Abstract: Thrust compensating apparatus for providing a thrust force to compensate for the thrust forces applied to the shaft of single stage overhung turbo machines by the fluid pressure in the cavity of the turbo machine is disclosed and includes a thrust compensating member attached to the shaft of the turbo machine and having a first surface subjected to the fluid pressure in the cavity, an annular seal, an annulus cavity formed by a second surface of the thrust compensating member and the annular seal and venting apparatus for controlling the fluid pressure in the annulus cavity resulting in a compensating thrust force being applied to the thrust compensating member as a result of the differential in pressure across the first and second surfaces of the thrust compensating member.