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

2. 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 : EP )
04th of June 2015

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

4. 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

5. 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