NJ Transit’s board yesterday unanimously approved the first tunneling contract for an $8.7 billion rail tunnel between New Jersey and Manhattan.

Barnard Construction Co. of Pompton Plains, NJ, and Judlau Contracting of New York will be paid $583 million to dig the mile-long tube.

The project is expected to double train capacity into and out of Manhattan by adding two single-track tunnels under the Hudson River.