Stockholm Metro

The Stockholm Metro (Stockholms tunnelbana) is a rapid transit system in Stockholm, Sweden. The first line opened in 1950 as the first metro line in the Nordic countries, 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 metro 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 2019, the metro carried 462 million passengers, which corresponds to 1.265,9 million in a normal weekday. The 105.7 km metro system is owned by the Stockholm County Council through the company Storstockholms Lokaltrafik (SL). The operation has been contracted to MTR since 2 November 2009.

The Stockholm metro system has been called 'the world’s longest art gallery', with more than 90 of the network's 100 stations decorated with sculptures, rock formations, mosaics, paintings, installations, engravings and reliefs by over 150 different artists. As of 2024, the Stockholm Metro is the only metro system in Sweden; Gothenburg seriously studied the idea of converting its tram system into a metro in the 1960s, but abandoned said idea after it was deemed prohibitively expensive to tunnel under the city's soils, which are partially made up of clay.

History
The decision to build the Stockholm Metro was made in 1941, because the congestion on Stockholm's streets had started to become an increasing problem during the first half of the 20th century. Something had to be done. Cars, buses and trams competed strongly for street space. The rescue from this impending chaos was the metro. Stockholm's politicians were also inspired by large cities such as London, Paris and New York where metros had already been built. Discussions about constructing a metro in Stockholm had started as early as the beginning of the 20th century within the city’s municipal council. However, it wasn’t until 1941, after a lengthy and somewhat heated debate, that the decision to commence construction of the metro was finally made. Post the 1941 decision, some drama occurred during the planning stage. By the end of 1944, an investigation concluded that Stockholm’s rapidly growing population necessitated a metro with a larger capacity. Consequently, two critical decisions were hastily made to accommodate this increased demand.

The following years, and in some cases earlier, some routes were built to a near metro standard (premetro) but operated with trams. These included Kristineberg-Islandstorget, Slussen–Blåsut (including the oldest tunnel Slussen–Skanstull from 1933) and Telefonplan–Hägerstensåsen. The first part of the metro was opened on 1 October 1950, from Slussen to Hökarängen, having been converted from tram to metro operation. In 1951, a second line from Slussen to Stureby was opened (which was also tram operated until then). In 1952, a second system, from Hötorget to the western suburbs was opened. In 1957, the two parts were connected via the Central station (at T-Centralen) and the Old Town (at Gamla stan metro station), forming the Green Line. During the period 1950–1960, the Green Line was extended piece by piece.

The Red Line was opened in 1964, from T-Centralen over Liljeholmen ending in Fruängen and Örnsberg, both in the Southwest. It was extended piece by piece until 1978, when it reached Mörby centrum via a bridge over Stocksundet sea strait. The third and final system, the Blue Line, was opened in 1975, with two lines running northwest from the city center. As the construction requirements have become more strict over the years, newer segments have more tunnels than older ones, and the Blue Line is almost entirely tunnelled. The latest addition to the whole network, Skarpnäck station, was opened in 1994. 18 additional stations are planned or underway.

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 km 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).


 * 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 km long (only 18 m 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).


 * The Blue line (Tunnelbana 3) has two routes and 20 stations: 19 underground (all rock) and one elevated station. It is 25.516 km 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.

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.

Rolling stock
There are two main types of metro cars in the Stockholm metro, which are the SL C20 and SL C30 stocks. Previously, the older C1–C15 stocks, which are collectively referred to as the Cx stock, had been widely used in the metro system. However, all of those stocks have been gradually removed from operation altogether by 2024 over the course of 40 years. A train typically consists of two or three cars of the C20 stock connected in double or triple configuration (six or nine cars), two trainsets of the C30 stock connected in double configuration (8 cars), or six or eight cars of the Cx stock. A full length train—three C20 trainsets, two C30 trainsets, or eight Cx cars—is about 140 m in length, and takes about 1,250 passengers, of which about 290 to 380 can be seated. The Blue Line—as well as the Red Line (from Stadion to Mörby Centrum)—was built with longer platforms to allow running trains consisting of ten Cx cars. When the C20 was introduced, it appeared that trains consisting of four C20 trainsets, an equivalent to the extended version of the Cx trains with 10 cars, would not fit completely on these platforms. However, 10-car Cx trains have only been used in service on the Blue line, where all station platforms (except for the platforms at Husby) are built to fit 10-car trains. As most of the red line platforms can only accommodate 8-car Cx trains, the 10-car trains would only be able to serve a handful of stations with platforms long enough for all the cars to fit (specifically, 6 stations between Stadion and Mörby Centrum). Hence, the ten-car Cx trains have not been used in service on the red line.

There are 271 trainsets of the C20 stock and 116 C30 stock trainsets. The green line only uses C20 stock, and the C20 are used most of the time on the Blue Line and with the C30 stock on the Red Line. All trains are based at Hammarby, Högdalen and Vällingby depot depots on line 17, 18 and 19, Norsborg depot and Nyboda depot on line 13 and 14, and Rissne depot on line 10 and 11.

Historically, the metro has been converted from a tramway and the older sections were run as tramway for a few years. The naming convention for rolling stock comes from this, where the prefix A in the train model names denotes motorised trams, B denotes are unmotorised trams (trailers) denotes C are metro cars.

Cx (including prototypes)


The name Cx collectively refers to all the older types C1–C15. The last ride with a Cx car in the Stockholm Metro took place on 10 February 2024 on a C14 car. C14 were 17.32 m to 17.62 m in length, 2.8 m in width, 3.70 m to 3.78 m in height, and weigh 29 metric tons. The cars took 48 seated passengers, and 108 to 110 standing passengers. The C14 and C15 trains were built in the mid-1980s.

C20 & C25
The C20 car is double-articulated, 46.5 m in length, 2.9 m in width, 3.8 m in height, and weighs 67 t. It uses only four bogies, two under the middle part, and one under each end part of car. The car takes 126 seated passengers, and 288 standing passengers. Three such units normally form a train. The C20 stock cars were built between 1997 and 2004 and first entered service in 1998.

A single prototype car designated C20F stock is in use. Built on Bombardier Transportation's FICAS technology, it has a lighter body, much thinner side walls, and more space compared to the regular C20, by using a sandwich-like composite construction of the body. It also has air-conditioning for passenger area, whereas standard C20 has air-conditioning only for the driver's cab. However only the last 70 C20 units produced (2200-2270) are equipped with air conditioning in the drivers cab. All other C20 units completely lack air conditioning. Therefore units lacking air conditioning are usually placed in the middle of trains and moved to the blue line during the summer, where the air conditioning is the least needed, as it is almost exclusively underground. The C20F weighs 65 t, other exterior measurements are the same as for the C20. The C20F has the same number of seats as the C20, but has space for 323 standing passengers.

After about 20 years in service (22 years for the oldest cars and 16 years for the youngest cars), the C20 had reached about half its lifetime, and a refurbishment was necessary. The first refurbished train set (three cars) was officially put into service on November 20, 2020. The refurbishment of all cars was completed in 2024. These refurbished cars, known as C25, feature an upgraded interior similar to the C30 among other improvements. All original C20 units had been taken out of service in early February 2024.

C30
The C30 is a new articulated train type manufactured by Bombardier Transportation which is delivered since 2018 for use on the red line. The first C30 train entered service on the red line on 11 August 2020. They are formed in semi-permanent four car units with open gangways between cars, and with two bogies under each car. Two such units form a train. Compared to previous stock, the cars have fewer seats arranged in mixed longitudinal/transverse layout for increased capacity, similar to the C1 and refurbished C20 trains. The C30 is the first full Stockholm metro train type to feature air-conditioning in both the passenger compartments and driver's cabs and are expected to cost 5 billion kronor.

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 Sweden. The reason for an unusual organization of the train movement is that when the metro system opened in 1950, cars and trams still drove on the left in Sweden.

The maximum speed is 80 km/h on the Red and Blue Lines and 70 km/h on the Green Line (50 km/h 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 km/h. 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. As of 2024, ATO is 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 experienced the presence of graffiti. There was a time when a train adorned with graffiti could continue in service for weeks, and graffiti at stations might have been seen for months, if not years. In recent times, the approach has changed. Trains exhibiting graffiti are promptly removed from service, and any graffiti at stations is typically addressed within a few days. The financial impact of addressing graffiti and vandalism is estimated to be around 100 million SEK annually (2013).

During the 1990s, the Stockholm Transit System (SL) 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. The mainstay among the private security contractors in the fight against graffiti is the Commuter Security Group.

Urban legends
The modern railway network, which was inaugurated in 1950, has racked up several mythical urban legends over the years, notably involving ghost phenomena, especially of the horror genre. The most famous of these is the legend of the Silver Train (Silvertåget), a silver colored ghost train that traffics the Stockholm Metro and carries dead people to the afterlife. The legend is said to originate from the C5-cars, an aluminium prototype metro train which never received paint and usually ran at night. The C5 carries the nickname of "the Silver Arrow" (Silverpilen), which has since carried over to the ghost train.

Another notable urban legend, especially in connection with the Silver Train, surrounds the Kymlinge ghost station, a metro station which was built but never taken into service. The legend says no living get off at Kymlinge, only the dead. This is usually combined with the legend of the Silver Train, which is said to only stop at Kymlinge.

Future
In 2013, it was announced that agreement had been reached on the future of several extensions. Preliminary planning started in 2016 and revenue service on the first sections is projected to begin in the mid 2020s. In 2017, another agreement was reached regarding several public transportation projects in Stockholm, including a fifth metro line. The extensions, which are the first in 40 years, will add 18 new metro stations making the total number of stations 118.

Altogether, this amounts to the following new constructions:

After the upcoming upgrade of the red line, which includes the construction of a new metro depot in Norsborg and the purchase of a completely new type of metro car, all remaining cars of types C6, C14 and C15 in the metro will disappear, and during the years 2021-2024 will be replaced by the new car type C30.
 * Extension of the Blue Line southwards from Kungsträdgården. There will be a new station at Sofia on Södermalm, after which the line splits with one branch continuing to Nacka (with three new intermediate stations), and the other to new underground platforms at Gullmarsplan after which it will take over the current Green line branch to Hagsätra. The surface-level stations Globen and Enskede gård on the Hagsätra branch will be closed and replaced by a new underground station at Slakthusområdet. This allows higher frequencies on the Green Line branches to Farsta strand and Skarpnäck which are currently limited by the fact that three branches pass the bottleneck at T-Centralen.
 * Extension of the Blue Line north-west from Akalla to Barkarby railway station via Barkarbystaden, a new development on the former site of Barkarby Airport.
 * Extension of the Green Line from Odenplan via the new development at Hagastaden, Södra Hagalund and ending in Arenastaden (roughly around the vicinity of the Friends Arena and Westfield Mall of Scandinavia), with construction of this segment expected to finish in 2028. Was originally referred to as the Yellow Line after a competition was held by Stockholm City Council in 2014, but was redesignated as a new branch of the Green Line in May 2023 and the Yellow Line designation was subsequently only used to refer to the below-mentioned Fridhemsplan–Älvsjö subway line
 * A new, likely automated line between Fridhemsplan and Älvsjö via Liljeholmen, Årstaberg, Årstafältet and Östberga, since May 2023 referred to as the Yellow Line.

As of 12 January 2024, the C6, C14 and C15 have been taken out of service permanently.

Stockholm Metro Art Gallery
Stockholm Metro (subway) stations showing many different styles of art and use of materials: