The Manhattan Bridge, built in 1909, total length is 6,090 feet and supported by 4 main cables. This two-deck suspension bridge carries automobile, truck, subway, bicycle, and pedestrian traffic over the East River connecting Brooklyn with Manhattan. On an average weekday, the bridge accommodates 78,000 vehicles, 3,000 bicyclists and pedestrians and 320,000 transit riders. It supports seven lanes of vehicular traffic, four transit train lines, a pedestrian walkway, a bikeway and is also a major truck route. The Manhattan Bridge is the most heavily traveled of all the East River spans. In 1982 New York City Department of Transportation began a massive $834 million reconstruction program consisting of 14 contracts, of which Skanska Koch has performed several. This Skanska Koch project, contract #14, scope of work includes the replacement of the suspender cables at all 628 locations across the bridge. This includes changing the majority of the suspender anchor points from the bottom chord to the top chord of the bridge truss. Additionally, the main cables are undergoing a major upgrade. All of the existing wire wrapping around the main cables is being removed and replaced with a composite system. This includes the removal of an existing hazardous lead paste corrosion inhibitor and the installation of new wrapping wire covered by a waterproofing membrane. New main cable hand ropes and necklace lighting will also be installed under this contract. In addition to those major facets of work, all of the main cable bands will be repainted, the cable band bolts will be replaced, eight truss bearings will be replaced with new multi-rotational bearings, and multiple reinforcing plates will be installed along the truss chords. Most operations take place during normal business hours. The work happens adjacent to live vehicular, train and pedestrian traffic. The lane closure windows are limited which restricts the majority of the heavy hoisting work to off-peak traffic hours (10am-3pm).
