6 minutes - magazine 01 | 2026
Upgrade in the Alps
A project of the century in the Swiss Alps was completed on schedule in autumn. After five years of construction, a new, massive wall was completed at the Grimsel reservoir in the Bernese Oberland, at an altitude of almost 2,000 metres.
A once-in-a-century project between cliffs and ice
Its sheer scale is impressive – both visually and technically. More than half a million tonnes of concrete were transported into the formwork for the horizontally and vertically curved dam, which is over 100 metres high. The work was completed with the use of a Liebherr mobile crane to dismantle the last of the large construction cranes.
Solid: The enormous bases of the cranes were specially constructed for this project. The firmly anchored steel elements were designed to withstand even an avalanche. Ramon Goglione is one of the project’s construction managers.
Anyone travelling up the Grimsel Pass in Switzerland is treated to a breathtaking panorama. As you climb the hairpin bends, the two mighty walls of the Grimsel reservoir appear just before the ridge. The right-hand arched wall is a mighty construction that impresses with its enormous width and height. It stretches over 200 metres at its crown between the mountain slopes and looks like a stone wall closing off the valley. The stored water has been used to produce electricity since the 1930s. Almost 100 years old, the old structure was in dire need of renovation. Instead of demolition and new construction, the Swiss decided in favour of a visionary concept: a new wall directly in front of the old one.
Ramon Goglione, construction site management team
Power production without interruption
“As far as I know, this is the first time ever that a second dam has been built in front of an existing one,” says Ramon Goglione during our meeting at the construction site. He is part of the construction site management team of ARGE Grimsel, which consists of Frutiger AG, Implenia Schweiz AG and Ghelma AG Baubetriebe. “This meant that the reservoir could continue to be used during the five-year construction period. Due to the ongoing power generation, this was more economical than demolishing and replacing the old wall,” reports the young foreman. In the winter of 2024/25, the lake was finally drained and the old wall was breached at one point over an area of a few square metres. In future, it will stand in the lake, surrounded by the masses of water.
Curtain up on Lake Grimsel: At the start of construction work on the new dam in 2019, an LTM 1130-5.1 from Frutiger AG placed the containers for the construction workers’ accommodation.
Now that the work has been completed, Goglione and the entire construction team have to dismantle the construction site. Concrete foundations and assembly areas have to disappear – around 3,000 cubic metres of concrete have to be removed before winter arrives up here in October. After years of use, the imposing cranes that have so impressively characterised the image of the construction site are now also being dismantled. “Four years ago we erected the luffing jib cranes, today we are dismantling the last one – with our LTM 1650-8.1,” explains Michael Egger, Managing Director of Emil Egger AG from St. Gallen. “The crane is available with a system length of over 130 metres. It has a boom extension and a 63-metre-long luffing jib.” Egger also travelled up to Lake Grimsel that morning. “Dismantling takes several days because the tower system is completely bolted together. Finally, we have to dismantle the massive crane towers into individual parts for road transport.”
Flooded: The almost hundred-year-old dam wall has been breached and will now stand in the water of the Alpine reservoir.
Michael Egger: “Here in the mountains, the construction period from May to October is very short. That’s why the entire logistics had to be organised very efficiently.”
“Really powerful and compact”
A second Liebherr mobile crane is also on site to lend support. “The LTM 1150-5.3 loads the dismantled construction crane parts and also has attached the long lattice jib to the large mobile crane,” says Egger, looking at his large mobile crane, which stretches upwards. “The LTM 1650-8.1 is ideal for such missions. As an 8-axle crane, it is compact enough to be used on narrow mountain construction sites, as shown here. It did not have to be dismantled for the journey, as 12 tonnes axle load is permitted on the route. If necessary, we can transport the main boom separately so that the crane weighs just over 50 tonnes. That is often important to us.”
Alpine climbing with a twist: After work on the dam wall has been completed, industrial climbers remove a large banner – the shadow of the LTM 1650-8.1’s lattice boom is clearly visible on the concrete.
“We purchased the LTM 1650-8.1 primarily to be equipped with a powerful and modern machine for infrastructure projects of this kind,” continues Egger. “It is the most powerful 8-axle crane on the market. We mainly use it when replacing bridges, moving steel elements or, as shown here, assembling large construction cranes. Thanks to VarioBase® in combination with VarioBallast®, the crane manages with footprints that were previously reserved for a 6-axle crane. This means that we can offer our customers significantly more. The crane is as strong as an ox and yet still compact.”
Steel and cliffs:The large luffing jib of the construction crane is suspended from heavy chains for dismantling.
Wall with expansion reserve
All is now quiet again on the Grimsel. Winter is approaching. Cranes, workers and construction machines are gone. The finished building stands – itself as strong as a rock – between the steep mountain flanks. There is no more construction noise. However, this calm could be deceptive.
That’s because there have long been plans to increase the water barrier. An increase in height of 23 metres has been discussed in Switzerland for years and is also being negotiated in the courts. “The statics of the new wall are designed for this,” confirms Ramon Goglione. For the operator of the reservoir, Kraftwerke Oberhasli AG, this would increase its storage capacity immensely. They could produce significantly more electricity in winter. However, this measure would also significantly change the landscape. Parts of the lakeshore landscape and the glacier foreland would have to be flooded and a section of the Grimsel Pass road relocated.
Whether it will actually come to this, remains to be seen. One thing is for sure, however: the wall on the Grimsel is ready for it. Perhaps one day it will once again be the scene of a major Liebherr operation.
This article was published in the UpLoad magazine 01 | 2026.
