Table 1: Details of Sauda-Snna underground construction

Project element Tunnel length (m) Tunnel section (m2) Excavation volume (m3) Comments
Snna H
Headrace tunnel 11,225 52
Tailrace tunnel 1250 90 Common to Snna L
Access tunnels 1050 + 370 30 + 22 Common to Snna L
Transfer tunnels 4188 + 8140 18.5 + 9.6
Intake shaft 1060
Power station cavern 51,500 Common to Snna L (two units of three)
Surge shaft 550 10-30
Snna L
Headrace tunnel None
Tailrace tunnel 1250 90 Common to Snna H
Access tunnels 1050 40 Common to Snna H
Pressure shaft 280 14
Transfer tunnels None
Intake shaft None
Power station cavern 51,500 Common to Snna H (one unit of three)
Surge shaft None