Châtelard: quality assurance for the renewal of the Corbes high-pressure shaft.

This massive shaft (interior diameter 2000m and 1400m long) carries water from the Emosson dam to the two Châtelard power plants. The surface area to be treated was 8920m² (inclusive of the distributors) and the project duration was 4.5 months, from March to mid-July. The works were carried out by Marty Korrosionsschutz AG (Jona).

HYDRO Exploitation monitored and carried out acceptance procedures for all stages of the works, from the point that water blasting of the previous coating finished. Checks were carried out in accordance with our technical standard for anticorrosion protection systems, based on ISO 12944, ISO 8501, ISO 8502, ISO 8503 etc.

The flexible approach of our staff allowed all the acceptance procedures to be carried out without affecting the works on site. Procedures for acceptance of the substrate - cleanliness of the steel after abrasive blasting - were carried out weekly to ensure that the primer would be applied to a surface conforming to the required standards and climate conditions. There was a single acceptance of the primer, although interim checks were carried out at the same time as acceptance procedures for the substrate.

Final acceptance of the works was achieved in early July, allowing handover of the site. Collaboration between the client (CFF), the anticorrosion company (Marty Korrosionsschutz AG) and the external audit body (HYDRO Exploitation) was excellent, enabling the works to be delivered within deadline and guaranteeing high quality anticorrosion protection for decades to come.