As of June 1st 2009
Tunnel is 4245 meters (13,927 feet) long
continuous roof line over-break of 1.4 metres
average 10 metres per day
This will be its happiest time, zooming along at max speed under the sandstone. Too bad it can't stay there forever! I wonder what the rock squeeze is like right under that roof? All depends on the adhesion of shale to the sandstone. Soon they'll be down to almost zero overbreak and 15 m a day!
Then the shit hits the fan.