Tales from the deep with New York 'sandhog'
18 August 2012 Last updated at 01:11 BST
Tom Petrizzo is a Sandhog, a New York City urban miner. He has been working underground for 13 years.
Currently, he is tunnelling the East Side Access, a public works project that will connect the Long Island Rail Road to Grand Central station. He's in the team opening the four tunnels that will run underneath the East River into Grand Central.
New York City underground workers work on three shifts around the clock - day, swing and graveyard. Almost exclusively men, some have done this for generations. They are hierarchically organised in "gangs" of six men led by a foreman.
Tom Petrizzo took the BBC down to the tunnels and into the "hog-house", explaining the dangers, the mud and the heat, but also the camaraderie that develops among sandhogs.
Produced for the BBC by Anna Bressanin; camera by Ilya Shnitser.