The Pulaski Skyway is a 3.5-mile, four-lane steel bridge located in the northeastern part of New Jersey that was originally constructed in the 1930’s. The bridge is part of a major highway system that helps connect NJ motorists with New York City. Inspections of the Pulaski Skyway revealed the poor condition of the bridge, highlighting signs of significant deterioration and section loss. It was found that the outdated design and current condition of the bridge made it structurally deficient and functionally obsolete.
McLaren Engineering Group was hired to provide construction engineering services and developed the means and methods for installing the new precast panels for the northbound lanes of the roadway. Overhead clearances, weight restrictions, and temporarily unbraced members on the bridge made conventional construction methods difficult – but McLaren made the difference by working with the contractor to explore several alternative options for each of the different sections of the skyway. For the river spans, McLaren developed and designed a custom gantry crane, along with a low-profile custom rigging frame. The gantry would pick the new precast panels from a delivery truck, located in a staging area right outside the overhead through-truss span, and then carry the panel out to its final location.
For the more typical spans, McLaren’s construction engineering team developed two primary solutions. The first was a temporary stringer bracing system and timber crane mats as a temporary deck, to allow a hydraulic crawler crane to set panels around the clock, regardless of adjacent lane closures. The second solution was achieved by performing an advanced analysis of the existing bridge to justify the structure for placing a hydraulic crawler on the lanes adjacent to the work zone. This solution could only be implemented during temporary full bridge closures, on nights and weekends, but yielded extremely high productivity.