This week we got a call from a customer who had a 17.5 kW Jacobs Wind Turbine (Jake) that was free spinning. We estimate that the blades were spinning approximately 50 rpms/minute…pretty fast.
A coupling on the turbine’s drive shaft had broken before (above) the breaking mechanism (an unfortunate design flaw), so engaging the brake was not an option. It was necessary to climb the 100’ free standing tower and approach the blades from the backside, near the tail boom.
The tail was secured and positioned so that the turbine was out of the wind, slowing the blades down. This made it easier to slip a 3/8”, 6’ long Galvanized Aircraft Cable (GAC), which had been fed through an old hose to protect the blades from any damage, around the nacelle and over one of the blades. The GAC was tightly secured with saddle clamps to ensure it remains arrested until a new coupling can be replaced, (or the customer updates to a Bergey 10 kW!).