The special vessel that will immerse the Fehmarnbelt Tunnel elements has passed the last critical tests and received approval from the Danish Maritime Authority.
The approval means contractor Femern Link Contractors (FLC) can begin preparing to immerse the first tunnel element into the dredged tunnel trench off Lolland’s coast this spring.
The special vessel IVY consists of two distinct units: IVY 1 & 2. Prior to the transportation and immersion of a 217m-long standard tunnel element, each end is secured to IVY 1 & 2 to provide buoyancy. For the handling of the 39m-long special elements, IVY 1 & 2 are joined to form a single vessel.
Together, IVY 1 & 2 are equipped with 23km of steel wire spread over 66 winches, enabling them to submerge tunnel elements to depths of up to 40m.
Sund & Bælt deputy contract director Lasse Vester said IVY was a unique vessel developed exclusively for the construction of the Fehmarnbelt Tunnel.
“Its task is complex, so a long sequence of tests had been necessary to ensure that it meets the high technical and safety requirements set by both us and the authorities. We now have approval for the vessel and are ready for immersion,” he said.
In parallel with the numerous tests, FLC has prepared the first part of the tunnel trench.
This month, IVY 1 & 2 – with the tunnel element secured between them – will be taken to the jetty at the Danish work harbour. Here, ballast concrete will be added to the element to ensure it is heavy enough to sink. IVY 1 & 2 will then transport the element to the trench and immerse it.
Vester said the immersion would be “a challenging operation”, repeated a further 88 times until all elements were in place.
In September last year it was announced that construction of the 18km-long tunnel between Denmark and Germany is delayed for at least two years. Sund & Bælt, the tunnel owner, will update the Fehmarnbelt project’s schedule once the first tunnel elements have been immersed.
