Inclined plane (railroad)

A cable railway (also known as an incline or inclined plane) is a steeply graded railway that uses a cable or rope wound about a cable winch system similar to a ski lift mechanism powered by a stationary engine to haul trains on adversely steep grades. Many such were funicular railroads, where one descending load in part counterbalanced an ascending consist, much like a cable car.

Cable railways are typically built where the gradient of the route is so steep that a conventional adhesion train could not climb the track. Most commonly the cable is operated by a stationary engine, although other methods such as gravity or water-balance are also used.

Many cable railways connect to conventional adhesion lines at their top and bottom, allowing trains to be lifted from a lower line to a higher one. A specific type of cable railway is the funicular, which is a cable railway with the cars permanently fixed to the cable. Usually funiculars are self-contained and not connected to other railway networks.

The majority of inclines were used in industrial settings, predominantly in quarries and mines, or to ship bulk goods over a barrier ridgeline as the Allegheny Portage Railroad and the Ashley Planes feeder railway shipped coal from the Pennsylvania Canal/Susquehanna basin via Mountain Top to the Lehigh Canal in the Delaware River Basin. The Welsh slate industry made extensive use of inclines to connect quarry galleries and underground chambers with the mills where slate was processed. The Ashley planes were used to transship heavy cargo over the Lehigh-Susquehanna drainage divide for over a hundred years and became uneconomic only when average locomotive traction engines became heavy and powerful enough that could haul long consists at speed past such obstructions yard to yard faster, even if the more roundabout route added mileage.

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