'Inclined Plane on the Morris Canal', United States, mid 19th century.
© Science Museum / Science & Society Picture Library
Lithograph by A Ducotes after an original drawing by A Hervieu. Inclined planes were introduced on canals to overcome the requirement of having a series of closely-spaced locks, which slowed down journeys and created bottlenecks. Instead of progresing through a series of locks, each of which had to be alternately drained and filled, a boat would dock in a chamber. This would be emptied of water and raised up or lowered down a slope on rails. The inclined plane was a particularly valuable innovation on the Morris Canal, built in 1824-1836 between Phillipsburg, Pennsylvania and Jersey City, New Jersey. An elevation change of 1674 feet over its 102 mile length meant a total of 23 inclined planes were built on the canal.