Friday, September 28, 2007

Ulstein X-Bow vs UT-Design

Revolutionary new bow from Ulstein versus traditional flared monohull bow. Ulstein claims significant reductions in vibration and noise and less pounding than with conventional bow. From the video, it's hard to tell. One would have to actually be on the vessel. Also, the conventional bow in the video is considerably smaller than the X-bow. Although I'm sure both vessels are roughly the same length and breadth, comparisons like this can be misleading.

For one thing, you can tell that if a wave were tall enough there's a chance it could climb the X-bow unimpeded to the bridge windows, whereas with a flared conventional hull, the curve of the flare serves to peel the power of the wave in a way that protects the bridge.

By the same token, excessive flare can be a impediment to vessel buoyancy. If a vessel is driven bow down by the force of the sea, the flatter and greater surface area of the forward deck created by the flare makes it harder for the bow to recover. In the X-bow, you can see how the bow would pop up quickly if ever it were driven under by the force of its own motion and the sea.

Funny thing about vessel designs. What makes a vessel more stable and more comfortable in certain pre-critical conditions makes the same vessel less capable when the seas exceed a given state.

You would think that if the vessel were built large enough, as appears to be the case with the bow on the Ulstein service or utility vessel, nothing much would challenge it. But only time and mother nature know for sure.

-seabgb

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