Monaco offshore extension

The maritime infrastructure, which will enable the development of a new district in the Principality of Monaco, consists of a land reclaimed from the sea surrounded by a protective belt made out of 18 reinforced concrete caissons placed on top of an underwater rockfill embankment. To carry out this offshore extension, Bouygues Travaux Publics has developed innovative new construction methods, aimed, in particular, at reducing the impact of the project on the environment and preserving the Principality’s natural marine heritage.

The 18 reinforced concrete caissons – 85 feet high and weighing 11,000 short tons each – were built in the Grand Port Maritime de Marseille using the submersible Marco Polo floating construction dock. The only one of its kind in France, this floating dock was designed specifically for the needs of this extraordinary project. It can operate at shallow draught and can be sunk and raised again quickly, enabling it to achieve high productivity. It also has an innovative automatic ballasting system, guaranteeing greater stability.