A membrane cartridge is transported to the installation site using an underslung travelling crane.
The entire construction project took place in several stages over three-and-a-half years, owing to the short construction period between Easter and Christmas. Zermatt is a small village with a population of approximately 6,000 people, but that spirals to 60,000 for the winter season from December to April, during which time the sewage system had to be working at full capacity.
Lukas Bühlmann, of GIS, said: "The installation of the lifting equipment took place in a short window of less than four weeks during the summer months. There was no flexibility and we had to complete successful installation of the cranes, monorails and hoists to the day."
Bühlmann, who anticipates the system to be in use for at least 20 years, explained that parts and components were manufactured “as small as possible” so they could be delivered to the site by truck before being unloaded and transferred into the tunnel system by electric forklift truck.
GIS won the order via tender, which involved a site visit and a subsequent bidding process. This was the first time the hoist manufacturer and ARA Zermatt had worked together, although GIS has worked with many other wastewater treatment plants in the past. It has since led operator training and will fulfill an annual maintenance contract.