IM 2016 May 2016 | Page 18

HOF _proof 26/04/2016 16:29 Page 6 INTERNATIONAL MINING HALL OF FAME Underground Development inductee, the late Jim Robbins, was responsible for the hard rock tunnel boring machine (TBM) TBM for Mitry Constructors who were working on the Oahe Dam diversion project near Pierre, South Dakota, USA. The major breakthrough in the design of hard rock TBMs occurred in 1956 when disc cutters were first used exclusively to cut rock. That first machine utilised a dual counterrotating cutterhead fitted with rows of drag bits and dumbbell