The pros and cons of an innovative traction cable system

Stillger & Stahl Vermögensverwaltung GbR has been advising investors on the topic of renewable energy for over 20 years. When trying to find cost-effective alternative methods for replacing blade bearings on several Kenersys K110 turbines, the company made the decision to use the ground-based winch system (BGWS). The system, which was developed by GFW, would now be tested in a practical setting for the first time. Greater risk or calculation? Björn Lahnstein, project manager at Stillger & Stahl, spoke about his experiences.

Why did you decide to use the innovative BGWS for the first time to replace the blade bearings?

First and foremost, it was the openness and transparency of the whole GFW team. Because of this, we understood from the beginning that more practical experience would be needed. This was also evident in their attractive, detailed offer, which turned out to be almost identical to the final bill. In addition, the work was not outsourced. Instead, all tasks were carried out by the team of specialists themselves. That was important to us!

Did any unforeseeable events occur?

During implementation we realised that the technical data for the rotor blades was quite different from reality in some cases. Essential static calculations had to be corrected in these cases by the team on site. In addition, we found that the schedule set for implementation proved to be overly ambitious. Both these factors caused a slight delay to the whole blade bearing replacement process. Ultimately, however, everyone involved worked intensively together to get the project completed quickly. Overall, we are very satisfied with how the project went.

Which advantages offered by the BGWS technology made a contribution to the positive outcome?

We were able to get by without using a large crane. In addition to avoiding the crane-specific costs, this meant we were also able to avoid the cost of expanding local infrastructure, coordinating with residents and obtaining bureaucratic authorisations. This allowed many work steps to be skipped, so we were able to begin earlier. This is also ultimately reflected in the project costing, which was significantly higher without the BGWS.