For vessels where the best possible operational characteristics are vital, the Captain’s first choice will be to place the X-STERN towards the weather instead of the bow. When placing the stern towards the weather, the X-STERN has a major effect on the vessel’s capabilities and flexibility. Stern first, the vessel will be less influenced by weather, and pitch motion and wave drift will be reduced. The work deck aft is enclosed, with no sea on deck or ice build-up and increased safety for crew, passengers, cargo and equipment. Deeper drafts increase the benefits.
The advantages include:
- Reduced pitch motion and increased operational window when placing stern to weather (weather vaning).
- Up to 50% less propulsion power required with stern to weather vs bow to weather
- Significant reduction in wave response and slamming. Stern is quartering seas, which decreases accelerations and improves comfort
- Safer workplace due to sheltered aft deck and high freeboard, less probablility of green water on deck
- Reduction in resistance in calm water and waves by up to 28%
- The option to sail astern and with up to 60% reduction in power consumption
- Massive reduction in trim and draft sensitivity
"The X-STERN met all our expectations. It is amazing to see a vessel going backwards in bad weather without slamming and having spray on deck."
'Windea La Cour', BS Offshore
'With the stern towards the weather, we experience absolutely no slamming and vibrations, not even when we are in transfer, and people love it.' Matthias, DP operator, Windea La Cour
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.X-STERN feedback
Reduced weather dependency
X-BOW® and X-STERN: Studies, documentation and experiences
The X-STERN EXTENDER concept is a feature which turns a relatively small vessel into a flexible subsea vessel with an extendable moon pool in the aft.X-STERN EXTENDER
TWIN X-STERN for walk-to-work services
Is a bow really a necessity for large ships? A heightened stern, the TWIN X-STERN, can operate either way, thus facilitating on-site DP positioning. This idea was nominated for the Innovation of the Year Award at the OSJ Conference 2016.TWIN X-STERN®
The ULSTEIN X-BOW®, the inverted bow concept, redefined marine engineering. The bow concept was launched in 2005, together with the first shipbuilding contract, and gained immediate interest from shipowners. The X-BOW hull line design has been tried in most weather conditions.X-BOW®