On April 23, 1951, the New York Central announced that work replacing the swing bridge over the Harlem River with a vertical lift bridge would begin on May 1, and that it would be completed in 1954. The new bridge was constructed to the west of the existing bridge, and consisted of two spans, each carrying two tracks. Each of the spans had its own tower and lift machinery so service could continue if either set of lift machinery stalled while its span was raised. The new bridge reduced the time needed to allow ships to pass from nine minutes to four minutes.