The Whirlpool Rapids Bridge, commonly known as the Whirlpool Bridge or the Lower Steel Arch Bridge (before 1937), crosses the international border between Canada and the United States, connecting Niagara Falls, Ontario and Niagara Falls, New York. This bridge is located approximately 1.5 kilometres north of the Rainbow Bridge and about 2 kilometres from the Falls. It was acquired by the Niagara Falls Bridge Commission in January 1959. Immediately upstream is the similar arch-style Michigan Central Railway Bridge, which has been out-of-service since 2001.
The predecessor of the Whirlpool Rapids Bridge was the Niagara Falls Suspension Bridge, which carried foot and rail traffic. That bridge, opened in 1855, was most notable for being the world's first working railway suspension bridge and for being the bridge abolitionists running the Underground Railroad used to get slaves to freedom in Canada. By the late 1800s, the suspension bridge was becoming outdated for railroad needs. The weight of trains exceeded the specifications of the Suspension Bridge, and the bridge companies took the opportunity to replace of the bridge.
Construction on this new bridge commenced on April 9th, 1896. The new bridge would be constructed around the existing structure as to not interrupt railway traffic. Two halves were built out from the gorge wall in cantilever form, each anchored solidly to prevent it from falling into the gorge below. It was constructed under the old bridge which rested on top of the arch. This was done so that at the completion of the new, but before the removal of the old, there would be two complete bridges built into each other. Once the new bridge was completed the old suspension cables and towers were removed as well as any other parts which were not incorporated into the new bridge. During construction, no train was delayed and the highway floor was closed only two hours per day.
The bridge was completed on August 27th, 1897. Extensive tests proved that a steel arch bridge possessed much greater strength than ever anticipated. This bridge continues in use to this day. With only minor changes from the original, it is capable of handling the heaviest of loads. Bridge engineers do not indicate how many years the future lifespan of this bridge might have.
In 1939, the name of this bridge was changed from the Lower Arch Bridge to the Whirlpool Rapids Bridge. Located just upriver of the Whirlpool Rapids, the Whirlpool Rapids Bridge serves both vehicle/pedestrian and rail traffic.
The bridge has two decks; the upper deck carries the railway traffic while the lower deck is a roadway. There is one lane of traffic to the United States and one lane to Canada. Originally built with two tracks, the second track was removed sometime prior to the early 1970's and the remaining track was centered on the bridge upper deck. The single train track crosses over the bridge on the upper deck. The track is currently used exclusively by Amtrak trains for the Maple Leaf international train service between Toronto and New York City. The Via Rail Niagara Falls Station is immediately located on the Canadian side of the bridge in Niagara Falls, Ontario and the Amtrak Niagara Falls Station is immediately located on the American side of the bridge in Niagara Falls, New York.