San Esteban II Power Plant

Project Information: Excavation of the mainly carvern, transformer cavern and control gates caverns and shafts.

The design includes 12 access , reconnaissance, cross and emergency tunnels that add up to 1,267 m long with 8.4 to 43.5 m² cross sections.

Also the penstock, control gates and outflow.

Country: Spain

Province: Orense

Place: Nogueira de Ramuín


  • Sección: 19 m2 / 500 m2
  • Longitud: 2,000 m

Overburden: Medium

Method of Tunneling:

  • Roadways by drill and blast full section
  • Caverns by NATM
  • Raise borer

Geology and Geotechnical Data:

  • Granites showing different weathering and fracturation process

Tunnel Equipment:

  • Jumbos Atlas Copco Boomer and Atlas Copco Rocket (Two booms and service plataform)
  • Wet – mix Robojet Putzmeister Sika η = 30 m³/h