April 7th 2011 -
OPG has stated in a media release issued today that the date of the final break-out of the 14.4 meter diameter TBM named "Big Becky" will occur on Friday May 13th 2011. The TBM remains at 10,136 meters (33,254 feet) at an elevation of 137 meters. This finale will bring to an official end the mining phase of the Niagara Tunnel Project construction. The breakout will occur at 10,143.026 meters. The final push will be 1.5 meters
The tunnel ends at Station 10143 meters at the Intake Structure, a few meters have been excavated by drill and blast. Difference between 10143 meters and 10158 meters is due to the alignment change. Final push is about 1.5 meters.
April 3rd 2011 -
The TBM is at 10,136 meters (33,254 feet) at an elevation of 137 meters. The TBM has stopped mining until the official Breakthrough Ceremony. Work in the tunnel continues. A ventilation bulkhead is being constructed in the tunnel behind the TBM. This is to prevent the loss of air pressure inside the tunnel following the breakthrough. Parts of the TBM that are unnecessary for the final breakthrough continue to be dismantled and removed.
Wow. So, it's just sitting there, ready for the big show. Fireworks? They have to build a big air curtain so that there isn't a giant fart when it breaks through. I love show business!