Floating breakwater and marina in Ljansbruket,
The Municipality of Oslo plans to build a floating harbour and breakwater at Ljansbruket, Norway (around 15km in the distance from Oslo). The new breakwater will extend capacity of the current marina, and will protect berthed ships and boats. The projected capacity is around 450 berthing places for small-sized vessels. The expected total length of the breakwater is approximately 640m. There will be two main floating bodies, which would consist of smaller elements with a length of 16 – 30m. The width of the pontoons is around 10m. The width is relatively large due to need for a proper damping of the waves by 80% and for a comfortable use. The floating concrete pontoons offer a storage capacity inside the hollow body. The concept of the floating breakwater has been chosen because of large water depth at the location (varying between 10 – 100m) and strict environmental requirements. The floating harbour is intended to be built from standard concrete, but also high-strength concrete HSC seems to be a very convenient solution.
Top view of the marina with the two floating breakwaters (green), which will be installed in order to enable calm berthing conditions for the boats.
Typical cross-section of the floating pontoons with a possibility to have a storage inside the hollow body.