An Aerial Ship Railway

By “Awake!” correspondent in Belgium

A 1,350-ton ship floating along sixty feet above the solid earth! And without any of the traditional canal locks! No, you are not imagining things. You are at Ronquières in Belgium.

Between Brussels and Charleroi this vital link in an international waterway enables boats and barges of up to 1,350 tons to clear, in one stride, so to speak, a difference in water levels of 223 feet. But how do they take ships from one level to the other without locks and a water channel?

Instead of an aerial water channel here, there are parallel railroad tracks, each having four rails. Huge water containers, metal, and having a water capacity varying in depth from 9 to 12 feet, run on these tracks, each equipped with a roller train consisting of 236 28-inch diameter pulleys. Each pulley is capable of carrying a load of 22 tons. Six electric motors, developing a total force of 1,000 horsepower, operate eight two-inch-thick cables, each about one mile long. By these the water containers are raised or lowered on the inclined railway track.

The docks at the two extremities of the project, upstream and downstream, measure 1,000 feet long by 200 feet wide. The containers, 300 feet long by 39 feet wide, are lodged in the prolongation of these docks, and can be maneuvered independently of one another​—one ascending while the other descends, for example. Each container can take either one 1,350-ton ship or several barges.

The vessel floats into the submerged container at one end of the project, upon which both the canal and container gates are closed. The container then carries its floating load either up or down the slope separating the two levels. At the other end the canal and container gates open and the vessel continues on its way. When in operation the weight of one container varies between 5,000 and 5,700 tons.

To assure the junction between the upper embankment and the actual inclined plane, there is a canal bridge 950 feet long, supported by seventy 6-1/2-foot diameter columns, each 63 feet high. The overall aerial portion of this undertaking stretches over a distance of some 2,300 feet. Thus you can view the spectacular sight of ships floating along, up above the solid ground!

Special care was taken not to impair the beauty of the surroundings. But there were more serious problems to be foreseen and provided for. Should there be a failure of outside electrical supply, for example, the installation has its own hydroelectric powerhouse. All the intricate operations, especially when traffic is heavy, are easily supervisable from a distance by television screens. The ‘brain’ of the inclined plane is housed upstream in a control room surmounted by a 410-foot tower.

The effects of frost are kept in check by covering the outside walls of the containers with thermal insulating material. To avoid skidding in cold weather, there is a system of defrosting the cables. Safety pulleys or rollers control the movement of the containers. The movement of the water and the vessels in the containers was one of the most delicate problems that had to be solved.

A compensation system automatically corrects any possible unevenness in the ground below or in the inclined rails. Automatic bolts prevent any false maneuvers. In periods of drought, supplementary reservoirs guarantee the water supply for the whole project, and could, if required, keep it going for a month.

This outstanding engineering production has permitted the number of locks on the Brussels-Charleroi canal to be cut from fifty-five to ten. It has cut in half the time needed to cover the distance between Charleroi and Antwerp, thereby reducing the transportation costs by more than 60 cents a ton.

The entire complex has also become an interesting tourist attraction, bringing each year an influx of thousands of visitors. In 1968 there were more than 250,000, most of whom enjoyed the unforgettable panorama that can be viewed from the top of the large tower.