Installation and commissioning of a submerged cofferdam in Monaco is successfully completed

29 August 2016

Strukton Immersion Projects successfully completed the installation and commissioning of a submerged cofferdam in Port Hercule, Monaco. A U-shaped structure called “Batardeau” has been installed around a submerged ball joint, which is connecting the floating jetty Quai Rainier III with the abutment of Terre-Plein. This job is part of the contract for the Maintenance décennale de la Rotule de la Digue flottante.

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The Batardeau is 12m wide and 16m high and has a weight of 45t. It consists of a steel box equipped with inflatable rubber seals. The unique structure has been designed and build by Strukton Immersion Projects. The inflatable rubber seals are developed in close cooperation with Trelleborg Ridderkerk. The construction and its components are fitted and tested in Netherlands before it was transported to Monaco. The Batardeau was hoisted, submerged and moved in sideways around the ball joint using a crane barge. Thereafter the Batardeau was turned vertically using hoists. After connecting the Batardeau to the horizontal and vertical locking structures above the joint, the rubber gaskets were inflated and the space inside was drained.

The atmospheric cofferdam provides a dry and safe work area for the personnel of French JV partner NFM, to carry out the decennial maintenance work to the ball joint. The cofferdam is able to follow the movements of the floating jetty by using an innovative interconnected hydraulic jacking system provided by Strukton Infratechnieken.  Strukton Maatvoering & Monitoring has developed a real-time monitoring system showing online values like the pressure in the seals and jacking system and various parameters inside the cofferdam.  Diving works was carried out with equipment and expertise from OTN and local dive company Prodive.