Floating suspension bridges

Floating suspension bridges

Karusell floating suspension bridges

  • Illustration of possible tension-leg platform (TLP) based floating suspension bridge across the Bjørnafjord. Credit: Plan Arkitekter/The Norwegian Public Roads Administration.



  • Illustration of a floating bridge anchoring concept. Credit: The Norwegian Public Roads Administration.



Tekst Floating suspension bridges

The Norwegian Public Roads Administration (NPRA) is running a project “Ferry free coastal route E39” that aims to eliminate all ferries along the coastal highway E39 in Norway. Some of the straits are up to 5 kilometers wide and 1.5 kilometers deep and will call for significant extension of present bridge technology. The installations have to resist extreme environmental loads and accidental actions with acceptable safety levels. Floating suspension bridges, which represents a combination of offshore ocean engineering and bridge engineering, are one of the proposed solutions.

Floating suspension bridges represent new challenges when it comes to prediction of the dynamic behavior. There is a complex interaction between the moorings and the floating towers, and the towers and the bridge deck. Hydrodynamic and aerodynamic modelling is a crucial issue. The objective of this project is to develop a dynamic model of such bridges including fluid-structure interaction where hydroelastic, aeroelastic and nonlinear structural behaviour are taken into account. Furthermore, this model will be applied in uncertainty analysis to quantify the relative influences of the basic variables in order to identify further research priorities. There is a special focus on the stability of the structure in strong winds, prediction of the extreme values of the dynamic response when the structure is subjected to harsh environmental conditions and simplified methods that may be useful in the initial design phase.


Numerical model in Abaqus CAE of a floating suspension bridge (leftmost picture) and panel model of TLP in hydrodynamic software (rightmost picture). Illustration by NTNU/Sondre Halden, Shun Wei Gong and Yuwang Xu.


Contact bridge


Professor Ole Øiseth

Phone: +47 735 91 493

E-mail: ole.oiseth@ntnu.no