coal question, page-12

I also listened to JH reference to possible "mining" of coal resource. I recently posted re this possibility!

Now being practical about all this if you do simple high school maths on the average amount of coal encountered from each hole so far and given that on the extremities of the enclosed area there is still an average of 100m of coal you can easily calculate a trillion tonnes of coal in the included area and then if you make a brave decision all coal will deplete within 30 kms outside the area of holes so far driven you can easily calculate another half a trillion tons of coal making at least 1.5 trillion tons..(now that is being really conservative!!))
So given they have drilled road tunnels under Sydney Harbour and the Brisbane river and plenty of other tunnels elsewhere in our capital cities using very sophisticated tunneling equipment ( which may now be laying redundant!) why can we not drill say a 1 in 10 slope approach to our reserves (say 3 kms to shallowest coal ..half of which is open cut!) and then access trillions of tones of coal from one access ramp?

It is just the enormous scale of things which in my mind makes this possible. (I.E. you would not think of underground mining today for a Bilion tons .. would you?)

Having said all that my personal preference is underground Coal to Liquids because it has a small footprint and uses conventional drilling equipment!! But it has yet to be proven as a successful technology!! Meanwhile it is worth monitoring LNC and CNX who are well advanced with Underground Coal Gassification!!
Don