Ulstein Introduces the ‘X-Stern’

From the makers of the unmistakable X-Bow hull design reminiscent of a modern-day viking ship, the Norwegian shipbuilding group Ulstein today unveiled its latest design feature: the X-STERN™.

The main characteristic of the X-Stern is a sloping and higher stern, which allows for a sharp stern shape where the transom plate is replaced by a pointed aft. According to Ulstein, this results in increased station keeping, reduced wave response, improved crew safety and comfort, and reduced power consumption. Ulstein says that the design is particularly useful for vessels where the best possible motion characteristics are essential. For station keeping, this means that a vessel featuring the X-Stern can be positioned with the stern faced towards the weather instead of the bow. This, in turn, will lead to improved weathervaning for greater operability and reduced power and fuel consumption by as much as 25% while on DP.

Ulstein says that the patent pending X-Stern has several of the same characteristics of the X-Bow and, when coupled together, will result in an improved X-Bow effect on seakeeping, particularly in harsh weather conditions. Ulstein introduced the X-Bow in 2005 and currently close to 100 X-Bow vessels are being constructed or have been delivered world-wide.

“An innovation process is a long process, in which we work strategically in order to come up with safer, smarter and greener solutions,” says Tore Ulstein, deputy CEO and Head of Markets & Innovations in Ulstein. “We discuss operational challenges with our customers, and work on how to transfer these chal-lenges into technical solutions which can be turned into commercial products. The X-STERN™ is patent-pending in several countries, including the USA and in the EU.”

STATION KEEPING

• Stern shape improves positioning capabilities
• Higher operability
• Lower pitch
• Reliable and comfortable work platformReduced wave drift forces, less weather influence
• Reduction in aborted operations
• Larger ability to operate
• Lower fuel consumption

WEATHERVANING

• Increased operability
• Improved motion characteristics;
• Reduced power consumption on DP, or:
• Operate in wider sector with same power consumption

WAVE RESPONSE AND COMFORT

• Reduced acceleration
• Reduced pitch
• Reduced heave movements
• Less wave drift, less weather influence
• No slamming
• Increased crew comfort
• No transom resistance

SAFETY AND ENVIRONMENT

• Avoids sea on deck and ice build-up
• Safety for crew and equipment
• Reduced acceleration
• No slamming
• Reduced emissions to air
• Reduced power consumption by 25% on DP

More about the Ulstein X-STERN™ can be found on the Ulstein website.