Project Trois-Ponts, Belgium

Coo-Trois-Ponts Hydroelectric Power Station

Our team works in the enchanting setting of the Coo-Trois-Ponts hydraulic power station on behalf of Renotec / Galère / T. de Neef. The drilling happens as part of the renovation of the lower basin structures (lot 2).

Technical details

Micropile technique

  • 4 vents realized
  • Ø 204, 142 and 90 mm
  • 20.5 m deep

Our techniques at the service of your projects

For once, we are using micropile technique to .. not make piles (!) but to drill holes:

At the Coo power station, during electricity production, the water is turbined from the upper basins to the lower basin through galleries and turbines, with a flow rate of up to a volume of 10 Olympic swimming pools per minute. ! We are drilling vents there to bring the galleries (connecting the units to the lower basin) to atmospheric pressure when emptying these galleries for maintenance work.
Considering the different layers to go through and the precision work required, we came up with a complex solution that could be achieved with a single drilling machine. We first drill through the rock using a down-the-hole hammer (diameter 204 mm), then we partially drill the reinforced concrete constituting the structure of the galleries using a tube equipped with a crown (diameter 142 mm). The borehole is then fitted with a tube and sealed. Finally, the last cm of reinforced concrete are drilled (diameter 90 mm) in order to open the vent.

3 drilling operations and 3 different diameters!

Project details

Project name

Coo-Trois-Ponts Hydroelectric Power Station


Power plants



Contract type



Trois-Ponts, Belgium

External partner(s)



Renotec, BAM Galère, T. de Neef Engineering

Building Period

2021 - 2021

Morning light

morning light

Rainbow piling

Rig operator

Related Projects

Member of logo