When the trails come to a halt in an alpine area, it is usually time to call in the helicopter. But this was not the case in the Gastein Valley, not far from Schlossalm, when elaborate and costly aerial operations were largely avoided. The innovative combination of crawler and crane was used instead, as it was able to operate on the area’s difficult terrain.
After the crane had been transported to within reach of the site by truck, its crawlers took it across the—at times—almost completely impassable terrain to the lift supports.
During the five-day job, the machine required no additional assistance, conquering an altitude difference of more than 800m and gradients of up to 40%. The crawler crane was still far from reaching the limits of its climbing capacity of up to 60%, as confirmed by the operations managers who were on site during the smooth removal of the nine lift supports.
Once it had reached a support, the crane had to be optimally positioned and aligned. The precision control of the crane’s support feet made it possible to compensate for level differences to the nearest centimetre. This was an important feature as stability, reliability and efficiency go hand in hand for special applications like these and lifting loads of up to one tonne. Fears that the crawler crane might damage the fragile alpine floor proved unfounded in practice. Even when the machine needed to turn itself around, it left only a few traces in the ground.
Cable lift construction specialist Prommegger, in partnership with Palfinger, implemented the pilot project. For managing director David Prommegger, it was a pioneering project that was long overdue: “We have been thinking about using cranes in off-road terrain since 2009, almost ten years ago. And then during the Schlossalm project, we stumbled across the Palfinger crawler crane almost by accident. The crane functions as a real alternative to a helicopter. Furthermore, it doesn’t need any additional permits and you can work largely independently of the weather.
“The crawler crane will be useful for us in the future whenever we have large-scale projects coming up in an environment that is difficult to access. I’m thinking of road construction in the mountains, but also of the new high-voltage power line. This project has a large construction site, where use of the crane would be ideal—particularly as there would be no time pressure because, unlike the helicopter, not every minute of use would be reflected in the bill.”