This Skanska Koch contract was part of a joint venture to replace the decks of the Triborough Bridge over the East River. The bridge spans three boroughs and carries more than 200,000 vehicles per day. Because of the heavy amount of vehicular traffic on this bridge, the client required the team to keep seven lanes of the bridge open during the process of replacing the decks and beams. This required the team to come up with an alternate method of replacing the decking since such work is usually done by closing traffic lanes and using cranes to remove old sections and replace them. The team used overhead double-girder bridge cranes, which spanned the entire 98 feet of roadway. The team removed the existing road surface from the bridge one lane at a time and replaced it with new steel deck sections. This was the first time double-girder bridge cranes had been used to replace suspension bridge sections in the United States. All of the work was done throughout normal working hours adjacent to traffic. The cranes were designed to be erected in a one-time operation, which took place at night. Each crane was installed in a three-lift operation, each lift taking only seven minutes. Two of the cranes were installed simultaneously. A total of 553 precast deck units were used on the project. Typical units are 10 feet wide and 35 feet to 38 feet long.
