Hydro power tunnel rehabilitation
Rehabilitating hydro power tunnels with steel arches made in our own workshop — delivered LTI-free for Comossa Hydropower in Brazil.
Overview
Manufactured in Roodepoort, installed in Brazil
Hydro power tunnels work under conditions few mine tunnels see: running water, long periods without access and very little tolerance for a support failure. When a hydro tunnel needs rehabilitation, the work has to be planned around the scheme’s shutdown window and finished in it.
For Comossa Hydropower in Brazil, ShaftCon rehabilitated the Comossa hydro power tunnel in 2013. The steel tunnel arches were manufactured in our own workshop in Roodepoort, South Africa, and installed in the tunnel by our crews, and the project was completed LTI-free. Making the arches ourselves meant we controlled their quality and delivery, rather than waiting on a third-party fabricator.
This sits alongside ShaftCon’s wider renewable-energy work: our CEO’s experience includes renewable energy, hydro and solar power projects, and we sink, support and line hydro power shafts as well as rehabilitating tunnels.
Safety in a confined, wet tunnel starts with people. Our crews are trained to identify hazards and to work safely around them, and every person on site is empowered to stop the job and deal with a risk. On Comossa that approach delivered the project without a lost-time injury.
What the work covers
- Rehabilitation of hydro power tunnels and shafts
- Design and manufacture of steel tunnel arches
- Installation of arches and new support
- Making safe and wet-crete
- Access platforms and working at height inside the tunnel
- Work planned around the scheme’s shutdown window
How a tunnel rehabilitation is delivered
Survey and plan
The tunnel’s condition and profile are recorded so the arches and support can be designed to fit and the work sequenced inside the shutdown.
Manufacture
Steel arches and fittings are manufactured in our Roodepoort workshop, so quality and delivery stay under our control.
Make safe
Loose and failed ground is made safe before the new support goes in.
Install
Arches are installed from mobile access platforms and the tunnel is re-supported section by section.
Finish
Wet-crete and finishing work close the rehabilitated sections, ready for the tunnel to return to service.
Safe completion
Comossa was completed with no lost-time injuries.
Projects
The Comossa project
Manufacturing
Tunnel arches, shaft steel and head houses from our own workshop.
Comossa hydro power tunnel
Related services
Conventional and mechanised development.
Sinking, support and lining of vent and hydro shafts.
Shaft steel, station steel, headgear and head houses.
Making safe, support and new shaft steel.
Planning a shaft, decline or tunnel?
Tell us about the project. We reply from our Beestekraal head office, and we can put you in touch with our teams in Namibia, Tanzania, Mali and the USA.