October 22 - Sarens has used a Terex CC 8800-1 crawler crane with its recently acquired Boom Booster kit to erect an Enercon E-126 wind turbine at the Windpark Noordoostpolder in the Netherlands.

Further to the news posted by HLPFI on October 13, reporting that Sarens had equipped its CC 8800-1 fleet with the Terex Boom Booster, the new kit has been used for the first time in the erection of an Enercon wind turbine.

The Terex Boom Booster kit is a lattice boom structure with a width of 10 m and a length of up to 72 m that is designed to increase the capacity of CC 8800-1 crawler cranes by up to 60 percent.

"It's as if the kit had been designed specifically for our project at Windpark Noordoostpolder," said Sarens project manager Hendrik Sanders.

The kit was delivered directly to the job site in the Netherlands from the factory in Zweibrücken with the frame pre-assembled, in order to allow Sarens to save time during assembly on site.

A total of 12 trucks and a special permit were needed to get the Boom Booster kit to Noordoostpolder in a week. Meanwhile, Sarens used 48 trucks to transport the crane, and another 28 vehicles to take the superlift counterweight to its destination.

Sanders explained that the work conditions on site were unique: it was necessary to set up an adequate supporting surface for the CC 8800-1, which meant that Enercon had to use track ballasts to create a platform, so that the crane would end up 3 m above ground level.

"Sure, the Boom Booster kit is about 50 percent heavier than the CC 8800-1 crane's standard boom, but the way it was designed made self-assembly possible with the superlift," said Sanders.

With a main boom length of 138 m - 72 m of which were contributed by the Boom Booster kit - and an 18 m LF extension, the CC 8800-1 crane reached a total boom system length of 156 m.

This was enough to lift the wind turbine components to a hub height of 135 m, while using an angular offset of 20°. To do this, the superstructure was equipped with a counterweight of 295 tonnes, the central ballast amounted to 60 tonnes, and 400 tonnes of superlift counterweight were used.

Once the two assist cranes had erected the Enercon E-126's tower, the Terex crane lifted the last components to a height of 135 m: the 170-tonne nacelle using a working radius of 40 m; the 260-tonne generator using a working radius of 36.5 m; the 375-tonne hub using a working radius of 33 m; and the three fibreglass rotor blades, each weighing 40 tonnes, using a working radius of 23.5 m. 

This whole process will be repeated for another 37 wind turbines.