A rotation system for a felling head mounted to a boom, the rotation system including: an adapter which is pivotally mounted to the boom a housing fixed to the adapter a gear system enclosed between the housing and the felling head and operable to allow the felling head to rotate with respect to the housing about an axis of rotation and a plurality of actuators mounted to the housing and engaging the gear system, the plurality of actuators being operable to drive the rotation of the felling head, the plurality of actuators engaging the gearing system at positions below the axis of rotation so as to provide a vertical support therefor.
