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RS4 Codici
RS4 Codici is a train protection system used in Italy. The term is an abbreviation of ''Ripetizione Segnali a 4 codici'' (''signal repetition system with 4 codes''). It is a simple cab signalling system, displaying the aspect of the next (and, in some cases, the next but one) signal. It helps the driver to reliably determine the aspect of the next signal even in poor visibility and at high velocities. The information is conveyed via amplitude modulation of a 50 Hz alternating current of the Blocco Automatico a Correnti Codificate (BAcc) in the rails. Receiver coils in front of the first axle of a locomotive or control car are used to detect the signal. The frequency of the modulating signal encodes the signal aspect: The driver must acknowledge a code change by pressing a button labeled ''RIC'' within three seconds, otherwise the system will apply emergency brakes. As trains got faster an additional set of codes sent with a 178 Hz carrier were added. The new system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Train Protection System
A train protection system is a railway technical installation to ensure safe operation in the event of human error. Development Train stops The earliest systems were train stops, as still used by the New York City Subway, the Toronto subway, the London Underground, the Moscow Subway (only on the older lines) and the Berlin S-Bahn. Beside every signal is a moveable arm. If the signal is red, levers connected to valves on any passing train hit the arm, opening the brake line, applying the emergency brake, If the signal shows green, the arm is turned away from the levers and there is no contact. The Great Western Railway in the UK introduced its 'automatic train control' system in the early years of the 20th century. Each distant signal had before it a ramp between the running rails. If the signal showed green, the ramp was energised with a low voltage current which was passed to the locomotive when a shoe came into contact with the ramp. A bell rang in the locomotive's cab t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Italy
Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical region. Italy is also considered part of Western Europe, and shares land borders with France, Switzerland, Austria, Slovenia and the enclaved microstates of Vatican City and San Marino. It has a territorial exclave in Switzerland, Campione. Italy covers an area of , with a population of over 60 million. It is the third-most populous member state of the European Union, the sixth-most populous country in Europe, and the tenth-largest country in the continent by land area. Italy's capital and largest city is Rome. Italy was the native place of many civilizations such as the Italic peoples and the Etruscans, while due to its central geographic location in Southern Europe and the Mediterranean, the country has also historically been home ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cab Signalling
Cab signaling is a railway safety system that communicates track status and condition information to the cab, crew compartment or driver's compartment of a locomotive, railcar or multiple unit. The information is continually updated giving an easy to read display to the train driver or engine driver. The simplest systems display the trackside signal, while more sophisticated systems also display allowable speed, location of nearby trains, and dynamic information about the track ahead. Cab signals can also be part of a more comprehensive train protection system that can automatically apply the brakes stopping the train if the operator does not respond appropriately to a dangerous condition. Overview The main purpose of a signal system is to enforce a safe separation between trains and to stop or slow trains in advance of a restrictive situation. The cab signal system is an improvement over the wayside signal system, where visual signals beside or above the right-of-way gov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Railway Signal
A railway signal is a visual display device that conveys instructions or provides warning of instructions regarding the driver’s authority to proceed. The driver interprets the signal's indication and acts accordingly. Typically, a signal might inform the driver of the speed at which the train may safely proceed or it may instruct the driver to stop. Application and positioning of signals Originally, signals displayed simple stop or proceed indications. As traffic density increased, this proved to be too limiting and refinements were added. One such refinement was the addition of distant signals on the approach to stop signals. The distant signal gave the driver warning that they were approaching a signal which might require a stop. This allowed for an overall increase in speed, since train drivers no longer had to drive at a speed within sighting distance of the stop signal. Under timetable and train order operation, the signals did not directly convey orders to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amplitude Modulation
Amplitude modulation (AM) is a modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave. In amplitude modulation, the amplitude (signal strength) of the wave is varied in proportion to that of the message signal, such as an audio signal. This technique contrasts with angle modulation, in which either the frequency of the carrier wave is varied, as in frequency modulation, or its phase, as in phase modulation. AM was the earliest modulation method used for transmitting audio in radio broadcasting. It was developed during the first quarter of the 20th century beginning with Roberto Landell de Moura and Reginald Fessenden's radiotelephone experiments in 1900. This original form of AM is sometimes called double-sideband amplitude modulation (DSBAM), because the standard method produces sidebands on either side of the carrier frequency. Single-sideband modulation uses bandpass filters to eliminate one of the sidebands and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hertz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one hertz is the reciprocal of one second. It is named after Heinrich Rudolf Hertz (1857–1894), the first person to provide conclusive proof of the existence of electromagnetic waves. Hertz are commonly expressed in multiples: kilohertz (kHz), megahertz (MHz), gigahertz (GHz), terahertz (THz). Some of the unit's most common uses are in the description of periodic waveforms and musical tones, particularly those used in radio- and audio-related applications. It is also used to describe the clock speeds at which computers and other electronics are driven. The units are sometimes also used as a representation of the energy of a photon, via the Planck relation ''E'' = ''hν'', where ''E'' is the photon's energy, ''ν'' is its freq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alternating Current
Alternating current (AC) is an electric current which periodically reverses direction and changes its magnitude continuously with time in contrast to direct current (DC) which flows only in one direction. Alternating current is the form in which electric power is delivered to businesses and residences, and it is the form of electrical energy that consumers typically use when they plug kitchen appliances, televisions, fans and electric lamps into a wall socket. A common source of DC power is a battery cell in a flashlight. The abbreviations ''AC'' and ''DC'' are often used to mean simply ''alternating'' and ''direct'', as when they modify ''current'' or ''voltage''. The usual waveform of alternating current in most electric power circuits is a sine wave, whose positive half-period corresponds with positive direction of the current and vice versa. In certain applications, like guitar amplifiers, different waveforms are used, such as triangular waves or square waves. Audio a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blocco Automatico A Correnti Codificate
Blocco automatico a correnti codificate (BACC or BAcc, ''automatic block with codified currents'') is a signalling block system used in Italy on railway lines using 3 kV DC electrification. The track circuits used to detect the presence of a train also transmit coded signals to the trains which are used for train protection and cab signaling. Train protection systems that use BAcc are RS4 Codici, RS9 Codici and SCMT. Codes The information is conveyed by superposition of two amplitude-modulated alternating currents in the rails (with a carrier frequency of 50 Hz and 178 Hz, respectively). Receiver coils in front of the first axle of a locomotive or control car are used to detect the signal. The frequency of the modulating signal encodes the signal aspect: {, class="wikitable" , - ! modulation frequency of 50 or 83.3 Hz carrier , , modulation frequency of 178 Hz carrier , , code , , meaning , - , (none) , , (none) , , AC(''Assenza di Codice'') , , transmi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Locomotive
A locomotive or engine is a rail transport vehicle that provides the Power (physics), motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, Motor coach (rail), motor coach, railcar or power car; the use of these self-propelled vehicles is increasingly common for passenger trains, but rare for freight (see CargoSprinter). Traditionally, locomotives pulled trains from the front. However, Push-pull train, push-pull operation has become common, where the train may have a locomotive (or locomotives) at the front, at the rear, or at each end. Most recently railroads have begun adopting DPU or distributed power. The front may have one or two locomotives followed by a mid-train locomotive that is controlled remotely from the lead unit. __TOC__ Etymology The word ''locomotive'' originates from the Latin language, Latin 'from a place', Ablative case, ablative of 'place', and the Medieval Latin 'causing mot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Car (rail)
A control car, cab car (North America), control trailer, or driving trailer (UK and Ireland) is a non-powered rail vehicle from which a train can be operated. As dedicated vehicles or regular passenger cars, they have one or two driver compartments with all the controls and gauges required to remotely operate the locomotive, including exterior locomotive equipment such as horns, bells, ploughs, and lights. They also have communications and safety systems such as GSM-R or European Train Control System (ETCS). Control cars enable push-pull operation when located on the end of a train opposite its locomotive by allowing the train to reverse direction at a terminus without moving the locomotive or turning the train around. Control cars can carry passengers, baggage, and mail, and may, when used together with diesel locomotives, contain an engine-generator set to provide head-end power (HEP). They can also be used with a power car or a railcar. European railways have used control c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backward Compatible
Backward compatibility (sometimes known as backwards compatibility) is a property of an operating system, product, or technology that allows for interoperability with an older legacy system, or with input designed for such a system, especially in telecommunications and computing. Modifying a system in a way that does not allow backward compatibility is sometimes called " breaking" backward compatibility. A complementary concept is forward compatibility. A design that is forward-compatible usually has a roadmap for compatibility with future standards and products. A related term from programming jargon is hysterical reasons or hysterical raisins (near-homophones for "historical reasons"), as the purpose of some software features may be solely to support older hardware or software versions. Usage In hardware A simple example of both backward and forward compatibility is the introduction of FM radio in stereo. FM radio was initially mono, with only one audio channel represented ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Railway Signalling In Italy
Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a prepared flat surface, rail vehicles (rolling stock) are directionally guided by the tracks on which they run. Tracks usually consist of steel rails, installed on sleepers (ties) set in ballast, on which the rolling stock, usually fitted with metal wheels, moves. Other variations are also possible, such as "slab track", in which the rails are fastened to a concrete foundation resting on a prepared subsurface. Rolling stock in a rail transport system generally encounters lower frictional resistance than rubber-tyred road vehicles, so passenger and freight cars (carriages and wagons) can be coupled into longer trains. The operation is carried out by a railway company, providing transport between train stations or freight customer faciliti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
