In rail transport, track gauge or track gage is the spacing of the rails on a railway track and is measured between the inner faces of the load-bearing rails. All vehicles on a rail network must have running gear, compatible with the track gauge, in the earliest days of railways the selection of a proposed railway's gauge was a key issue; as the dominant parameter determining interoperability, it is still used as a descriptor of a route or network. In some places there is a distinction between the nominal gauge and the actual gauge, due to divergence of track components from the nominal. Railway engineers use a device, like a caliper, to measure the actual gauge, this device is referred to as a track gauge; the terms structure gauge and loading gauge, both used, have little connection with track gauge. Both refer to two-dimensional cross-section profiles, surrounding the track and vehicles running on it; the structure gauge specifies the outline into which altered structures must not encroach.
The loading gauge is the corresponding envelope within which rail vehicles and their loads must be contained. If an exceptional load or a new type of vehicle is being assessed to run, it is required to conform to the route's loading gauge. Conformance ensures. In the earliest days of railways, single wagons were manhandled on timber rails always in connection with mineral extraction, within a mine or quarry leading from it. Guidance was not at first provided except by human muscle power, but a number of methods of guiding the wagons were employed; the spacing between the rails had to be compatible with that of the wagon wheels. The timber rails wore rapidly. In some localities, the plates were made L-shaped, with the vertical part of the L guiding the wheels; as the guidance of the wagons was improved, short strings of wagons could be connected and pulled by horses, the track could be extended from the immediate vicinity of the mine or quarry to a navigable waterway. The wagons were built to a consistent pattern and the track would be made to suit the wagons: the gauge was more critical.
The Penydarren Tramroad of 1802 in South Wales, a plateway, spaced these at 4 ft 4 in over the outside of the upstands. The Penydarren Tramroad carried the first journey by a locomotive, in 1804, it was successful for the locomotive, but unsuccessful for the track: the plates were not strong enough to carry its weight. A considerable progressive step was made. Edge rails required a close match between rail spacing and the configuration of the wheelsets, the importance of the gauge was reinforced. Railways were still seen as local concerns: there was no appreciation of a future connection to other lines, selection of the track gauge was still a pragmatic decision based on local requirements and prejudices, determined by existing local designs of vehicles. Thus, the Monkland and Kirkintilloch Railway in the West of Scotland used 4 ft 6 in; the Arbroath and Forfar Railway opened in 1838 with a gauge of 5 ft 6 in, the Ulster Railway of 1839 used 6 ft 2 in Locomotives were being developed in the first decades of the 19th century.
His designs were so successful that they became the standard, when the Stockton and Darlington Railway was opened in 1825, it used his locomotives, with the same gauge as the Killingworth line, 4 ft 8 in. The Stockton and Darlington line was immensely successful, when the Liverpool and Manchester Railway, the first intercity line, was built, it used the same gauge, it was hugely successful, the gauge, became the automatic choice: "standard gauge". The Liverpool and Manchester was followed by other trunk railways, with the Grand Junction Railway and the London and Birmingham Railway forming a huge critical mass of standard gauge; when Bristol promoters planned a line from London, they employed the innovative engineer Isambard Kingdom Brunel. He decided on a wider gauge, to give greater stability, the Great Western Railway adopted a gauge of 7 ft eased to 7 ft 1⁄4 in; this became known as broad gauge. The Great Western Railway was successful and was expanded and through friendly associated companies, widening the scope of broad gauge.
At the same time, other parts of Britain built railways to standard gauge, British technology was exported to European countries and parts of North America using standard gauge. Britain polarised into two areas: those that used standard gauge. In this context, standard gauge was referred to as "narrow gauge" to indicate the contrast; some smaller concerns selected other non-standard gauges: the Eastern Counties Railway adopted 5 ft. Most of them converted to standard gauge at an early date, but the GWR's broad gauge continued to grow; the larger railway companies wished to expand geographically, large areas were considered to be under their control. When a new
Direct current is the unidirectional flow of electric charge. A battery is a good example of a DC power supply. Direct current may flow in a conductor such as a wire, but can flow through semiconductors, insulators, or through a vacuum as in electron or ion beams; the electric current flows in a constant direction, distinguishing it from alternating current. A term used for this type of current was galvanic current; the abbreviations AC and DC are used to mean alternating and direct, as when they modify current or voltage. Direct current may be obtained from an alternating current supply by use of a rectifier, which contains electronic elements or electromechanical elements that allow current to flow only in one direction. Direct current may be converted into alternating current with a motor-generator set. Direct current is used as a power supply for electronic systems. Large quantities of direct-current power are used in production of aluminum and other electrochemical processes, it is used for some railways in urban areas.
High-voltage direct current is used to transmit large amounts of power from remote generation sites or to interconnect alternating current power grids. Direct current was produced in 1800 by Italian physicist Alessandro Volta's battery, his Voltaic pile; the nature of how current flowed. French physicist André-Marie Ampère conjectured that current travelled in one direction from positive to negative; when French instrument maker Hippolyte Pixii built the first dynamo electric generator in 1832, he found that as the magnet used passed the loops of wire each half turn, it caused the flow of electricity to reverse, generating an alternating current. At Ampère's suggestion, Pixii added a commutator, a type of "switch" where contacts on the shaft work with "brush" contacts to produce direct current; the late 1870s and early 1880s saw electricity starting to be generated at power stations. These were set up to power arc lighting running on high voltage direct current or alternating current; this was followed by the wide spread use of low voltage direct current for indoor electric lighting in business and homes after inventor Thomas Edison launched his incandescent bulb based electric "utility" in 1882.
Because of the significant advantages of alternating current over direct current in using transformers to raise and lower voltages to allow much longer transmission distances, direct current was replaced over the next few decades by alternating current in power delivery. In the mid-1950s, high-voltage direct current transmission was developed, is now an option instead of long-distance high voltage alternating current systems. For long distance underseas cables, this DC option is the only technically feasible option. For applications requiring direct current, such as third rail power systems, alternating current is distributed to a substation, which utilizes a rectifier to convert the power to direct current; the term DC is used to refer to power systems that use only one polarity of voltage or current, to refer to the constant, zero-frequency, or varying local mean value of a voltage or current. For example, the voltage across a DC voltage source is constant as is the current through a DC current source.
The DC solution of an electric circuit is the solution where all currents are constant. It can be shown that any stationary voltage or current waveform can be decomposed into a sum of a DC component and a zero-mean time-varying component. Although DC stands for "direct current", DC refers to "constant polarity". Under this definition, DC voltages can vary in time, as seen in the raw output of a rectifier or the fluctuating voice signal on a telephone line; some forms of DC have no variations in voltage, but may still have variations in output power and current. A direct current circuit is an electrical circuit that consists of any combination of constant voltage sources, constant current sources, resistors. In this case, the circuit voltages and currents are independent of time. A particular circuit voltage or current does not depend on the past value of any circuit voltage or current; this implies that the system of equations that represent a DC circuit do not involve integrals or derivatives with respect to time.
If a capacitor or inductor is added to a DC circuit, the resulting circuit is not speaking, a DC circuit. However, most such circuits have a DC solution; this solution gives the circuit currents when the circuit is in DC steady state. Such a circuit is represented by a system of differential equations; the solution to these equations contain a time varying or transient part as well as constant or steady state part. It is this steady state part, the DC solution. There are some circuits. Two simple examples are a constant current source connected to a capacitor and a constant voltage source connected to an inductor. In electronics, it is common to refer to a circuit, powered by a DC voltage source such as a battery or the output of a DC power supply as a DC circuit though what is meant is that the circuit is DC powered. DC is found in many extra-low voltage applications and some low-voltage applications where these are powered by batteries or solar power systems. Most electronic circuits require a DC power supply.
Domestic DC installations have differ
Notre-Dame-de-Commiers is a commune in the Isère department in southeastern France. Communes of the Isère department INSEE statistics
Isère is a department in the Auvergne-Rhône-Alpes region in eastern France named after the river Isère. Isère is one of the original 83 departments created during the French Revolution on March 4, 1790, it was created from the main part of the former province of Dauphiné. Its area has been reduced twice, in 1852 and again in 1967, on both occasions losing territory to the department of Rhône. In 1852 in response to rapid urban development around the edge of Lyon, the communes of Bron, Vaulx-en-Velin, Vénissieux and Villeurbanne were transferred to Rhône. In 1967 the redrawing of local government borders led to the creation of the Urban Community of Lyon. At that time intercommunal groupings of this nature were not permitted to straddle departmental frontiers, accordingly 23 more Isère communes found themselves transferred to Rhône; the affected Isère communes were Chaponnay, Communay, Corbas, Décines-Charpieu, Genas, Jons, Meyzieu, Pusignan, Saint-Bonnet-de-Mure, Saint-Laurent-de-Mure, Saint-Pierre-de-Chandieu, Saint-Priest, Saint-Symphorien-d'Ozon, Sérézin-du-Rhône, Solaize and Toussieu.
Most on 1 April 1971, Colombier-Saugnieu was lost to Rhône. Banners appeared in the commune's three little villages at the time proclaiming "Dauphinois toujours" Isère was the name of the French ship which delivered the 214 boxes holding the Statue of Liberty. Isère is part of the current region of Auvergne-Rhône-Alpes and is surrounded by the departments of Rhône, Savoie, Hautes-Alpes, Drôme, Ardèche, Loire. Isère includes a part of the French Alps; the highest point in the department is the Sub-Peak "Pic Lory" at 4,088 metres, subsidiary to the Barre des Écrins. The summit of La Meije at 3,988 metres is well known; the Vercors Plateau aesthetically dominates the western area of the department. Inhabitants of the department are called Isérois; the President of the General Council is André Vallini of the Socialist Party. The Grande Chartreuse is the mother abbey of the Carthusian order, it is located 14 miles north of Grenoble. As early as the 13th century, residents of the north and central parts of Isère spoke a dialect of the Franco-Provençal language called Dauphinois.
It continued to be spoken in rural areas of Isère into the 20th century. Isère features many ski resorts, including the Alpe d'Huez, Les Deux Alpes, the 1968 Winter Olympics resorts of Chamrousse, Villard de Lans, Autrans. Other popular resorts include Les 7 Laux, Le Collet d'Allevard, Méaudre, Saint-Pierre-de-Chartreuse, Alpe du Grand Serre, Gresse-en-Vercors. Grenoble has a dozen museums, including the most famous created in Grenoble in 1798, the Museum of Grenoble, it is the third largest ski and winter destination of France, after Savoie and Haute-Savoie, before Hautes-Alpes. It hosts Coupe Icare, an annual festival of free flight, such as paragliding and hang-gliding, held at the world-renowned paragliding site at Lumbin. Cantons of the Isère department Communes of the Isère department Arrondissements of the Isère department
Gare de Marseille-Saint-Charles
Marseille – Saint-Charles is the main railway station and intercity bus station of Marseille. It is the southern terminus of the Paris–Marseille railway, it opened on 8 January 1848, having been built for the PLM on the land of the Saint Charles Cemetery. The station is perched on top of a small hill and is linked to the city centre by a monumental set of stairs. Since 2001 the TGV has reduced the travel time between Marseille and Northern France, traffic has increased from 7.1 million annual passengers in 2000 to 15 million in 2007 and the station is the 11th busiest in France. The station was once a key stage on the sea voyage to Africa, the Middle-East and the Far East, before the popularisation of flying. To the rear of the station along Boulevard Voltaire was the goods yard, used up until the end of the 1990s by the SNCF's road freight operations, Sernam; the station isolated from the city, was equipped with a grand staircase, envisioned by Eugène Senès in 1911 and opened in 1926. It is bordered by statues inspired by all the distant locations to which people sailed from Marseille's port.
Saint-Charles has 14 terminal platforms and four tracks which run through, all equipped with 1500 V DC overhead wire. Tracks run in various directions, towards Ventimiglia, the north, Briançon, the harbour station of La Joliette. A first extension was opened after World War II; the buildings on the north side had been destroyed and were rebuilt to house the administration offices of the SNCF. A new between level was opened to enhance the flow of passengers. On New Year's Eve 1983, a bomb at the station killed two people. At the end of the 1990s a redevelopment project began with the opening of the Marseille underground and bus interchange as well as the arrival of the TGV Méditerranée. Since 2001 new underground parking lots and a tunnel have allowed the station to be renewed. A new hall, the Halle Honnorat, was created housing services; the displacement of the regional coach station on the other side of the station allowed a new pedestrian square to be created, between the station and the Aix-Marseille University site of Saint-Charles.
New pedestrian spaces with cafe terraces have been created atop the grand stairs. Paulin Talabot started the Marseille-Avignon line. On 1 October 2017, two women were killed in a knife attack at the train station before the attacker was shot dead by police; the station is served by the following services: High speed services Paris-Lyons Station - - Avignon TGV - Aix-en-Provence TGV mp airport - Marseille Saint Charles High speed services Brussels-Midi - Lille Europe / Lille-Flandres - Charles de Gaulle Airport 2 TGV - Lyons Part-Dieu - Avignon TGV - Aix-en-Provence TGV mp airport - Marseille Saint Charles - Cannes - Nice Ville High speed services Madrid-Atocha - Barcelona-Sants - Perpignan - Beziers - Montpellier Saint Roch - Avignon TGV - Aix-en-Provence TGV mp airport - Marseille Saint Charles High speed services Basel-SBB - Mulhouse-Ville - Dijon-Ville - Lyons Part-Dieu - Avignon TGV - Marseille Saint Charles High speed services Frankfurt-am-Mein Hbf - Strasbourg-Ville - Mulhouse-Ville - Lyons Part-Dieu - Avignon TGV - Aix-en-Provence TGV mp airport - Marseille Saint Charles High speed services Metz-Ville - Nancy - Dijon-Ville - Lyons Part-Dieu - Avignon TGV - Marseille Saint Charles - Cannes - Nice-Ville High speed services Geneva-Cornavin - Marseille Saint Charles High speed services Lyons Part-Dieu - Valence TGV Southern Rhône-Alps - Avignon TGV - Aix en Provence TGV mp airport - Marseille Saint Charles - Toulon - Les Arcs-Draguignan - Cannes - Nice-Ville High speed services Annecy - Chambéry-Challes les Eaux - Grenoble - Avignon TGV - Aix-en-Provence TGV mp airport - Marseille Saint Charles High speed services Le Havre - Rouen-Rive Droite - Versailles-Chantiers - Lyons Part-Dieu - Avignon TGV - Marseille Saint Charles High speed services Rennes / Nantes - Le Mans - Lyons Part-Dieu - Avignon TGV - Marseille Saint Charles High speed services Amsterdam-Centraal - Rotterdam-Centraal - Antwerp-Central - Brussels-Midi - Avignon TGV - Aix-en-Provence TGV mp airport - Marseille Saint Charles High speed services London Saint Pancras Intl - Ashford Intl - - Avignon TGV - Marseille Saint Charles EuroCity services Marseille Saint Charles - Cannes - Nice-Ville - Monaco - Ventimiglia - Genoa - Milan-Centrale Intercity services Bordeaux Saint Jean - Toulouse-Matabiau - Narbonne - Béziers - Montpellier Saint Roch - Arles - Marseille Saint Charles High speed services Marne-la-Vallée / Lyons-Perrache - Lyon Saint-Exupéry - Avignon TGV - Marseille Saint Charles Regional intercity services Lyons Part-Dieu - Montelimar - Orange - Avignon-Centre - Arles - Miramas - Marseille Saint Charles Regional intercity services Portbou - Perpignan - Beziers - Montpellier Saint Roch - Miramas - Vitrolles mp airport - Marseille Saint Charles Regional intercity services Briançon - Gap - Sisteron - Aix en Provence Ville - Marseille Saint Charles Regional intercity services Marseille Saint Charles - Toulon - Les Arcs-Draguignan - Cannes - Nice-Ville - Monaco - Ventimiglia Regional services Avignon-Centre - Arles - Miramas - Vitrolles mp airport - Marseille Euromediterranee - Marseille Saint Charles Regional services Avignon TGV - Avignon Centre - Salon - Miramas - Vitrolles mp airport - Marseille Euromediterranee - Marseille Saint Charles Local services Miramas - Fos-sur-Mer - Carry-le-Rouet - Séon St Henry - Marseille Saint Charles Local services Pertuis - Aix-en-Provence Ville - Gardanne - Saint Antoine - Marseille Saint Charles Local services Marseille Saint Antoine - Marseille Saint Charles Local services Mars
Railway electrification system
A railway electrification system supplies electric power to railway trains and trams without an on-board prime mover or local fuel supply. Electric railways use electric locomotives to haul passengers or freight in separate cars or electric multiple units, passenger cars with their own motors. Electricity is generated in large and efficient generating stations, transmitted to the railway network and distributed to the trains; some electric railways have their own dedicated generating stations and transmission lines but most purchase power from an electric utility. The railway provides its own distribution lines and transformers. Power is supplied to moving trains with a continuous conductor running along the track that takes one of two forms: overhead line, suspended from poles or towers along the track or from structure or tunnel ceilings. Both overhead wire and third-rail systems use the running rails as the return conductor but some systems use a separate fourth rail for this purpose. In comparison to the principal alternative, the diesel engine, electric railways offer better energy efficiency, lower emissions and lower operating costs.
Electric locomotives are usually quieter, more powerful, more responsive and reliable than diesels. They have an important advantage in tunnels and urban areas; some electric traction systems provide regenerative braking that turns the train's kinetic energy back into electricity and returns it to the supply system to be used by other trains or the general utility grid. While diesel locomotives burn petroleum, electricity can be generated from diverse sources including renewable energy. Disadvantages of electric traction include high capital costs that may be uneconomic on trafficked routes. Different regions may use different supply voltages and frequencies, complicating through service and requiring greater complexity of locomotive power; the limited clearances available under overhead lines may preclude efficient double-stack container service. Railway electrification has increased in the past decades, as of 2012, electrified tracks account for nearly one third of total tracks globally. Electrification systems are classified by three main parameters: Voltage Current Direct current Alternating current Frequency Contact system Third rail Fourth rail Overhead lines Overhead lines plus linear motor Four rail system Five rail systemSelection of an electrification system is based on economics of energy supply and capital cost compared to the revenue obtained for freight and passenger traffic.
Different systems are used for intercity areas. Six of the most used voltages have been selected for European and international standardisation; some of these are independent of the contact system used, so that, for example, 750 V DC may be used with either third rail or overhead lines. There are many other voltage systems used for railway electrification systems around the world, the list of railway electrification systems covers both standard voltage and non-standard voltage systems; the permissible range of voltages allowed for the standardised voltages is as stated in standards BS EN 50163 and IEC 60850. These take into account the number of trains drawing their distance from the substation. Increasing availability of high-voltage semiconductors may allow the use of higher and more efficient DC voltages that heretofore have only been practical with AC. 1,500 V DC is used in Japan, Hong Kong, Republic of Ireland, France, New Zealand, the United States. In Slovakia, there are two narrow-gauge lines in the High Tatras.
In the Netherlands it is used on the main system, alongside 25 kV on the HSL-Zuid and Betuwelijn, 3000 V south of Maastricht. In Portugal, it is used in Denmark on the suburban S-train system. In the United Kingdom, 1,500 V DC was used in 1954 for the Woodhead trans-Pennine route; the system was used for suburban electrification in East London and Manchester, now converted to 25 kV AC. It is now only used for the Wear Metro. In India, 1,500 V DC was the first electrification system launched in 1925 in Mumbai area. Between 2012-2016, the electrification was converted to 25 kV 50 Hz AC, the countrywide system. 3 kV DC is used in Belgium, Spain, the northern Czech Republic, Slovenia, South Africa, former Soviet Union countries and the Netherlands. It was used by the Milwaukee Road from Harlowton, Montana to Seattle-Tacoma, across the Continental Divide and including extensive branch and loop lines in Montana, by the Delaware, Lackawanna & Western Railroad in the United States, the Kolkata suburban railway in India, before it was converted to 25 kV 50 Hz AC. DC volt