Abstract: 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.

Abstract: The present disclosure relates to a tunneling apparatus including a pipe string having a distal end and a proximal end. The pipe string includes a plurality of pipe-sections connected end-to end. The pipe string also includes a cutting head coupled to a distal-most one of the pipe-sections. The pipe string defines a vacuum passage that extends through the pipe string from the proximal end to the distal end of the pipe string. A source of vacuum is in fluid communication with the vacuum passage for drawing cuttings through the vacuum passage. A blockage sensor can be used for sensing whether a precursor blockage condition exists within the vacuum passage. A source of air pressure can be used to force air distally through the pipe string to assist in moving cuttings proximally through the vacuum passage.