The inclined plane of Ronquières

The construction of the inclined plane of Ronquières started in March 1962, based on a decision by the Ministry of Public Works, and was due to open to shipping in 1968. By enabling 1350 tonne barges to pass through, this structure enabled 14 old locks to be superseded. Like other civil engineering structures on the waterways, the Electricity, Electromechanics, Computer and Telecommunications Division (D.E.E.I.T.) manages problems relating to electromechanic problems on the inclined plane.

Operating principles

Overall characteristics

Panoramic view
Panoramic view
Operating principle
Movement of the cages.
Movement of the cages.

The inclined plane at Ronquières consists of two concrete channels 1432 meters long, arranged side by side, with a useful width of 2 x 15 m. Each channel is equipped with a cage and a counterweight, linked together by 8 steel cables of 55 mm in diameter. The two cages function independently, and can each transport simultaneously one 1350 tonne barge, or several barges of lower tonnage.

A cage is fitted with 236 runner rollers (70 cm in diameter) with a counterweight of 204 rollers. The runner rollers of each cage are grouped in two rows of 59 axles. These flangeless rollers run on rails (EB63) fixed to the channel. Each cage is equipped with an oleohydraulic system (coupling) which spreads the strain in the traction cable automatically and identically (approximately 35 tonnes per cable). Another oleohydraulic system (mooring) automatically limits the strain in the mooring cables of the barges in the event of an impact or an accident.

Each counterweight consists of two independent chassis ballasted with heavyweight concrete and cast iron (weight of the two ballasted chassis 5500 t). The traction cables, 1480 m long, are pulled by KOEPE type driving winches 5.50 m in diameter. The cables are guided onto the drive drums by pulleys 5.5 m in diameter. There are a total of 32 guide pulleys (16 per cage). Each winch is driven by 6 motors.

The inclined plane, with the tower and the channel in direction of Hainaut.
The inclined plane, with the tower and the channel in direction of Hainaut.
Schematic diagram

Schematic diagram.
Schematic diagram.
A barge travelling along the inclined plane

All the manoeuvres on the inclined plane are centralised. They are carried out by the lock personnel, who have a bird's eye view of the structure from the 6th floor of the tower. In practice, an acceleration of 10 mm/s² is applied for about 32 seconds. It remains constant for about 1.30 minutes, before reducing to 0 for about 32 seconds. At this time, the cage reaches its normal speed of 1.20 m/s. Another speed may be selected by the operator (for example 0.30 m/s, 0.60 m/s, 0.90 m/s or 1.30 m/s). Once the chosen speed has been reached, the cage maintains that speed under the control of the regulation equipment.
To avoid excessive oscillation of the barges in the cage, the regulation takes account of its instantaneous speed, the wind strength on its walls, the ambient temperature, whether the cage is rising or falling, its acceleration or deceleration. The position and speed of the cage are determined by 3 pulse generators (20,000 pulses/s.). Taking account of the speed of the cage and the remaining distance to be travelled, the regulation determines the exact spot where deceleration should start to decelerate to dock with the recess (the end of the canal) gently. The law of the deceleration of the cage is the inverse of that for its acceleration.

The two concrete hoppers include the guide rails, the tension cables and the counterweights and are separated by a concrete quay level.
The two concrete hoppers include the guide rails, the tension cables and the counterweights and are separated by a concrete quay level.
A few numbers

The outlet profits from a lighting. The gantry which spans it contains the mechanisms of lifting of the doors of the vats and the levels.
The outlet profits from a lighting. The gantry which spans it contains the mechanisms of lifting of the doors of the vats and the levels.

Big Projects