Increased operational window Lower fuel consumption

Reduced emissions Safer workplace Increased volume

Improved comfort

WWW.ULSTEINGROUP.COM

X-BOW®HULL LINE DESIGN

X-BOW® - GENERAL DESCRIPTION

PRINCIPAL CHARACTERISTICS– A novel hull shape with a redistributed foreship volume and substantially reduced flare– A raised foreship, which normally incorporates accommodation

OPTIMISED HULL SHAPEThe shape of the hull has been optimised with a view to high top speeds, low resistance and reduced fuel consumption. Great emphasis has been placed on the crew’s safety and comfort.

X-BOW® BENEFITSAn X-BOW® vessel is characterised by its slender hull water line and a smoother volume distribution in the foreship. The many benefits of the X-BOW® hull line design have been documented through tank tests performed by recognised maritime institutions and feedback from the owners and users of vessels with X-BOW®:

EFFICIENCY AND ENVIRONMENT - Significantly more energy-efficient shape in waves- Higher transit speed- Reduced power consumption- Improved fuel efficiency

- Reduced emissions- Increased operational time- Increased schedule-keeping

SAFETY AND COMFORT - Elimination of slamming and bow impact- Soft entry in waves - Less spray- Low acceleration levels- Reduced vibration levels- Increased comfort and available crew rest time - Safer workplace due to smoother motions

and protection provided by hull

INTRODUCING A NEW BOWAt the beginning of the new millennium, ULSTEIN started a design innovation project challenging traditional solutions and conventions. Drawing on decades of ship design experience, a new bow concept slowly emerged on paper. By introducing a larger and smoother volume distribution in the foreship, which allows for submersion, combined with a sharper bow shape, the typical challenges of conventional bow shapes were solved. Preliminary sketches of a vessel with the new, backward-sloping bow were presented in a company magazine. VISION POSSIBLEBourbon Offshore Norway believed in the new bow concept and worked closely with ULSTEIN on the development of the first vessel design with the X-BOW® hull line design - an anchor handling tug supply vessel (AHTS) of the AX104 type - launched in 2005. The first vessel of this type, Bourbon Orca, was delivered in 2006 and received a number of awards, including the Norwegian Design Council’s design award, the Engineering Feat of the Year, and Offshore Support Journal’s and Skipsrevyen’s “Ship of the Year” Awards. Other vessel designs with the X-BOW® hull line design have since received similar distinctions.

FROM VISION TO WORLDWIDE REALITYSince the new bow concept was first launched, it has been in demand, and today over 40 ULSTEIN vessels with the X-BOW® hull line design have been delivered or are under construction world-wide. The first X-BOW® designs were for AHTS and platform supply vessels, but it has later been introduced on construction, rescue, and seismic vessels, as well as into the heavy offshore and short-sea shipping segments.

Seismic vessel Oceanic Vega delivered in 2010 is one of the over 20 vessels with the X-BOW® hull line design already in operation.

The anchor handling tug supply vessel Bourbon Orca was delivered in 2006 and received numerous awards for engineering and innovation. Crew feedback has been very positive, including on the X-BOW® vessels’ ability to maintain higher speed in rough sea conditions and thereby increasing operational time, and on the softer movements and the absence of slamming, which provide increased comfort and a safer work environment for the crew.

The X-BOW® is a backward-sloping bow that starts at the extreme front of the vessel. This allows for the sharpest possible bow shape.Result: A continuous and sharp bow shape, which smoothly divides both waves and calm water. Increased volume above and up front allows the vessel to efficiently respond to large waves.

A conventional bow has a forward-sloping bow shape that starts at the extreme front of the vessel and drops down and back. The actual start of the bow at the waterline is moved back, and the bow shape at the start of the waterline is less sharp. Result: A bow that pushes the waves down and forward - this absorption of energy slows the vessel.

The photos above show comparison testing of an offshore vessel with X-BOW® hull line design and an equivalent offshore vessel with a conventional bow. The wave height is 2.8 metres, with a wave period of 10.5 seconds and a speed of 15 knots.

SPEED LOSS IN WAVESThe table below shows the attainable speed and the speed loss in waves for a container vessel with the X-BOW® hull line design compared to an equivalent vessel with a conventional bow. The performed tests indicate that the X-BOW® hull line design offers a significant speed advantage in sea states most probable on a North Atlantic trade route, where waves are expected to be above 2.5 metres 74% of the time. The X-BOW® has an average improvement in speed loss of 19% in the 2.5-10.0 metre wave height range.

The photo above left shows the X-BOW® vessel. With a sharp hull shape, there is no spray and there is a soft entry into the waves. As the waves are parted efficiently, wave energy transfer is minimised. This means that speed losses are reduced.

FUEL CONSUMPTIONAn independent maritime institution has performed a comparison study between a short sea container vessel with X-BOW® hull line design and an equivalent container vessel with a conventional bow under expected service conditions. With a design speed of 18 knots, the difference in fuel consumption is shown in the chart below. Results show 7-16% fuel reduction, depending on ship speed and sea state.

The photo above right shows the vessel with a conventional bow. With a blunt hull shape, there is spray generation, high bow impact and slamming. The waves are pushed forward and wave energy is moved against the hull. This makes for greater speed losses.

X-BOW® - CONCEPT COMPARISON

SPIRIT OF INNOVATIONCONTACTSULSTEIN DESIGN & SOLUTIONS ASP. O. Box 278NO-6067 UlsteinvikNorway Tel.: +47 7000 8000

ULSTEIN offers a broad range of ship designs for demanding operations. We design with a focus on the environment, cost-efficiency, reliability and total life-cycle cost. We offer ship design packages to the international market with an emphasis on offshore support, heavy offshore, and shortsea vessels. Vessels designed by ULSTEIN are built at shipyards world-wide.

WWW.ULSTEINGROUP.COM

The X-BOW® hull line design is patented in Norway (reg. no. 324744), Russia (reg. no. 2374120), Singapore (reg. no. 135279 (WO/2006/096066)), Ukraine (reg. no. 95070), USA (reg. no. 7,658,159) and Vietnam (reg. no. 8437). Patent is pending in Brazil, China, Europe (EPA), Hong Kong and India.

TURNING VISIONS INTO REALITY

20 M

ay 2

011

ULSTEIN SEA OF SOLUTIONS B.V.Churchillsingel 432-4463137 XB VlaardingenNetherlands Tel.: +31 10 475 00 11

ULSTEIN ES-CAD MÜHENDISLIK DENIZCILIK SAN. VE TIC. ASZümrütevler Mah. Hanimeli Cad. 2/1Maltepe 34852 IstanbulTurkeyTel.: +902 16 458 7100

ULSTEIN DESIGN COMPANIES

ULSTEIN DESIGN & SOLUTIONSUlstein Design & Solutions in Ulsteinvik, Norway, focuses on product development and offers ship designs, engineering services and ship equipment packages to the international market, with an emphasis on the offshore support segment (platform supply, anchor handling tug supply, seismic research, and construction vessels).

ULSTEIN SEA OF SOLUTIONSUlstein Sea of Solutions in Vlaardingen, the Netherlands,specialises in the design of heavy offshore vessels, including pipelay vessels, drillships, heavy lift vessels and offshore construction vessels. In addition, the company designs ships and equipment for the offshore wind market. The company develops projects for operators, contractors and shipowners.

ULSTEIN ES-CADUlstein Es-Cad in Istanbul, Turkey, develops designs for shortsea vessels, including ro-ro, container, dry cargo, and liquid carriers.