how long is the seikan tunnel
For the deepest tunnel in the world in general go here -. Eiksund Tunnel-The deepest tunnel in the World. Seikan tunnel is nearly ' 53.85 kilometer long ' with a 23.3 kilometer section under the sea-bed which has been continuously welded.The track is 460 ft(140 meters) below the seabed and total depth from sea level to the tracks is 240 meters (790 ft) .inally with all those brutal conditions, the Seikan tunnel was opened on 13 March 1988 and the cost of construction reached 3.6 billion Dollars. Seikan Tunnel holds the record for Deepest operational Railway Tunnel in the World and also as the longest Tunnel in the World. : Deepest Cave in the World (2kms Deep).