Ventilation shaft water inflow control rossarden tin mine,Tasmania, Australia

The Rossarden tin and tungsten mine in Tasmania Australia was opened in 1923 and was operated until recently by Aberfoyle Ltd. The last major development operation in this mine was the construction of a 1.2m diameter ventilation shaft to permit the expansion of workings in a new orebody, “The Lutwyche Prospect”, 380m below ground level. Because of a long history of reasonably dry mine workings and for reason of economics it was decided to construct the new ventilation shaft using the raise bore pilot hole as an investigation hole in advance of raise boring operations. The only water inflows expected were near the bottom where water had been intersected in mineral exploration holes. This paper examines the course of the shaft construction operations, the problems of water inflow and analyses the impact of assumptions made in advance on likely ground conditions on the project.