In 1912 the Smiths Falls Bascule Bridge was built to carry the Canadian Northern Railway mainline over the Rideau Canal. It is a Scherzer rolling-lift railway bridge and is one of the oldest remaining bascule bridges in Canada. Originally designed to be run with a DC powered electric motor, in 1915 the bridge was forced to be operated manually for the next 63 years until it was closed in 1978. The bridge was designated a National Historic Site in 1983.