Every mine is different in its layout, scheduling and ventilation system however it is not uncommon for an escapeway rise which is permanently located in the return airway to spend its first two or three months bypassing precious primary ventilation from the main decline into the return airway and therefore losing that ventilation capacity further down in the mine where it is needed most.  Miners have to decide whether to put a large vent wall up at the decline early to save on lost ventilation or to put up a small one in the main primary ventilation drive then another one in the decline later on to stop the fresh air from bypassing up the ladderway.  All the while limiting access to developed areas which may be required for other services such as power, pumping or even diamond drilling.

 

At a recent installation the use of our vent curtain on the Laddertube has meant two things, it has reduced the critical nature of timing on the installation of a permanent ventilation wall and it has saved approximately 5m^3/s of primary air flow being lost over a two month period until the level is scheduled to be closed off permanently.  Without considering the cost benefit of the flexible timing of permanent ventilation walls or the possibility that a permanent ventilation wall may no longer be required in this area, the saving just on ventilation flow alone over the two month period is approximately $8-10,000.