For the repairs to the rail tracks of the Visart Lock in Zeebrugge, VSF supplied the compressed air equipment for the underwater habitat.
Volker Staal en Funderingen was responsible for all facilities and supervision of the work under overpressure. The Flemish government commissioned the combination of Benelux Diving and Baeck & Jansen to completely replace the railtrack of the lock gates. The lock gates are roughly 20 metres wide, 10 metres high and 4 metres thick. It was not possible to create a constructionpit to carry out the work in a dry condition due to the risk of rupturing the lock bed. The work was therefore carried out 'a pressurized habitat' at a depth of around 10 metres. From a habitat, the new railtracks were bolted to the concrete foundation and then grouted with a special casting compound. The habitat was ballasted with around 200 tonnes of steel plates to keep it 'in its place'. With an air overpressure of approximately 1 bar (= 2 atm) the water was pushed out of the habitat so the work could be carried out without diving equipment. The air quality and air pressure are extremely important here. VSF employs specially-trained people to operated the equipment .
The work was carried out on both sides of the lock.