I saw an excellent show on WNYE the other night about the work boring the tunnels deep under Park Avenue.
Link The show was a rerun of an episode that originally appeared on the History Channel about six years ago. Sandhogs: Band of Brothers. I think the episode I saw was episode 10 and it will be reshown on WNYE on Sunday at 1200 PM.
Schedule
Watching the crews at work you begin to realize that when project people talk about the complexity and difficulty of the job they're not just mouthing cliches. The ESA project has been widely criticized for falling behind schedule. Watching the episode you see vividly how much pressure the construction crews are under to meet the schedule and how difficult it is for them to do that.
At the start of the episode the boss says he wants to bore 25 feet on this day. Instead they do 18 inches. Why? Problems with the Tunnel Boring Machine (TBM) which the workers call The Mole. The Mole's cutting head has forty-five diamond drill bits. All forty-five must stay precisely aligned in order to drill a properly aligned tunnel. When they start drilling they constantly monitor the rock being carried away on the conveyor belt. The rock should be pulverized, any big pieces indicate one or more bits has become misaligned. When that happens -- and on the episode it happens almost immediately -- they have to stop and physically inspect the cutting face. They find one of the bits has not only become misaligned, on closer inspection they discover it's mount is broken. Workers have to crawl into the space and weld a repair. A slow dangerous job.
In another part they have to move the Mole which runs on tracks. They have a derailment. This requires jacking up the Mole and putting cribbing in, a very risky job. Once they get the Mole jacked up they discover another problem: one of the steel supports is broken. Now they switch to airbags to lift the Mole up. It was amazing to me to see, how 'hands-on' a job like this is. These guys are risking life and limb to get this project finished. They spend a lot of time down in the muck on their hands and knees.
Part of this episode also shows sandhogs blasting the entry cavern for the 7 Train extension to the Javits Center. They run into constant problems too.
It was an excellent episode. I'd love to buy a copy but have been unable to find a source.