Service & maintenance

The challenge

Getting the hub and rotor blades onto the ground

The required service work at the Glinzendorf wind farm in Marchfeld required active help from old hands. The plan for the work on two wind turbines (replacing a blade bearing on one turbine and the main shaft on another turbine) was to lift the entire “star”, not just for cost reasons but also for time reasons.

Our solution

Experience counts

The first wind turbine in the Glinzendorf wind farm started to turn in 2012. Over the years, the wind farm was developed further. The wind farm now comprises a total of 11 wind turbines. Together, they produce green electricity for around 12,600 households in the region every year. Important repair work now had to be carried out on two of these turbines. Prangl is an experienced partner in the wind power sector. The customers also rely on the yellow team’s expertise for these very demanding projects.

600 tonne lattice boom crane

To perform the repairs, the “star” comprising the hub and rotor blades and weighing around 45 tonnes had to be lifted down from a height of 100 metres from two turbines. This resulted in a required hook height of 110 metres for the large crane. As a result, the team selected a 600 tonne lattice boom crane as the main crane because it is perfect for this turbine type. It is very strong, has a long boom and is quick to set up and move. The lattice boom crane was configured according to the requirements: 120 metre system length, 160-tonne counterweight and 65-tonne SL counterweight.

100-tonne telescopic crawler crane

Of course, one crane is not sufficient to lift a complete “star”. A 100-tonne telescopic crawler crane with a 52-metre main boom and a maximum system length of 71 metres was used as an auxiliary crane in Glinzendorf. Both cranes had to be used in tandem to move and position the “star” both when lifting down and lifting up. The “star” from the first turbine floated slowly to the ground in this way, where it was then disassembled. The rotor blades were removed from the hub, the blade bearings were replaced and the blades were re-inserted into the hub.

Tandem lifting four times

The renovated “star” was then lifted back into its position and installed on the turbine. The “star” on the second wind turbine was also lifted down using the lattice boom crane and placed on the ground with the aid of the auxiliary crane. The old, 45-tonne nacelle main shaft was then lifted out and replaced with a new one. The “star” that has been stored intermediately can be re-inserted into the turbine. The work was completed according to plan and the wind turbines can now carry on doing what they’re meant to: deliver green electricity.