Kolsås Line

Kolsås Line
T1300 train near Avløs
Overview
Type	Rapid transit
System	Oslo Metro
Status	Partially closed for renovation
Termini	Smestad Kolsås
Stations	21
Operation
Opening	1924
Owner	Kollektivtransportproduksjon
Operator(s)	Oslo T-banedrift
Rolling stock	MX3000
Technical
Line length	12.2 km (7.6 mi)
No. of tracks	Double
Track gauge	1,435 mm (4 ft 8 1⁄2 in)
Electrification	750 V DC (overhead)
Operating speed	70 km/h (43 mph)
Highest elevation	94.6 m (310 ft)
Route map Legend 17.3 km Kolsås1930 65 m 16.5 km Hauger1930 15.5 km Gjettum1930 89.7 m 14.8 km Valler1930–2006 13.6 km Avløs1924 82.0 m Avløs Metro depot 13.0 km Haslum1924 68.5 m Øverlandselven 11.8 km Gjønnes1924 11.4 km Bekkestua1924 58.9 m 10.8 km Egne hjem1924–2006 10.5 km Ringstabekk1924–2009 67.3 m 10.2 km Ringstabekk2011 (new) 9.9 km Tjernsrud1924–2009 9.1 km Jar1924 68.2 m Lilleaker Line Lysakerelven 8.4 km Lysakerelven1942–2006 8.2 km Bjørnsletta2010 7.8 km Bjørnsletta1942–2006 81.3 m 7.4 km Åsjordet1942 68.2 m 6.8 km Ullernåsen1942 94.6 m 6.0 km Montebello1942 Husebybakken2006–08 Røa Line 5.1 km Sørbyhaugen1935–95 82.0 m 4.6 km Smestad1912 63.7 m Røa Line

The Kolsås Line (Norwegian: Kolsåsbanen) is a rapid transit line on the Oslo Metro network of Norway. It branches off from the Røa Line at Smestad, and runs 12.2 kilometres (7.6 mi) to Kolsås; the terminus being 17.3 kilometres (10.7 mi) from Stortinget. While the eastern part of the line is in Oslo, most of the line is in the neighboring municipality of Bærum. The line is owned by Kollektivtransportproduksjon, while the trains are operated by Oslo T-banedrift on contract with Ruter. The line is served by route 2, that continues through the city center into the Furuset Line.

The line was opened to Avløs as part of the Lilleaker Line in 1924. It was extended to Kolsås in 1930, and from Jar to Sørbyhaugen in 1942. Since 1995, it has been part of the T-bane. The line has been closed since 2006 for upgrades, with the first section to Åsjordet opening in 2008. Between 2006 and 2008 the terminus was at Husebybakken, and currently, the terminus is Avløs. The upgrade is scheduled to be completed by October 2014.

History

The station building at Jar in 1924

Background

Bærum started developing as a suburb of Oslo after the Drammen Line of the Norwegian State Railways was opened through the southern part of the municipality in 1872. The areas around the stations became popular among the middle class, while the lower class started to settle further north. In particular the areas around Nadderud and Presterud became populated with the working class, often by subdivisions being built by trade unions. In 1897, local investors applied to establish a tramway that would run parallel to the Drammen Line from Oslo to Sandvika—which at the time was steam-hauled, narrow gauge and single tracked and suffered from low regularity. The application was rejected by the Ministry of Labour in 1906 because they did not want competition with the railway. Instead, the state started to modernize the Drammen Line by converting it to standard gauge, electrifying it and building double track.^[1]

In 1917, two proposals were made for a suburban tram line further north. The southern proposal was to build the line as an extension of the Lilleaker Line, which would open in 1919. The line would go from the initial terminus at Lilleaker and extend towards Jar and Nadderud to Haslum. The northern proposal was for an extension of the Røa Line (at the time called the Smestad Line) via Røa to Hosle, Haslum and Fleskum to Kolsås. The latter was essentially a combination of the current Røa and Kolsås Line. The two proposals caused local debate with people in western Bærum in general supporting the northern line and people in eastern Bærum supporting the southern line. An agreement was quickly reached with Kristiania Elektriske Sporvei (KES), that owned the Lilleaker Line. In 1921, the municipal council voted in favor of the southern line after rejecting a proposal to negotiate trackage rights with Holmenkolbanen. The main argument for the southern alternative was that the municipality would not have to pay any of the investment costs for the section of the line that would be localed within Aker.^[1]

A Class A train at Jar in 1935

In 1924, KES' operations in Oslo were expropriated and became Oslo Sporveier. However, the Lilleaker Line was kept outside the expropriation. The expansion to Bærum was financed in part by the cash from the sale and in part from free land from the municipality. Concession from Lilleaker to Bekkestua was granted in 1922, and on 28 December the municipality voted to extend the line from Bekkestua to Haslum. The line to Bekkestua opened on 1 July 1924 and the extension to Hslum on 4 November. KES rebranded itself and became Bærumsbanen. The company bought twelve Class A trams with twelve trailers from Zypen & Charlier of Germany. After running along the Bærum Line to Skøyen, the trams continued along the Oslo Sporveier-owned Skøyen Line to Athenæum in the center of Oslo. The stations had a small building where there was a kiosk, telephone, ticket sale and freight handling.^[1]

The depot was originally planned to be at Haslum, but a more suitable lot was found at Avløs. A subdivision for 39 employee families was also built at Avløs. On 27 August, the ground around Bekkestua started to sink; the track was lifted and covered with stone. Two days later, the track had sunk into the ground and a small island was created in a nearby lake. It turned out that the area was resting on clay that had transformed to quick clay after a water pipe had broken. It took two weeks to repair the damage. In 1924, it became clear that Bærumsbanen was forced to also operate city services along the Skøyen Line in Oslo. This caused the company to order three trams and trailers, this time from Skabo Jernbanevognfabrikk. At the time it cost NOK 0.15 to take the tram within the city limits of Oslo, and NOK 1 from the city to Bekkestua. In 1924, the company became subject to a passenger strike, resulting is slightly cheaper tickets, but at the same time the trams and stations were equipped with advertisements.^[1]

Passengers disembarking a Class C train at Kolsås

Kolsås extension

The initial plans called for an expansion from Haslum to Kolsås. It was initially planned to run past Bærum Hospital to Løken Farm, but lack of funding instead forced the company to build the line along a cheaper section about one kilometer (half a mile) from the hospital. The free land for the extension was only valid for a limited time, and to be able to construct the line before the deadline, a single track solution was chosen. The plans were passed by the municipal council in 1927 and concession granted on 10 February 1928. Construction started immediately and the track laying started in June 1929. The 4.3 kilometres (2.7 mi) extension opened on 1 January 1930. Valler Station had a passing loop and a balloon loop was built at Kolsås. The line caused the bus from Haslum to Bærum Hospital to be closed, and the bus from Lommedalen was rerouted to correspond with the tram at Kolsås.^[1]

A Class C tram at Kolsås

A mixed route scheme was introduced, where full-service trams operated all stations from the city center to Jar, while express trams would only serve boarding passengers from Athenæum to Tjernsrud. The full-services ran every 12 minutes and the express services every 30 minutes. The full-service routes were reduced to a 15-minute headway in 1932, but a 15-minute headway was introduced to Bekkestua with the express service. During rush-hour, there was a 7-minute headway to Jar and additional services to Haslum.^[1]

In 1924, one of the conditions for the concession was that the line was to be connected to the Common Tunnel of the Holenkollen Line. Oslo Municipality demanded that the company either turn its trams at Skøyen or allow the municipality to purchase the company cheap. On 1 October 1934, the Bærumsbanen was bought by Oslo Sporveier and made a subsidiary. The two companies had a common executive management, but retained separate operations. At the same time, Aker Municipality's tram company Akersbanerne was left operating a single line east of the city center. In 1936, it was decided that Bærumsbanen would take over operation of this line, by operating the trams from the Kolsås Line through the city center to connect to the Østensjø Line. Operations started on 4 January 1937, and the 25 kilometres (16 mi) line was marketed as the Østensjø–Bærum Line. Although Bærumsbanen took over Akersbanerne's three Class A trams, up to three units from Ekebergbanen were also leased.^[1]

Lysakerelven before the upgrade to metro standard

Underground connection

Since the birth of the line, plans had existed to connect to the Common Tunnel of the Holmenkollen Line. The tunnel would allow the trams to operate straight to the city center at Nationaltheatret, giving faster travel times and removing the heavy Class A trams from the city streets. A plan for the route from Jar to Sørbyhaugen on the Røa Line had been made in 1919, but by the 1930s, the Norwegian Radium Hospital and a tuberculosis hospital at Ullern had been built in the immediate vicinity of the line. Concession for this route was granted on 30 April 1937, but Aker Municipality protested, because they did not want noise pollution at the hospitals. Another concern was that the magnetic field from the overhead wires could affect the instruments at the hospitals. The route was therefore moved, but this made construction more difficult due to worse geological conditions.^[1]

Construction started in 1939, but was put on hold in 1940 because of the break-out of World War II. Construction commenced in April 1941 and later the same year the first Class C trains were put into service. The work also involved widening the profile between Jar and Egne Hjem so the Class C could operate on the whole line. The connection from Jar to Sørbyhaugen opened on 15 June 1942. From Haslum to Kolsås, the line was upgraded to double track; this opened on 23 December. The Class C was a class of eight larger trams that matched the width of Holmenkolbanen's lines. In addition, two Class A trams were converted to the wider and longer Class D.^[1]

With the opening of the connection, the 16.4 kilometres (10.2 mi) section from Sørbyhaugen to Kolsås was designated the Kolsås Line, and the 3.8 kilometres (2.4 mi) section from Jar to Skøyen was designated as the Lilleaker Line. A balloon loop was built at Jar, and the new Class B trams that served the Lilleaker Line could start turning there. This allowed for transfer between the two lines. The distance from Kolsås to Nationaltheatret was 16.4 kilometres (10.2 mi). During World War II, ridership on the whole tramway, including the Kolsås Line, skyrocketed. In 1938, the line transported 5.7&nsbp;million passengers, while in 1944 it transported 19 million. In 1944, the ownership of rolling stock and all but two employees in Bærumsbanen were transferred to Oslo Sporveier. However, the ownership of the tracks and the formal operation rights remained with Bærumsbanen.^[1]

Post-war operations

SL79 tram at Jar

At the end of the war in 1945, the line was in need of a major overhaul, in particular the overhead wires. Lack of materials and money caused the extraordinary maintenance to take four years. Limitations of freight were imposed in 1946, and were terminated the following year. At the same time, the Kolsås Line services were internally numbered 14, but it was first many years later that the number appeared on the destination signs and schedules. In 1948, a former barracks was moved to Avløs where it was used as office space. Until 1951, the line had had constant fares since 1939; a 27 percent fare increase in 1951 was not sufficient to cover the 170 percent cost increase in the same period.^[1]

From 1949 to 1966, Avløs Depot built nine new Class C trams. In 1963, the line also received two Class T trams that were prototypes for the first Oslo Metro rolling stock. On 5 July 1957, Mærradalen was closed and Ullernåsen was moved mid-way between its old location and that of Mærradalen. On 19 June 1961, Husebybakken was closed for traffic, due to low ridership and close proximity to nearby stations. During the 1960s, the rectifier at Jar was replaced with a more modern one at Øraker and a new garage built at Avløs Depot. Since the 1960s, ridership lay stable at about four million passengers per year. From 1971, Bærumsbanen was liquidated and ownership and all aspects of operation of the line was transferred to Oslo Sporveier.^[1]

In 1978, Holmenkolbanen started taking delivery of the T1300 series of combined metro and tram multiple units. This caused Oslo Sporveier to put into service HKB 500 units on the Kolsås Line. To use T1300 stock on the Kolsås Line, several upgrades were needed: the platforms height was raised and the power supply was improved with new rectifiers at Ringstabekk and Kolsås. With the second delivery of T1300 stock in 1980 and 1981, the new units were put into service on the Kolsås Line. The T6 series of fifteen units was built with a driver's cab at both ends, so single-car trains could be operated in the evenings. This resulted in Class D being taken out of use in 1982. From 21 June 1982, the conductor was removed from the service. During rush hour, Class C units were still in use, and these still were manned with a conductor.^[1]

T1300 stock at Valler. When the line reopened, the overhead wire was gone.

On 7 March 1987, Stortinget Station opened and Line 14 was extended further into the city center. This section was incompatible with Class C and these were retired. To meet the required number of trains, six T1000 units were converted to T1300. On 18 May 1995, the Røa Line from Sørbyhaugen to Volvat closed and the Røa Line upgraded to metro standard. At the same time, the Lillaker Line tram was extended from Jar to Kolsås. The upgrade involved the line receiving automatic train control with cab signaling, third-rail power supply and longer platforms. Until 20 August, Line 14 only operated between Kolsås and Montebello. After the Røa Line reopened, the third rail had been laid to Montebello, and the trains had to switch power supply and signaling system there.^[1]

On 19 November, the Kolsås Line was connected with the Lambertseter Line east of the city center, given line number 4 and started operating through the city center. Oslo Sporveier decided that it wanted to remove the rush-hour services and instead introduced three-car trains. Because of this, all station platforms were extended in 1997, with the changes taking effect from 7 April. From 5 April 1998, the Kolsås Line was connected to the Østensjø Line and given number 4. From 21 March 1999, all T1300 stock were overnighted at Majorstuen Depot and Avløs was reduced to a maintenance center.^[1]

In 1995, the new T2000 stock that was bought for the Holmenkollen Line was tested on the Kolsås Line, but the lower voltage made operations impossible. At Gjønnesjordet the current was measured at 311 volt. From 4 August 1995, the current on the line was increased to 680 volt and from 3 March 1999 to 750 volt. The latter was done after the trams had been rebuilt to handle the increased voltage and this taken into use on the entire tramway.^[1]

Metro standard

On 1 July 2003, budgetary disagreements between local politicians in Oslo, Bærum and Akershus led to the closure of the Bekkestua to Kolsås leg. It was temporarily reopened 22 November 2004. There was a debate about what standard the line should have; many Akershus politicians wanted to convert the section west of Jar to light rail, that would operate along the Lilleaker Line.

Montebello was one of the first three upgraded stations to open

In early 2006, Akershus County Council passed a NOK 750 million upgrade of the line. The line will be upgraded to metro standard all the way to Kolsås. Metro standard is an upgrade to the line that will raise it to the same standard as the Røa and Sognsvann Lines have had since 1995. The overhead wire will be removed, and replaced by a third rail; this will require the few remaining level crossings to be removed. Station platforms will be extended to accommodate six-car trains, instead of the former three-car limit. Signalling will be moved to inside the cabs, using automatic train control. The metro standard will allow the new MX3000 stock to operate on the line. In addition, a light rail service will share the tracks between Jar and Bekkestua. The intention is to create a transport hub at Bekkestua enabling interchange with local bus services.

The upgrade will also reduce the number of stations. Lysakerelven and Bjørnsletta will both be replaced by a new station named Bjørnsletta, though located between the two. Similarly, Tjernsrud, Ringstabekk and Egne hjem will be replaced by a new station named Ringstabekk. In addition, the consulting form Norconsult proposed to replace the station Avløs with a new station called Durud, located 100 metres west of Avløs,^[2] but this has not been approved.

The line was closed on 1 July 2006, and the only operational station unique to the Kolsås Line was the new, temporary station Husebybakken, which temporarily replaced Montebello from 31 July. Montebello was formerly the station where the metro switched from overhead wire to third rail.^[3] From 20 August 2007, Line 13 of the Oslo Tramway, that operates along the Lilleaker Line, was extended from Jar to Bekkestua, after a NOK 2.3 million upgrade to the line, and lowering of the platforms.^[4] From 16 February 2009, this service was trunkated to Lilleaker, following the closing of the stations from Jar to Bekkestua for upgrades.^[5][6]

In August 2008, the stations between Montebello and Åsjordet were opened, after the upgrade was completed. The next section to be opened was the new Bjørnsletta, in 2010. The section from Jar to Bekkestua reopened the following year. The final section to Kolsås is not estimated to be finished upgraded until October 2014,^[7] after initial plans had called for the upgrade to be completed by 2011.^[4] The project has received much criticism from users and politicians, since the metro line is being closed for eight years to allow an upgrade that takes 18 months to complete. Ruter has stated that the reason for the delays is a budget calculation error, that shows that the cost of upgrading is NOK 2.5 billion, and not NOK 0.7 billion. The error was made because the planners used price estimates for tramways instead of rapid transit.^[7]

While the Kolsås Line was closed, and the replacement trams drove no further than Bekkestua, a bus service—line 42—was set up to accommodate passengers all the way to Kolsås. It serves a slightly different sequence of stations. Starting at Majorstuen, stops are made at the demolished metro stations Volvat and Heggeli in addition to the stations normally served by the metro. From the junction at Smestad it follows the highway Ring 3, stopping at Montebelloveien and Radiumhospitalet. After leaving Ring 3 to follow the Norwegian National Road 160, the bus stops at Blokkajordet before reconnecting with the metro tracks to stop at Lysakerelven. In Bærum the stations Tjernsrud and Egne hjem were skipped due to technical reasons, instead adding three extra stops further west, at Løkebergveien, Bjørnekollen and Toppåsveien.

References

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