Counterweight for a mooring pontoon

Project scope

Commissioned by Rijkswaterstaat (the executive organization of the Ministry of Infrastructure and Water Management in the Netherlands), Van der Straaten Aannemingsmaatschappij B.V. revised the mooring pontoon of the central storage area in Vrouwenpolder. Part of this work is removing old ballast and putting in new ballast. How is this done most efficient? Which method prevents damage to the newly applied top layer and coatings? How do you slow down oxidation of the metal structure?

Conditions

The ballast has to compensate for the weight of the bridge, resting on top of the pontoon and will be installed whilst the pontoon is located at it’s final destination. Our pump is located on the quay as close as possible to the bridge, where the ballast has to be pumped over a distance of 40 to 50 meters.

Divided over 2 ballast tanks, a total of 28 barrels are installed (capacity 220 liters), ready to be filled with solid ballast. The tanks, with an internal height of 1,4 meter, are accessible via 2 manholes. At least 15 tons of solid ballast has to be distributed among the 28 barrels and the additional task is to work as carefully and cleanly as possible.