The three mammoth projects require creative solutions and the latest technology.
When crews prepared to drill the giant new cavity under Second Avenue, they first had to freeze the ground to about minus 20 degrees so as not to destabilize the buildings above as the boring machine cut through. For that, aluminum tubes were inserted from the street and a special chemical solution was poured into the ground and cooled by a refrigeration plant.
The Second Avenue tunnels hold a space-age surprise: The ceilings are coated with a material once used to fireproof the space shuttle.
The new line has another major improvement. Instead of ventilation grates that allow rainwater to pour in, the new stations will be aired using enclosed cooling plants. When Superstorm Sandy hit the city last October, floodwaters washing over the East Side did not penetrate subway construction sites.
‘‘We’re using the best technology available today, but this is really people-intensive work,’’ says Horodniceanu, who supervises a team of thousands of workers on any given day.
‘‘I feel I have the most exciting job in the world,’’ he says. ‘‘It’s an incredible feeling to be able to build a legacy project. I hope that one day, my grandchildren will be able to say their granddad built this!’’