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Wolffkran takes stock after 4.5 years of operation on the Grimsel Pass
In June, the newly built replacement Spitallamm dam on Switzerland's Grimsel Pass was officially inaugurated - and it was not a routine project.
Wolffkran takes stock after 4.5 years of operation on the Grimsel Pass
According to a press release, the inauguration was a special moment for project manager Ralph Stump and the six crane drivers after four and a half years of challenging construction. The project attracted a lot of international attention over the years. After their Alpine use, the two XXL luffing cranes were sent directly by ship - halfway around the world - to the next mega construction site.
500,000 tons in 32,000 strokes
Wolffkran's largest rocker, the Wolff 1250 B, moved around 500,000 tonnes of concrete in a total of around 32,000 lifts. Due to the high work frequency, the hoist rope on each crane had to be changed twice per season.
Wolffkran specially developed the XXL tower element TV 60 with a side length of six meters for use on the Grimsel Pass. It formed the lower, stable base for the almost 100 meter high cranes, both of which rested on a concrete foundation weighing over 1,500 tons - on average ten times as heavy as a conventional foundation. "Standard towers and foundations would not have been able to withstand the extreme weather conditions. With the TV 60, the Wölffe were able to work free-standing," says Ralph Stump, Managing Director Wolffkran Switzerland.
24/7 work in three shifts
© WOLFFKRAN/ grimselfoto.ch
“Behind all these superlatives is a unique team effort,” emphasizes Stump. The short construction phase from May to October made it necessary for the crane operators to work 24/7 in three shifts. “Seven days of work, three days off, eight hours per shift on the crane, a demanding job.”
Added to this were the special features of the mountains: thick fog within a few minutes, meters of snow overnight, avalanches and storms. Nevertheless, all Wolff employees would have been motivated. “If the call came at half past ten that a rope needed to be replaced, our fitters had the replacement part on top of the crane by midday and operations were up and running again by 5:30 p.m.,” says Stump. "Replacing a 120 kilo bolt at a height of over 90 meters on the crane - our team was there too. The demand for this job was high despite the demands and each of the six crane operators - two women and four men - are happy to have been part of this special operation."
Dismantling began in October 2024, and the last parts were transported into the valley in June 2025 - a total of 4,205 cubic meters of crane volume with a total weight of 1,281 tons distributed over over 60 truck journeys, some of which were extra wide.
Head for the next stops
In addition to the team, technology and logistics, the sophisticated winterization concept has also proven itself. Each crane was moved automatically three times a day during the winter season; the lifting winch, the winch of the pull-in mechanism and the control cabinet were wrapped with special mats. An effort that was worth it, because after the Alpine mission the “Wolves” can travel directly to the next construction site: the Prince Mohammed Bin Salman Stadium in Qiddiya in Saudi Arabia, for which the contract was only recently signed. Also on this construction site, an exposed cliff with harsh weather conditions, the TV will enable 60 free-standing tower heights of around 100 meters.
The completion of the Spitallamm dam marks the end of a project for Wolffkran that, according to a press release, has set standards – technically, logistically and humanely. "For us, this was more than just an operation. It was a milestone that shows what our technology and our team are capable of," said Stump.
There is a good chance that the experiences from the Grimsel Pass will also be incorporated into future construction projects. “There was great interest in our crane concept throughout the entire construction period,” says Ralph Stump. "Numerous experts and representatives of renowned construction companies, planners and specialist engineers - including many from abroad - visited the construction site and were impressed by the red giants. We are already in discussions about possible follow-up projects."
