Development of the Vertical Lift Bridge: Squire Whipple to J. A. L. Waddell, 1872–1917

Abstract

The development of canals started in the mid 18th century in England and Europe and in the 1820s in the United States. They required the design and construction of many bridges to provide canal crossings for carriages, wagons, animal herds, and pedestrians. The cost of building bridges of masonry or wood to carry roadway traffic high over the towpaths and waterways of canals was very great so engineers of the day developed bridges that could be moved out of the way when a canal boat was coming through and then moved back over the canal to provide roadway access. The Dutch developed a type of bascule bridge for many canals, while the British developed swing or pull back bridges. The swing bridge for narrow canals had a turntable on shore with a short counterweight span over land and a cantilever span over the canal. This bridge could be worked by hand with a simple crank. The pull back bridges, while not as common, ran on tracks and had the same type of counterweight span and cantilever span over the canal. On wide canals, as well as on the C & O Canal in the 1830s, the swing bridges had a central pier on which the turntable was mounted and the bridge cantilevered out on both sides to the shore when closed, and frequently onto an extended pier parallel to the canal when the bridge was open for canal boat passage. In the United States the most common bridge on canals and waterways was a side mounted or center mounted swing bridge well into the 20th century. The development of the metal vertical lift bridge can be traced to the late 1840s in England where several small lift spans were built. After a review of early European spans, this paper covers the period starting in 1872 with Squire Whipple and his Erie Canal bridges, and terminates in 1917 with Waddell's Columbia River Bridge.