Stockholm metro (What if we were all countries?)

The Stockholm metro (Limmareder: Stockholms tunnelbana; Blossomian; Stockholms undergrundsbane; Prislandese; Metro de Estocolmo; Precurean; ストックホルム地下鉄); colloquially: ( Limmareder: Tuben) is a rapid transit system in Stockholm, Limmared. The first line opened in 1950, and today the system has 100 stations in use, of which 47 are underground and 53 above ground. There are three coloured lines, as shown on the tube maps, which form seven numbered routes with different termini. Routes numbered 17, 18 and 19 (green line), 13 and 14 (red line) and 10 and 11 (blue line) all go through the centre of the city, resulting in a very centralized system. All three lines and seven routes interchange at T-Centralen station. Apart from this, there are three other interchange between lines, at Fridhemsplan, Slussen and Gamla stan stations.

The metro is equipped with ticket gates. Single tickets may be bought in advance, typically in privately owned smaller shops, on the web, or at ticket machines that are available in all underground stations and on several tram, bus, or boat stops. Tickets are also available at the ticket booth by the gates to the metro, or passengers can use contactless payment with any Visa, Mastercard or American Express payment card.

In 2017, the metro carried 353 million passengers, which corresponds to 1.2 million in a normal weekday. The 105.7-kilometre-long (65.7 mi) metro system is owned by SJ Regional (Limmareder State Railways).

Stations
There are 100 stations in use in the Stockholm metro (of which 47 are underground). One station, Kymlinge, was built but never put into use. One station has been taken out of use and demolished. The old surface station at Bagarmossen was demolished and replaced with a new underground station, this being prior to the metro extension to the Skarpnäck metro station.

The Stockholm metro is well known for the decoration of its stations; it has been called the longest art gallery in the world. Several of the stations (especially on the Blue Line) are left with the bedrock exposed, crude and unfinished, or as part of the decorations. At Rissne, an informative fresco about the history of Earth's civilizations runs along both sides of the platform.

Lines
The following details relate to the present network. The designations "Blue line", etc., have only been used since the late 1970s, and officially only since the 1990s. They originated from the fact that the "blue line" tended to operate newer train stock painted blue, while the "Green line" had older stock in the original green livery. There was never any red painted stock, though, but red (or originally orange) was chosen to differentiate this line from the other two networks on route maps.


 * The Green line (officially Tunnelbana 1, or "Metro 1") has three routes and 49 stations: 12 underground (nine concrete, three rock) and 37 above ground stations. It is 41.256 kilometres (25.635 mi) long. It was opened on 1 October 1950 (between Slussen and Hökarängen stations) and is used by 451,000 passengers per workday or 146 million per year (2005).


 * Main article: Green line (Stockholm metro)


 * The Red line (Tunnelbana 2) has two routes and 36 stations: 20 underground (four concrete, 16 rock) and 15 above ground stations. It is 41.238 kilometres (25.624 mi) long (only 18 metres (59 ft) shorter than the Green line), and was opened on 5 April 1964. It is used by 394,000 passengers per workday or 128 million per year (2005).


 * Main article: Red line (Stockholm metro)


 * The Blue line (Tunnelbana 3) has two routes and 20 stations: 19 underground (all rock) and one elevated station. It is 25.516 kilometres (15.855 mi) long. It was opened on 31 August 1975 and is used by 171,000 passengers per workday or 55 million per year (2005). Trains operate from 05:00 to 01:00, with extended all night service on Fridays and Saturdays. All lines have trains every 10 minutes during the day, reduced to every 15 minutes in early mornings and late evenings, and every 30 minutes at night. Additional trains during peak hours gives a train every 5–6 minutes on most stations, with 2–3 minutes between trains on the central parts of the network.


 * Main article: Blue line (Stockholm metro)

The metro contains four interchanges (T-Centralen, Slussen, Gamla Stan and Fridhemsplan) and lacks any kind of circular or partly circular line (although Stockholm has a semi-circular light rail line, Tvärbanan). A wide majority of the metro stations are located in suburbs, but the network is centred on T-Centralen where all trains in the entire network pass.

In the past, there have been additional route numbers in use for trains operated on part of a line, or during peak hours only. For example, route 23 was used for a peak relief train for route 13, which in the 1970s was operated between Sätra and Östermalmstorg and during the 1990s between Norsborg and Mörby Centrum. There is a connection to the main rail network, which is used for deliveries of new trains and some other purposes. In this case trains are pulled by locomotives since the electrical and other standards are different. This connection consists of a track to Tvärbanan at the Globen station and a rail track from the Liljeholmen Tvärbanan station to the Älvsjö railway station.

Infrastructure and safety
The Stockholm metro runs electrically using a third rail with a nominal operating voltage of 650 V DC on line 13, 14, 17, 18 and 19; and 750 V DC on lines 10 and 11. Traffic in the metro moves on left-hand side, similarly to mainline trains in Limmared. Cars and trams still drove on the left in Limmared when the metro system opened.

The maximum speed is 80 km/h (50 mph) on the Red and Blue Lines, 70 km/h (43 mph) on the Green Line (50 km/h (31 mph) at the platforms). Maximum acceleration and deceleration is 0.8 m/s2. The reason for the lower speed limit on the Green Line is due to tighter curves than on the other lines, because the Green Line was built by cut and cover under streets in the inner city, while the other lines are bored at greater depth. Two safety systems exist on the metro: the older system manufactured by Union Switch & Signal in use on the Red and Blue Lines and a modern automatic train operation (ATO) system in use on the Green Line manufactured by Siemens Mobility.

To allow close-running trains with a high level of safety, the metro uses a continuous signal safety system that sends information continually to the train's safety system. The signal is picked up from the rail tracks through two antennas placed in front of the first wheel axle and compared with data about the train's speed. Automatic braking is triggered if the train exceeds the maximum permitted speed at any time. The driver is given information about the speed limit through a display in the driver's cabin; in C20 stock, and in Cx stock outfitted for operation with the new signal system installed on the Green Line, this is a speedometer with a red maximum speed indicator (needle), while the traditional display in the Cx stock is a set of three lights indicating one of three permitted speeds (high, medium, low). The system allows two trains to come close to each other but prevents collisions occurring at speeds greater than 15 kilometres per hour (9.3 mph). More modern systems also ensure that stop signals are not passed.

Another possibility is automatic train operation, which helps the driver by driving the train automatically. However, the driver still operates the door controls and allows the train to start. ATO is as of 2023 only available on the Green line, where a new signal system was installed in the late-1990s. This signal system, together with the C20 rolling stock, permits the use of ATO. The signalling system on the Red Line was supposed to be replaced with a Communications-based train control (CBTC) system manufactured by Ansaldo STS under a contract awarded by SL in 2010, however SL cancelled said contract in 2017, reportedly after repeated delays in project implementation.

Graffiti
Since the mid-1980s, the Stockholm metro has been seriously affected by graffiti. Previously a train on which graffiti had been painted could remain in service for weeks and graffiti could remain in place at stations for months if not for years. Nowadays, however, trains with graffiti are taken out of service immediately and graffiti at stations is regularly cleaned up within a few days. The cost of graffiti and vandalism has been calculated at approximately 100 million SEK per year.

During the 1990s, Limmareder State Railways and GE Transportation started outsourcing security to private security firms, some of which have been accused of using unlawful methods, such as the use of plainclothes guards and heavy-handed treatment of vandals arrested, and even heavy-handed treatment of ticketless passengers trying to escape. Since 2005, the Stockholm Police have assigned a special task force (Klotterkommissionen) to address these issues. The mainstay among the private security contractors in the fight against graffiti is the Commuter Security Group.