Hydraulic Crane Used To Speed Roof Bolting At Goderich Mine

Sifto Salt Div. of Domtar Chemicals Ltd. has developed a new method for installing roof bolts in the high backs of its 1-million-tpy rock-salt mine at Goderich, Ontario, on the east shore of Lake Huron. The method teams a telescoping- boom hydraulic crane with a specially developed combination auger-drill and bolt-tightening ma- chine. One man, controlling all operations from a basket supported at the end of the crane's telescoping boom, installs an average of 100 5-ft roof bolts per shift, at heights to 45 ft. The mine has very long backs that are not as stable as might be expected. The result has been that roof scaling has occupied an unusually high percentage of the underground work force. About six years ago, company officials decided to go to 100% roof bolting of all backs as a safety measure. The present roof-bolting equipment is the result of a development program instituted at that time to find a faster and more economical method for doing the job.