Precision work: working high up at the Gouwespoor bridge

Mennens replaces lifting wire ropes and corrects misalignment at Gouda railroad bridge

The Gouwespoor bridge is about 60 meters long. There are two bridges with a double track in the middle. This lift bridge has two spans which move up and down separately. Attached to the span are balance ropes, both short and long. The long balance ropes generate more stretch than the short ones. This can lead to misalignment on the span. To correct this misalignment, we need to adjust the tension in the different balance ropes. At the same time, we also replace the lifting ropes, which have reached the rejection criteria according to the standards.

Pre-stretching wire ropes

When we receive an order to make wire ropes for a bridge (or lock), they must comply with the RWS (Directorate-General for Public Works and Water Management) standard standard. This requires the wire ropes to be pre-stretched: the stretching must be removed. We do this before the installation, otherwise the bridge can’t be raised or lowered properly because the steel wire ropes grow uncontrollably longer over time. 

Pre-stretching goes per four wire ropes at Mennens. This is one trip. The wire ropes are put under tension in the pre-stretching machine, measured and cut. Then we do another run of four wire ropes. We wind the ropes onto a hawser and transport them to the railroad bridge in Gouda. 

Challenge: counterweight with wire rope fitting

The tricky thing about this railroad bridge in Gouda is that a wire rope fitting is attached to the underside of the counterweight. This location can’t be reached by normal means, without running into problems with the blockage. Dismantling and reassembling this fitting high up is a job for our colleagues at Safe Site – Powered by Mennens. They are specialized in working high up and can reach the most difficult places with Rope Access techniques. 

Excellent result 

The railroad bridge now spans the water with millimeter accuracy, both in length and in cross section. Thanks to close cooperation with our project partners Movares and Strukton, the misalignment in the bridge was corrected. Mennens remains continuously involved in the inspection and maintenance of the steel wire ropes.  
 

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