Alfred H. Smith Memorial Bridge

Alfred H. Smith Memorial Bridge
Foreground: Alfred H. Smith Bridge; Background: Castleton Bridge. Seen from the west shore, south of the bridges.
Coordinates	42°30′31″N 73°46′30″W / 42.5087°N 73.775°W / 42.5087; -73.775Coordinates: 42°30′31″N 73°46′30″W / 42.5087°N 73.775°W / 42.5087; -73.775
Carries	Railroad freight
Crosses	Hudson River
Locale	Castleton-on-Hudson, New York
Maintained by	CSX Transportation
Characteristics
Design	Truss bridge
Total length	1,601.7 metres (5,255 ft)
Clearance below	139 ft
History
Opened	1928, 1924
Alfred H. Smith Memorial Bridge Location in New York

The Alfred H. Smith Memorial Bridge is a railroad bridge spanning the Hudson River at Castleton-on-Hudson and Selkirk, New York in the United States.

The bridge is owned by CSX Transportation and was originally built for the New York Central Railroad, which was subsequently merged into the Penn Central and then Conrail before being acquired by CSX. The bridge forms part of the Castleton Subdivision of CSX.

The bridge is named in honor of Alfred Holland Smith, the president of the New York Central Railroad who authorized the construction of this bridge as part of an extensive project known as the Castleton Cut-Off. He died in a horse-riding accident in Central Park in 1924, prior to the completion of the bridge in that same year. He is sometimes confused with Alfred E. Smith, New York's governor at the time.

The bridge has been the southernmost rail freight route across the Hudson River since 1974, after a fire damaged the Poughkeepsie Bridge, 55 miles further south. Rail freight traveling between New York City or Long Island and all points south must take a 280-mile detour along the Hudson River and across the bridge, a route known as the Selkirk hurdle. The Cross-Harbor Rail Tunnel project has been proposed as a direct route between Long Island and the US mainland, cutting across New York Harbor.