Table 2: Details of two main smaller project excavations

Project Dalvatn Slettedalselva
Contractor Veidekke ASA Kruse Smith A/S
Headrace tunnel length inc. pipe trench (m) 1300 (new) 3660
– section (m2) 14.5-25 (depending on alternative) 18.5
Tailrace tunnel length (m) 280 490
– section (m2) 25 18.5
Access tunnels length (m) 310 + 350 615
– section (m2) 30 + 22 31
Transfer tunnels length (m) 1150 + 2910 + 16,270 0
– sections (m2) 22 + 10 +9.6 0
Intake shaft length (m) 880 0
Power station cavern volume (m3) 13,500 6000
Surge shaft length (m) 190 280
– section (m2) 4-52 6.5