Copenhagen Tunnel

Copenhagen Tunnel
Copenhagen Tunnel southern portals
Interactive map of Copenhagen Tunnel
Overview
LineEast Coast Main Line
LocationBarnsbury
Coordinates51°32′45″N 0°07′14″W / 51.5457°N 0.1206°W / 51.5457; -0.1206
OS grid referenceTQ 30404 84602
Status
  • Original bore: operational
  • Second bore: operational
  • Third bore: road access
SystemNational Rail
Start
  • Original bore: 1850 (1850)
  • Second bore: 1877
  • Third bore: 1886
Operation
OwnerNetwork Rail
OperatorSee East Coast Main Line § Operators
Technical
Design engineerThomas Brassey
Length594 yd (543 m)
No. of tracks4 (6 until 1977)
Track gauge1,435 mm (4 ft 8+12 in)
Electrified25 kV 50 Hz AC

The Copenhagen Tunnel is a railway tunnel in London, United Kingdom, that is situated approximately 0.8 miles (1.3 km) down the East Coast Main Line from London King's Cross railway station. It comprises three twin-track bores, of which only the central and western have been in use since the remodelling of Kings Cross in 1977. Passenger trains travel through the slow lines in the western bore at 40 miles per hour (64 km/h) and through the fast lines in the central bore at 60 miles per hour (97 km/h); this speed limit is reduced for other train categories.

The tunnel was situated at the end of Thomas Brassey's contract to build the Great Northern Railway between London and Peterborough. It originally only comprised one bore but a second was added in 1877 and a third in 1886. The western bore is elevated above the others to allow the Holloway Flyover to begin immediately after the northern portals, which converts the four tracks into being quadrupled by direction instead of speed heading northbound.