Tanum Tunnel
Encyclopedia
Tanum Tunnel is 3590 metres (11,778.2 ft) 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. The tunnel was built by AF Gruppen
for the Norwegian National Rail Administration using the drilling and blasting
, although the 800 metres (2,624.7 ft) furthest east were built using cut-and-cover. After the tunnel opened, there has been problems with leaks damaging the superstructure. The tunnel has double track, is electrified
and allows for a for maximum speed of 160 kilometres per hour (99.4 mph). The cost to build the tunnel, excluding the superstructure, was ? million Norwegian krone
(NOK). The tunnel will accelerate intercity and regional traffic west of Oslo
and free up capacity for the Oslo Commuter Rail
.
Asker Line between Asker Station and Solstad. The tunnel runs mostly through Cambrian
-Silurian
sedimentary slate
, nodular limestone and shale
, with local occurrences of Permian
igneous rock. There is also a 400 metres (1,312.3 ft) long section of less stable sedimentary rock in the Asker Group. The tunnel had a cover most of the way of between 50 metre; however at Billingstad
there was a much lower margin, laying for the most at 10 metre and at the least at 1.5 metres (4.9 ft). At Åstad, the line runs 600 metres (1,968.5 ft) in the open before entering the Skaugum Tunnel
. The line is double track, electrified at and allow a maximum speed of 160 kilometres per hour (99.4 mph). The tunnel has frost isolation 300 metres (984.3 ft) into the tunnel form each end. The tunnel has frost fans which ensure that the air stays put in the middle of the tunnel to hinder cold air from reaching in past the frost isolation.
The Asker Line runs from Lysaker Station
via Sandvika Station
to Asker Station, in the municipalities of Bærum and Asker. The line was built to increase the traffic on the west corridor. The only railway west of Oslo was the Drammen Line, which has limited capacity, and a mix of local, regional, intercity and freight trains. This 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 3590 metres (11,778.2 ft) long Skaugm Tunnel and the 5.5 kilometres (3.4 mi) long Bærum Tunnel
.
The contract to build the Tanum Tunnel was awarded to AF Spesialprosjekt, part of AF Gruppen, for the Norwegian National Rail Administration. It cost NOK 370 million, including the open section between Solstad and Åstad, but excluding superstructure. The main part of the tunnel was built using the drilling and blasting
method, using two points of entry. The eastern-most 800 metres (2,624.7 ft) was built using cut-and-cover. Work started in 2002 and was concluded in February 2004. Construction included the removal of 486000 cubic metres (17,162,927.8 cu ft) of earthwork, and the laying of 160000 tonnes (157,472.6 LT) of ballast. Laying of tracks, signaling, power supply and other superstructures were done by Baneservice
. The cost for the entire section from Asker to Sandvika was NOK 70 million. The work was completed by November 2004. The opening of the tunnel and the rest of the section from Asker to Sandvika was done on 27 August 2005.
A concern from people living along the tunnel was that they would be subject to low-frequency noise. Originally the municipalities of Asker and Bærum had demanded that residents be subject to a maximum of 27 decibel
A-weighting
(dBA), but the National Rail Administration appealed the requirements and was permitted to allow up to 32 dBA. In March 2004, a test was done in the tunnel to insure that the requirements would be met, as low-frequency sound is difficult to predict. Measurements after the opening of the tunnel showed background noise of 30 dBA, that no-one was subject to 32 dBA or higher, and that it was nearly impossible to measure the passing of trains.
Among the major concerns was leaks; during the construction on the Romerike Tunnel, there was a one-year delay and severe cost overrun
s due to improper methods. One of the main focuses in the Skaugum Tunnel project was therefore to avoid similar leaks, and the criteria were set to 4 litres (8.5 US pt) per minute per 100 metres (328.1 ft). This was achieved by using sufficient time for the pre-injection. However, there was still water dripping into the tunnel, which caused several types of damage. Some places there was dripping onto the track which caused it to rust, other places onto electrical equipment. There was also issues with water running down the walls and collecting in the cable conduit, and the limestone in water hitting the ballast and mixing the ballast with limestone. By 2011, the emergency lighting system had to be replaced because of the high humidity. The National Rail Administration has stated that savings made to the specifications in the water and frost methods have caused high maintenance costs because the small leaks which are present do a lot of harm. In addition, areas with leaks suffer from icing. This has been part of a trend where older tunnels are nearly maintenance-free, while newer tunnels have incurred high maintenance costs.
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...
on the Asker Line, between Jong
Jong, Norway
Jong is a district in the municipality of Bærum, Norway. Mainly a residential area, the population is 4,778.This residential area is located west of the city Sandvika, on top of the hill Jongsåsen....
in Bærum and Åstad in 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...
, 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...
. It was built as part of the first state of the Asker Line, between Asker and Sandvika
Sandvika
is the administrative centre of the municipality of Bærum in Norway. It was declared a city by the municipal council in Bærum on 4 June 2003.Sandvika is situated approximately west of Oslo. It is the main transportation hub for Western Bærum, and has a combined bus and railway station. Sandvika is...
; construction started in February 2002 and the tunnel opened on 27 August 2005. The tunnel was built by AF Gruppen
AF Gruppen
The AF Group ASA is the third largest civil engineering and construction company in Norway. The company headquarters is located in Oslo. The AF Group is listed on the Oslo Stock Exchange.-Property:...
for the Norwegian National Rail Administration 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...
, although the 800 metres (2,624.7 ft) furthest east were built using cut-and-cover. After the tunnel opened, there has been problems with leaks damaging the superstructure. The tunnel has double track, is 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 allows for a for maximum speed of 160 kilometres per hour (99.4 mph). The cost to build the tunnel, excluding the superstructure, was ? 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 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
The Tanum Tunnel is a 3590 metres (11,778 ft) tunnel with a cross-section varying between 105 square metre. The tunnel consists of a 2718 metres (8,917.3 ft) long blasted section and a 800 metres (2,624.7 ft) cut-and-cover section, the latter in the east end. It carries the 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 :...
Asker Line between Asker Station and Solstad. The tunnel runs mostly through Cambrian
Cambrian
The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...
-Silurian
Silurian
The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya , to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya . As with other geologic periods, the rock beds that define the period's start and end are well identified, but the...
sedimentary slate
Slate
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. The result is a foliated rock in which the foliation may not correspond to the original sedimentary layering...
, nodular limestone and shale
Shale
Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...
, with local occurrences of Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
igneous rock. There is also a 400 metres (1,312.3 ft) long section of less stable sedimentary rock in the Asker Group. The tunnel had a cover most of the way of between 50 metre; however at Billingstad
Billingstad
Billingstad is a village in Asker municipality, Akershus county, Norway. It is close to the border to Bærum and Vestmarka. It has 2,349 residents ....
there was a much lower margin, laying for the most at 10 metre and at the least at 1.5 metres (4.9 ft). At Åstad, the line runs 600 metres (1,968.5 ft) in the open before entering the 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...
. The line is double track, electrified at and allow a maximum speed of 160 kilometres per hour (99.4 mph). The tunnel has frost isolation 300 metres (984.3 ft) into the tunnel form each end. The tunnel has frost fans which ensure that the air stays put in the middle of the tunnel to hinder cold air from reaching in past the frost isolation.
History
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...
via 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...
to Asker Station, in the municipalities of Bærum and Asker. The line was built to increase the traffic on the west corridor. The only railway west of Oslo was the Drammen Line, which has limited capacity, and a mix of local, regional, intercity and freight trains. This 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 3590 metres (11,778.2 ft) long Skaugm Tunnel and the 5.5 kilometres (3.4 mi) long Bærum Tunnel
Bærum Tunnel
The Bærum Tunnel is a long double track railway tunnel in Bærum, Norway. Running between Marstranderveien and Engervannet, it will make up most of the long section of the Asker Line between Lysaker Station and Sandvika Station, which was taken into use on 26 August 2011. The tunnel was...
.
The contract to build the Tanum Tunnel was awarded to AF Spesialprosjekt, part of AF Gruppen, for the Norwegian National Rail Administration. It cost NOK 370 million, including the open section between Solstad and Åstad, but excluding superstructure. The main part of the tunnel was 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, using two points of entry. The eastern-most 800 metres (2,624.7 ft) was built using cut-and-cover. Work started in 2002 and was concluded in February 2004. Construction included the removal of 486000 cubic metres (17,162,927.8 cu ft) of earthwork, and the laying of 160000 tonnes (157,472.6 LT) of ballast. Laying of tracks, signaling, power supply and other superstructures were done by 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 cost for the entire section from Asker to Sandvika was NOK 70 million. The work was completed by November 2004. The opening of the tunnel and the rest of the section from Asker to Sandvika was done on 27 August 2005.
A concern from people living along the tunnel was that they would be subject to low-frequency noise. Originally the municipalities of Asker and Bærum had demanded that residents be subject to a maximum of 27 decibel
Decibel
The decibel is a logarithmic unit that indicates the ratio of a physical quantity relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities...
A-weighting
A-weighting
A Weighting curve is a graph of a set of factors, that are used to 'weight' measured values of a variable according to their importance in relation to some outcome. The most commonly known example is frequency weighting in sound level measurement where a specific set of weighting curves known as A,...
(dBA), but the National Rail Administration appealed the requirements and was permitted to allow up to 32 dBA. In March 2004, a test was done in the tunnel to insure that the requirements would be met, as low-frequency sound is difficult to predict. Measurements after the opening of the tunnel showed background noise of 30 dBA, that no-one was subject to 32 dBA or higher, and that it was nearly impossible to measure the passing of trains.
Among the major concerns was leaks; during the construction on the Romerike Tunnel, there was a one-year delay and severe cost overrun
Cost overrun
A cost overrun, also known as a cost increase or budget overrun, is an unexpected cost incurred in excess of a budgeted amount due to an under-estimation of the actual cost during budgeting...
s due to improper methods. One of the main focuses in the Skaugum Tunnel project was therefore to avoid similar leaks, and the criteria were set to 4 litres (8.5 US pt) per minute per 100 metres (328.1 ft). This was achieved by using sufficient time for the pre-injection. However, there was still water dripping into the tunnel, which caused several types of damage. Some places there was dripping onto the track which caused it to rust, other places onto electrical equipment. There was also issues with water running down the walls and collecting in the cable conduit, and the limestone in water hitting the ballast and mixing the ballast with limestone. By 2011, the emergency lighting system had to be replaced because of the high humidity. The National Rail Administration has stated that savings made to the specifications in the water and frost methods have caused high maintenance costs because the small leaks which are present do a lot of harm. In addition, areas with leaks suffer from icing. This has been part of a trend where older tunnels are nearly maintenance-free, while newer tunnels have incurred high maintenance costs.