Your right plough, the Prince of Wales mine at Tarnagulla used...

Your right plough, the Prince of Wales mine at Tarnagulla used that method and it is the normal way most shaft mines across he world operate. Big infrastructer change in the hoisting system though,, don't think the M/S headframe would be up to it.

Basicaly, bog the face as usual but instead of the 3/4tonne box trucks used now you have 1 tonne side tippers, when you push /pull the trucks to the plat they are side tipped into a hopper in the floor of the plat.

The cage/skip is lowered to a loading chute below the plat and filled, then gets hoisted to the surface.

As the skip travels up the skyshaft there are 'scrolls' in the cage guides that pushes the bottom of the skip out and also opens the bottom allowing the dirt to fall onto a chute beside the headframe. The whole process is automatic (you only ned the winder driver at the surface).

A loader can then do what ever with the dirt in the stockpile. (another advantage is that you can have a divider and split the stockpile according to ore grades or mullock etc)

But like I mentioned big design costs etc, the 1 tonne skips used at Tarnagulla cost about $28,000 each in 1988 and there woud be a at least few hundred $thou on design and mods to the headframe, loading pockets underground and sidetipper or trucks.

I think M/S will probably stick to it's current system until a decline is employed.

I'll stick my neck out and say that 18 - 20k tonnes p/a with the current system would be an exceptional feat.