By rosebell
The Fehmarnbelt tunnel project has received an unique vessel that is due to play a crucial role in the immersion of elements of this project at the Rødbyhavn construction site on Lolland.
As a two vessels that can be assembled and disassembled, the immersion pontoon has been delivered to the tunnel contractor, Femern Link Contractors (FLC), whereas it sailed to Rødbyhavn from the Crist shipyard in Gdynia, Poland.
In order to supporting the Fehmarnbelt tunnel elements during their journey from the work harbour, Ivy 1 and Ivy 2 have been designed. Considering that immersing the dredged tunnel trench on the seabed is important, prior to the immersion process several thousand tonnes of ballast concrete will be added to make the elements heavy enough, while the 217m-long elements when are leaving the factory are light enough to float. From here the tunnel element will only be supported by the two immersion pontoons, which will serve as the tunnel element’s bathing wings.
Being operated by a 22-person crew, Ivy 1 and Ivy 2 will support opposite ends of each standard element, and the special elements, which are significantly shorter, will be supported by the two vessels coupled together.
Supporting the elements and controling the immersion process are the two main functions of the immersion pontoon and using the vessel contains winches with over 200km of steel wire as well as a control room, the immersion process will be managed.
According to Femern construction marine manager Baris Nacar: “It will require a steady hand and some highly advanced equipment to immerse the tunnel elements with the precision we require. Our immersion pontoon, therefore, has been specially built for this purpose.”
The scheduled date for installation of the additional technical equipment will be the coming months,while the vessel is then slated to be tested at sea before the immersion of the first tunnel element can being.
