A water slope is a type of canal inclined plane

Canal inclined plane

An inclined plane is a system used on some canals for raising boats between different water levels. Boats may be conveyed afloat, in caissons, or may be carried in cradles or slings. It can be considered as a specialised type of cable railway....

 built to carry boats from a canal or river at one elevation up to or down to a canal or river at another elevation.

Operation

The water slope uses a moveable gate in a sloping channel invented by the German engineer Julius Greve at the end of the 19th century and described by the French engineer Jean Aubert

Jean Aubert (engineer)

Jean Aubert was a French engineer. In 1961 he used the idea of the German engineer Julius Greve from the last century to describe a pente d'eau, which was a way of moving boats up the gradient of a canal without locks. The design consisted of a sloping channel through which a wedge of water on...

 in 1961. To ascend the slope the gate can be opened to allow a boat to enter the concrete channel. The gate then closes off the bottom of the channel and seals off a wedge of water on which the boat is floating, within the channel. The moveable gate is drawn up the sloping concrete channel pushing the wedge of water before it until reaching the upper water level. The water level in the wedge is equalised with that of the upper canal and the boat is then allowed to float free.

Descending the water slope is the reverse of the ascent.

Water slopes in use

There are two water slopes in France, both in the south of the country. The Montech water slope

Montech water slope

The Montech water slope is a type of canal inclined plane built on the Canal de Garonne, in the commune of Montech, Tarn-et-Garonne, South West France...

  is on the Canal de Garonne

Canal de Garonne

The Canal de Garonne, formerly known as Canal latéral à la Garonne, is a French canal dating from the 19th century which connects Toulouse to Castets-en-Dorthe. The remainder of the route to Bordeaux uses the Garonne River. It is the continuation of the Canal du Midi which connects the...

. The Fonsérannes Water Slope

Fonserannes water slope

The Fonserannes Water Slope, is a disused inclined plane on the Canal du Midi parallel to the Fonserannes Lock. It has a rise of and a slope of five degrees.This technique for a water slope was described by the French engineer Jean Aubert in 1961....

 is near to , on the Canal du Midi

Canal du Midi

The is a long canal in Southern France . The canal connects the Garonne River to the on the Mediterranean and along with the Canal de Garonne forms the Canal des Deux Mers joining the Atlantic to the Mediterranean. The canal runs from the city of Toulouse down to the Étang de Thau...

, having been built to allow commercial barge traffic to bypass the adjacent lock flight. The latter water slope was abandoned on 11 April 2001.