Skanska, as part of a joint venture, was awarded a $25 million contract by Amtrak to reconstruct and upgrade existing shaft facilities serving the two North River Tunnels at Weehawken, N.J.
The existing ventilation facilities were replaced to provide improved safety to the tunnels in the event of a fire.
The scope of work for this project included construction of:
· construction of a 100-foot-high (50 feet above ground) reinforced concrete ventilation structure to house four 500 horsepower, 265,000 cubic feet per minute axial emergency ventilation fans
· construction of a one-story 13,200 volt sub-station
· demolition of five existing structures
· excavation to the top of the tunnel roof
· temporary relocation of electrical and mechanical sump pump discharge lines
· demolition of ventilation shafts
· construction of access stairs and utility shafts
· construction of concrete exterior walls
· installation of interior beams and supported slabs
· installation of cast-in-place stairs to grade level
· renovation of a 50-foot-high steel framed masonry building
· installation of new electrical and mechanical systems including ventilation fans, pump discharge lines, fire lines, storm water lift station and a standby diesel generator
Work was performed in an extremely confined area of 15,000 square feet. To add to the constraints, the site is located in a New Jersey Transit bus parking lot that is used throughout the day.
