Professional Development Short Courses for 2008 ...
The Mining Studies Institute at the University of British Columbia and EduMine bring you a program of 27 short courses on mining topics presented in Vancouver. Courses qualify for the UBC Certificate in Mining Studies. All courses are presented in downtown Vancouver ...
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Mining Field: Collars and Portals Area: Collars (Rule#199)
The minimum depth for a timber shaft collar is 48 feet (15m).
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