Advent of the Small Boring Unit

The contractor, Fithian, was attempting to excavate a 36″ tunnel in rock with an auger boring machine using a carbide bit “Christmas tree” head. The head wasn’t cutting the rock and the contractor turned to Robbins for a solution. The Small Boring Unit (SBU) was invented for the job, and Fithian completed the tunnel in just one week with this new method.