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A single-track railway is a railway where trains traveling in both directions share the same track. Single track is usually found on lesser-used rail lines, often branch lines, where the level of traffic is not high enough to justify the cost of constructing and maintaining a second track.
Single track is significantly cheaper to build and maintain, 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 safely. By contrast, a double track with signal boxes four minutes apart can allow up to 15 trains per hour in each direction safely, provided all the trains travel at the same speed. This hindrance on the capacity of a single track may be partly 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 if the passing stretches are not long enough. Other disadvantages include the propagation of delays, since one delayed train on a single track will also delay any train waiting for it to pass. Also, a single track does not have a "reserve" track that can allow a reduced capacity service to continue if one track is closed.
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If a single-track line is designed to be used by more than one train at a time, it must have passing loops (also called passing sidings or crossing 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, usually long enough to hold one train. The capacity of a single-track line is determined by the number of passing loops. Passing loops may also 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 (such as the Abbey Line in Great Britain or L202 railway in Croatia) 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 (and countries using 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 (e.g. the Highlands of Scotland) this has been superseded by radio communication, known as Radio Electronic Token Block.
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, and so would not enter a single-track stretch when they were not scheduled to. This generally worked but was inflexible and inefficient. It was improved with the invention of the telegraph and the ability to issue train orders.
Converting a single-track railway to double track is called duplication or doubling; converting double track to single track is known as singling. A double-track railway operating only a single track is known as single-line working. Kirkby railway station (until 1977) and Ormskirk railway station (until 1970) were double-track railway, when they were converted into single-track railway with cross-platform interchange.
Building bike trails on rail corridors has occurred in limited examples; however, developing rail rights of way for a bike trail can restrict a train corridor to a single track. Also reclaiming a railway corridor to use trains again limits the use of double tracks. The bike path is usually where the second track would be, and there may be fierce opposition by bikers and hikers. An example of a bike, single-track corridor is the E&N Railway in Victoria, Canada. [1]
A railroad switch (AE), turnout, or [set of] points (BE) is a mechanical installation enabling railway trains to be guided from one track to another, such as at a railway junction or where a spur or siding branches off.
The Island Line is a railway line on the Isle of Wight which runs along the island's east coast and links Ryde Pier Head with Shanklin. Trains connect at Ryde Pier Head with passenger ferries to Portsmouth Harbour, and these ferries in turn connect with the rest of the National Rail network via the Portsmouth Direct Line. The line also connects to the Isle of Wight Steam Railway, a heritage railway, at Smallbrook Junction. For much of its length the line runs alongside the A3055, criss-crossing this road by means of the Ryde Tunnel and bridges at Rowborough, Morton Common, Lake Hill and Littlestairs.
The Eastern Suburbs & Illawarra Line is a commuter railway line in the eastern and southern suburbs of Sydney and is a part of the Sydney Trains network. The line was constructed in the 1880s to Wollongong to take advantage of agricultural and mining potentials in the Illawarra area. In March 1926, it became the first railway in New South Wales to run electric train services.
In railway signalling, a token is a physical object which a train driver is required to have or see before entering onto a particular section of single track. The token is clearly endorsed with the names of the section it belongs to. A token system is more commonly used for single lines because of the greater risk of collision in the event of a mistake being made by a signaller or traincrew, than on double lines.
The Belgrave railway line is a commuter rail line operating between Flinders Street in the Melbourne central business district and Belgrave through Melbourne's eastern suburbs including Richmond, Cremorne, Burnley, Hawthorn, Hawthorn East, Camberwell, Canterbury, Surrey Hills, Mont Albert, Box Hill, Blackburn, Nunawading, Mitcham, Ringwood, Heathmont, Bayswater, Boronia, Ferntree Gully, Upper Ferntree Gully, Upwey, Tecoma and Belgrave. It is part of the Melbourne rail network, which is operated by Metro Trains Melbourne.
A rail trail is a shared-use path on railway right of way. Rail trails are typically constructed after a railway has been abandoned and the track has been removed, but may also share the right of way with active railways, light rail, or streetcars, or with disused track. As shared-use paths, rail trails are primarily for non-motorized traffic including pedestrians, bicycles, horseback riders, skaters, and cross-country skiers, although snowmobiles and ATVs may be allowed. The characteristics of abandoned railways—gentle grades, well-engineered rights of way and structures, and passage through historical areas—lend themselves to rail trails and account for their popularity. Many rail trails are long-distance trails, while some shorter rail trails are known as greenways or linear parks.
The Main North Line is a major railway in New South Wales, Australia. It runs through the Central Coast, Hunter and New England regions. The line was the original main line between Sydney and Brisbane, however this required a change of gauge at Wallangarra. As of 1988, the line closed progressively north of Armidale with services gradually withdrawn till 2004, with the main route between Sydney and Brisbane now the North Coast line.
The Highland Main Line is a railway line in Scotland. It is 118 mi (190 km) long and runs through the Scottish Highlands linking a series of small towns and villages with Perth at one end and Inverness at the other. Today, services between Inverness and Edinburgh, Glasgow and London use the line. At Inverness the line connects with the Far North Line, the Aberdeen-Inverness Line and services on the Kyle of Lochalsh Line. All trains are diesel-powered.
Radio Electronic Token Block is a system of railway signalling used in the United Kingdom. It is a development of the physical token system for controlling traffic on single lines. The system is slightly similar to North American Direct Traffic Control, which unlike RETB does not have a cab display unit.
The Heart of Wales line is a railway line running from Craven Arms in Shropshire to Llanelli in southwest Wales. It serves a number of rural centres, including the nineteenth-century spa towns Llandrindod Wells, Llangammarch Wells and Llanwrtyd Wells. At Builth Road, two miles (3.3 km) from the town of Builth Wells, the line crosses the former route of the earlier Mid Wales Railway, which closed in the 1960s.
Gauntlet track or interlaced track is an arrangement in which railway tracks run parallel on a single track bed and are interlaced such that only one pair of rails may be used at a time. Since this requires only slightly more width than a single track, all rails can be carried on the same crossties/sleepers. Trains run on the discrete pair of rails appropriate to their direction, track gauge or loading gauge.
A double-track railway usually involves running one track in each direction, compared to a single-track railway where trains in both directions share the same track.
A passing loop or passing siding is a place on a single line railway or tramway, often located at or near a station, where trains or trams travelling in opposite directions can pass each other. Trains/trams going in the same direction can also 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, which is much less convenient, can be used. A similar arrangement is used on the gauntlet track of cable railways and funiculars, and in passing places on single-track roads.
A balloon loop, turning loop, or reversing loop allows a rail vehicle or train to reverse direction without having to shunt or stop. Balloon loops can be useful for passenger trains and unit freight trains.
The West Wales lines are a group of railway lines from Swansea through Carmarthenshire to Pembrokeshire, West Wales. The main part runs from Swansea to Carmarthen and Whitland, where it becomes three branches to Fishguard, Milford Haven and Pembroke Dock.
The Belair railway line is a suburban rail commuter route in the city of Adelaide, South Australia, that runs from the Adelaide station to Belair in the Adelaide Hills via the Adelaide-Wolseley line using diesel 3000/3100 class railcars. Prior to 1995, this part of Adelaide-Wolseley was a two-track broad gauge line. In 1995, Adelaide-Wolseley was converted to standard gauge meaning Adelaide to Belair is now effectively two separate single-track lines running in parallel: the Belair commuter line and the Adelaide-Wolseley standard gauge freight line.
Signalling block systems enable the safe and efficient operation of railways by preventing collisions between trains. The basic principle is that a track is broken up into a series of sections or "blocks". Only one train may occupy a block at a time, and the blocks are sized to allow a train to stop within them. That ensures that a train always has time to stop before getting dangerously close to another train on the same line. The block system is referred to in the UK as the method of working, in the US as the method of operation, and in Australia as safeworking.
Opened on the 8th of October 1998, the only high-speed rail in Norway, on the railways of Norway is on Gardermobanen, a 64 kilometer line between Oslo Central Station and Eidsvoll via Oslo Airport. The main service on this route is Flytoget, commuting between Oslo Airport and the metropolitan areas of Oslo at speeds of up to 210 km/h (130 mph). It was extended westwards to include the city of Drammen in 2008, though not at high speed. The high-speed section is also used by express and regional trains between Oslo and Eidsvoll.
The Follo Line is a 22.5-kilometer (14.0 mi) high-speed railway under construction between Oslo and Ski, Norway. Running parallel to the Østfold Line, it will be engineered for 250 km/h (160 mph). Terminal stations will be Oslo Central Station and Ski Station. Most of the line, 19 kilometres (12 mi), will be in a twin-tube tunnel named the Blix Tunnel, which will be the longest railway tunnel in the country. Construction started in 2014, and is estimated to be completed by December 2022. The Follo Line will increase capacity from twelve to forty trains per hour along the South Corridor, and will allow express and regional trains to decrease travel time from Ski to Oslo from 22 to 11 minutes. The line was prospected to cost over 26 billion Norwegian krone (NOK) in 2014.
The Bendigo V/Line rail service is a regional passenger rail service operated by V/Line in Victoria, Australia. It serves passengers between state capital Melbourne, Victoria and the regional city of Bendigo, Victoria.
