The X-BOW (and later, the X-STERN) is one of ULSTEIN's main contributions to maritime history. X-BOW vessels are being built at shipyards on many continents. Currently, more than 100 vessels with this bow concept are being constructed or in operational work around the world.
The X-BOW introduces the gentle displacer; a tapered fore ship shape with a different volume distribution as well as sectional angles, resulting in a wave piercing effect at small wave heights, and also reduces pitching and bow impact loads in bigger seas. When comparing fore ship volumes with more conventional, bulbous bow shapes, the X-BOW has more displacement volume starting from the waterline.
The experience is quite amazing. I cannot imagine myself ever travelling with a conventional bow vessel again in winter time. Captain of the AHTS 'Bourbon Orca'
While a traditional bow vessel rises on the waves and then drops violently onto the surface of the water, an X-BOW vessel, less subject to the vertical motions induced by the waves, continues on course more smoothly, while maintaining its speed. And because it uses less fuel to get through the waves, it also helps to save energy
Improved power efficiency
Safety & less damage
Accepts anything the sea throws at it
The X-BOW is in its element in the more harsh environments, but is not any worse in lower weather conditions. The benefit is the security for the crew and ship that the bow can accept anything the sea throws at it. This becomes stories, remembered and told by the crew on these vessels, and this is where the X-BOW design excels.
From a HSE point of view, reduced accelerations and slamming fores mean less wear and tear on people and equipment. The X-BOW has very little spray, so the deck remains dry behind. It takes very little water on deck to start being a hazard, or simply a nuisance.
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.The development of the X-BOW
When presenting the X-BOW® design in 2005, the designers claimed that these vessels would be easier and less resource intensive to build. In 2006, this statement was tested in reality through the construction of an X-BOW® hull at Maritim Ltd: "It was easier to build the backward-sloping bow than a conventional bow."Simplified shipbuilding
TANK TEST AND REAL-LIFE COMPARISON
When new hull designs are undergoing tank tests, a scale model must endure various waves and wave length conditions. We have performed model tests and comparative model tests for X-BOW hulls and bulbous bows in areas such as supply, seismic, offshore construction, drill, short-sea and anchor handling tug supply.TANK TESTING