Head of Hydrodynamic department ATW Active Trim Wedge Loïc Morand Head of Hydrodynamic department STX France 04th of June 2015

Extreme wave condition in head waves Approach : ATW Problem : Trim wedge works well but his efficiency is dependent of the following : Ship speed Loading conditions Different trim wedge angles can improve the seakeeping performance in special conditions : Mooring configuration: Specially when waves are coming from stern or beam waves. Extreme wave condition in head waves Approach : The idea is to adapt the trim wedge angle to these conditions. (Existing STX patent : EP20090793932 20090703) 04th of June 2015

System consists of the following : Hydraulic jacks ATW Technical Solution System consists of the following : Hydraulic jacks Control / command system 04th of June 2015

The benefit is several % in power depending of the project. ATW Results Following conclusion have been obtained based on model tests results on an over panamax cruise ship : In calm water The benefit is several % in power depending of the project. Different angle applied for different wedge lead to additional improvement Moreover it allows to cancel the degradation of a static trim to the aft which give more flexibility in terms of operation. 04th of June 2015

Confort in term of vibration : ATW Results In waves : Roll motion : The system reduce roll motion in moderate sea states without fins stabilizers which cancel the speed lost due to the use of stabilizer. Confort in term of vibration : Better VDV values are obtained with adapted trim wedge angle. 04th of June 2015