Apr 11, 2008 8:30 pm US/Eastern
Venturing Into The North Shore Connector Big Dig
PITTSBURGH (KDKA) ―
The digging of the tunnel for the North Shore Connector reached a milestone today.
Officials say for the first time, the machine is boring beneath the Allegheny River and heading for the Golden Triangle.
While officials say the work is progressing quickly, they are also moving along cautiously.
Officials say safety training for the workers is becoming more and more important as the work progresses.
"The further in you get, you get ground that has not been exposed to oxygen for a number of years, decades perhaps and longer and at that point you have organic decomposition and the main gas you'll run into is methane," said Port Authority Rail Engineering Officer, Winston Simmonds. "And methane in small quantities can be explosive so that's one of our major concerns."
Officials say that when the crews have to access the machines blade they wear special suits and go through hatches because the blade area is pressurized. As a result, there is a decompression chamber on site in case a worker has a problem.
Meanwhile, the tunnel boring, or mining operation, continues chewing away about 700 feet in and 50 feet below the surface of the Allegheny River's North Shore.
"As we are proceeding across the river we're going to make a left turn and another right turn to line up with Stanwix Street where the receiving pit is almost constructed right now," said Port Authority Rail Engineering Officer, Winston Simmonds.
If everything continues to go well, crews say the boring machine will pop out in the Stanwix Street pitt around the first week of June.
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