The X-STERN is the X-BOW® effect implemented in the aft ship. While the traditional transom plate causes slamming and vibrations when the vessel is backing, the pointed X-STERN has no such effect. The softer motions are energy saving and increase comfort and safety.
Market insight from the offshore wind industry shows that 70 % of the vessels operate backwards in-field, despite the slamming experienced with the flat transom plate. The X-STERN hull solution was welcomed and taken in use on service vessels for the offshore wind industry shortly after its introduction in 2015.
The SOV crews give various reasons for astern operations:
- All the work is being performed at the aft. Keeping the aft first leads to a better overview of the vessel’s positioning, as the gangway, the turbine and the ship’s side can all be observed from the bridge.
- Most power is installed in the aft part of the ship, enabling it to keep positioned more easily.
- The vessel doesn’t have to turn around before leaving for the next turbine, saving manoeuvering time between turbines.
Crews on X-STERN vessels have additional reasons for operating astern:
- The X-STERN is kept towards the weather while on standby during night. The service crews get complete rest in between their maintenance shift due to no slamming or vibrations.
- There will also be no slamming due to the X-STERN while on DP or even when transferring between the turbines.
- If the weather is not too adverse, the ship stays on the spot with two thrusters running, which leads to substantial reduction in fuel consumption.