Development of a high energy impact breaker for shaft sinking :initial feasibility and field trials in a rectangular shaft : final report

Author:	Phillips, S. H. E.
Year:	1978
Document Type:	MAIN
Issuing Agency:	The Company,
Series:	[Open-file report] - U.S. Bureau of Mines ;
Report Number:	1979-78
Subjects:	Shaft sinking
	Drilling and boring machinery
Link:	https://hdl.handle.net/2027/mdp.39015095081793