Nockebybanan is a tram line between Nockeby and Alvik in the western suburbs of Stockholm, Sweden. The 5.6 kilometers long line is part of the Storstockholms Lokaltrafik public transport network, connects with the Stockholm Metro and Tvärbanan light rail at Alvik. Nockebybanan known as line 12, is operated by Arriva; the first part of the current line to Alléparken was opened in 1914, following the construction of a pontoon bridge across Tranebergssund. The line was gradually extended westwards, reaching the current terminus at Nockeby in 1929. To the east, the line ran to Tegelbacken in central Stockholm; the pontoon bridge was replaced in 1934 with the new Tranebergsbron. Planning for a Metro system started around this time, in 1944 the Ängbybanan route was built from Alvik to Åkeshov, operated with trams but designed as a grade-separated route for conversion. Conversion happened in 1952; the Nockebybanan was cut off from running into the city and became a feeder route for the Metro at Alvik.
Nockebybanan and Lidingöbanan were the only tram lines in the Stockholm region not to be withdrawn in conjunction with the switch to right-hand traffic in 1967. Since the line does not run on the street, was simple and self-contained, bi-directional rolling stock was available from the pre-metro tram lines, it was easier to convert to right-hand running than the rest of the network. Trams now run on the right from Nockeby to the penultimate station at Alléparken, where they cross over and run on the left into Alvik, permitting cross-platform interchange with the Metro. By the 1990s, the line and rolling stock was in a poor state of repair and was expected to be dismantled and replaced with bus services. In 1975, the line had been re-numbered from 12 to 120, matching the numbering scheme used by local buses. However, a concerted local campaign saved the line and from June 1997 to June 1998 the line was closed and renovated, new Flexity Swift trams were introduced from 1999. A running race in the surrounding neighbourhoods, Tolvanloppet takes both name and distance from the line number.
Nockebybanan has a single line with ten stops, running from Nockeby to Alvik in Bromma borough. At Alvik, passengers can change to Tvärbanan; the tramway has some level crossings. The journey time from Alvik to Nockeby is 14 minutes, with service intervals varying between 6 minutes in the morning and evening peaks, 20 minutes during the evening and weekend. Typical weekday traffic is around 10,000 passengers; the line is served by 30 meter long Flexity Swift trams. The depot and traffic control center at Alvik are shared with Tvärbanan; as of 2018, new CAF Urbos trams were ordered for the Tvärbanan extension to Solna. But after Tvärbanan modernisation all A35 were put on whole Tvärbanan, 28% are A35 and 72% are A32. Trams access the depot at Alvik via tracks to the west of the station; these are shared with the metro, therefore are electrified with both overhead lines for trams and third rail for the Metro. Roslagsbanan Trams in Stockholm Public transport in Stockholm List of tram and light rail transit systems PDF map of Nockebybanan and Tvärbanan lines Storstockholms Lokaltrafik —Official site
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
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
Minimum railway curve radius
The minimum railway curve radius is the shortest allowable design radius for the center line of railway tracks under a particular set of conditions. It has an important bearing on constructions costs and operating costs and, in combination with superelevation in the case of train tracks, determines the maximum safe speed of a curve. Minimum radius of curve is one parameter in the design of railway vehicles as well as trams. Monorails and guideways are subject to minimum radii; the first proper railway was the Liverpool and Manchester Railway, which opened in 1830. Like the tram roads that had preceded it over a hundred years, the L&M had gentle curves and gradients. Among other reasons for the gentle curves were the lack of strength of the track, which might have overturned if the curves were too sharp causing derailments. There was no signalling at this time, so drivers had to be able to see ahead to avoid collisions with other trains on the line; the gentler the curves, the longer the visibility.
The earliest rails were made in short lengths of wrought iron, which does not bend like steel rails introduced in the 1850s. Minimum curve radii for railroads are governed by the speed operated and by the mechanical ability of the rolling stock to adjust to the curvature. In North America, equipment for unlimited interchange between railroad companies are built to accommodate 288-foot radius, but 410-foot radius is used as a minimum, as some freight cars are handled by special agreement between railroads that cannot take the sharper curvature. For handling of long freight trains, a minimum 574-foot radius is preferred; the sharpest curves tend to be on the narrowest of narrow gauge railways, where everything is proportionately smaller. As the need for more powerful locomotives grew, the need for more driving wheels on a longer, fixed wheelbase grew too, but long wheel bases are unfriendly to sharp curves. Various types of articulated locomotives were devised to avoid having to operate multiple locomotives with multiple crews.
More recent diesel and electric locomotives do not have a wheelbase problem and can be operated in multiple with a single crew. The Tasmanian Government Railways K class was 610 mm gauge 99 ft radius curves Example Garratt 1,000 mm gauge 25 kg/m rails Main line radius - 175 m Siding radius - 84 m 0-4-0 GER Class 209 1,435 mm Not all couplers can handle sharp curves; this is true of the European buffer and chain couplers, where the buffers extend the profile of the railcar body. For a line with maximum speed 60 km/h, buffer-and-chain couplings increase the minimum radius to around 150 m; as narrow gauge railways and metros do not interchange with mainline railroads, instances of these types of railroad in Europe use bufferless central couplers and build to a tighter standard. A long heavy freight train those with wagons of mixed loading, may struggle on sharp curves, as the drawgear forces may pull intermediate wagons off the rails. Common solutions include: marshalling light and empty wagons at rear of train intermediate locomotives, including remotely controlled ones.
Easing curves reduced. More, shorter trains. Equalizing wagon loading better driver training driving controls, and c2013 Electronically Controlled Pneumatic brakes. A similar problem occurs with harsh changes in gradients; as a heavy train goes round a bend at speed, the reactive centrifugal force can cause negative effects: passengers and cargo may feel unpleasant forces, the inside and outside rails will wear unequally, insufficiently anchored track may move. To counter this, a cant is used. Ideally the train should be tilted such that resultant force acts straight "down" through the bottom of the train, so the wheels, track and passengers feel little or no sideways force; some trains are capable of tilting to enhance this effect for passenger comfort. Because freight and passenger trains tend to move at different speeds, a cant cannot be ideal for both types of rail traffic; the relationship between speed and tilt can be calculated mathematically. We start with the formula for a balancing centripetal force: θ is the angle by which the train is tilted due to the cant, r is the curve radius in meters, v is the speed in meters per second, g is the standard gravity equal to 9.80665 m/s²: tan θ = v 2 g r Rearranging for r gives: r = v 2 g tan θ Geometrically, tan θ can be expressed in terms of the track gauge G, the cant ha and cant deficiency hb, all in millimeters: tan θ ≈ sin θ = h a + h b G This approximation for tan θ gives: r = v 2 g h a + h b G
Dagen H, today called "Högertrafikomläggningen", was the day on 3 September 1967, in which the traffic in Sweden switched from driving on the left-hand side of the road to the right. The "H" stands for "Högertrafik", the Swedish word for "right traffic", it was by far the largest logistical event in Sweden's history. There were various major arguments for the change: All of Sweden's neighbours drove on the right, with 5 million vehicles crossing those borders annually. 90 percent of Swedes drove left-hand drive vehicles. This led to many head-on collisions when passing on narrow two-lane highways, which were common in Sweden due to the fact that the country's low population density and traffic levels made road-building expensive in per capita terms. City buses were among the few vehicles that conformed to the normal opposite-steering wheel rule, being right-hand drive. However, the change was unpopular. On 10 May 1963, the Swedish Parliament approved the Prime Minister Tage Erlander's government proposal of an introduction of right hand traffic in 1967, as the number of cars on the road tripled from 500,000 to 1.5 million, was expected to reach 2.8 million by 1975.
A body known as Statens Högertrafikkommission was established to oversee the changeover. It began implementing a four-year education programme, with the advice of psychologists; the campaign included displaying the Dagen H logo on various commemorative items, including milk cartons and underwear. Swedish television held a contest for songs about the change; as Dagen H neared, every intersection was equipped with an extra set of poles and traffic signals wrapped in black plastic. Workers roamed the streets early in the morning on Dagen H to remove the plastic. A parallel set of lines were painted on the roads with white paint covered with black tape. Before Dagen H, Swedish roads had used yellow lines. 350 000 signs had to be removed or replaced, 20 000 in Stockholm alone. On Dagen H, Sunday, 3 September, all non-essential traffic was banned from the roads from 01:00 to 06:00. Any vehicles on the roads during that time had to follow special rules. All vehicles had to come to a complete stop at 04:50 carefully change to the right-hand side of the road and stop again before being allowed to proceed at 05:00.
In Stockholm and Malmö, the ban was longer — from 10:00 on Saturday until 15:00 on Sunday — to allow work crews to reconfigure intersections. Certain other towns saw an extended ban, from 15:00 on Saturday until 15:00 on Sunday. One-way streets presented unique problems. Bus stops had to be constructed on the other side of the street. Intersections had to be reshaped to allow traffic to merge; the smooth changeover saw a temporary reduction in the number of accidents. On the day of the change, only 157 minor accidents were reported, of which only 32 involved personal injuries, with only a handful serious. On the Monday following Dagen H, there were 125 reported traffic accidents, compared to a range of 130 to 198 for previous Mondays, none of them fatal. Experts suggested that changing to driving on the right reduced accidents while overtaking, as people drove left-hand drive vehicles, thereby having a better view of the road ahead. Indeed, fatal car-to-car and car-to-pedestrian accidents dropped as a result, the number of motor insurance claims went down by 40%.
These initial improvements did not last, however. The number of motor insurance claims returned to'normal' over the next six weeks and, by 1969, the accident rates were back to the levels seen before the change. Trams in central Stockholm, in Helsingborg and most lines in Malmö were withdrawn and replaced by buses, over one thousand new buses were purchased with doors on the right-hand side; some 8,000 older buses were retrofitted to provide doors on both sides, while Gothenburg and Malmö exported their right-hand drive buses to Pakistan and Kenya. The modification of buses, paid by the state, was the largest cost of the change. Although all road traffic in Sweden became right handed and railways did not switch to new rules and continue to drive on the left, with the exception of tram systems. Additionally, many of them were abandoned as a result of Dagen H. Gothenburg had high cost for rebuilding trams, while Stockholm had cost only for bus purchasing, since the remaining lines had bidirectional trams with doors on both sides.
In any event, most trams in Stockholm were replaced by the metro, a decision made long before the Dagen H decision. Fellow Nordic country Iceland changed to driving on the right in May 1968, on a day known as H-dagurinn. 730 Switch to right-hand traffic in Czechoslovakia Transport in Sweden Television coverage of changeover, Sveriges Television The Day Sweden Turned Right, BBC World Service, 2 September 2016 Border crossing between Sweden and Finland, 1967 "A ‘thrilling’ mission to get the Swedish to change overnight", BBC, 18 April 2018
Djurgårdslinjen is a heritage tram line with the route number 7N, running between Norrmalmstorg and Waldemarsudde in Stockholm, Sweden. The line, along with every other tram line in Stockholm, was withdrawn in conjunction to the switch to right-hand side traffic in 1967, but was restored as a heritage tram line in June 1991 and operated on a non-profit basis by members of the Swedish Tramway Society through its operating company AB Stockholms Spårvägar; the infrastructure for the heritage line was constructed and owned by Stiftelsen Stockholms Museispårvägar, a non-profit foundation created by the city of Stockholm and the Stockholm County Council, but it was handed over to SL in 2005. Since the line was reopened, there have been several proposals to extend the tracks to Sergels torg and Stockholm Central Station, with the intention to replace current bus line 47 with modern light-rail vehicles. In the 1990s, the proposals were met with indifference by local politicians, but since the opening of Tvärbanan and with the introduction of the new Flexity Swift A32 trams, there is now majority support for an extension.
The vintage trams operate from the beginning of April to the end of December, every day between June and August. The trams used on the line are from Stockholm, along with a few Gothenburg trams and some from the Oslo Tramway; the vintage of the tram cars varies from early 20th century to late 1950s. On weekends a modified trailer named "Rolling Café" is coupled to one of the motorcars on the line, where one can have a cup of coffee or tea along with some pastries whilst enjoying the scenery. All SL fares are valid on Djurgårdslinjen, including coupons. In 2008 it was decided that the line would be extended from the current end station at Norrmalmstorg to the new city development in Lindhagen, via Stockholm Central station. In August 2010, under the Spårväg City project, line 7 began regular service with new Flexity Classic trams, the route extended from Norrmalmstorg to Sergels Torg. Plans to extend the line to Hornsberg and northeast Ropsten by 2014 have, not been fulfilled. Trams in Stockholm Public transport in Stockholm List of tram and light rail transit systems Media related to Djurgårdslinjen at Wikimedia Commons Swedish Tramway Society – The Djurgården line no 7 Tram Travels: Djurgårdslinjen 7N
Public transport is transport of passengers by group travel systems available for use by the general public managed on a schedule, operated on established routes, that charge a posted fee for each trip. Examples of public transport include city buses, trolleybuses and passenger trains, rapid transit and ferries. Public transport between cities is dominated by airlines and intercity rail. High-speed rail networks are being developed in many parts of the world. Most public transport systems run along fixed routes with set embarkation/disembarkation points to a prearranged timetable, with the most frequent services running to a headway. However, most public transport trips include other modes of travel, such as passengers walking or catching bus services to access train stations. Share taxis offer on-demand services in many parts of the world, which may compete with fixed public transport lines, or compliment them, by bringing passengers to interchanges. Paratransit is sometimes used for people who need a door-to-door service.
Urban public transit differs distinctly among Asia, North America, Europe. In Asia, profit-driven, privately-owned and publicly traded mass transit and real estate conglomerates predominantly operate public transit systems In North America, municipal transit authorities most run mass transit operations. In Europe, both state-owned and private companies predominantly operate mass transit systems, Public transport services can be profit-driven by use of pay-by-the-distance fares or funded by government subsidies in which flat rate fares are charged to each passenger. Services can be profitable through high usership numbers and high farebox recovery ratios, or can be regulated and subsidised from local or national tax revenue. Subsidised, free of charge services operate in some towns and cities. For geographical and economic reasons, differences exist internationally regarding use and extent of public transport. While countries in the Old World tend to have extensive and frequent systems serving their old and dense cities, many cities of the New World have more sprawl and much less comprehensive public transport.
The International Association of Public Transport is the international network for public transport authorities and operators, policy decision-makers, scientific institutes and the public transport supply and service industry. It has 3,400 members from 92 countries from all over the globe. Conveyances designed for public hire are as old as the first ferries, the earliest public transport was water transport: on land people walked or rode an animal. Ferries appear in Greek mythology—corpses in ancient Greece were buried with a coin underneath their tongue to pay the ferryman Charon to take them to Hades; some historical forms of public transport include the stagecoach, traveling a fixed route between coaching inns, the horse-drawn boat carrying paying passengers, a feature of European canals from their 17th-century origins. The canal itself as a form of infrastructure dates back to antiquity – ancient Egyptians used a canal for freight transportation to bypass the Aswan cataract – and the Chinese built canals for water transportation as far back as the Warring States period which began in the 5th century BCE.
Whether or not those canals were used for for-hire public transport remains unknown. The omnibus, the first organized public transit system within a city, appears to have originated in Paris, France, in 1662, although the service in question failed a few months after its founder, Blaise Pascal, died in August 1662; the omnibus was introduced to London in July 1829. The first passenger horse-drawn railway opened in 1806: it ran between Swansea and Mumbles in southwest Wales in the United Kingdom. In 1825 George Stephenson built the Locomotion for the Stockton and Darlington Railway in northeast England, the first public steam railway in the world; the first successful electric streetcar was built for 12 miles of track for the Union Passenger Railway in Richmond, Virginia in 1888. Electric streetcars could carry heavier passenger loads than predecessors, which reduced fares and stimulated greater transit use. Two years after the Richmond success, over thirty two thousand electric streetcars were operating in America.
Electric streetcars paved the way for the first subway system in America. Before electric streetcars, steam powered subways were considered. However, most people believed that riders would avoid the smoke filled subway tunnels from the steam engines. In 1894, Boston built the first subway in the United States, an electric streetcar line in a 1.5 mile tunnel under Tremont Street’s retail district. Other cities such as New York followed, constructing hundreds of miles of subway in the following decades. Aerial lift Aerial tramway Funifor Chairlift Detachable chairlift Funitel Gondola lift Maritime transport Ferry Cable ferry Reaction ferry Water taxi Land transport Personal public transport Bicycle-sharing system Carsharing Personal rapid transit Rail transport Inter-city rail High-speed rail Maglev Urban rail transit Airport rail link Atmospheric railway Automated guideway transit Cable car Cable railway Commuter rail Elevated railway Funicular Inclined elevator Light rail Medium-capacity rail system Mono