RINGSCAFF stair towers 1,900 metres above sea level

Use of modular scaffolding in the construction of a new dam on the Grimsel Pass in Switzerland

There was a time when working with concrete was still one of the pioneering feats of the building trade. And as always with such pioneering endeavours, mistakes were made that were only noticed much later and could only be rectified with a great deal of effort. On the Grimsel Pass in Switzerland, an entire dam wall is currently being sent into early retirement after it was discovered that, among other things, annual centimetre-by-centimetre concrete displacements meant that the structural safety requirements of the structure could no longer be sustainably guaranteed.

The problem is that since a demolition or renovation is logistically and financially unfeasible and, in addition, it would no longer be possible to operate the reservoir for power generation during this time, the operator, Kraftwerke Oberhasli AG (KWO), is simply building a complete new dam in front of the old one. As soon as the new wall is in place – the construction time is planned at 6 years – the old wall will be made permeable at several points so that the water will dam up to the new wall and the old wall will have water contact on both sides (and thus be free of load). The Grimselsee reservoir, with a volume of 94 million cubic metres, is a centrepiece of the KWO power plant sites.

Burn und Künzi Gerüstbau AG from Oey in Switzerland was contracted to erect various scaffolds. Among other things, the RINGSCAFF modular scaffold from Scafom-rux was used to provide access to the construction sites on the various levels of the steep walls intended for anchoring the new concrete arch. The experienced scaffolders from Burn and Künzi rappelled from the rocks to assemble the scaffolding structures, sometimes from dizzying heights – naturally, while observing extensive safety precautions. Then the stair towers were built in stages from top to bottom. Furthermore, pedestrian bridges and platforms had to be constructed from scaffolding material.