Underground

Few updates this month because I've been underground. And I don't mean I've joined some kind of strange sub-culture or gone in hiding, I mean literally 1.5km vertically underground to commission a Transmin automated Rockbreaker (there's not much internet down there!). A few things I learnt / experienced about hard-rock underground mines (most of which are very obvious):

• Block caving is insane. The idea is to create an extraction level under the ore body, then continuously blast the ore into smaller rocks that can be processed, leaving a massive growing "sink" hole on the surface. You also need a very very very long conveyor belt.
  
• The tunnels are quite large, as some very large vehicles need to drive through the mine.
  
• All the tunnels have a 'clean' look to them, largely thanks to the use of shotcrete (i.e. concrete reinforcement around the tunnel rock).
  
• It takes 45 minutes to drive down to a depth of 1.5km
  
• When driving, give way to larger vehicles, or vehicles with explosives.
  
• Its difficult to move around quickly, you will easily break a sweat in no time.
  
• Batteries weigh a lot when you need to carry them around on a belt all day
  
• You use a lot more oxygen if you panic, or move around a lot
  
• There is a complex system of ventilation channels with really really big fans providing all the air
  
• It is really easy to get lost in a large underground mine
  
• There is an underground dining area. It is called the 'crib'. I don't know why.
  
• If anything bad happens, you don't have much of a chance, especially if you are not aware of all the intimate details of how the mine operates. (ie: haven't been there for more than a year)
  
• Explosions are loud
  
• Ground movement is bad and very very loud
  
• There is an awful lot of dust
  

All in all an interesting experience, but all the dust certainly didn't do any good for my eyes or my lungs. I've been coughing a lot even after being out of the mine for a week as the very fine dust just gets everywhere.