Inclined plane railroad
An inclined plane railroad was a type of water-driven railroad that allowed barge traffic of canals to ascend and descend steep hills. They were used primarily in the early 19th century, especially during the height of the canal-building era in the 1830s in the United States.
The railroads operated by allowing water in feeder canals at the top of the plane to drive a turbine, raising or lowering a canal barge along a steep slow. In general, the barges were maintained level during the operation. Along level sections, the railroads essentially operated as standard towpath canals, with the barges typically drawn by horse or mule.
Examples of inclined plane railroads included the Allegheny Portage Railroad, part of the Pennsylvania Main Line Canal in the United States, built in 1834 with ten planes as the first railroad across the Allegheny Mountains of Pennsylvania. Similarly, the Morris Canal in New Jersey connected the Delaware River with the Passaic River using 23 planes, as well as a series of locks along the gentler gradients.
Considered technological marvels in their heydey, inclined plane railroads were rendered obsolete by the arrival of steam locomotive railroads in the 1850s.