromagnetic generators was discovered in the years of 1831–1832 by Michael Faraday; the principle called Faraday's law, is that an electromotive force is generated in an electrical conductor which encircles a varying magnetic flux. He built the first electromagnetic generator, called the Faraday disk, it produced a small DC voltage.
This design was inefficient, due to self-cancelling counterflows of current in regions of the disk that were not under the influence of the magnetic field. While current was induced directly underneath the magnet, the current would circulate backwards in regions that were outside the influence of the magnetic field; this counterflow limited the power output to the pickup wires, induced waste heating of the copper disc. Homopolar generators would solve this problem by using an array of magnets arranged around the disc perimeter to maintain a steady field effect in one current-flow direction. Another disadvantage was that the output voltage was low, due to the single current path through the magnetic flux. Experimenters found that using multiple turns of wire in a coil could produce higher, more useful voltages. Since the output voltage is proportional to the number of turns, generators could be designed to produce any desired voltage by varying the number of turns. Wire windings became a basic feature of all subsequent generator designs.
Independently of Faraday, the Hungarian Ányos Jedlik started experimenting in 1827 with the electromagnetic rotating devices which he called electromagnetic self-rotors. In the prototype of the single-pole electric starter both the stationary and the revolving parts were electromagnetic, it was the discovery of the principle of dynamo self-excitation, which replaced permanent magnet designs. He may have formulated the concept of the dynamo in 1861 but didn't patent it as he thought he wasn't the first to realize this. A coil of wire rotating in a magnetic field produces a current which changes direction with each 180° rotation, an alternating current; however many early uses of electricity required direct current. In the first practical electric generators, called dynamos, the AC was converted into DC with a commutator, a set of rotating switch contacts on the armature shaft; the commutator reversed the connection of the armature winding to the circuit every 180° rotation of the shaft, creating a pulsing DC current.
One of the first dynamos was built by Hippolyte Pixii in 1832. The dynamo was the first electrical generator capable of delivering power for industry; the Woolrich Electrical Generator of 1844, now in Thinktank, Birmingham Science Museum, is the earliest electrical generator used in an industrial process. It was used by the firm of Elkingtons for commercial electroplating; the modern dynamo, fit for use in industrial applications, was invented independently by Sir Charles
Type 205 submarine
The Type 205 was a class of German diesel-electric submarines. They were single-hull vessels optimized for the use in the shallow Baltic Sea; the Type 205 is a direct evolution of the Type 201 class with lengthened hull, new machinery and sensors. The biggest difference though is that ST-52 steel is used for the pressure hull since the Type 201's non-magnetic steel proved to be problematic. Type 206, the follow-on class succeeded with non-magnetic steel hulls; the Type 205 was in service with the Royal Danish Navy until 2004, in which it was known as Narhvalen class. The Danish boats differed from the German ones to meet special Danish demands. Responsible for the design and construction was the Ingenieurkontor Lübeck headed by Ulrich Gabler; these last two boats were built by the Howaldtswerke, in Denmark at The Naval Dockyard, Copenhagen. Notes: U-1 was given back to Nordseewerke and was used to test an experimental closed-cycle diesel air-independent propulsion system before being scrapped U-11 was transformed to a Type 205A double-hulled boat and used as torpedo target U-12 was used for sonar trials as Type 205B Karr, Hans.
Deutsche Uboote seit 1956. Stuttgart: Motorbuch. ISBN 9783613037083. Kobben class submarine Submarines of the Narhvalen class - Danish Naval History
The Kobben class is a customized version of the German Type 205 submarine. Fifteen vessels of this class were built for use by the Royal Norwegian Navy in the 1960s; the class saw service with Denmark and Poland. The boats have since been withdrawn from service in the Danish Navy; the Polish Navy still operates four Kobben-class submarines, as of 2016. Along with the rest of the Royal Norwegian Navy, the submarine fleet was to be modernized according to the Fleet plan of 1960. After the war, Norway needed a navy more suited for coastal operations rather than large, seagoing vessels; this made the choice of a new type of submarines rather slim, not many NATO submarines being suited for this type of operations. A German Type 201 submarine was lent to the Royal Norwegian Navy for adaptation; the result was the Type 207, of which 15 vessels were delivered to Norway in the period 1964 – 67. All Kobben-class submarines were built by Rheinstahl Nordseewerke GmbH in Emden. Between 1985 – 93, six boats were lengthened by 2 m and modernized, most notably with new sonar equipment.
During that period, four others were sold to the Royal Danish Navy, three operational and one for spare parts. HDMS Sælen served in the 2003 invasion of Iraq from May 2002 until June 2003. In 2001, the Kobben class was phased out in Norwegian service, replaced by the newer Ula class. Five modernized vessels were given to the Polish Navy, four as operational units and one for spare parts. Before they were transferred, the Polish crews were trained and the boats were overhauled. During 2004, all of the operational Danish boats were decommissioned, they were mothballed as of 2005, waiting to be transferred to another nation. The Kobben is mentioned in Tom Clancy's 1986 techno-thriller Red Storm Rising. Sites with information about the Kobben class. Nordseewerke - manufacturer's website Polish Navy - with Polish commission dates and information Danish Naval History - information about Danish use
Copenhagen is the capital and most populous city of Denmark. As of July 2018, the city has a population of 777,218, it forms the core of the wider urban area of the Copenhagen metropolitan area. Copenhagen is situated on the eastern coast of the island of Zealand; the Øresund Bridge connects the two cities by road. A Viking fishing village established in the 10th century in the vicinity of what is now Gammel Strand, Copenhagen became the capital of Denmark in the early 15th century. Beginning in the 17th century it consolidated its position as a regional centre of power with its institutions and armed forces. After suffering from the effects of plague and fire in the 18th century, the city underwent a period of redevelopment; this included construction of the prestigious district of Frederiksstaden and founding of such cultural institutions as the Royal Theatre and the Royal Academy of Fine Arts. After further disasters in the early 19th century when Horatio Nelson attacked the Dano-Norwegian fleet and bombarded the city, rebuilding during the Danish Golden Age brought a Neoclassical look to Copenhagen's architecture.
Following the Second World War, the Finger Plan fostered the development of housing and businesses along the five urban railway routes stretching out from the city centre. Since the turn of the 21st century, Copenhagen has seen strong urban and cultural development, facilitated by investment in its institutions and infrastructure; the city is the cultural and governmental centre of Denmark. Copenhagen's economy has seen rapid developments in the service sector through initiatives in information technology and clean technology. Since the completion of the Øresund Bridge, Copenhagen has become integrated with the Swedish province of Scania and its largest city, Malmö, forming the Øresund Region. With a number of bridges connecting the various districts, the cityscape is characterised by parks and waterfronts. Copenhagen's landmarks such as Tivoli Gardens, The Little Mermaid statue, the Amalienborg and Christiansborg palaces, Rosenborg Castle Gardens, Frederik's Church, many museums and nightclubs are significant tourist attractions.
The largest lake of Denmark, Arresø, lies around 27 miles northwest of the City Hall Square. Copenhagen is home to the University of Copenhagen, the Technical University of Denmark, Copenhagen Business School and the IT University of Copenhagen; the University of Copenhagen, founded in 1479, is the oldest university in Denmark. Copenhagen is home to the FC Brøndby football clubs; the annual Copenhagen Marathon was established in 1980. Copenhagen is one of the most bicycle-friendly cities in the world; the Copenhagen Metro launched in 2002 serves central Copenhagen while the Copenhagen S-train, the Lokaltog and the Coast Line network serves and connects central Copenhagen to outlying boroughs. To relieve traffic congestion, the Fehmarn Belt Fixed Link road and rail construction is planned, because the narrow 9-9.5 mile isthmus between Roskilde Fjord and Køge Bugt forms a traffic bottleneck. The Copenhagen-Ringsted Line will relieve traffic congestion in the corridor between Roskilde and Copenhagen.
Serving two million passengers a month, Copenhagen Airport, Kastrup, is the busiest airport in the Nordic countries. Copenhagen's name reflects its origin as a place of commerce; the original designation in Old Norse, from which Danish descends, was Kaupmannahǫfn, meaning "merchants' harbour". By the time Old Danish was spoken, the capital was called Køpmannæhafn, with the current name deriving from centuries of subsequent regular sound change. An exact English equivalent would be "chapman's haven". However, the English term for the city was adapted from Kopenhagen. Although the earliest historical records of Copenhagen are from the end of the 12th century, recent archaeological finds in connection with work on the city's metropolitan rail system revealed the remains of a large merchant's mansion near today's Kongens Nytorv from c. 1020. Excavations in Pilestræde have led to the discovery of a well from the late 12th century; the remains of an ancient church, with graves dating to the 11th century, have been unearthed near where Strøget meets Rådhuspladsen.
These finds indicate. Substantial discoveries of flint tools in the area provide evidence of human settlements dating to the Stone Age. Many historians believe the town dates to the late Viking Age, was founded by Sweyn I Forkbeard; the natural harbour and good herring stocks seem to have attracted fishermen and merchants to the area on a seasonal basis from the 11th century and more permanently in the 13th century. The first habitations were centred on Gammel Strand in the 11thcentury or earlier; the earliest written mention of the town was in the 12th century when Saxo Grammaticus in Gesta Danorum referred to it as Portus