Bærum Tunnel
Encyclopedia
The Bærum Tunnel is a 5.5 kilometres (3.4 mi) long double track railway tunnel
in Bærum
, Norway
. Running between Marstranderveien and Engervannet
, it will make up most of the 6.7 kilometres (4.2 mi) long section of the Asker Line between Lysaker Station
and Sandvika Station
, which was taken into use on 26 August 2011. The tunnel was constructed from 2007 using the drilling and blasting
method with three crosscuts. The tunnel will have double track
, be electrified
and allow for maximum speeds of 160 kilometres per hour (99.4 mph). The whole section between the stations is estimated to cost 2.7 billion Norwegian krone
(NOK). The tunnel will accelerate intercity and regional traffic west of Oslo
and free up capacity for the Oslo Commuter Rail
.
The Bærum Tunnel is 5.5 kilometres (3.4 mi) long and is part of the 6.7 kilometres (4.2 mi) long section of the Asker Line between Lysaker and Sandvika. At Engervannet, at the Sandvika end, the tunnel mouths out with two 400 metres (1,312.3 ft) long arms, one on each side of the Drammen Line, allowing trains to connect to the correct direction of traffic through Sandvika. The excavated cross-section is 110 square metres (131.6 sq yd). At the Lysaker end, the tunnel has an end-piece which consists of a 150 metres (492.1 ft) long culvert
and the Drammen Line branches off on both sides of the tunnel. The three crosscuts, at Blommenholm
, Fossveien and Skallum
, will be used as emergency exit
s. In addition, there are three additional exits, to allow for an emergency exit every 1000 metres (3,280.8 ft), located at Ballerud, Engerjordet and Njålveien. Each consists of a spiral staircase
up to 55 metres (180.4 ft) deep. These are primarily intended to allow access for emergency personnel, rather than as an escape route for passengers. Each staircase ends in a smoke-tight room. The line will have double track, be electrified at and allow for maximum speeds of 160 kilometres per hour (99.4 mph).
, in the municipalities of Bærum and Asker
. The line is built to increase the traffic on the west corridor. The only railway west of Oslo has been the Drammen Line, which has limited capacity, and a mix of local, regional, intercity and freight trains. This has caused many delays and poor utilization of tracks, as some trains make many stops and others only a few. The Asker Line allows regional and intercity trains to by-pass the local stations east of Asker, by running local trains and freight trains on the Drammen Line, while faster trains run on the new track. The Asker Line was built in two stages: the first from Asker to Sandvika was built from 2001 to 2005, and the second stage, from Sandvika to Lysaker, between 2007 and 2011. The other two tunnels on the Asker Line are the 3790 metres (12,434.4 ft) long Skaugum Tunnel
and the 3590 metres (11,778.2 ft) long Tanum Tunnel
.
There were four main contracts for building the line issued after public tenders. Three of these involved part of the tunnel, and were awarded to Skanska
, Veidekke
and NCC. Mesta, Mika, Bestonmast and Spesialprosjekt bid, but failed to win any contracts. Work was done from 06:00 through 02:00, and noisy work was avoided before 07:00 or after 22:00. Any work outside the tunnels was only done between 07:00 to 18:00, and from 08:00 to 16:00 on Saturdays. The tunnel is built using the drilling and blasting
method, which involved blasting sections of 5 metres (16.4 ft) of rock at a time, with a progress of 15 metres (49.2 ft) per week per team. Blasting started on 26 June 2007. Construction is done from three crosscuts, a 60 metres (196.9 ft) long section at Engervannet, a 250 metres (820.2 ft) long section at Fossveien, and a 420 metres (1,378 ft) long section at Skallum. At Skallum, a rinsing system for the water using in the tunneling was established, allowing the water to be recycled.
The tunneling resulted in 800000 cubic metres (28,251,733 cu ft) of earthwork, most of which was used for the expansion of the Port of Drammen. It was transported away from the tunnel with up to 12 truckloads per hour. The first breakthrough took place on 5 June 2008. On 19 October 2008, there was a ground failure at a storage area of earthwork. This caused a land slip which pressed up earthwork nearby at Gjønnes Station
on the Kolsås Line of the Oslo Metro; a 50 metres (164 ft) long section of one platform and track was pressed up 3 metres (9.8 ft), resulting in the other track laying on its side. Because of changes to European Union
regulations after planning of the project, three extra emergency staircases had to be installed in late 2009. The final breakthrough in the tunnel occurred on 26 July 2009. The tunneling took place under the groundwater
level. To avoid similar problems which occurred during the construction of the Romerike Tunnel, where massive leaks took a year to fix, several test bores were made in the area to measure the groundwater level. Any indications of a change would immediately be automatically communicated to the on-site geologists, who would be able to act accordingly. The system also automatically pumped water into the affected areas to compensate for any leaks until they could be fixed.
To make the tunnel water and frost tight, the walls were covered with polyethylene
mats. Because they are highly inflammable, they were then covered in a layer of gunite. Also installed were fire water pipes and ventilation systems to remove smoke. To sound-insulate the tunnel and avoid vibrations spreading to nearby housing, the entire tunnel was covered in a layer of rock wool. By December 2010, the ballast had been laid, and in January 2011 laying of the tracks and ties started. The work to build the tracks and overhead wires has been contracted to Baneservice
. The contract for the electro-technical installations was awarded to YIT Building Systems for NOK 120 million. As of 2006, the whole section from Lysaker to Sandvika was estimated to cost NOK 2.7 billion.
Freight trains started using the tunnel on 26 August 2011, and passenger trains on 28 August. The official opening took place on 2 September. Along with several other projects west of Oslo, including a new Lysaker Station
and Høvik Station
, and an upgrade to the Drammen Line between Lysaker and Etterstad
, the completion of the Asker Line will allow higher service frequency, higher regularity and faster trains west of Oslo. A new high-frequency schedule, named Route Plan 2012, was planned for introduction in early 2013 following delivery of new Stadler FLIRT
trains. This will also allow for more trains that stop at all stations on the Drammen Line and introduce three hourly trains to Vestfold
and six hourly trains stopping at the main stations west of Oslo.
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...
in Bærum
Bærum
is a municipality in Akershus county, Norway. The administrative centre of the municipality is the town of Sandvika. Bærum was established as a municipality on 1 January 1838. A suburb of Oslo, Bærum is located on the west coast of the city....
, 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...
. Running between Marstranderveien and Engervannet
Engervannet
Engervannet is a lake between Blommenholm and Sandvika in the municipality of Bærum in Akershus county, Norway....
, it will make up most of the 6.7 kilometres (4.2 mi) long section of the Asker Line between Lysaker Station
Lysaker Station
Lysaker Station is Norway's third-largest railway station, located at Lysaker on the Drammen Line. It serves express, regional, local and Airport Express trains. The station opened in 1872, and is located west of Oslo S at elevation...
and Sandvika Station
Sandvika Station
Sandvika Station is a railway station located in downtown Sandvika in Bærum, Akershus, Norway. The station serves as a local public transport hub and is located on the Asker Line and the Drammen Line. The station was opened with the Drammen Line in 1872. In 2005 the Asker Line opened allowing...
, which was taken into use on 26 August 2011. The tunnel was constructed from 2007 using the drilling and blasting
Drilling and blasting
Before the advent of tunnel boring machines, drilling and blasting was the only economical way of excavating long tunnels through hard rock, where digging is not possible. Even today, the method is still used in the construction of tunnels, such as in the construction of the Lötschberg Base Tunnel...
method with three crosscuts. The tunnel will have double track
Double 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 :...
, be electrified
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...
and allow for maximum speeds of 160 kilometres per hour (99.4 mph). The whole section between the stations is estimated to cost 2.7 billion 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 tunnel will accelerate intercity and regional traffic west 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...
and free up capacity for the Oslo Commuter Rail
Oslo Commuter Rail
Oslo Commuter Rail is a commuter rail centered in Oslo, Norway, connecting the capital to six counties in Eastern Norway. The system is operated by the Norwegian State Railways and its subsidiary NSB Gjøvikbanen, using Class 69 and Class 72 electric multiple units . The network spans eight routes...
.
Specifications
Culvert
A culvert is a device used to channel water. It may be used to allow water to pass underneath a road, railway, or embankment. Culverts can be made of many different materials; steel, polyvinyl chloride and concrete are the most common...
and the Drammen Line branches off on both sides of the tunnel. The three crosscuts, at Blommenholm
Blommenholm
Blommenholm is a district in the municipality of Bærum, Norway. Its population is 2,936.It is served by the train station Blommenholm on the Drammen Line....
, Fossveien and Skallum
Skallum
Skallum is an area at Stabekk in Bærum, Norway. Named after the local farm, Skallum is known locally for its art gallery and as a recreational area, and nationally as the site of an event in the closing days of World War II in Europe.-Geography:...
, will be used as emergency exit
Emergency exit
An emergency exit in a structure is a special exit for emergencies such as a fire: the combined use of regular and special exits allows for faster evacuation, while it also provides an alternative if the route to the regular exit is blocked by fire, etc....
s. In addition, there are three additional exits, to allow for an emergency exit every 1000 metres (3,280.8 ft), located at Ballerud, Engerjordet and Njålveien. Each consists of a spiral staircase
Stairway
Stairway, staircase, stairwell, flight of stairs, or simply stairs are names for a construction designed to bridge a large vertical distance by dividing it into smaller vertical distances, called steps...
up to 55 metres (180.4 ft) deep. These are primarily intended to allow access for emergency personnel, rather than as an escape route for passengers. Each staircase ends in a smoke-tight room. The line will have double track, be electrified at and allow for maximum speeds of 160 kilometres per hour (99.4 mph).
History
The Asker Line runs from Lysaker Station via Sandvika Station to Asker StationAsker Station
Asker is a railway station located in downtown Asker in Akershus, Norway. The station serves as the main public transportation hub for the municipalities located around the Asker Line, the Drammen Line and the Spikkestad Line. The station was opened with the Drammen Line in 1872...
, in the municipalities of Bærum and Asker
Asker
Asker is a municipality in Akershus county, Norway. It is part of the Viken traditional region. The administrative centre of the municipality is the village of Asker. The municipality is a suburb of Oslo, the national capital...
. The line is built to increase the traffic on the west corridor. The only railway west of Oslo has been the Drammen Line, which has limited capacity, and a mix of local, regional, intercity and freight trains. This has caused many delays and poor utilization of tracks, as some trains make many stops and others only a few. The Asker Line allows regional and intercity trains to by-pass the local stations east of Asker, by running local trains and freight trains on the Drammen Line, while faster trains run on the new track. The Asker Line was built in two stages: the first from Asker to Sandvika was built from 2001 to 2005, and the second stage, from Sandvika to Lysaker, between 2007 and 2011. The other two tunnels on the Asker Line are the 3790 metres (12,434.4 ft) long Skaugum Tunnel
Skaugum Tunnel
The Skaugum Tunnel is long railway tunnel in Asker, Norway, on the Asker Line. The tunnel runs between Asker Station and Solstad and was built as part of the first stage of the Asker Line, between Asker and Sandvika. Construction started in February 2002 and the tunnel opened on 27 August 2005...
and the 3590 metres (11,778.2 ft) long Tanum Tunnel
Tanum Tunnel
Tanum Tunnel is long double track railway tunnel on the Asker Line, between Jong in Bærum and Åstad in Asker, Norway. It was built as part of the first state of the Asker Line, between Asker and Sandvika; construction started in February 2002 and the tunnel opened on 27 August 2005...
.
There were four main contracts for building the line issued after public tenders. Three of these involved part of the tunnel, and were awarded to Skanska
Skanska
Skanska AB, is a multinational construction and development company based in Sweden, where it also is the largest construction company. The company's head office is in Solna, north of Stockholm.-History:...
, Veidekke
Veidekke
Veidekke is the largest Norwegian construction company and the fourth largest in Scandinavia. Veidekke’s business involves a network of Scandinavian construction operations, rehabilitation work, major heavy construction contracts and development of dwellings for the company’s own account as well...
and NCC. Mesta, Mika, Bestonmast and Spesialprosjekt bid, but failed to win any contracts. Work was done from 06:00 through 02:00, and noisy work was avoided before 07:00 or after 22:00. Any work outside the tunnels was only done between 07:00 to 18:00, and from 08:00 to 16:00 on Saturdays. The tunnel is built using the drilling and blasting
Drilling and blasting
Before the advent of tunnel boring machines, drilling and blasting was the only economical way of excavating long tunnels through hard rock, where digging is not possible. Even today, the method is still used in the construction of tunnels, such as in the construction of the Lötschberg Base Tunnel...
method, which involved blasting sections of 5 metres (16.4 ft) of rock at a time, with a progress of 15 metres (49.2 ft) per week per team. Blasting started on 26 June 2007. Construction is done from three crosscuts, a 60 metres (196.9 ft) long section at Engervannet, a 250 metres (820.2 ft) long section at Fossveien, and a 420 metres (1,378 ft) long section at Skallum. At Skallum, a rinsing system for the water using in the tunneling was established, allowing the water to be recycled.
The tunneling resulted in 800000 cubic metres (28,251,733 cu ft) of earthwork, most of which was used for the expansion of the Port of Drammen. It was transported away from the tunnel with up to 12 truckloads per hour. The first breakthrough took place on 5 June 2008. On 19 October 2008, there was a ground failure at a storage area of earthwork. This caused a land slip which pressed up earthwork nearby at Gjønnes Station
Gjønnes (station)
Gjønnes is a station on the Kolsås Line of the Oslo Metro system. It is located between Haslum and Bekkestua, from Stortinget.The station was opened in 1924 as part of the tramway Lilleaker Line....
on the Kolsås Line of the Oslo Metro; a 50 metres (164 ft) long section of one platform and track was pressed up 3 metres (9.8 ft), resulting in the other track laying on its side. Because of changes to European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
regulations after planning of the project, three extra emergency staircases had to be installed in late 2009. The final breakthrough in the tunnel occurred on 26 July 2009. The tunneling took place under the groundwater
Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...
level. To avoid similar problems which occurred during the construction of the Romerike Tunnel, where massive leaks took a year to fix, several test bores were made in the area to measure the groundwater level. Any indications of a change would immediately be automatically communicated to the on-site geologists, who would be able to act accordingly. The system also automatically pumped water into the affected areas to compensate for any leaks until they could be fixed.
To make the tunnel water and frost tight, the walls were covered with polyethylene
Polyethylene
Polyethylene or polythene is the most widely used plastic, with an annual production of approximately 80 million metric tons...
mats. Because they are highly inflammable, they were then covered in a layer of gunite. Also installed were fire water pipes and ventilation systems to remove smoke. To sound-insulate the tunnel and avoid vibrations spreading to nearby housing, the entire tunnel was covered in a layer of rock wool. By December 2010, the ballast had been laid, and in January 2011 laying of the tracks and ties started. The work to build the tracks and overhead wires has been contracted to Baneservice
BaneService
BaneService is a Norwegian government owned railway construction and maintenance company. It is by far the largest subcontractor for Jernbaneverket and is owned by the Norwegian Ministry of Transport and Communications.-History:...
. The contract for the electro-technical installations was awarded to YIT Building Systems for NOK 120 million. As of 2006, the whole section from Lysaker to Sandvika was estimated to cost NOK 2.7 billion.
Freight trains started using the tunnel on 26 August 2011, and passenger trains on 28 August. The official opening took place on 2 September. Along with several other projects west of Oslo, including a new Lysaker Station
Lysaker Station
Lysaker Station is Norway's third-largest railway station, located at Lysaker on the Drammen Line. It serves express, regional, local and Airport Express trains. The station opened in 1872, and is located west of Oslo S at elevation...
and Høvik Station
Høvik Station
Høvik Station is a railway station located at Høvik in Bærum, Norway on the Drammen Line. The station is served by the Oslo Commuter Rail line 400 operated by Norwegian State Railways with two hourly services. The station opened in 1874, two years after the Drammen Line....
, and an upgrade to the Drammen Line between Lysaker and Etterstad
Etterstad
Etterstad is a neighborhood in Oslo, located between the river Alna and Strømsveien, north of Vålerenga. It was incorporated into Oslo in 1946, two years before the merger of Oslo and Aker. The area is mainly residential.-History:...
, the completion of the Asker Line will allow higher service frequency, higher regularity and faster trains west of Oslo. A new high-frequency schedule, named Route Plan 2012, was planned for introduction in early 2013 following delivery of new Stadler FLIRT
Stadler FLIRT
Stadler FLIRT is an electric multiple unit produced by Stadler Rail AG. The articulated trainset comes in units of two to six cars with two to six motorized axles. The maximum speed is 200 km/h...
trains. This will also allow for more trains that stop at all stations on the Drammen Line and introduce three hourly trains to Vestfold
Vestfold
is a county in Norway, bordering Buskerud and Telemark. The county administration is in Tønsberg.Vestfold is located west of the Oslofjord, as the name indicates. It includes many smaller, but well-known towns in Norway, such as Larvik, Sandefjord, Tønsberg and Horten. The river Numedalslågen runs...
and six hourly trains stopping at the main stations west of Oslo.