Bærum Tunnel

Bærum Tunnel

Lysaker end of the tunnel
Overview
Line	Asker Line
Location	Bærum, Norway
Coordinates	59°54′29″N 10°34′12″E / 59.908°N 10.570°E / 59.908; 10.570Coordinates: 59°54′29″N 10°34′12″E / 59.908°N 10.570°E / 59.908; 10.570
Status	Under construction
System	Norwegian railway network
Start	Marstranderveien
End	Engervannet
Operation
Opened	26 August 2011
Owner	Norwegian National Rail Administration
Technical
Line length	5.5 km (3.4 mi)
No. of tracks	Double
Track gauge	1,435 mm (4 ft 8 1⁄2 in)
Electrified	15 kV  16 2⁄3 Hz AC
Operating speed	160 km/h (99 mph)

The Bærum Tunnel (Norwegian: Bærumstunnelen) is a 5.5-kilometer (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-kilometer (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 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 kilometers (3.4 mi) long and is part of the 6.7-kilometer (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-meter (1,300 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 meters (1,200 sq ft). At the Lysaker end, the tunnel has an end-piece which consists of a 150-meter (490 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 exits. In addition, there are three additional exits, to allow for an emergency exit every 1,000 meters (3,300 ft), located at Ballerud, Engerjordet and Njålveien. Each consists of a spiral staircase up to 55 meters (180 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 15 kV  16 ²⁄₃ Hz AC and allow for maximum speeds of 160 kilometres per hour (99 mph).