Ship Lifts and Inclined Planes

devices designed to carry ships from one level to another. Ship lifts and inclined planes may be used to overcome changes in water level along inland waterways, for example, at hydraulic engineering complexes, or to raise and lower ships at shipyards. In those structures installed on inland waterways, the ship is usually maintained afloat in a movable, water-filled chamber. Each end of the chamber is fitted with a gate, through which ships enter and leave. The chambers move on rails, usually by means of mechanical or electrical traction.

Inclined planes may be of longitudinal design, in which the ship is pointed in the direction of travel, or of transverse design, in which the ship is positioned perpendicular to the direction of travel. There are also single- and double-incline systems, the latter type having a turntable device for transporting ships over a divide or dam. The large inclined plane built in 1969 at Ronquiéres, Belgium, transports ships with displacements of up to 1,350 tons across a 70-m rise. In the USSR a unique inclined plane was placed in service in 1975 at the Krasnoiarsk Hydroelectric Power Plant. It is equipped with a hydraulically driven, self-propelled ship chamber and a turntable mechanism. It is designed to raise and lower ships with displacements of up to 2,000 tons across a 101-m rise.

Vertical ship lifts may be operated by means of counterweights or hydraulic rams or by flooding. The most common mechanical lifts are used to transport ships with displacements less than 1,000 tons across rises of less than 36 m. The ship lift constructed on the Oder-Havel Canal in 1934 at Niederfinow, German Democratic Republic, is an example of this type.

The most common devices not used for transportation are marine railways and slips. Vertical lifting is accomplished primarily by means of floating docks with one or two towers, although jib and bridge cranes and hydraulic lifts are also used.