Between Denmark And Germany The longest submarine tunnel in the world will be made: the Fehmarnbelt. With a length of 18.2 km and a depth of 4thit will be made up of two motorway lanes and two electrified railway tracks, while a fifth central rod will be prepared with service and safety functions. The maximum speeds allowed inside will be 110 km/h for vehicles e 200 km/h for trains, in just 10 minutes cars, and in 7 minutes The trains will be able to complete the crossing between Rødbyhavn And Puttgardenshortening the route of about 160 km. The project will be completed by 2029, subtracting from Ryfylke tunnel14.4 km long and inaugurated on 30 December 2019 in Norway, the primacy of longest submarine road tunnels in the world.
The characteristics of the Fehmarnbelt tunnel
Positioned inside an underwater excavation 60 meters wide and 16 high, the tunnel will consist of 89 box structures long 217 meters and from the weight of 73 500 tons. These will be made of reinforced concrete and once prefabricated on site will be positioned and interconnected with each other style Lego (of always Danish origin!). With a total investment of 10 billion eurosthis work, together with eight other mega projects, will be part of the trans-European transport networks (Ten-t), to which the Tav Turin-Lyon Tav also belongs.
Of the 89 individual prefabricated elements 10 are defined “special“. In Denmark it is not the first tunnel built with this method of construction, in fact, very similar is the process used for the tunnel under the Oresund bridge between Denmark and Sweden. By expanding the experience gained by that project, the “special” councils have an extra basement that will allow to carry out repairs and maintenance without ever disturbing traffic.
How the longest submarine tunnel in the world will be built
The tunnel will require about 360 000 tons of steel And 3.2 million cubic meters of cementwith 2 million cubic meters of sand necessary only for concrete. The construction site was opened in 2020, and before starting the construction of the tunnel it was necessary to create the mega-fibbric of the councils together with the work port of Rødbyhavn in Lolland, these, together, cover an area of about 1.5 million square meters the equivalent of 310 football fields!
The installation of the councils is carried out with the help of a hydraulic arm for their positioning and special rubber gaskets ensure full connection between the elements. The marine water used for sinking, once pumped outside, makes a pressure difference in the cavity and the strong external watering pressure, much greater than the internal one due to the depth, is created, ensures the keeping of the innovative rubber seals. Positioned the Concio The connection is completed with a continuous jet of concrete armed with a thickness of about 1 m On the bottom of the element, this also helps to contrast the floating push.
Safety in the Fehmarnbelt
For a work of this kind, ensuring high safety standards is fundamental, already the choice of separate rods by direction and type of traffic is a strong safety element. The tunnel will be monitored 24 hours a day Both from the local tunnel control center, LCC, on the Danish side of the Fehmarnbelt, and from the Copenhagen railway traffic control center, TCC.
All rods will be connected to emergency exits at least each 100 ma much lower distance of the standard requirement of Community directives that provide for an interdistance of 500 m And all the structures will have a fire -fighting coating that will allow them to resist temperatures up to 1 350 ° C for fire exhibitions up to 3 hours.
