There will be an engineer responsible for the ventilation system. This person will have to work closely with the leading hand of the service crew to get things done in a timely way. However always get the bosses go ahead first, you don’t want to step on any toes.
This is how we replace the air underground. Big fans on the surface suck the air through the mine at 150 cubic metres per second. The aim is to replace the air underground every 20 -40 minutes. In larger mines this may require more than one return air way, some of the larger underground mines in Australia can move between 450 – 900 cubic metres of air per second through their main decline.
The primary ventilation goes down the main decline however it does not go up the levels that extend off the main decline. In order to pump the fresh air up into the levels we use big electric fans that push the fresh air through ventilation bags onto the levels. This causes the level to be positively pressured with air, meaning as the fresh air is pushed in, the stale air is pushed back out to the main decline. This air then continues down to the bottom of the mine where it is sucked out through the primary ventilation shaft (vertical hole).