Skaugum Tunnel
Encyclopedia
The Skaugum Tunnel is 3790 metres (12,434 ft) 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 tunnel was built by Mika for the Norwegian National Rail Administration using the drilling and blasting
method with one crosscut. During construction there was one blasting accident. 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 450 million Norwegian krone
(NOK). The tunnel has accelerated intercity and regional traffic west of Oslo
and free up capacity for the Oslo Commuter Rail
on the old Drammen Line.
-Silurian
sedimentary slate
, nodular limestone and shale
, with local occurrences of Permian
igneous rock. The line is electrified at and allows for maximum speeds of 160 kilometres per hour (99.4 mph). The tunnel has frost isolation 300 metres (984.3 ft) into the tunnel form each end and 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. Traditionally, 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 3.8 kilometres (2.4 mi) long Tanum Tunnel
and the 5.5 kilometres (3.4 mi) long Bærum Tunnel
.
The contract to build the tunnel and all other earthwork on the section from Solstad to Hønsveien was awarded to Mika, with the tunneling costing NOK 425 million. The tunnel was built using the drilling and blasting method using two points of entry, the entrance on the Asker side and from a crosscut at Skaugum
. Work started in February 2002 and was concluded in May 2005. Construction involved blasting 450000 cubic metres (15,891,599.8 cu ft) of earthwork and drilling 275 kilometres (170.9 mi) of holes for pre-injection. The construction used 14000 cubic metres (494,405.3 cu ft) of gunite, 14000 cubic metres (494,405.3 cu ft) of concrete, 24,000 bolts, 35000 cubic metres (1,236,013.3 cu ft) of water- and frost protection, 25000 cubic metres (882,866.7 cu ft) of noise- and frost isolation and 9.4 metres (30.8 ft) of cable conduit. At the thinnest—near the entrance at Asker—the tunnel runs between 2 metre below the basement of residential houses. During the construction of those parts, the construction was as slow as 8 metre per week, of which half the time was used for injections to choke the tunnel.
During the construction there was an accident where a worker driving a wheeled loader
was only 20 metre from a blasting. He became disabled, but did not received any compensation because he was working for the contractor as a sole proprietor, not as a wage earner. The Norwegian Labour Inspection Authority
criticized Mika for improper safety routines and required them to improve them, but concluded that no criminal offenses had been committed.
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 construction 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 water 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 the water mixing with the ballast
. By 2011, the emergency lighting system had to be replaced because of the high humidity. The National Rail Administration has stated that savings made by the specifications in the water and frost protection 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.
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 done in February and March 2005. The opening of the tunnel and the rest of the section from Asker to Sandvika took place on 27 August 2005.
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...
, on the Asker Line. The tunnel runs between Asker Station
Asker 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...
and Solstad and was built as part of the first stage 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 Mika 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...
method with one crosscut. During construction there was one blasting accident. After the tunnel opened, there has been problems with leaks damaging the superstructure. The tunnel has 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 :...
, 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 450 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 has accelerated 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...
on the old Drammen Line.
Specifications
The Skaugum Tunnel is a 3790 metres (12,434 ft) long tunnel with a cross-section varying between 105 square metre. It carries the double-tracked Asker Line between Asker Station and Solstad. The tunnel runs mostly through CambrianCambrian
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. The line is electrified at and allows for maximum speeds of 160 kilometres per hour (99.4 mph). The tunnel has frost isolation 300 metres (984.3 ft) into the tunnel form each end and 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
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....
and Asker. The line was built to increase the traffic on the west corridor. Traditionally, the only railway west of Oslo was the Drammen Line, which has limited capacity, and a mix of local, regional
Regional rail
Commuter rail, also called suburban rail, is a passenger rail transport service that primarily operates between a city center, and the middle to outer suburbs beyond 15km and commuter towns or other locations that draw large numbers of commuters—people who travel on a daily basis...
, intercity
Inter-city rail
Inter-city rail services are express passenger train services that cover longer distances than commuter or regional trains.There is no precise definition of inter-city rail. Its meaning may vary from country to country...
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 3.8 kilometres (2.4 mi) 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...
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 tunnel and all other earthwork on the section from Solstad to Hønsveien was awarded to Mika, with the tunneling costing NOK 425 million. The tunnel was built using the drilling and blasting method using two points of entry, the entrance on the Asker side and from a crosscut at Skaugum
Skaugum
Skaugum is the official residence of Crown Prince Haakon of Norway and of his wife Crown Princess Mette-Marit.The estate is located in Asker municipality, about 15 miles southwest of Oslo. Owned by the Church in the Middle Ages, it passed through several owners until 1909, when Fritz Wedel...
. Work started in February 2002 and was concluded in May 2005. Construction involved blasting 450000 cubic metres (15,891,599.8 cu ft) of earthwork and drilling 275 kilometres (170.9 mi) of holes for pre-injection. The construction used 14000 cubic metres (494,405.3 cu ft) of gunite, 14000 cubic metres (494,405.3 cu ft) of concrete, 24,000 bolts, 35000 cubic metres (1,236,013.3 cu ft) of water- and frost protection, 25000 cubic metres (882,866.7 cu ft) of noise- and frost isolation and 9.4 metres (30.8 ft) of cable conduit. At the thinnest—near the entrance at Asker—the tunnel runs between 2 metre below the basement of residential houses. During the construction of those parts, the construction was as slow as 8 metre per week, of which half the time was used for injections to choke the tunnel.
During the construction there was an accident where a worker driving a wheeled loader
Loader (equipment)
A loader is a heavy equipment machine often used in construction, primarily used to load material into or onto another type of machinery .-Heavy equipment front loaders:A loader A loader is a heavy equipment machine often used in construction, primarily used to load material (such as asphalt,...
was only 20 metre from a blasting. He became disabled, but did not received any compensation because he was working for the contractor as a sole proprietor, not as a wage earner. The Norwegian Labour Inspection Authority
Norwegian Labour Inspection Authority
The Norwegian Labour Inspection Authority is Norwegian government agency under the Ministry of Labour. It is responsible for supervising the Working Environment Act, the Annual Holidays Act, the National Holidays Act as well as certain sections of the Smoking Act.The organization consists of a...
criticized Mika for improper safety routines and required them to improve them, but concluded that no criminal offenses had been committed.
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 construction 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 water 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 the water mixing with the ballast
Track ballast
Track ballast forms the trackbed upon which railway sleepers or railroad ties are laid. It is packed between, below, and around the ties. It is used to facilitate drainage of water, to distribute the load from the railroad ties, and also to keep down vegetation that might interfere with the track...
. By 2011, the emergency lighting system had to be replaced because of the high humidity. The National Rail Administration has stated that savings made by the specifications in the water and frost protection 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.
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 done in February and March 2005. The opening of the tunnel and the rest of the section from Asker to Sandvika took place on 27 August 2005.