Ulstein X-BOW 10 years, photo by Marius Beck Dahle.

X-BOW® - how it started

​When times are tough, it is still possible to nurture and grow good ideas. That’s the story behind the ULSTEIN X-BOW® hull line design, which upon its introduction in 2005 literally turned the image of the ship’s bow upside down.
18 November 2018
  • Esvagt Leah and Esvagt Heidi, photo Uavpic.com.
  • 'NatGeo Resolution' in Antarctica, photo: Lindblad Expeditions/Sarah Culler.
  • ULSTEIN FX101.
  • Paintwork on the PX121 designed platform supply vessel NAO Thunder. Photo: Karl Otto Kristiansen.
    Service- og ettermarknadstilbodet innan skipsbyggingsområdet inkluderer sandblåsing, maling, botnsmøring, overhaling, reparasjon, stålarbeid, vedlikehald, dokking, kranløft, transport, kalkuleringar og berekningar. Vi har multiwheeler, fleire kraner, automatisert rørlinje. Fotoet syner malingsarbeid på NAO Thunder.
  • Observation wings on the Greg Mortimer, photo Øyvind Gjerde Kamsvåg.
  • The LNG powered, DP2, heavy lift crane vessel 'Stella Synergy' for Jumbo.
  • WINDEA JULES VERNE, a Service Operation Vessel for the offshore wind industry.
  • Ocean Victory, expedition cruise vessel for SunStone.
  • The offshore wind vessel Acta Centaurus at work in offshore wind park. Photo: Flying Focus.
  • The multipurpose offshore construction vessel Fortitude.
  • The 'Kasteelborg' W2W vessel, originally designed and built as a platform supply vessel (Blue Queen) of the PX121 design.
  • The subsea rock installation vessel 'Bravenes', designed by Ulstein for Van Oord.
  • Greg Mortimer in icy waters, photo courtesy of Aurora Expeditions.
  • The platform supply vessel 'NAO Protector' (previously Blue Protector), PX121 design, photo Ulstein
  • The 'Seven Viking' subsea vessel, photo: Christian Romberg
  • Viking Poseidon, an offshore construction vessel of the SX121 design from Ulstein.
  • Bourbon Orca on seatrial
  • Bourbon Mistral PSV vessel
    Bourbon Monsoon, a platform supply vessel of the PX105 design, built by Ulstein Verft, designed by Ulstein Design & Soluions AS, for Bourbon Offshore Norway.
  • The SX120 design, the Oceanic Vega, met the tropical hurricane 'Igor' on her way across the Atlantic.
  • Launch of PX121 for Britoil in Batam, Indonesia.
  • The seismic research vessel 'Polarcus Nadia' of the ULSTEIN SX124 design.
  • 'Go Matilda' is the second Ulstein ship design being constructed for Otto Offshore.
  • 'Sea Springer', a platform supply vessel of the PX105 design.

The X-BOW was developed during 2003-2004 ? one of the latest tough periods for the offshore industry - and revealed in 2005, together with the contract for the first vessel, 'Bourbon Orca', an anchor handling tug supply vessel for Bourbon Offshore Norway.

With a slender hull water line and a smoother volume distribution in the foreship, the vessel is particularly suited to navigational conditions in harsh waters such as the North Sea. The payoff is better handling and reduced pitching in rough seas.

The first X-BOW vessels were purposed for the offshore oil and gas industry. In later years, the X-BOW has been introduced on vessels for other segments, such as the offshore renewables industry, expedition cruise and trawling.

'National Geographic Endurance' - the first polar newbuild for Lindblad Expeditions. Photo: Marius Ertesvåg.

When the X-BOW was introduced, the press release stated the following (on 4 April 2005):

Quoting Tore Ulstein, at the time president of the design company Ulstein Design AS:
"The vessel cleaves the waves in such a way that noise and vibration in the vessel are reduced. The hull's shape reduces slamming against the vessel, and there is little sea spray on deck. This contributes to greater operational safety in rough seas. Thinking new is important at Ulstein Design and something we try to do. However, thinking new is not enough; you have to have bold shipping companies who dare to be the first. Bourbon Offshore Norway has proved to be in this category. They immediately got excited about the bow's shape, and the vessel is thus now being built," he says.

Quoting Trond Myklebust, at the time marketing director in Bourbon Offshore Norway:
"We really liked the bow design, and the model tests showed that it is terrific compared with conventional designs. Besides lower fuel consumption, the bow improves comfort on board, which results in a better-rested crew. By choosing a vessel of this type, we are setting a completely new standard for offshore vessels of the future."

Gunvor Ulstein continues:
"The ship owner, having seen an early sketch, challenged us to present some realistic ideas for a vessel with a backwards-sloping bow. 'This instigated a dedicated effort from design experts in ULSTEIN and some other players'. Bourbon Offshore Norway was convinced by the bow design that came about from this exchange of ideas because the bow would eliminate slamming, keep up speed in head sea and protect the fore-deck area from green sea and spray, while simultaneously improving comfort and rest for crews in transit."

Feedback from crews

The 'Bourbon Orca' was delivered in 2006. The first vessel feedback came from the steward: "I don't have to ask the Captain to reduce speed while I'm preparing dinner. The casseroles stay put." The next feedback was from the Captain: "We're surfing on top of the waves".


Innovation is a key strategy in Ulstein Group. Thinking outside the box and challenging accepted thinking is what drives our development. A challenge we all face is facilitating step change, often called disruptive innovation. Time is often a bottleneck when it comes to focusing on innovative work in good times. In one way, tough times are good for business, as it allows room for creativity. The maritime industry is cyclical, with upturns and downturns. This can be an opportunity, and Ulstein is committed to bringing forward new ideas, solutions and products to the market.

Concept designs ULSTEIN THOR and ULSTEIN SIF joint operations
The conceptual designs ULSTEIN THOR and ULSTEIN SIF joint operations

Later (2015), the X-STERN® was introduced. This aft design element is a natural evolvement of the X-BOW®, and the first deliveries (2016/2017) were two service operation vessels for the offshore wind industry.

X-BOW NO. 100

In 2016, the number of sold X-BOW designs passed the number 100 mark, with the contract on two Service Operation Vessels, Windea La Cour and Windea Leibniz, for Bernhard Schulte.

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