High wall no hurdle for Liebherr cranes
By Christian Shelton23 February 2017
A range of Liebherr cranes are currently being used to construct an innovative energy project in Germany. This includes the erection of wind turbines up to 240 metres high, making them among the tallest in the world.
The energy generation and storage project is being executed by international construction company Max Bögl Group in the north-east of Baden-Württemberg, Germany. A pump accumulator power plant is being built which will feature four wind turbines located in the centre of a circular water basin. The concept is that surplus energy can be used to pump water from the valley up into these water basins; then, when electricity is then required, it can be released to flow down to the power plant.
The largest of the four basins, which will be able to hold a total of 160,000 cubic metres of water, is being made up of seven rings, each consisting of 28 concrete elements. It is estimated that it will take an operator around one month using a Liebherr LTR 1220 telescopic crawler crane to assemble the 200 curved wall segments that make up one of the basins.
According to Liebherr, a key reason why an LTR 1220 has been selected for this task was due to its flexibility. For example, the basins have a diameter of 63 metres, whilst the crane features a telescopic boom range of up to 60 metres, a maximum radius of 88 metres, a maximum load capacity of 220 tonnes, and a maximum hoist height of 101 metres. This, combined with the crane’s small footprint, means that it can be positioned in the centre of the circular foundation from where it only needs to move a few metres to reach every point of the water basin. In addition, the LTR 1220 is also able to move with 12 tonne reinforced concrete components attached to it. Liebherr says this streamlines efficiency and means construction work can progress quickly.
However, a key challenge to this approach is that, once built, the Liebherr LTR 1220 telescopic crawler crane will be effectively trapped within the basin. The solution will be to use another Liebherr mobile crane to lift it up to 15 metres out of the basin, after its crawler tracks have been removed.
An LTM 11200-9.1 mobile crane will then be used to construct 40-metre-high water storage towers that will rise out of the basins. These towers will provide the foundations for the wind turbines, which will be erected using a Liebherr 630 EC-H 70 top-slewing crane located on top of the tower, effectively giving it an impressive hook height of 191 metres above ground level.
Other Liebherrtop top-slewing cranes are being used on the site, including two new 280 EC-H 16 models.