Acta Auriga leaving the construction yard, Ulstein Verft, for her new work base at Eemshaven.

X-STERN®

The X-STERN introduces the documented X-BOW® effect to the aft ship, harnessing the benefits of improved safety for crew and equipment, increased flexibility in operations and reduced fuel consumption.

Elevate your maritime journey

X-STERN brings groundbreaking stability, eco-efficiency, and an uncompromised commitment to safety.

Enhanced stability
With the X-STERN facing the weather, vessels experience reduced pitch motion and a broader operational window, especially during weather vaning.
Efficiency boost
When the stern is positioned toward the weather, propulsion power requirements can decrease by up to 50% compared to a bow-facing orientation.
Superior comfort
The stern's quartering seas design minimizes wave response and slamming, leading to decreased accelerations and improved onboard experience.
Safety first
A sheltered aft deck and elevated freeboard reduce the risk of green water on deck, ensuring a safer environment for crew, passengers, and equipment.
Streamlined performance
The X-STERN design offers up to a 28% reduction in resistance in calm waters and waves.
Power conservation
Sailing astern using the X-STERN allows up to a 60% reduction in power consumption, emphasizing fuel efficiency and environmental responsibility.

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 first X-STERN vessel from ULSTEIN. (Photo: SjimpHansen Media)

X-STERN feedback

X-STERN, inspired by X-BOW®, revolutionizes aft-ship design. Eliminating traditional slamming and vibrations, it ensures energy efficiency, heightened comfort, and superior safety during voyages.

Proven design - see our references

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Windea La Cour connected to offshore wind turbine.

Why is backing preferred in SOVs?

Operational feedback shows that SOV crews choose to operate the vessels in astern mode while in-field. The 'aft first' experience is improved with the X-STERN, which has been introduced to several offshore wind service ships.

Acta Auriga at work Coen de Jong
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This is why Acta Auriga was chosen for BARD Offshore 1

Acta Auriga was contracted to work at the offshore wind farm BARD Offshore 1: “Ocean Breeze Energy decided on this vessel due to a favourable combination of capability, capacity, design and fuel consumption. The delivery precision from Ulstein was also important.”
Enjoying the silence: Hard rock vocalist, and senior DP Operator, Matthias Giebichenstein on the SOV vessel Windea La Cour.
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Hard rocker at work, enjoying the silence

Checking out that ocean view! If the weather is good, this is Matthias Giebichenstein's everyday sight. He works six weeks as a senior DP operator on the Windea La Cour, on one of the world's largest wind farms. Then he goes ashore and takes on his alter ego, 'Chief Mad', as the singer of the hard rock band Magic Hum.
E book

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Learn more about the key benefits of the X-BOW and X-STERN hull lines. 

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Redefining maritime efficiency

Experience transformative maritime efficiency with Ulstein's designs. We're setting new benchmarks in sustainable seafaring excellence by bridging fuel optimisation with heightened comfort and safety.

Polar Onyx dockhall Marius Beck Dahle

X-BOW®

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.

Acta Auriga leaving the construction yard, Ulstein Verft, for her new work base at Eemshaven.

X-STERN®

The X-STERN introduces the documented X-BOW® effect to the aft ship, harnessing the benefits of improved safety for crew and equipment, increased flexibility in operations and reduced fuel consumption.

SX222 below view

TWIN X-STERN®

The TWIN X-STERN® is the latest addition to the innovative designs of X-BOW® and X-STERN® that enhance fuel efficiency and operability. Its unique features distinguish it from others, and its exceptional quality lies beneath the waterline.

Ul