STATION KEEPING OF HIGH-SPEED FERRIES

摘要

A proposed analytical/iterative method allows determination of three parameters from three station-keeping equations, one of them being the maximum wind speed the vessel can maintain station at various headings to the wind. Two other parameters found from the analytical solution are the thrust of waterjets, propellers and thrusters, or thrust angles of waterjets and thrusters, or rudder angles. Other parameters of waterjets, propellers, rudders and thrusters can be found by iterations. A wind velocity profile with lower speeds towards the free surface is applied to improve accuracy of calculations, typically resulting in 10-18% wind speed increase. This correction for the wind profile depends on the superstructure height and the lateral area distribution. Practical considerations and examples demonstrate a difference of station keeping between catamarans, trimarans and monohulls with different propulsion options. Practicality of the station keeping method and a more complicated slow manoeuvring approach are discussed.