Princess Maxima Locks

A bend in the Meuse, nothing special on the face of it. From a VHF radio point of view, however, it presents the necessary challenges

The Princess Máxima Locks is a lock complex in the Maas near Lith. The complex consists of two locks. The first lock was commissioned in 1936, the second officially in 2002. Just after the locks there is a bend in the Meuse.

With the marine telephone system in use at the time, the staff at the control building could not ‘hear’ the ships coming until they had already passed the bend before the lock and thus had already almost reached the lock. As the new lock has a larger capacity than the old lock and is therefore accessible to all modern shipping, there was an increasing desire to ‘hear’ these ships coming even before they had passed through the bend.

SAIT designed and implemented a new VHF system for this purpose, using the latest technology. The design also opted for a different antenna arrangement that took shadow areas into account. Achieving this involved quite a bit of ‘art and craft’.

Paul Swaneveld, Senior Operational Management Officer at Water District Nijmegen Maas, remembers this well: “The installation was technically quite special. For instance, antennas had to be placed on the “bridge” between the lock’s lifting towers and it was necessary to pull a cable into the counterweight shaft. Fortunately, SAIT staff were very flexible in solving unusual situations and even built scaffolding to pull the cable through the lifting shaft to the antenna!”