Park Avenue Bridge (New York City)
|Park Avenue Bridge|
|Carries||4 tracks of the Metro-North Railroad|
|Locale||Manhattan and the Bronx in New York City|
|Maintained by||Metropolitan Transportation Authority|
|Design||Vertical lift bridge|
|Longest span||340 ft (100 m)|
|Clearance below||25 ft (7.6 m). (closed) and 135 ft (41 m). (open)|
|Opened||1956 (replacing 1897 bridge)|
The Park Avenue Bridge is a vertical lift bridge carrying the Metro-North Railroad across the Harlem River between the boroughs of Manhattan and the Bronx in New York City. The average weekday ridership on Metro-North Railroad is 265,000.
First two bridges 
The first bridge on this site was constructed by the New York and Harlem Railroad in 1841. It was composed of four 90-foot (27 m)-long box truss spans, three of which were fixed iron spans, while the remaining span was a wooden swing span. In the closed position, the bridge had a clearance of only seven feet above mean high water. Masonry piers supported the four box-truss spans. In 1867, the wooden drawbridge was replaced with an iron one that gave a clearance of 50 feet. It was very busy. By the 1880s, the bridge was crossed by more than 200 trains a day.
Third bridge 
The 1867 bridge was soon made obsolete by heavy traffic and dredging of the Harlem River Ship Canal. Alfred P. Boller worked with the railroad to create a new four-tracked swing bridge. The railroad and the city split the cost.
The new swing bridge was built in conjunction with the Army Corps of Engineers' project to build the Harlem River Ship Canal. The Park Avenue railroad viaduct was also extended north of 115th Street at the same time. While the bridge was being built, a temporary bridge was built and the old span was demolished.
The bridge opened in 1897, and the project included construction of a long new viaduct to raise the level of the rail line between 115th Street and the river. The new bridge had a 300-foot (91 m)-long steel truss span supported by masonry piers. When closed, the vertical clearance was 25 feet (7.6 m).
Existing bridge 
Between 1954 and 1956, the New York Central Railroad built a fourth rail bridge on this site, this time a vertical-lift bridge, to replace the 1897 bridge. Opened in 1956, the four-track bridge remains in use today and consists of two parallel double-track spans, 340 feet (100 m) long. It has 25 feet (7.6 m) of clearance when closed and 135 feet (41 m) when open. During the 1960s, the bridge came under the ownership of several different companies, including Penn Central Railroad. Today, Metro-North operates it.
- Commuter Rail Transit Ridership Report First Quarter 2010, p. 5, American Public Transportation Association, June 1, 2010. Accessed June 27, 2010.
- Gray, Christopher (February 19, 1995; with correction dated March 19, 1995). "The Park Avenue Railroad Viaduct: A $120 Million Renovation for an 1897 Behemoth". The New York Times. Retrieved 2009-08-15.
- Guide to Civil Engineering Projects In and Around New York City (2nd ed.). Metropolitan Section, American Society of Civil Engineers. 2009. pp. 52–53.