THE THIRD BRIDGE (1895): Even after the repairs, the bridge had become dangerous once again by the early 1880's. The wooden chords on the Howe trusses had deteriorated significantly, and additional piers constructed to support the bridge had weakened. At times, the dilapidated bridge had to be closed to all traffic. George S. Greene, construction engineer for the New York City Parks Department, recommended constructing a new bridge made of iron, a material that provided strength and efficiency.
A number of rehabilitative measures, including replacing the wooden trusses with iron trusses on the old bridge, were undertaken between 1883 and 1889 to buttress the existing span. During this time, the New York City Parks Department selected engineer Alfred P. Boller, who would go on to design the Madison Avenue, 145th Street and University Heights draw spans, to create plans for a new bridge.
In 1890, the parks department voted to replace the bridge, and one year later, the New York City Board of Estimate followed suit. That year, the New York State Legislature authorized construction of the new bridge, which was to take on the historically significant "Macombs Dam" name, and allocated $1.25 million for construction and right-of-way acquisition. The bridge was to be free of tolls, but no horse, cable or other trolley tracks were to be permitted. It was to be built in conjunction with an Army Corps of Engineers project to construct the Harlem River Ship Canal, which was to provide a navigable channel between the East River and the Hudson River.
Upon approval from the War Department, construction began in April 1892 under contract from the Passaic Rolling Mill Company. The old bridge was closed immediately, and demolition work on it commenced while work on the new bridge continued. (However, the old masonry pier remained until 1897.) A temporary bridge carried traffic from 156th Street, one block north of the new span. When it became apparent that the cost of the bridge would exceed $1.25 million, the state legislature allocated additional funds for construction and right-of-way acquisition expenses.
The new Macombs Dam Bridge opened to traffic on May 1, 1895 at a cost of $1.8 million. Initially, steam power propelled the draw mechanisms, and gas lighting provided illumination for the roadway. In 1904, steam and gas power sources were replaced with electrical sources.
Sharon Reier, author of The Bridges of New York, described the design of the Macombs Dam Bridge and its abutments as follows:
The bridge has been humorously likened to a raffish tiara. Following the precedent of the currently novel Tower Bridge in London, which had used Tudor-style architecture in its abutments, Boller had designed Gothic-revival structures to abut the Macombs swing span. This choice of architectural style makes some sense, as drawbridges did originate with the moats surrounding medieval castles… It is the only movable bridge over the Harlem that warrants a walking tour. The others, also completed around the turn of the century, are less interesting, or are downright blights on the river.
DESIGN AND CONSTRUCTION: The Macombs Dam Bridge, a rim-bearing swing bridge, features a 412-foot-long draw span that allows 150 feet of horizontal clearance through the two navigable channels, and 25 feet of vertical clearance in the closed position. A two-stage electric engine powers the swing span. The 40-foot-wide roadway between the two exterior trusses permits two lanes of vehicular traffic in each direction, as well as two sidewalks.
The foundation of the Manhattan pier was sunk on a pneumatic caisson to rock, as was the foundation of the center pier. The Bronx pier was built on rock also, but in an open sheet-pile dam, and from that point across the swamp to 161st Street the plans called for pile foundations. However, the unstable swamp on the eastern bank required surrounding on Bronx pier in with collar of sand and concrete.
RAIL SERVICE ON THE BRIDGE: When the Macombs Dam Bridge opened, the New York City Department of Bridges had a provision prohibiting rail service across the span. This provision was lifted in 1907, when the IRT began trolley service over the bridge. The trolley service ran until 1918, when the IRT replaced the trolleys with an extension of the Ninth Avenue El. The new subway line, which provided continuous subway service from Manhattan to the then-new IRT Jerome Avenue Elevated (part of today's IRT #4 subway line), was built on a separate swing span - the Sedgwick Avenue Bridge - that ran parallel to the Macombs Dam Bridge. The parallel span was torn down in the early 1960's.
CONNECTING TO THE STREET GRID: The Macombs Dam Bridge has viaduct approaches connect to 155th Street and Bradhurst Avenue in Manhattan, and to Jerome Avenue and 161st Street in the Bronx. During the 1950's, the eastern viaduct was connected to the Major Deegan Expressway (at EXIT 5). According to the New York City Department of Transportation (NYCDOT), which now maintains the span, the Macombs Dam Bridge carries approximately 40,000 vehicles per day (AADT).
REBUILDING THE MACOMBS DAM BRIDGE: In 1999, the NYCDOT began a three-stage, $145 million project to rehabilitate the Macombs Dam Bridge. The project included the following work:
rehabilitating and repainting the superstructure
refurbishing the draw mechanism and electrical systems on the draw span
reconstructing the camelback truss over the Metro-North Railroad, the deck truss over the CSX Railroad, and the viaducts over the Major Deegan Expressway (I-87) and the Harlem River Drive
replacing the roadway deck on the bridge and connecting ramps
The project, which was undertaken during the winter months so as not to interfere with Yankee Stadium-bound traffic, was completed in 2004.
In 2010, the NYCDOT plans to begin a three-year, $36 million project to perform seismic retrofitting work on the bridge. Engineers plan to build small piles in the existing piers that support the swing span, strengthen columns and floor beams on the 155th Street Viaduct section, and install lock-up devices that would distribute loads during a seismic event.