A single-track railway is a railway where trains traveling in both directions share the same track. Single track is found on lesser-used rail lines branch lines, where the level of traffic is not high enough to justify the cost of constructing a second track. Single track is cheaper to build, but has operational and safety disadvantages. For example, a single-track line that takes 15 minutes to travel through would have capacity for only two trains per hour in each direction. By contrast, a double track with signal boxes four minutes apart can allow up to 15 trains per hour in each direction, provided all the trains travel at the same speed; this hindrance on the capacity of a single track may be overcome by making the track one-way on alternate days, if the single track is not used for public passenger transit. Long freight trains are a problem. Other disadvantages include the propagation of delays, since one delayed train on a single track will delay any train waiting for it to pass. A single track does not have a "reserve" track that can allow a reduced capacity service to continue if one track is closed.
If a single-track line is designed to be used by more than one train at a time, it must have passing loops at intervals along the line to allow trains running in different directions to pass each other. These consist of short stretches of double track long enough to hold one train; the capacity of a single-track line is determined by the number of passing loops. Passing loops may be used to allow trains heading in the same direction at different speeds to overtake. In some circumstances on some isolated branch lines with a simple shuttle service a single-track line may work under the "one train working" principle without passing loops, where only one train is allowed on the line at a time. On single-track lines with passing loops, measures must be taken to ensure that only one train in one direction can use a stretch of single track at a time, as head-on collisions are a particular risk; some form of signalling system is required. In traditional British practice, single-track lines were operated using a token system where the train driver had to be in possession of a token in order to enter a stretch of single track.
Because there was only one unique token issued at any one time for each stretch of single track, it was impossible for more than one train to be on it at a time. This method is still used on some minor lines but in the longest single-track lines in Britain this has been superseded by radio communication. In the early days of railways in North America it was common to rely upon simple timetable operation where operators knew where a train was scheduled to be at a particular time, so would not enter a single-track stretch when they were not scheduled to; this worked but was inflexible and inefficient. It was improved with the invention of the ability to issue train orders. Converting a single-track railway to double track is called duplication or doubling. A double-track railway operating only a single track is known as single-line working. Building bike trails on rail corridors has occurred in limited examples, however developing rail right of ways for a bike trail can restrict a train corridor to a single track.
Reclaiming a railway corridor to use trains again, that have become bike paths, limits the use of double tracks. The bike path is where the second track would be. An example of a bike, single-track corridor is the E&N Railway in Canada. Rails to trails
Jordanhill railway station
Jordanhill railway station is a side platformed suburban railway station in the Jordanhill area in the West End of Glasgow, Scotland. The station, governed by Transport Scotland and managed by Abellio ScotRail, lies on the Argyle Line and the North Clyde Line. In operation since 1887, the station stemmed losses for an area, in decline, it is located near the Jordanhill Campus of the University of Strathclyde and sits atop Crow Road, an important western thoroughfare in Glasgow and the main route to the Clyde Tunnel. The station is eleven minutes' journey time from Glasgow Central on the Argyle Line. Trains on the North Clyde Line pass through without stopping at the station; the station opened on 1 August 1887 as part of the Glasgow and Clydebank Railway. Construction of the station structure was not completed until 1895, with modular-design wooden buildings seen on the new suburban railway lines, being built on both platforms; the station is located on part of the former site of brick and tile works, Jordanhill being an area of artisans and miners until the close of the nineteenth century.
The railway station arrived just as much of the local industry was declining, giving residents, who had to walk to Hillhead or Partick to find transport into Glasgow, proper access to the city centre. The station's opening filled a gap in provision, as lines in the area had been constructed. A new link allowed services to Whiteinch Victoria Park to begin in 1897, but they ceased in 1951 and the link was closed to freight in 1967; the route of the link has been converted into a nature walk from Victoria Park to Jordanhill station, running alongside the existing line for half its length. On 15 January 1898, J. Johnstone, a member of the Whiteinch Harriers running club, was killed while attempting to run across the line west of the station. A small lead memorial stood on the spot for many years; the freight line saw near-disaster on 28 December 1932, when seventeen wagons laden with coal ran away on a slight incline on the sidings operated by the Great Western Steam Laundry. A serious accident occurred on 28 April 1980, when a three-coach train carrying 80 passengers from Dalmuir to Motherwell derailed at Hyndland West Junction, just after leaving Jordanhill.
All the bogies on the leading coach left the rails, causing fifteen people to be injured enough for them to be taken to the Western Infirmary. In 1998, Strathclyde Passenger Transport undertook a study into the possible relocation of the station west to Westbrae Drive. A December 2002 report from the Scottish Executive included this station as part of their High Resource Scenario, estimating the project cost at £2 million. By 2004, SPT had identified this station as one of their top three priorities, Glasgow City Council had identified it as a "main priority". An alternative proposal would keep the existing station open but with many services calling only at a new Westbrae Drive station; this proposal was backed in August 2001 by Charlie Gordon leader of Glasgow City Council, who said that having a second station in Jordanhill would assist students at the nearby Jordanhill campus of the University of Strathclyde. The proposed new station would have been only 500 yd away; the station at Jordanhill is to be rebuilt, one of six new stations in the west of Scotland, according to an announcement made on 19 May 2006 by SPT chief executive Ron Culley.
Jordanhill Station will be rebuilt for the 2014 Commonwealth Games, one of a number of stations that will be rebuilt for the Commonwealth Games through a £300 million transport legacy plan. As part of the Argyle Line, the station is used—along with Glasgow Central and Anderston—by those commuting to and from Central Glasgow, near the heart of its business and financial district; the typical hourly service from the station is four trains per hour to Dalmuir via Yoker, two trains to Whifflet via Glasgow Central and two trains to Cumbernauld via Glasgow Queen Street. In SRA's 2002/3 financial year, 85,861 people boarded trains at Jordanhill station, 94,613 disembarked, making it the 1,029th busiest station in the United Kingdom, twenty-fifth busiest on the Argyle Line in 2003. In 2016 the Queen Street High Level tunnel closure will see restricted services for part of the year, with frequencies dropping to half-hourly from here; the station has a small car park and is not permanently staffed, but it contains a ticket machine, one of an initial batch of ten installed by SPT in late 2003 and early 2004 as part of a drive to curb fare dodging, estimated to be costing the company £2 million a year.
Both platforms are elevated and each has a wheelchair ramp. There is a connecting footbridge between the two platforms; the Jordanhill Campus of the University of Strathclyde, which hosts the Faculty of Education, is located nearby. Several schools are in the area, including Jordanhill School, Broomhill Primary, St Thomas Aquinas. For the part of the 1980s and the early part of the 1990s, a huge Jolly Giant toy centre lay just across Crow Road, was a major local attraction, it closed in the 1990s and after housing a discount clothing store for a few years it is now an Arnold Clark Volkswagen car dealership. Backing onto platform 2 is a Scout hall, home to the 72nd Scout Troop. There are two sports facilities accessible from the station: New Anniesland, a rugby union and cricket playing f
In railway and rapid transit parlance, the Spanish solution is a station layout with two railway platforms, one on each side of the track. This platform arrangement allows the separation of passenger streams by using one platform only for boarding and the other one only for alighting; the concept of separate platforms for boarding and alighting has been proven effective at stations with high passenger numbers. An example of the Spanish Solution is the Marienplatz station on the Munich S-Bahn, with island platform for boarding and side platforms for alighting. Media related to Spanish solution at Wikimedia Commons
Hong Kong the Hong Kong Special Administrative Region of the People's Republic of China and abbreviated as HK, is a special administrative region on the eastern side of the Pearl River estuary in southern China. With over 7.4 million people of various nationalities in a 1,104-square-kilometre territory, Hong Kong is the world's fourth most densely populated region. Hong Kong became a colony of the British Empire after Qing Empire ceded Hong Kong Island at the end of the First Opium War in 1842; the colony expanded to the Kowloon Peninsula in 1860 after the Second Opium War, was further extended when Britain obtained a 99-year lease of the New Territories in 1898. The entire territory was transferred to China in 1997; as a special administrative region, Hong Kong's system of government is separate from that of mainland China and its people identify more as Hongkongers rather than Chinese. A sparsely populated area of farming and fishing villages, the territory has become one of the world's most significant financial centres and commercial ports.
It is the world's seventh-largest trading entity, its legal tender is the world's 13th-most traded currency. Although the city has one of the highest per capita incomes in the world, it has severe income inequality; the territory has the largest number of skyscrapers in most surrounding Victoria Harbour. Hong Kong ranks seventh on the UN Human Development Index, has the sixth-longest life expectancy in the world. Although over 90 per cent of its population uses public transportation, air pollution from neighbouring industrial areas of mainland China has resulted in a high level of atmospheric particulates; the name of the territory, first spelled "He-Ong-Kong" in 1780 referred to a small inlet between Aberdeen Island and the southern coast of Hong Kong Island. Aberdeen was an initial point of contact between local fishermen. Although the source of the romanised name is unknown, it is believed to be an early phonetic rendering of the Cantonese pronunciation hēung góng; the name translates as "fragrant harbour" or "incense harbour".
"Fragrant" may refer to the sweet taste of the harbour's freshwater influx from the Pearl River or to the odor from incense factories lining the coast of northern Kowloon. The incense was stored near Aberdeen Harbour for export. Sir John Davis offered an alternative origin; the simplified name Hong Kong was used by 1810 written as a single word. Hongkong was common until 1926, when the government adopted the two-word name; some corporations founded during the early colonial era still keep this name, including Hongkong Land, Hongkong Electric and Shanghai Hotels and the Hongkong and Shanghai Banking Corporation. The region is first known to have been occupied by humans during the Neolithic period, about 6,000 years ago. Early Hong Kong settlers were a semi-coastal people who migrated from inland and brought knowledge of rice cultivation; the Qin dynasty incorporated the Hong Kong area into China for the first time in 214 BCE, after conquering the indigenous Baiyue. The region was consolidated under the Nanyue kingdom after the Qin collapse, recaptured by China after the Han conquest.
During the Mongol conquest, the Southern Song court was located in modern-day Kowloon City before its final defeat in the 1279 Battle of Yamen. By the end of the Yuan dynasty, seven large families had settled in the region and owned most of the land. Settlers from nearby provinces migrated to Kowloon throughout the Ming dynasty; the earliest European visitor was Portuguese explorer Jorge Álvares, who arrived in 1513. Portuguese merchants established a trading post called in Hong Kong waters, began regular trade with southern China. Although the traders were expelled after military clashes in the 1520s, Portuguese-Chinese trade relations were reestablished by 1549. Portugal acquired a permanent lease for Macau in 1557. After the Qing conquest, maritime trade was banned under the Haijin policies; the Kangxi Emperor lifted the prohibition, allowing foreigners to enter Chinese ports in 1684. Qing authorities established the Canton System in 1757 to regulate trade more restricting non-Russian ships to the port of Canton.
Although European demand for Chinese commodities like tea and porcelain was high, Chinese interest in European manufactured goods was insignificant. To counter the trade imbalance, the British sold large amounts of Indian opium to China. Faced with a drug crisis, Qing officials pursued ever-more-aggressive actions to halt the opium trade; the Daoguang Emperor rejected proposals to legalise and tax opium, ordering imperial commissioner Lin Zexu to eradicate the opium trade in 1839. The commissioner destroyed opium stockpiles and halted all foreign trade, forcing a British military response and triggering the First Opium War; the Qing ceded Hong Kong Island in the Convention of Chuenpi. However, both countries did not ratify the agreement. After over a year of further hostilities, Hong Kong Island was formally ceded to the United Kingdom in the 1842 Treaty of Nanking. Administrative infrastructure was built up by early 1842, but piracy and hostile Qing policies towards Hong Kong prevented the government from attracting merchants.
The Taiping Rebellion, when many wealthy Chinese fled mainland turbulence and settled in the colon
A grand union is a rail track junction where two double-track railway lines cross at grade in a street intersection or crossroads. A total of sixteen railroad switches allow streetcars coming from any direction to take any of the three other directions; the same effect may be achieved with two adjacent wyes. These types of complex junction are expensive to maintain. Special parts, sometimes made of manganese steel, are needed for each location where one rail crossed another. A full grand union junction consists of 88 frogs, 32 switchpoints if single-point switches are not used. A tram or train crossing the junction will encounter four or twenty frogs within the space of crossing the junction. For all of the possible tracks of a grand union to be used during normal operation, at least six different tram routes have to cross the union. In an intersection with lines oriented towards cardinal directions, these could be: north-south, north-east, north-west, south-east, south-west, east-west. Three-quarter unions are similar to grand unions in that they are rail track junctions where two double-track railway lines cross at grade in a street intersection or crossroads.
Half unions are similar, but have curved junction tracks on only two adjoining corners of the intersection, with a total of eight switches. Butterfly unions share the total of eight switches, but the curved junction tracks are on opposing corners. Graz has a grand union at Jakominiplatz, 47° 4'1.45"N 15°26'30.92"E Brussels has a grand union at carrefour Buyl - Général JAcques, 50° 49'05.9"N 4°22'45.8"E Brno, has a 3/4 union located at 49°12'16.24"N 16°37'25.54"E. Olomouc, has one grand union located at 49°35'44.42"N 17°14'50.27"E. Prague, has three grand unions, first at 50°6'12.65"N, 14°28'23.89"E the second at 50°5'55.94"N, 14°25'59.76"E. and the third at 50° 4'23.19"N 14°24'50.30"E, this Grand Union was rebuilt in 2003 and has curved trackwork as the streets are not aligned at the river crossing. Cologne has one grand union at the stop Aachener Straße / Gürtel at 50°56'13.2"N 6°54'30.4"E, one 3/4 grand union at Barbarossaplatz 50°55'42.9"N 6°56'33.7"E Cottbus has one grand union at 51°45'39.86"N 14°19'51.39"E and a 3/4 grand union at 51°44'57.54"N 14°19'42.50"E. Dresden has a grand union at 51° 3'49.47"N 13° 44'48.95"E.
Leipzig has a grand union at 51°20'39.35"N 12°22'15.99"E it is unique in interfacing with four tracks at Goerdelerring tram stop. There is a 3/4 grand union at 51°19'56.49"N 12°20'19.68"E, a half union at 51°20'31.31"N 12°21'31.15"E and butterfly unions at 51°19'12.95"N 12°19'48.80"E, 51°20'20.36"N 12°21'44.96"E and 51°21'44.93"N 12°21'55.79". Karlsruhe's system has three grand unions located at Stop Mathystrasse, located at Entenfang. and the third one established in 2018 at intersection Rüppurrer Str. and Baumeisterstr.. A fourth one is planned at the next intersection of Kriegsstr. and Baumeisterstr. Kassel's system has a single grand union located at 51°19'4.87"N 9°30'1.02"E and a 3/4 grand union at 51°18'43.02"N 9°29'29.64"E. Munich has one real grand union at Ostfriedhof since the last track alteration in 2015 at 48°07'8.6"N 11°35'1"E. While not a traditional grand union, the Munich tram system has a "Grand Circle" which has the same route function as a grand union and provides a loop for all lines, it is located at Maxmonument in Maximilianstrasse, 48° 8'15.27"N, 11°35'17.02"E. Milan: the Milan tram network has two grand unions.
The first is a non standard design with divided North South tracks around a monument located at piazza 24 Maggio, the second located nearby at piazzale Porta Lodovica. There used to be another large one until the 1990s located at piazza della Repubblica, but it has since reduced to a wye junction still keeping the layout of diverging routes by the removal of the straight route to via Vittor Pisani. Amsterdam, Netherlands: As of 2009, the Amsterdam tram system continues to have four grand unions. However, none of them has tram routes running in all directions under normal operation, they are located at 52°21'17.39"N 4°54'4.49"E. There is a "Grand Circle" at Centralny Square, 50° 4'19.56"N 20° 2'14.46"E, the "Grand Circle" which has the same route function as a grand union and provides a loop for all lines. There is a 3/4 union at 50° 3'6.26"N 19°56'30.22"E and a 5/8 union at 50° 4'24.31"N 20° 1'2.89"E. Poznań: The Poznań Tram system has 6 grand unions, which may be the most extant in any city.
They are located
A passing loop or passing siding is a place on a single line railway or tramway located at a station, where trains or trams travelling in opposite directions can pass each other. Trains/trams going in the same direction can overtake, provided that the signalling arrangement allows it. A passing loop is double-ended and connected to the main track at both ends, though a dead end siding known as a refuge siding, much less convenient, can be used. A similar arrangement is used on the gauntlet track of cable railways and funiculars, in passing places on single-track roads. Ideally, the loop should be longer than all trains needing to cross at that point. If one train is too long for the loop it must wait for the opposing train to enter the loop before proceeding, taking a few minutes. Ideally, the shorter train should leave second. If both trains are too long for the loop, time-consuming "see-sawing" operations are required for the trains to cross. On railway systems that use platforms high-level platforms, for passengers to board and disembark from trains, the platforms may be provided on both the main and loop tracks or on only one of them.
The main line has straight track. If the station has only one platform it is located on the main line. If passenger trains are few in number, the likelihood of two passenger trains crossing each other low, the platform on the loop line may be omitted; the through road has straight track. A possible advantage of this layout is that trains scheduled to pass straight through the station can do so uninterrupted; this layout is used at local stations where many passenger trains do not stop. Since there is only one passenger platform, it is not convenient to cross two passenger trains if both stop. An example is Scone railway station, but the northern end was rearranged to resemble a main and loop configuration. A disadvantage of the platform and through arrangement is the speed limits through the turnouts at each end. In the example layout shown, trains take the left-hand track in their direction of running. Low-speed turnouts restrict the speed in one direction. Two platform faces are needed, they can be provided either at a single island platform or two side platforms.
Overtaking is not possible at this kind of up-and-down loop as some of the necessary signals are absent. Crossing loops using up-and-down working are common in British practice. For one thing, fewer signals are required if the tracks in the station are signaled for one direction only. In France, they use spring switches and the speed is restricted in both directions; the speed restriction in one direction can be eliminated with higher-speed turnouts, but this may require power operation, as the longer and heavier high-speed turnouts may be beyond the capability of manual lever operation. It is possible to cross trains at stations equipped with only a siding. At Bombo, the crossing loop had no platform, as freight trains became longer it became inadequate to hold them. Molong used to have a short loop, but it was replaced by a long stretch of a former branch line, a dead-end siding. Berry has had its short loop removed and an shorter dead-end siding substituted. Long freight trains do not need to cross each other here, freight trains can cross passenger trains waiting in that short siding provided that the freight train arrives second and leaves first.
If a crossing loop is several times the length of the trains using it, is suitably signalled trains proceeding in opposite directions can pass each other without having to stop or slow down. This reduces the time lost by the first train to arrive at the crossing loop for the opposing train to go by; this system is referred to as a dynamic loop. In the AusLink project for the Junee to Melbourne line every other section of single line will be duplicated to provide so-called passing lanes. About 220 km of the 450 km line will be duplicated. In Sweden, the passing loops are 750 m long, made for cargo trains. Passenger trains are much shorter, at least on most single track lines, less than 200 m; the signalling system now allows two passenger trains to cross without stopping, but one has to slow down to 40 km/h, because of the limited length of the loop and the sharp curves in the switch points. For Norway an investigation has been made about future high-speed railways, using 250 km/h as cruise speed.
The most promising link would be a new Oslo-Trondheim railway, suggested to be a single track along a 370 km-long route. It is suggested to have about 15 km-long passing loops, more like 15 km double track, located about 80 km apart; this would enable passing at 160 km/h, but there could be only one train per hour per direction on the rail line. See High-speed rail in Norway; some railways fit catchpoints at the ends of crossing loops so that if a train overruns the loop, it is derailed rather than collide with an opposing train. Since the available space for crossing loops is limited, they do not have an overlap between the starting signals and the end of the double line. In Australia, the Australian Rail Track Corporation policy provides for overlaps of about 500 m and 200 m in an effort to avoid derailment or colli
A double-track railway involves running one track in each direction, compared to a single-track railway where trains in both directions share the same track. In the earliest days of railways in the United Kingdom, most lines were built as double-track because of the difficulty of co-ordinating operations before the invention of the telegraph; the lines tended to be busy enough to be beyond the capacity of a single track. In the early days the Board of Trade did not consider any single-track railway line to be complete. In the earliest days of railways in the United States most lines were built as single-track for reasons of cost, inefficient timetable working systems were used to prevent head-on collisions on single lines; this improved with the development of the train order system. In any given country, rail traffic runs to one side of a double-track line, not always the same side as road traffic, thus in Belgium, France, Sweden and Italy for example, the railways use left-hand running, while the roads use right-hand running.
In Switzerland, the Lausanne Metro and railways at the Germany border area use RHT as well as all tram systems. The Semmering Railway in Austria uses LHT while most of the country is RHT. In countries such as Indonesia, it is the reverse. In Spain, where roads are RHT, metro systems in Madrid and Bilbao use LHT. In Sweden, the tram systems in Gothenburg, Norrköping and Stockholm are RHT; the railroads use LHT in general. In the Ukraine, some sections of Kryvyi Rih Metrotram use LHT due to tramcars have doors only on right side, which makes it impossible to use RHT at stations with island platforms. On the French-German border, for example, flyovers were provided so that trains moving on the left in France end up on the right in Germany and vice versa. Handedness of traffic can affect locomotive design. For the driver, visibility is good from both sides of the driving cab so the choice on which side to site the driver is less important. For example, the French SNCF Class BB 7200 is designed for using the left-hand track and therefore uses LHD.
When the design was modified for use in the Netherlands as NS Class 1600, the driving cab was not redesigned, keeping the driver on the left despite the fact that trains use the right-hand track in the Netherlands. The left/right principle in a country is followed on double track. On single track, when trains meet, the train that shall not stop uses the straight path in the turnout, which can be left or right. Double-track railways older ones, may use each track in one direction; this arrangement simplifies the signalling systems where the signalling is mechanical. Where the signals and points or rail switches are power-operated, it can be worthwhile to signal each line in both directions, so that the double line becomes a pair of single lines; this allows trains to use one track where the other track is out of service due to track maintenance work, or a train failure, or for a fast train to overtake a slow train. Most crossing loops are not regarded as double-track though they consist of multiple tracks.
If the crossing loop is long enough to hold several trains, to allow opposing trains to cross without slowing down or stopping that may be regarded as double-track. A more modern British term for such a layout is an extended loop; the distance between the track centres makes a difference in cost and performance of a double-track line. The track centres can be as narrow and as cheap as possible, but maintenance must be done on the side. Signals for bi-directional working cannot be mounted between the tracks so must be mounted on the'wrong' side of the line or on expensive signal bridges. For standard gauge tracks the distance may be 4 metres or less. Track centres are wider on high speed lines, as pressure waves knock each other as high-speed trains pass. Track centres are usually wider on sharp curves, the length and width of trains is contingent on the minimum railway curve radius of the railway. Increasing width of track centres of 6 metres or more makes it much easier to mount signals and overhead wiring structures.
Wide centres at major bridges can have military value. It makes it harder for rogue ships and barges knocking out both bridges in the same accident. Railway lines in desert areas affected by sand dunes are sometimes built on alternate routes so that if one is covered by sand, the other are still serviceable. If the standard track centre is changed, it can take a long time for most or all tracks to be brought into line. On British lines, the space between the two running rails of a single railway track is called the "four foot", while the space between the different tracks is called the "six foot", it is not safe to stand in the gap between the tracks when trains pass by on both lines, as happened in the Bere Ferrers accident of 1917. Narrow track centres on the Liverpool and Manchester Railway contributed to a fatal accident on opening day. A US naval scientist and submarine pioneer, Captain Jacques, was killed getting out of the wrong side of a train at Hadley Wood in 1916. Narrow track centres contribute to "Second Train Coming" accidents at level crossings since it is harder to see the second train – for example, the accident at Elsenham level crossing