04.11.2011

New altitude record for wind lift

Swiss based Welti-Furrer Pneukran & Spezialtransporte claims to have taken the world record for the highest altitude wind turbine installation ever completed.

The turbine a 2.3-megawatt Enercon E-70 with an 85 metre hub height was installed in the Swiss Alps near the border with Italy at an altitude of 2,465 metres.

The company selected a 600 tonne Terex TC 2800-1 lattice boom truck crane to carry out the lift and a 120 tonne Terex AC 120 All Terrain as an auxiliary crane to help with setting up the TC 2800-1’s boom.
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The approach road to the site

The challenges involved with this lift started from the outset, beginning with the site, which is only accessible to vehicles for four months during the summer, with snow blocking the way during the rest of the year.

To add to the challenge, the only way to transport the crane and massive components to the site was via the narrow, winding roads that were clearly not designed with this kind of project in mind.

“This is where the Terex TC 2800-1’s compact design and comparatively low weight came in, as it allowed us to avoid doing any damage to the roads,” explained Tobias Schöpfer, of SwissWinds Development, the company responsible for planning and realizing the project.

Once at the site, the team was faced with extremely limited space, the area available for setting up the crane was limited to a mere 20 x 20 metres. The crane was set up on the previously inspected edge of the slope, placing 20 square metre mats under each outrigger.
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The Terex TC2800-1 worked with 96 metres of straight boom and 200 tonnes of counterweight

Werner Häfliger, head of the Welti-Furrer office in Zürich said: “With its 14 x 14 metre support base, the TC2800 lifting capacities are significantly larger than those provided by comparable crawler cranes, which influenced our decision to use the Terex TC 2800-1 for this project.”

Once the location had been secured an additional 300 tonne crane was used to attach the top 50 metres of the boom while it floated freely in the air. After reeving the hook block and raising the main boom the crane was ready for action.

The lifts themselves were made more difficult by the fact that the tight space conditions at the site prevented the team from working with the crane’s derrick boom and Superlift ballast. The solution - a 96 metre SH/LH boom and a counterweight of 200 tonnes.
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The site was very restricted

The crane was located three metres above the wind turbine’s foundation and the lifting work started with the pre-assembly of the concrete towers, which, due to the space limitations, required working at a radius of 12 to 16 meters. In sharp contrast, unloading the rotor blades from the transport involved a 70 metre radius lift. The actual erection was carried out at working radius of 38 metres.

Finally the 50 tonne nacelle and 70 metre rotor were lifted into place at a hub height of 85 metres. The complete job took four weeks and finished on schedule. This in spite of a series of adverse circumstances including fog suddenly appearing, gusts of wind with speeds of up to 150 km/h, snowfall and freezing temperatures.
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The crane worked at radii of 12 to 70 metres

Welti-Furrer Pneukran & Spezialtransporte employs around 100 people and runs a fleet of more than 40 mobile cranes with capacities of 30 to 600 tonnes.