The present disclosure relates to a tunneling apparatus including a drill head having a main body and a drive stem rotatably mounted within the main body. The main body defines a vacuum passage offset from the drive stem that extends through the main body from a proximal end to a distal end of the main body. The tunneling apparatus also includes an axial bearing structure for transferring axial load between the drive stem and the main body of the drill head. The axial bearing structure is proximally offset from the distal end of the main body of the drill head. The tunneling apparatus further includes a first radial bearing structure for transferring radial load between the drive stem and the main body of the drill head. The first radial bearing structure is positioned between the axial bearing structure and the distal end of the main body of the drill head and is distally offset from the axial bearing structure.