It was a biggun, although the shaft wasn't particularly deep, as they go (75m).
The 11 different access shafts on the 23 kilometre Hong Kong project I worked on varied between 100m and 150m deep, and at 8m, probably half the diameter of the one on the programme, so they seem even deeper when you look over the edge.
We were going through granite too, and under the sea...none of your soft stuff.
This is the one I worked on:
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http://www.civcal.ust.hk/Tech/Sites_Tunnel.asp
Originally Posted by grahamw48
