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 By enabling 1350 tonne barges to pass through, this structure enabled 14 old locks to be superseded.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.
- Total length: 1800 m including the canal bridge
- Length of slope: 1432 m
- Angle of slope: 5%
- Difference in level: 67.73 m
- Number of cages: 2
- Lockage: 2 barges simultaneously, each weighing 1350 t
- Duration of a transverse movement ± 22 minutes
- Total time to pass through the structure: ± 50 minutes
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
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.
- Guide pulley
- Motorized driving pulley
- Coupling system
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.
- When the cage reached the end, it is locked into the recess: the sluice is closed;
- The gates between the reach and the cage are raised: the barge can leave the cage;
- The gates between the reach and the cage are lowered; the water between the reach and the cage is emptied through the sluice.
A few numbers
- Length of HV + LV electric cables: ± 225 km
- Length of electrical wiring: ± 205 km
- Length of TAL tubes: ± 47 km
- Number of programmable automatic control systems - 2048 (E.S.) : 2 p
- Number of relays: ± 3,500 p
- Number of LV contactors: 593 p
- Number of HT contactors: 3 p
- Number of LV circuit-breakers: 67 p
- Number of HV circuit breakers: 23 p
- Number of LV fuses: 1,112 p
- Number of LV motors: 252 p
- Number of HV motors: 2 p
- Number of mechanical stops: 550 p
- Length of VOB cables: ± 50 km
- Length of trolley wires: 18 km
- Length of rails, type UIC web 30 mm: 36 km approx.
- Number and length of traction cables 55 mm: 16 p each 1,480 m long
- Number of runner and guide rollers: 984 p
- Number of hours of operation as of 1st January 1998 : 124,615 h.