Bolt checks by drone for onshore wind turbine

Problem

The transition piece bolts on an onshore wind turbine were losing excessive amounts of tension due to vibration and relaxation. The necessary scheduled maintenance checks were still carried out by hydraulic tooling and were too costly for the turbine operator to continue without improvement.

Application

The application was a new self-erecting tower technology designed for hub heights greater than 120 m.

Existing solution

Standard maintenance schedule and hydraulic tension tightening, with no appreciation of load transfer relaxation.

James Walker solution

RotaBolt Vision was supplied, giving ongoing load monitoring and the ability to use drone inspection. Bolt loads can now be inspected quickly and safely. By only tightening those where tension has dropped below the minimum calibrated design limit, Rotabolt removes the need for costly time-consuming hydraulic tensioning on every bolt.

Results and benefits

Safer maintenance using drone inspection. The customer now monitors bolts with a drone while the maintenance technician is safely on the ground, very often no re-tightening is required and therefore no working at height risk, heavy tool use or time is wasted. A correct load is also now confirmed instead of estimated following relaxation after installation.

• Improved efficiency by ensuring less downtime
• Reduced health and safety risks
• Reduced cost of maintenance