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GeneralThe planThe constructionCable railwayMeasurementsSluiceBridge

For closing the northern gap a cable railway was constructed from the island Goeree-Overvlakkee to the central sand bank the Plaat van Oude Tonge. A French firm, Neyrpic, was hired to design and to build this railway. On the north shore and on the central sand bank loading dock were built. In the northern gully a pillar was placed to support the cable in the middle. On the central sand bank a construction was made with weights to keep a constant tension on the cable. Each cable car had it’s own engine and an engine driver. On each trolley nets made by thick steel chains were hung. These nets contained the stoned which had t be dropped in the gully.

On August 3 1964 the first of ten cable cars with a load of 10.000 kilograms of rocks made it’s first trip over the 92 millimeters thick cable. The maximum speed was 9 meters per second but the average speed was 5 meters per second (= 18 km/h).

On the Plaat van Oude Tonge an immense stock of 55.000 tons of large pebbles and 60.000 tons of rocks and stones was available. This was the first time a cable railway was used to built a dam, so it was an exiting experiment.
The first layer were the large pebbles with weights between 10 and 300 kilograms. After experimenting with time and speed on August 24 they started to drive also at nights. It took each cable car 20 minutes to make a trip to the other side and back. With 10 cable cars per hour 300 tons of materials could be dropped. In 24 hour this was 7.200 tons. A total of 190.000 tons of rocks and stones had to be dropped.
Because all the pebbles, rocks and stones were imported this was very expensive. They decided to use other materials. They wanted to use the sand present on the central sand bank. The developed four methods for using this sand.

1. mixing the sand with water so it becomes a thick mash. This was put in large bags made of natural and artificial fibers. Each filled bag weight 2.5 tons. One cable car could carry four bags and drop the on the right place.

2. mixing the sand with asphalt. Now the bag could be cheaper for the sand was mostly hold by the asphalt. Each filled bag weigh 2.5 tons.
3. this method is similar to method 2 only more asphalt was used so a bag was not needed.

4. sand was put in bags and then made vacuum         ( minus 15 cm Hg). The sand was compressed and became solid. This also could be handled as it was a stone.