From damage assessment to commissioning in twelve weeks
Deutsche Windtechnik currently has almost 500 Enercon turbines under service contracts. Replacing the rear main bearing, however, was not something we had included in our service activities with this type of turbine so far, so the project presented some special challenges because we needed to disassemble the rotor. Piet Wichmann, Site Manager on the Enercon team, spoke to us about why the E70 project went so quickly.

Piet, what was the biggest challenge for you with this project?

I had never been responsible for a project of this size before. Using the crane, slinging the rotor, handling the tools – it all had to work. A list of critical issues that we put together at the beginning of the project became more and more manageable thanks to the cooperation of the team, our specialist departments and external partners. That gave us certainty.

How were you able to carry out the project so quickly?

First of all, we were well prepared for this damage scenario because we had been thinking about the theoretical side of this type of incident since the middle of the year. That is why we knew exactly what was important, which people and which equipment we needed in our short-term planning. For example, we were able to quickly build the special tool with the help of a partner. In the end, luck also played a small part (laughs). As part of our preparations, we had already initiated a material procurement process, and this ensured that a suitable part was available shortly before the damage occurred. We were able to remove the drive shaft from the hub body and replace it with a new one. ["Achszapfen" is usually translated "axle journal", but "axle journal" does not sound right here because I've never heard the term "axle" being used in connection with a wind turbine drive train.] The old part had been destroyed in the bearing seat, so repairing it was not possible.

What role did the team play in this project?

The team brought everything to the table that we needed for the project: experience in servicing large components, willingness to work, ability to improvise and the motivation to carry out the project on schedule. I'd like to take this opportunity to thank them for their extraordinary commitment.