By Gabriela Resto-Montero
DNAinfo Reporter/Producer
UPPER EAST SIDE —Nearly two months after it was officially launched by the MTA, the Tunnel Boring Machine drilling for the Second Avenue Subway has made less progress than expected.
Fragmented rock has slowed the 450-ton machine, which so far has mined through 300 feet of rock, said Aaron Donovan, spokesman for the MTA.
"It was difficult for the machine to go through so it was slower than might have been expected," Donovan said.
Engineers first estimated that the TBM would chew through 50 feet of rock a day.
The first 700 feet of digging with the machine are considered the start-up phase and the TBM will soon meet the 50 feet of rock a day criteria, Donovan said.
The MTA launched the 450-Ton machine May 14 and the digging is projected to finish in 2011.