A shaft for use in a wind energy system is provided, with the shaft comprising a hollow shaft body; a cable fixation being connected to the hollow shaft body and extending axially in the hollow shaft body, the cable fixation being adapted for fixing a cable bundle; and a tensioner being adapted for tensioning the cable fixation in an axial direction of the hollow shaft body. Further, a fixation device and a wind energy system are provided. Furthermore, a method for constructing a fixation device for use in a wind energy system is provided.