Taking account of sea state to optimise ship routing

The energy consumption and security of ships are major issues both in terms of profitability for shipowners and competitiveness for shipyards, and in relation to the environment.

The OPTIROUTE project follows on from OPTNAV, which introduced tools for optimising the hydrodynamic performance of vessels during construction or refit phase. OPTIROUTE is aimed at reducing ships’ energy consumption, improving their safety and enhancing their life expectancy by making routing software take particular account of a ship’s response to its surrounding environment (sea state, wind, etc.). To this end, the project involves introducing a routing tool capable of taking into account the hydrodynamic, aerodynamic and hydro-structural behaviour of a ship.

Prospective developments relate to moving from a global oceanic-meteorological model to a representative deterministic model for studying ship performance in a given sea state, downscaling the model to define the overall performance of a ship using minimal calculations, and developing innovative routing algorithms integrating all the objectives and constraints of multi-purpose routing.
As an example, it will be possible to define the optimal route for a ship that minimises energy consumption while operating under the constraints of a specific destination arrival time by exploiting the effects of the wind, at the same time as avoiding areas with potential critical safety issues (parametric rolling, slamming, green water, etc.). The work resulting from this project will also, from design stage, improve performance and safety in a real-life environment including waves and wind. Target markets are ships under construction and those in service.

For Ifremer, the priority is to demonstrate the relevance of data obtained from wave and current models to contribute to the optimisation of ship routes. The modelling results will be compared with measurements taken during real journeys for which certain parameters have been recorded continuously (wind, waves, energy consumption, course, position, etc.). Through this project, a sea state measurement programme by LPO (Ocean Physics Laboratory) and LOS (Spatial Oceanography Laboratory) will be funded in order to more accurately calibrate the models.