Palisades Tunnel Project

under construction

The Palisades Tunnel Project involves boring two parallel tubes roughly 5,100 feet long from Tonnelle Avenue in North Bergen to the Weehawken shaft. Two German boring machines, each weighing 1,680 tons with a cutterhead over 28 feet across, are being assembled in a trench in New Jersey to bore through extremely hard and abrasive rock. The project includes connecting the tubes with six cross passages and installing concrete liners as the tunnel advances. The expected pace is 30 feet of lined tunnel per day, with the mile-long drive expected to take about a year. The machines are designed to handle the hard Palisades Sill rock, which averages around 35,000 psi and causes cutter wheels to wear out every two days. About 40 people work inside each machine during operation. Assembly is taking place inside a 600-foot launch box trench about 80 feet deep. The tunnels start about 80 feet below street level and drop to roughly 280 feet under the ridge.