Daishimizu Tunnel Japan

The 22km Daishimizu tunnel is the eighth longest rail tunnel in the world. It is located on the Joetsu Shinkansen line in Japan. It reduced the travel time between Niigata and Tokyo to about one hour and forty minutes.Drill and blast excavation methods were used to build the tunnel through the Mikuni mountain range. The steep geography of the location called for the division of construction into six sections by means of access shafts. Evacuation points were created at less than 10km intervals.Natural water was found during the construction of the tunnel. A fire accident also occurred during the tunnels construction, resulting in the death of 16 workers.