Fellestunnelen
Encyclopedia
The Common Tunnel sometimes called the Common Line , is a 7.3 kilometres (4.5 mi) long tunnel
of the Oslo Metro which runs through the city center
of Oslo
, Norway
. The name derives from the fact that all six lines of the metro use the tunnel, which runs from Majorstuen
to Tøyen
. The section has six stations, including the four busiest on the metro.
The tunnel was first built as two separate tunnels which were later connected. The Holmenkolbanen
company opened the western section of the tunnel from Majorstuen via Valkyrie plass
to Nationaltheatret
in 1928. In 1966, the Oslo Metro opened, including the tunnel from Tøyen via Grønland
to Jernbanetorget
. In 1977, the eastern end was extended to Sentrum
, but the extension was closed in 1983 because of water leakages. In 1987, the Sentrum station reopened as Stortinget, and became the terminus of both the western and eastern lines. By 1993, the western end had been upgraded to metro standard, Valkyrie plass was closed, and the first trains ran through the whole tunnel.
The section from Tøyen to Brynseng
, although not completely located within the tunnel, is considered part of the Common Line. At Majorstuen, the line splits into three; the Røa Line, the Holmenkollen Line and the Sognsvann Line. At Tøyen, the line splits into the Lambertseter Line and the Grorud Line. The tunnel is the bottleneck
of the metro, allowing 24 trains per hour in each direction west of Stortinget, and 28 east of Stortinget.
rapid transit line running east from Majorstuen to Tøyen and onwards to Brynseng. The section from Tøyen to Brynseng is partially above ground and is only sometimes considered part of the tunnel and the Common Line. At Tøyen, the Grorud Line branches and continues past Carl Berners plass
as part of the same tunnel. From Carl Berners plass to Ensjø
, there is a single-track branch, which allows trains access to the other eastern lines without having to change direction. Three stations serve the city center: Nationaltheatret, Stortinget and Jernbanetorget, while Majorstuen, Tøyen and Grønland serve mixed residential and commercial areas.
, which is increased to 30 minutes in the late evening and early on Sundays. In addition, Line 5, which runs on the Grorud Line, has its headway reduced to 7.5 minutes, but the extra trains all terminate at Stortinget. Travel time from Majorstuen to Tøyen takes eight minutes. The tunnel is the bottleneck of the metro, with a capacity for 24 trains per hour in each direction west of Stortinget, and 28 east of Stortinget.
Transfer to the Oslo Tramway is available at four stations, Majorstuen, Nationaltheatret, Stortinget and Jernbanetorget. Transfer to the mainline railway is available at Nationaltheatret to the railway station with the same name
, and at Jernbanetorget to Oslo Central Station (Oslo S). Nationaltheatret offers shorter transfer distance, but only serves trains along the Drammen Line. Interchange with buses is possible at all stations except Grønland. Majorstuen acts as an interchange between the western lines, while transfer between the eastern lines can be done at Tøyen. The public transport authority Ruter
recommends that interchange between lines in the same direction should be made at Grønland.
between Majorstuen to Holmenkollen
. The terminus at Majorstuen was an inconvenience for passengers as most people were bound for the city center and had to change to the street trams. For the operator Holmenkolbanen, there were two ways to solve the issue. They could sign trackage rights
with Kristiania Elektriske Sporvei
to usethe Briskeby Line
to reach the city center. Alternatively, a tunnel could be built to an underground station in the city center. Applications for a tunnel were sent to the municipality in 1901. However, disagreements as to whether the tunnel was to be considered a railway or tramway halted progress; the city considered the line a tramway while the company considered it to be a railway.
A new application was submitted in November 1907, which proposed a single track
line to the intersection of Karl Johans gate
and Fredriks gate, and was estimated to cost 1.5 million Norwegian krone
(NOK). The plans drew criticism from city officials, who stated that the line would take passengers away from the existing tram line and that it would stimulate migration to the areas along the Holmenkollen Line in the neighboring municipality
of Aker
, thus reducing the tax income for the city. In 1909, Oslo City Council stated in a letter to the government that they were opposed to the tunnel. On 9 June 1911, the city council had nonetheless changed its mind, and voted to accept the tunnel if the terminus was moved to the intersection of Karl Johans gate and Ruseløkkveien, but this was rejected by the company. On 27 May 1909, Aker Municipal Council voted in favor of the tunnel, and on 9 June 1911 the proposal was passed by the Parliament of Norway. Both municipalities wanted the redemption right, which would allow them to purchase the railway at a later date, but this was instead given to the state. On 15 December 1911, Holmenkolbanen received a concession
through a royal decree, which would last for 60 years from the date of opening.
Construction on the central parts of the tunnel started in 1912. At the time, an agreement had not been reached with the municipality about the location of the terminus. In October, there was a landslip at Valkyrie plass
, resulting in a cavity. Thirty properties sustained cracks and other damage, and the owners threatened Holmenkolbanen with a lawsuit to reclaim the cost of repairs. By October 1914, the tunnel works had been completed from Rosenborggaten to the statue of Karl Johan in the Palace Park
(Slottsparken). The issue of the terminus was still not resolved, and work was therefore halted. Holmenkolbanen were planning on building the line through the city center, and therefore wanted the terminus at Fredriks gate, while the municipality wanted it at Ruseløkkveien.
In 1915, the city launched a competition for a plan for city's light rail system. However, the invitations were not issued until two years later. The winner was announced in July 1918, and in September 1919, a municipal committee concluded on how the network should be expanded. Firstly, it proposed connecting the Lilleaker Line to Majorstuen. Secondly, it proposed a tunnel through the city center, from Majorstuen to Stortorvet
and Vaterland
, and onwards as an elevated line eastwards, along routes that closely resemble the current metro lines and the Ekeberg Line
. From Stortorvet, a northern branch was proposed which would be built towards Kjelsås
. Finally, the committee wanted a circular line north of the city center, closely resembling to the current Ring Line.
The proposal forced the municipality to reconsider the terminus of the tunnel. The executive committee supported terminating the tunnel at Eidsvolls plass
, but this was rejected by the city council on 13 July 1920. Holmenkolbanen convinced the municipality to establish a committee to look into the specific issue. In September 1921, the committee proposed creating a temporary terminus, following Holmenkolbanen's route, in the square behind the National Theatre . This was under the condition that experts concluded that construction would be done without damage to surrounding buildings. The proposal was passed by the city council on 13 October 1921. In June 1922, an expert committee concluded that construction would be satisfactory.
Aker Municipality held an option
to purchase the Røa Line, should the tunnel not be completed by November 1922. On 11 November 1922, the municipal council execute the option. Aker had recently established the tram company Akersbanerne
, and merged the Røa Line into Akersbanerne from 1 November 1924. In June 1923, the executive committee voted to allow a temporary terminus at Nationaltheatret, given that Holmenkolbanen would be obliged to continue the line onwards to Studenterlunden
. The company did not accept the new terms, and the city council finally passed a proposal that the company could accept on 3 April 1924. However, by then traffic had increased on the Holmenkollen Line, the Røa Line had been connected to Majorstuen, and the Sognsvann Line was under planning. This caused Holmenkolbanen to change the tunnel to double track. To finance the construction, the company borrowed NOK 11.5 million.
In 1925, Oslo District Court
found Holmenkolbanen not guilty in the lawsuit over damages at Valkyrie plass. A concession was granted on 15 January 1926, which demanded that the tunnel open by the end of 1928. A change of plans moved the line's route to Valkyriegaten under Valkyrie plass, which allowed the cavity from 1912 to became a station, despite it only being 300 metres (984.3 ft) from Majorstuen. Past Slottsparken, the original track had been built at an increased depth to allow for a future extension of the Drammen Line of the Norwegian State Railways
(NSB) to run above the light rail tunnel. By 1926, these plans had been discarded, and the second track was not built as deep.
The line was officially opened by King Haakon VII
on 27 June 1928. It became the first underground railway in the Nordic Countries
, five years before Stockholm
and six years before Copenhagen
. The tunnel was 1620 metres (5,315 ft) long and trams used three to four minutes to run through it. It was used by two companies,: Holmenkolbanen and Akersbanerne, with Holmenkolbanen operating both the Røa Line and the Holmenkollen Line. The Sognsvann Line was to be connected to the tunnel from 10 October 1934, and the two companies needed to find an agreement for paying for trackage rights. After negotiations failed, a decision was made by the Ministry of Labour on 7 July 1932, which stated that Akersbanerne would have to pay the additional fares collected for transport passengers through the tunnel, less the cost of running trains on the section.
On 16 May 1931, the Supreme Court
found Holmenkolbanen guilty in the lawsuit regarding the real estate damage, with the compensation payments making the company insolvent. This resulted in Aker Municipality purchasing the majority of Holmenkolbanen, and merging the Røa Line and Sognsvann Line into the company. In 1939, Bærumsbanen
started construction of a branch from the Lilleaker Line to Majorstuen. From 15 June 1942, the Kolsås Line, as it was renamed, started running via the tunnel to the city center. Bærumsbanen became part of Oslo Sporveier in 1971.
, with a later extension to Nationalhteatret included. However, it was quickly decided that the terminus instead should be at Jernbanetorget, next to Oslo East Station (today Oslo S).
The Lambertseter Line and the Østensjø Line existed as light rail lines, and were upgraded to metro standard. The Grorud Line and the Furuset Line were new and ran through previously undeveloped neighborhoods in Groruddalen. During construction, groundwork and electrical equipment was contracted to developers, while the trackage was done by the planning office. The original plans called for the use of 600 to 650 volt
(V) direct current
(DC) fed via a pantograph
, to allow comparability with the light rail. This was later changed to 750 V DC via a third rail
, allowing reduced maintenance costs and a larger contract surface, permitted a larger electric current
and more power to the trains. The system also used cab signaling and moving block
s, which were cutting-edge technology at the time, and had previously only been implemented on the Stockholm Metro
in Europe. The minimum allowed distance between trains was set to 90 seconds on the common section and 120 seconds on the branch lines. The tunnel, along with the upgraded Lambertseter Line, opened on 23 May 1966. The Grorud Line was connected on 16 October 1966, the Østensjø Line on 29 October 1967, and the Furuset Line on 18 November 1970.
During the 1960s, the Drammen Line was being planned to connect to Oslo East Station through the proposed Oslo Tunnel. This would make Oslo West Station unnecessary, and would allow a central station to be built at the location of the East Station. The railway tunnel was planned with an intermediate railway station at Nationaltheatret
. Simultaneously, Oslo Sporveier worked on possibilities to connect their eastern and western networks, and extend both to the city core. During the 1960s, the planning office for the metro proposed a tunnel between Nationaltheatret and Jernbanetorget, which would run parallel to the Oslo Tunnel. The initial plans called for a station at Slottsparken, close to Nationaltheatret, which would serve as the transfer point between the metro and the western light rail. This station was designed to handle 25,000 people per day.
At the time, the western and eastern networks were incompatible; in addition to different platform heights, the eastern network used six-car trains with a third-rail power supply, while the western network used overhead wires and two-car trains. The initial plans were met with criticism, following the media's discovery that the main planners had not consulted several hired specialists, and that alternatives to the preferred route had not been considered. As a consequence, several engineers working for NSB made two alternative suggestions for the route. By 1975, the plans were changed so that Nationaltheatret would become the transfer station, by building a balloon loop
for the metro, while allowing the western trains to terminate as before. This solution would allow the two networks to be connected later.
The decision to build Sentrum Station, located 700 metres (2,296.6 ft) west of Jernbanetorget, was taken by the city council on 22 May 1969. The decision also involved the transfer station being placed at Slottsparken/Nationaltheatret. Construction of Sentrum started in 1972, and was immediately followed by the first water leaks being discovered. By the time the station opened on 9 January 1977, there were still no adequate countermeasures for the leaks. During trials in January, it was discovered that the tracks were too low to allow all types of trains to open their doors, resulting in the tracks having to be raised. In 1978, the city planner discarded the proposal by Oslo Sporveier to build a new station at Slottsparken, and instead decided that Sentrum would become the interchange between the two systems. This would allow the western network to be upgraded to metro standard at a later date, and subsequently also allow metro trains to run through the center. The proposal was supported by all political parties except the Labour Party.
By 1978, the contractor and the municipality felt that the leaks were under control, and the municipality took over the station. On 20 February 1983, the station was closed for renovation to remove the leaks. At the time, it was expected that the station could reopen in 1984. The cause of the leaks was a combination of the wrong type of concrete
being used and the wrong construction method.These were specified correctly in the tender contracts, but after the contractor was chosen, an agreement was made between the municipality and Selmer for the use of the membrane method. Combined with the inferior quality of concrete, the leaks were unavoidable. In 1986, the municipality sued Selmer for the NOK 158 million it cost to repair the station.
The station reopened on 7 March 1987, and took the name Stortinget, which derives from the Parliament of Norway Building
, which is adjacent to the station. Trains from the western network terminated at the old platforms, where the metro had previously terminated. The metro trains instead ran through a balloon loop. The station featured a 40 metres (131.2 ft) step-free walk between the two systems. With the opening of Stortinget, the metro network was declared finished, after the last extension on the Furuset Line to Ellingsrudåsen
had been made in 1981.
On 7 October 1987, the city council decided to connect the four light rails west of the city center with the metro, allowing through trains. The Sognsvann Line was selected as the first line to be upgraded. The overhead wires were replaced with a third-rail power supply
, automatic train protection
was installed, platforms were built long enough to accommodate six-car trains instead of two-car trains, and the platform height
was increased. The upgrade also included the installation of third-rail power supply from Majorstuen to Stortinget. From 10 January 1993, the Sognsvann Line re-opened, and from 4 April, the line started operating through the Common Tunnel and connecting to the Lambertseter Line. The new service used T1000 rolling stock.
to finance NOK 58 billion worth of transport infrastructure investments between 2008 and 2027. Ruter has requested NOK 100 million to upgrade the tunnel between Nationaltheatret and Majorstuen, where in some places there is only a few centimeters (about an inch) clearance between the tunnel wall and the trains. The upgrade would also include upgrades to the signaling system. Due to the narrow tunnel profile, evacuation from the trains have be done from the ends of the trains.
Ruter has proposed building a new underground station at Majorstuen, which would be located closer to Valkyrie plass. The current station causes long transfer distances between the metro, tram and bus, in part because passengers have to cross Kirkeveien at street level. The proposed station would have an island platform
, easing transfer between westbound lines, and allow access to both sides of Kirkeveien. The station is estimated to cost NOK 1.8 billion and would have six entrances.
NOK 700 million has been allocated to build a new station at Homansbyen
, in the residential area of Frogner
, roughly mid-way between Nationaltheatret and Majorstuen. The station is estimated to have 10,000 daily travelers, and funding is scheduled for the period 2014 to 2017. Ruter has stated that they are opposed to building the station, and have made any decision in their long-term plan from 2010 to 2030 regarding if the station should be built. The company has stated that the area has a good tram service, and is in no need of rapid transit. Because the station would be deep underground, travel time gains to the city center for local residents would be small, compared to using the tram. Also, all travelers taking the metro west of the city center would receive longer travel time, since all trains would have to stop at Homansbyen. Ruter is also concerned that a rapid transit station would take ridership away from the trams, which previously have been threatened with closure. The imminent planned upgrades to the section of the tunnel do not include any intermediate stations.
The tunnel remains the bottleneck of the metro. Without infrastructure upgrades, the only way to increase capacity through the tunnel is by running six-car trains on services currently run with three-car trains. It is also possible to increase the capacity through the tunnel to 32 trains per hour per direction by changing the signaling system and using driver-less trains. In its long-term plans from 2009, Ruter stated that there is sufficient capacity in the tunnel until at least 2030. However, by 2011, the agency's plans stated that the capacity limit could be reached as early as or even before 2025. Any further increase in capacity would only be possible by building a second tunnel through the city center. The first plans called for a tunnel further north, roughly half-way between the Common Tunnel and the Ring Line, possibly in addition to a new tunnel through the city center.
Plans from 2011 have called for a new tunnel which runs from Majorstuen via Stortinget to Tøyen, but following a different route and with intermediate stations at Bislett
, Hammersborg and Olaf Ryes plass
, in the St. Hanshaugen
and Grünerløkka
boroughs north of the city center. Three of the lines would thus follow the existing tunnel to Stortinget and then switch to the new line, while the other three lines would follow the new tunnel to Stortinget and then run along the old tunnel onwards. This would allow for a six-minute headway on all but two branches, and also allow the proposed Fornebu Line to Skøyen
, Fornebu
and Nesodden
to be built as part of the metro. Ruter has stated that the current stations are located in the areas which the most people want to travel to, and that if a second tunnel should deviate from these areas, they would have to serve places which generate as much traffic as the current stations.
Ruter has stated that the estimated investment cost would be NOK 10 billion, but that the tunnel would give high utility
and would be one of the most economic investments they could make. There is no funding for a new tunnel in Oslo Package 3. By 2010, it was discovered that Oslo Package 3 was under-financed, and it is uncertain how much of the investment will be made by 2027. With the new tunnel being made a high priority by the city planners, this will either require additional grants from the municipality or the state, an increase in the toll fees, or the delay of investments in the program to a future Oslo Package 4. The left-wing parties have stated that they are willing to delay or abandon several road projects to allocate financing to a new tunnel, while the right-wing parties have stated that they are not willing to allow road projects to be undermined.
Tunnel
A tunnel is an underground passageway, completely enclosed except for openings for egress, commonly at each end.A tunnel may be for foot or vehicular road traffic, for rail traffic, or for a canal. Some tunnels are aqueducts to supply water for consumption or for hydroelectric stations or are sewers...
of the Oslo Metro which runs through the city center
Sentrum, Oslo
Sentrum meaning city-center is located on the southeast side of the city near the inner Oslofjord.The district is dominated by high rises like Postgirobygget and The Plaza. Oslos Central Station is located on the eastern side of the borough. Sentrum consists of Bjørvika which has a history as...
of Oslo
Oslo
Oslo is a municipality, as well as the capital and most populous city in Norway. As a municipality , it was established on 1 January 1838. Founded around 1048 by King Harald III of Norway, the city was largely destroyed by fire in 1624. The city was moved under the reign of Denmark–Norway's King...
, Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
. The name derives from the fact that all six lines of the metro use the tunnel, which runs from Majorstuen
Majorstuen (station)
Majorstuen is a subway station on the Oslo Metro and a light rail station on the Briskeby Line of the Oslo Tramway. It is located in the Majorstuen neighborhood in the Frogner borough....
to Tøyen
Tøyen (station)
Tøyen is a rapid transit station located in the Common Tunnel of Oslo Metro in Norway. Located in the borough of Gamle Oslo, it is also called "Tøyen-Munchmuseet" due to its proximity to the art museum. It is the last station on the east side shared by all lines; the Grorud Line and Ring Line...
. The section has six stations, including the four busiest on the metro.
The tunnel was first built as two separate tunnels which were later connected. The Holmenkolbanen
Holmenkolbanen
A/S Holmenkolbanen was a company that owned and operated part of the Oslo Tramway and Oslo Metro in Norway from 1898 until 1975 when services were taken over by the majority owner Oslo Sporveier. Holmenkolbanen opened the Holmenkoll Line in 1898, and expanded it to become the first Nordic...
company opened the western section of the tunnel from Majorstuen via Valkyrie plass
Valkyrie plass (station)
Valkyrie plass is a former subway station on the Oslo Metro.The station was opened when the Holmenkoll Line was extended from Majorstuen to Nationaltheatret on 28 June 1928...
to Nationaltheatret
Nationaltheatret (station)
Nationaltheatret is an underground metro station and tram stop serving Vika and the city center of Oslo, Norway. It is located on the Common Tunnel of the Oslo Metro and on the Briskeby Line of the Oslo Tramway. Also located at the same place is Nationaltheatret Station of the Drammen Line. The...
in 1928. In 1966, the Oslo Metro opened, including the tunnel from Tøyen via Grønland
Grønland (station)
Grønland is a rapid transit station on the Oslo Metro in the Common Tunnel serving all six lines. It is located in the business and residential area Grønland, between the stations Jernbanetorget to the west and Tøyen to the east. The station was opened on May 22 1966 with the opening of the subway,...
to Jernbanetorget
Jernbanetorget (station)
Jernbanetorget is both a rapid transit station on the Oslo Metro and a light rail station of the Oslo Tramway. The metro station is in the Common Tunnel used by all lines under the city centre. It is located between Stortinget to the west and Grønland to the east. Until the construction of the...
. In 1977, the eastern end was extended to Sentrum
Stortinget (station)
Stortinget is an underground rapid transit station on the Common Line of the Oslo Metro, Norway. It is located in the heart of the city center, next to Stortinget, the Parliament of Norway. The station is served by all six lines of the metro. At the street level, the station serves tram routes 17,...
, but the extension was closed in 1983 because of water leakages. In 1987, the Sentrum station reopened as Stortinget, and became the terminus of both the western and eastern lines. By 1993, the western end had been upgraded to metro standard, Valkyrie plass was closed, and the first trains ran through the whole tunnel.
The section from Tøyen to Brynseng
Brynseng (station)
Brynseng is a rapid transit station on the Oslo Metro system located in the Gamle Oslo borough. The station is shared by three lines, the Østensjø Line , the Furuset Line and the Lambertseter Line . The station has four platforms. The two northernmost platforms are for trains on the Østensjø- and...
, although not completely located within the tunnel, is considered part of the Common Line. At Majorstuen, the line splits into three; the Røa Line, the Holmenkollen Line and the Sognsvann Line. At Tøyen, the line splits into the Lambertseter Line and the Grorud Line. The tunnel is the bottleneck
Bottleneck
A bottleneck is a phenomenon where the performance or capacity of an entire system is limited by a single or limited number of components or resources. The term bottleneck is taken from the 'assets are water' metaphor. As water is poured out of a bottle, the rate of outflow is limited by the width...
of the metro, allowing 24 trains per hour in each direction west of Stortinget, and 28 east of Stortinget.
Route
The Common Tunnel is a 7.3 kilometres (4.5 mi) long double trackDouble track
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.- Overview :...
rapid transit line running east from Majorstuen to Tøyen and onwards to Brynseng. The section from Tøyen to Brynseng is partially above ground and is only sometimes considered part of the tunnel and the Common Line. At Tøyen, the Grorud Line branches and continues past Carl Berners plass
Carl Berners plass (station)
Carl Berners plass is an underground rapid transit station located on the Grorud Line of the Oslo Metro, and a tram stop on the Sinsen Line of the Oslo Tramway. The square also has a bus stop for lines 20, 21, 31, 33 and 57. Located at Grünerløkka in Oslo, Norway, the area has a mixture of...
as part of the same tunnel. From Carl Berners plass to Ensjø
Ensjø (station)
Ensjø is a station on the Oslo Metro located in the borough of Gamle Oslo. The station is shared by the Østensjø-, Lambertseter- and Furuset Line. It is the first station on the east side after emerging from the downtown Common Tunnel for these lines. The station is located between Tøyen and...
, there is a single-track branch, which allows trains access to the other eastern lines without having to change direction. Three stations serve the city center: Nationaltheatret, Stortinget and Jernbanetorget, while Majorstuen, Tøyen and Grønland serve mixed residential and commercial areas.
Service
All six lines of the Oslo Metro, numbered 1 through 6, run through the Common Tunnel. Each service has a 15-minute headwayHeadway
Headway is a measurement of the distance/time between vehicles in a transit system. The precise definition varies depending on the application, but it is most commonly measured as the distance from the tip of one vehicle to the tip of the next one behind it, expressed as the time it will take for...
, which is increased to 30 minutes in the late evening and early on Sundays. In addition, Line 5, which runs on the Grorud Line, has its headway reduced to 7.5 minutes, but the extra trains all terminate at Stortinget. Travel time from Majorstuen to Tøyen takes eight minutes. The tunnel is the bottleneck of the metro, with a capacity for 24 trains per hour in each direction west of Stortinget, and 28 east of Stortinget.
Transfer to the Oslo Tramway is available at four stations, Majorstuen, Nationaltheatret, Stortinget and Jernbanetorget. Transfer to the mainline railway is available at Nationaltheatret to the railway station with the same name
Nationaltheatret station
Nationaltheatret Station is an underground railway station on the Drammen Line serving Vika and the central business district of Oslo, Norway. It is the second-busiest railway station in Norway, behind Oslo Central Station , from which Nationaltheatret is away...
, and at Jernbanetorget to Oslo Central Station (Oslo S). Nationaltheatret offers shorter transfer distance, but only serves trains along the Drammen Line. Interchange with buses is possible at all stations except Grønland. Majorstuen acts as an interchange between the western lines, while transfer between the eastern lines can be done at Tøyen. The public transport authority Ruter
Ruter
Ruter As is the public transport authority for Oslo and Akershus, Norway. The company, organized as a limited company is responsible for managing, but not operating, public transport in the two counties, including bus, the Oslo Metro, the Oslo Tramway and ferries...
recommends that interchange between lines in the same direction should be made at Grønland.
History
West end
In 1898, the Holmenkollen Line was opened as a light railLight rail
Light rail or light rail transit is a form of urban rail public transportation that generally has a lower capacity and lower speed than heavy rail and metro systems, but higher capacity and higher speed than traditional street-running tram systems...
between Majorstuen to Holmenkollen
Holmenkollen
Holmenkollen is a neighborhood in the Vestre Aker borough of Oslo, Norway. In addition to being a residential area, the area has been a ski recreation area since the late 19th century, with its famous, eponymous, ski jump arena hosting competitions since 1892...
. The terminus at Majorstuen was an inconvenience for passengers as most people were bound for the city center and had to change to the street trams. For the operator Holmenkolbanen, there were two ways to solve the issue. They could sign trackage rights
Trackage rights
Trackage rights , running rights or running powers is an agreement whereby a railway company has the right to run its trains on tracks owned by another railway company....
with Kristiania Elektriske Sporvei
Kristiania Elektriske Sporvei
A/S Kristiania Elektriske Sporvei or KES, nicknamed the Blue Tram , is a defunct operator of parts of the Oslo Tramway, Norway. It opened the first electric tramway in Scandinavia in 1894, and remained in service until 1924 when it was merged into the municipal owned Oslo Sporveier.-History:Tram...
to usethe Briskeby Line
Briskeby Line
The Briskeby Line is a section of the Oslo Tramway which runs between Jernbanetorget, through the neighborhoods of Briskeby and Uranienborg, before arriving at Majorstuen...
to reach the city center. Alternatively, a tunnel could be built to an underground station in the city center. Applications for a tunnel were sent to the municipality in 1901. However, disagreements as to whether the tunnel was to be considered a railway or tramway halted progress; the city considered the line a tramway while the company considered it to be a railway.
A new application was submitted in November 1907, which proposed a single track
Single track (rail)
A single track railway is where trains in both directions share the same track. Single track is normally used on lesser used rail lines, often branch lines, where the traffic density is not high enough to justify the cost of building double tracks....
line to the intersection of Karl Johans gate
Karl Johans gate
Karl Johans gate is the main street of the city of Oslo, Norway. The street was named in honor of King Karl Johan, who was King of Sweden and of Norway....
and Fredriks gate, and was estimated to cost 1.5 million Norwegian krone
Norwegian krone
The krone is the currency of Norway and its dependent territories. The plural form is kroner . It is subdivided into 100 øre. The ISO 4217 code is NOK, although the common local abbreviation is kr. The name translates into English as "crown"...
(NOK). The plans drew criticism from city officials, who stated that the line would take passengers away from the existing tram line and that it would stimulate migration to the areas along the Holmenkollen Line in the neighboring municipality
Municipalities of Norway
Norway is divided into 19 administrative regions, called counties , and 430 municipalities...
of Aker
Aker, Norway
Aker is a former municipality in Akershus, which lends its name to a municipality and a county in Norway. The name originally belonged to a farm which was located near the current Old Aker Church...
, thus reducing the tax income for the city. In 1909, Oslo City Council stated in a letter to the government that they were opposed to the tunnel. On 9 June 1911, the city council had nonetheless changed its mind, and voted to accept the tunnel if the terminus was moved to the intersection of Karl Johans gate and Ruseløkkveien, but this was rejected by the company. On 27 May 1909, Aker Municipal Council voted in favor of the tunnel, and on 9 June 1911 the proposal was passed by the Parliament of Norway. Both municipalities wanted the redemption right, which would allow them to purchase the railway at a later date, but this was instead given to the state. On 15 December 1911, Holmenkolbanen received a concession
Concession (contract)
A concession is a business operated under a contract or license associated with a degree of exclusivity in business within a certain geographical area. For example, sports arenas or public parks may have concession stands. Many department stores contain numerous concessions operated by other...
through a royal decree, which would last for 60 years from the date of opening.
Valkyrie plass
Valkyrie plass is a square in Oslo, Norway, located one block southeast of Majorstuen.The square is triangular in shape, and boundaried by the streets Valkyriegata, Bogstadveien and Jacob Aall's gate...
, resulting in a cavity. Thirty properties sustained cracks and other damage, and the owners threatened Holmenkolbanen with a lawsuit to reclaim the cost of repairs. By October 1914, the tunnel works had been completed from Rosenborggaten to the statue of Karl Johan in the Palace Park
Palace Park
The Palace Park is a public park in the center of Oslo, Norway, surrounding the Royal Palace. It is . It was built during the 1840s and was designed by Hans Ditlev Franciscus Linstow, who was the main architect of the palace...
(Slottsparken). The issue of the terminus was still not resolved, and work was therefore halted. Holmenkolbanen were planning on building the line through the city center, and therefore wanted the terminus at Fredriks gate, while the municipality wanted it at Ruseløkkveien.
In 1915, the city launched a competition for a plan for city's light rail system. However, the invitations were not issued until two years later. The winner was announced in July 1918, and in September 1919, a municipal committee concluded on how the network should be expanded. Firstly, it proposed connecting the Lilleaker Line to Majorstuen. Secondly, it proposed a tunnel through the city center, from Majorstuen to Stortorvet
Stortorvet (station)
Stortorvet is a station on the Oslo Tramway in Oslo, Norway. The station is located on the square Stortorvet in the city centre.It is served by the lines 11, 17 and 18. In 2009, it was decided to improve the square, the station and the tram tracks in the street.-References:...
and Vaterland
Vaterland, Norway
Vaterland is a neighborhood in Oslo, Norway. It is located north of the tracks at Oslo Central Station, between Jernbanetorget, Storgata and Akerselva river. The area features Oslo Central Station and Oslo Bus Terminal, the shopping centers Oslo City and Byporten, Galleri Oslo, Radisson Blu Plaza...
, and onwards as an elevated line eastwards, along routes that closely resemble the current metro lines and the Ekeberg Line
Ekeberg Line
The Ekeberg Line is a long light rail line of the Oslo Tramway which runs from Gamlebyen to Ljabru in Oslo, Norway. Operated by lines 18 and 19, it serves the area of Nordstarand and the neighborhoods of Ekeberg, Jomfrubråten, Bekkelaget and Ljan. The line is operated by Oslo Sporvognsdrift using...
. From Stortorvet, a northern branch was proposed which would be built towards Kjelsås
Kjelsås
Kjelsås is a one of the northern suburbs of Oslo situated in Nordre Aker, the northern borough of Oslo, Norway.- History :Together with Grefsen, Kjelsås was part of the borough Grefsen-Kjelsås until January 1 2004, when they both became part of the new borough of Nordre Aker...
. Finally, the committee wanted a circular line north of the city center, closely resembling to the current Ring Line.
The proposal forced the municipality to reconsider the terminus of the tunnel. The executive committee supported terminating the tunnel at Eidsvolls plass
Eidsvolls plass
Eidsvolls plass is a square and park in Oslo, Norway, located west of the Parliament of Norway Building, south of Karl Johans gate and east of Studenterlunden and the National Theatre...
, but this was rejected by the city council on 13 July 1920. Holmenkolbanen convinced the municipality to establish a committee to look into the specific issue. In September 1921, the committee proposed creating a temporary terminus, following Holmenkolbanen's route, in the square behind the National Theatre . This was under the condition that experts concluded that construction would be done without damage to surrounding buildings. The proposal was passed by the city council on 13 October 1921. In June 1922, an expert committee concluded that construction would be satisfactory.
Option (law)
In law, an option is the right to convey a piece of property. The person granting the option is called the optionor and the person who has the benefit of the option is called the optionee .Options characteristically exist in one of two forms:* Call options, which give the beneficiary the right to...
to purchase the Røa Line, should the tunnel not be completed by November 1922. On 11 November 1922, the municipal council execute the option. Aker had recently established the tram company Akersbanerne
Akersbanerne
A/S Akersbanerne was a municipal owned company that operated tramways in the former Municipality of Aker in current Oslo, Norway. The company was established in 1917, and opened the suburban Østensjø Line tramway in 1926; it took over the majority ownership of Holmenkolbanen in 1933, that owned the...
, and merged the Røa Line into Akersbanerne from 1 November 1924. In June 1923, the executive committee voted to allow a temporary terminus at Nationaltheatret, given that Holmenkolbanen would be obliged to continue the line onwards to Studenterlunden
Studenterlunden
Studenterlunden is a park in the city center of Oslo, Norway. It is surrounded by Karl Johans gate, Stortingsgata, Universitetsgata and Frederiks gate. Within the park lays the National Theatre. It also contains one of the entrances to Nationaltheatret Station of the Oslo Metro and Nationaltheatret...
. The company did not accept the new terms, and the city council finally passed a proposal that the company could accept on 3 April 1924. However, by then traffic had increased on the Holmenkollen Line, the Røa Line had been connected to Majorstuen, and the Sognsvann Line was under planning. This caused Holmenkolbanen to change the tunnel to double track. To finance the construction, the company borrowed NOK 11.5 million.
In 1925, Oslo District Court
Oslo District Court
Oslo District Court is the district court serving Oslo, Norway. Cases may be appealed to Borgarting Court of Appeal. As the largest district court in Norway, it handles about 20% of all cases in the country...
found Holmenkolbanen not guilty in the lawsuit over damages at Valkyrie plass. A concession was granted on 15 January 1926, which demanded that the tunnel open by the end of 1928. A change of plans moved the line's route to Valkyriegaten under Valkyrie plass, which allowed the cavity from 1912 to became a station, despite it only being 300 metres (984.3 ft) from Majorstuen. Past Slottsparken, the original track had been built at an increased depth to allow for a future extension of the Drammen Line of the Norwegian State Railways
Norwegian State Railways (1883–1996)
The Norwegian State Railways was a state-owned railway company that operated most of the railway network in Norway. The government agency was created in 1883 to oversee the construction and operation of all state-owned railways in Norway...
(NSB) to run above the light rail tunnel. By 1926, these plans had been discarded, and the second track was not built as deep.
The line was officially opened by King Haakon VII
Haakon VII of Norway
Haakon VII , known as Prince Carl of Denmark until 1905, was the first king of Norway after the 1905 dissolution of the personal union with Sweden. He was a member of the House of Schleswig-Holstein-Sonderburg-Glücksburg...
on 27 June 1928. It became the first underground railway in the Nordic Countries
Nordic countries
The Nordic countries make up a region in Northern Europe and the North Atlantic which consists of Denmark, Finland, Iceland, Norway and Sweden and their associated territories, the Faroe Islands, Greenland and Åland...
, five years before Stockholm
Stockholm
Stockholm is the capital and the largest city of Sweden and constitutes the most populated urban area in Scandinavia. Stockholm is the most populous city in Sweden, with a population of 851,155 in the municipality , 1.37 million in the urban area , and around 2.1 million in the metropolitan area...
and six years before Copenhagen
Copenhagen
Copenhagen is the capital and largest city of Denmark, with an urban population of 1,199,224 and a metropolitan population of 1,930,260 . With the completion of the transnational Øresund Bridge in 2000, Copenhagen has become the centre of the increasingly integrating Øresund Region...
. The tunnel was 1620 metres (5,315 ft) long and trams used three to four minutes to run through it. It was used by two companies,: Holmenkolbanen and Akersbanerne, with Holmenkolbanen operating both the Røa Line and the Holmenkollen Line. The Sognsvann Line was to be connected to the tunnel from 10 October 1934, and the two companies needed to find an agreement for paying for trackage rights. After negotiations failed, a decision was made by the Ministry of Labour on 7 July 1932, which stated that Akersbanerne would have to pay the additional fares collected for transport passengers through the tunnel, less the cost of running trains on the section.
On 16 May 1931, the Supreme Court
Supreme Court of Norway
The Supreme Court of Norway was established in 1815 on the basis of the Constitution of Norway's §88, prescribing an independent judiciary. It is located in Oslo and is Norway's highest court...
found Holmenkolbanen guilty in the lawsuit regarding the real estate damage, with the compensation payments making the company insolvent. This resulted in Aker Municipality purchasing the majority of Holmenkolbanen, and merging the Røa Line and Sognsvann Line into the company. In 1939, Bærumsbanen
Bærumsbanen
A/S Bærumsbanen was a tram company that operated the Lillaker-, Kolsås and Østensjø Line of the Oslo Tramway, Norway, from 1924 to 1971 when the company became part of Oslo Sporveier.-History:...
started construction of a branch from the Lilleaker Line to Majorstuen. From 15 June 1942, the Kolsås Line, as it was renamed, started running via the tunnel to the city center. Bærumsbanen became part of Oslo Sporveier in 1971.
East end
In 1948, the Oslo and Aker were merged, and the new city government started planning suburban expansion, particularly in Groruddalen. On 15 September 1949, the Planning Office for the Suburban and Underground Lines was established as a division within the new municipality. The first specific plans were launched in March 1954, consisting of four branches which would connect to a common underground line from Tøyen to the city center. Originally the plans called for a terminus at Grønlands torgGrønlands torg
Grønlands torg is a square in Grønland, Oslo, Norway. It was previously the largest square in the city. It featured Slaktehuset, Kjeøtthallen and Garternhallen. The first two were demolished in 1974, while the latter burned down the same year. From the 1980s, it has received an urban renewal, with...
, with a later extension to Nationalhteatret included. However, it was quickly decided that the terminus instead should be at Jernbanetorget, next to Oslo East Station (today Oslo S).
The Lambertseter Line and the Østensjø Line existed as light rail lines, and were upgraded to metro standard. The Grorud Line and the Furuset Line were new and ran through previously undeveloped neighborhoods in Groruddalen. During construction, groundwork and electrical equipment was contracted to developers, while the trackage was done by the planning office. The original plans called for the use of 600 to 650 volt
Volt
The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...
(V) direct current
Direct current
Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...
(DC) fed via a pantograph
Pantograph (rail)
A pantograph for rail lines is a hinged electric-rod device that collects electric current from overhead lines for electric trains or trams. The pantograph typically connects to a one-wire line, with the track acting as the ground wire...
, to allow comparability with the light rail. This was later changed to 750 V DC via a third rail
Third rail
A third rail is a method of providing electric power to a railway train, through a semi-continuous rigid conductor placed alongside or between the rails of a railway track. It is used typically in a mass transit or rapid transit system, which has alignments in its own corridors, fully or almost...
, allowing reduced maintenance costs and a larger contract surface, permitted a larger electric current
Electric current
Electric current is a flow of electric charge through a medium.This charge is typically carried by moving electrons in a conductor such as wire...
and more power to the trains. The system also used cab signaling and moving block
Moving block
In railway signaling, a moving block is a signaling block system where the blocks are in real time defined by computers as safe zones around each train. This requires both the need to know the exact location and speed of all trains at any given time, and continual communication between the central...
s, which were cutting-edge technology at the time, and had previously only been implemented on the Stockholm Metro
Stockholm Metro
The Stockholm Metro is a metro system in Stockholm, Sweden. 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 seven lines numbered from 10 to 19, in three groups identified by a color: the Green, Red and Blue lines...
in Europe. The minimum allowed distance between trains was set to 90 seconds on the common section and 120 seconds on the branch lines. The tunnel, along with the upgraded Lambertseter Line, opened on 23 May 1966. The Grorud Line was connected on 16 October 1966, the Østensjø Line on 29 October 1967, and the Furuset Line on 18 November 1970.
The gap
Nationaltheatret station
Nationaltheatret Station is an underground railway station on the Drammen Line serving Vika and the central business district of Oslo, Norway. It is the second-busiest railway station in Norway, behind Oslo Central Station , from which Nationaltheatret is away...
. Simultaneously, Oslo Sporveier worked on possibilities to connect their eastern and western networks, and extend both to the city core. During the 1960s, the planning office for the metro proposed a tunnel between Nationaltheatret and Jernbanetorget, which would run parallel to the Oslo Tunnel. The initial plans called for a station at Slottsparken, close to Nationaltheatret, which would serve as the transfer point between the metro and the western light rail. This station was designed to handle 25,000 people per day.
At the time, the western and eastern networks were incompatible; in addition to different platform heights, the eastern network used six-car trains with a third-rail power supply, while the western network used overhead wires and two-car trains. The initial plans were met with criticism, following the media's discovery that the main planners had not consulted several hired specialists, and that alternatives to the preferred route had not been considered. As a consequence, several engineers working for NSB made two alternative suggestions for the route. By 1975, the plans were changed so that Nationaltheatret would become the transfer station, by building a balloon loop
Balloon loop
A balloon loop or turning loop allows a rail vehicle or train to reverse direction without having to shunt or even stop. Balloon loops can be useful for passenger trains and unit freight trains, such as coal trains....
for the metro, while allowing the western trains to terminate as before. This solution would allow the two networks to be connected later.
The decision to build Sentrum Station, located 700 metres (2,296.6 ft) west of Jernbanetorget, was taken by the city council on 22 May 1969. The decision also involved the transfer station being placed at Slottsparken/Nationaltheatret. Construction of Sentrum started in 1972, and was immediately followed by the first water leaks being discovered. By the time the station opened on 9 January 1977, there were still no adequate countermeasures for the leaks. During trials in January, it was discovered that the tracks were too low to allow all types of trains to open their doors, resulting in the tracks having to be raised. In 1978, the city planner discarded the proposal by Oslo Sporveier to build a new station at Slottsparken, and instead decided that Sentrum would become the interchange between the two systems. This would allow the western network to be upgraded to metro standard at a later date, and subsequently also allow metro trains to run through the center. The proposal was supported by all political parties except the Labour Party.
By 1978, the contractor and the municipality felt that the leaks were under control, and the municipality took over the station. On 20 February 1983, the station was closed for renovation to remove the leaks. At the time, it was expected that the station could reopen in 1984. The cause of the leaks was a combination of the wrong type of concrete
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
being used and the wrong construction method.These were specified correctly in the tender contracts, but after the contractor was chosen, an agreement was made between the municipality and Selmer for the use of the membrane method. Combined with the inferior quality of concrete, the leaks were unavoidable. In 1986, the municipality sued Selmer for the NOK 158 million it cost to repair the station.
The station reopened on 7 March 1987, and took the name Stortinget, which derives from the Parliament of Norway Building
Parliament of Norway Building
The Parliament of Norway Building is the seat of the Parliament of Norway, located in central Oslo. The building is located at Karl Johans gate 22 and was taken into use on 5 March 1866...
, which is adjacent to the station. Trains from the western network terminated at the old platforms, where the metro had previously terminated. The metro trains instead ran through a balloon loop. The station featured a 40 metres (131.2 ft) step-free walk between the two systems. With the opening of Stortinget, the metro network was declared finished, after the last extension on the Furuset Line to Ellingsrudåsen
Ellingsrudåsen (station)
Ellingsrudåsen is a subway station on the Oslo Metro, located at Ellingsrud in the Alna borough. Since its opening November 8, 1981, it has been the end station for the Furuset Line . Ellingsrudåsen is mostly a residential area, above the station are a few shops.Ellingsrudåsen is located deep...
had been made in 1981.
On 7 October 1987, the city council decided to connect the four light rails west of the city center with the metro, allowing through trains. The Sognsvann Line was selected as the first line to be upgraded. The overhead wires were replaced with a third-rail power supply
Railway electrification system
A railway electrification system supplies electrical energy to railway locomotives and multiple units as well as trams so that they can operate without having an on-board prime mover. There are several different electrification systems in use throughout the world...
, automatic train protection
Automatic Train Protection
Automatic Train Protection in Great Britain refers to either of two implementations of a train protection system installed in some trains in order to help prevent collisions through a driver's failure to observe a signal or speed restriction...
was installed, platforms were built long enough to accommodate six-car trains instead of two-car trains, and the platform height
Railway platform height
On a railway the platform height refers to the height of a platform above the rail. The value varies between railway systems. A related term is "train floor height" which is the height of the floor of the rail vehicle. There are a wide number of standards for platform heights and train floor heights...
was increased. The upgrade also included the installation of third-rail power supply from Majorstuen to Stortinget. From 10 January 1993, the Sognsvann Line re-opened, and from 4 April, the line started operating through the Common Tunnel and connecting to the Lambertseter Line. The new service used T1000 rolling stock.
Future
Oslo Package 3 is a political agreement between local and national politicians whereby state and municipal grants are combined with revenue from the toll ringFjellinjen
Fjellinjen AS is a municipal company owned by the City of Oslo and Akershus County Municipality . It is responsible for the collection from the toll ring around Oslo, with a total of nineteen toll plazas.-History:...
to finance NOK 58 billion worth of transport infrastructure investments between 2008 and 2027. Ruter has requested NOK 100 million to upgrade the tunnel between Nationaltheatret and Majorstuen, where in some places there is only a few centimeters (about an inch) clearance between the tunnel wall and the trains. The upgrade would also include upgrades to the signaling system. Due to the narrow tunnel profile, evacuation from the trains have be done from the ends of the trains.
Island platform
An island platform is a station layout arrangement where a single platform is positioned between two tracks within a railway station, tram stop or transitway interchange...
, easing transfer between westbound lines, and allow access to both sides of Kirkeveien. The station is estimated to cost NOK 1.8 billion and would have six entrances.
NOK 700 million has been allocated to build a new station at Homansbyen
Homansbyen (station)
Homansbyen is a tram station located at Homansbyen in Frogner borough of Oslo, Norway. It is on a connection line that connect the Briskeby Line and Ullevål Hageby Line of Oslo Tramway, and is served by line 11 using SL79 trams...
, in the residential area of Frogner
Frogner
Frogner is a borough of the city of Oslo, Norway. In addition to traditional Frogner, the borough incorporates Bygdøy, Uranienborg and Majorstuen....
, roughly mid-way between Nationaltheatret and Majorstuen. The station is estimated to have 10,000 daily travelers, and funding is scheduled for the period 2014 to 2017. Ruter has stated that they are opposed to building the station, and have made any decision in their long-term plan from 2010 to 2030 regarding if the station should be built. The company has stated that the area has a good tram service, and is in no need of rapid transit. Because the station would be deep underground, travel time gains to the city center for local residents would be small, compared to using the tram. Also, all travelers taking the metro west of the city center would receive longer travel time, since all trains would have to stop at Homansbyen. Ruter is also concerned that a rapid transit station would take ridership away from the trams, which previously have been threatened with closure. The imminent planned upgrades to the section of the tunnel do not include any intermediate stations.
The tunnel remains the bottleneck of the metro. Without infrastructure upgrades, the only way to increase capacity through the tunnel is by running six-car trains on services currently run with three-car trains. It is also possible to increase the capacity through the tunnel to 32 trains per hour per direction by changing the signaling system and using driver-less trains. In its long-term plans from 2009, Ruter stated that there is sufficient capacity in the tunnel until at least 2030. However, by 2011, the agency's plans stated that the capacity limit could be reached as early as or even before 2025. Any further increase in capacity would only be possible by building a second tunnel through the city center. The first plans called for a tunnel further north, roughly half-way between the Common Tunnel and the Ring Line, possibly in addition to a new tunnel through the city center.
Plans from 2011 have called for a new tunnel which runs from Majorstuen via Stortinget to Tøyen, but following a different route and with intermediate stations at Bislett
Bislett
Bislett is a neighbourhood in the St. Hanshaugen borough in north-central Oslo, Norway. It is internationally famous for the Bislett Games, held at Bislett stadion....
, Hammersborg and Olaf Ryes plass
Olaf Ryes plass
Olaf Ryes plass is a square and park placed centrally in the Grünerløkka borough of Oslo, Norway. It is more or less quadratic in shape.-History:...
, in the St. Hanshaugen
St. Hanshaugen
St. Hanshaugen is a borough of the city of Oslo, Norway.-Area:It has a triangular shape, with its northern border just north of the buildings of the Norwegian Broadcasting Corporation and Ullevål University Hospital, and south of the University of Oslo campus at Blindern...
and Grünerløkka
Grünerløkka
Grünerløkka is a borough of the city of Oslo, Norway. Grünerløkka became part of the city of Oslo in 1858.Grünerløkka was named after Friedrich Grüner who bought a mill in the area from king Christian V of Denmark in 1672 . During the 19th century, Grünerløkka became a working class area...
boroughs north of the city center. Three of the lines would thus follow the existing tunnel to Stortinget and then switch to the new line, while the other three lines would follow the new tunnel to Stortinget and then run along the old tunnel onwards. This would allow for a six-minute headway on all but two branches, and also allow the proposed Fornebu Line to Skøyen
Skøyen
Skøyen is a neighborhood of Oslo, Norway. It is located in the western part of the city, in the borough of Ullern.The name "Skøyen" comes from Old Norse Skǫðin, of unknown etymology....
, Fornebu
Fornebu
Fornebu is a peninsular area in the suburban municipality of Bærum in Norway, bordering western parts of Oslo.Oslo Airport, Fornebu served as the main airport for Oslo and the country since before WWII and until the evening of October 7, 1998, when it was closed down...
and Nesodden
Nesodden
Nesodden is a municipality in Akershus county, Norway. It is part of the traditional region of Follo. The administrative centre of the municipality is the village of Nesoddtangen. The parish of Næsodden was established as a municipality on 1 January 1838...
to be built as part of the metro. Ruter has stated that the current stations are located in the areas which the most people want to travel to, and that if a second tunnel should deviate from these areas, they would have to serve places which generate as much traffic as the current stations.
Ruter has stated that the estimated investment cost would be NOK 10 billion, but that the tunnel would give high utility
Utility
In economics, utility is a measure of customer satisfaction, referring to the total satisfaction received by a consumer from consuming a good or service....
and would be one of the most economic investments they could make. There is no funding for a new tunnel in Oslo Package 3. By 2010, it was discovered that Oslo Package 3 was under-financed, and it is uncertain how much of the investment will be made by 2027. With the new tunnel being made a high priority by the city planners, this will either require additional grants from the municipality or the state, an increase in the toll fees, or the delay of investments in the program to a future Oslo Package 4. The left-wing parties have stated that they are willing to delay or abandon several road projects to allocate financing to a new tunnel, while the right-wing parties have stated that they are not willing to allow road projects to be undermined.