x-bow

[XAM]

Good morning.
I open this discussion to discuss the topic of the new form of bow introduced by ulstein a few years ago (using the search function does not seem to me the topic has already been dealt with).
I believe that the new geometry has been patented by ulsyein and carries the x-bow commercial name. I think it is also interesting because in the naval field the architectural innovations is not that they are very frequent.

as seen from the photo it is a bow without flare that guarantees, according to the designers reduction of the resistance, better performance with big sea. to what I know for now it has been used mainly on supply vessels, trailers and similar

What do you think?

 

[Exatem]

you could answer “sometimes they come back”. the reverse prora is not an absolute novelty. until the Second World War practically all constructions adopted a vertical prora obverse if not even with negative angle, and it was not only a reminescence of the time of the spur.
with the abbreviation x-bow identifies a type of prora developed by the Norwegian company ulstein gruppen for offshore ships. in 2008 the ulstein launched the "island constructor" that is the largest unit with x-bow bow which would allow, according to the intentions of the manufacturer, to better bear the adverse weather conditions with a more stable behaviour and with an annual saving of fuel quantifiable in 4-7%.
the commercial director of ulstein design stated: “The offshore ships equipped with x-bow bow are designed to maintain speed even in case of bad weather and sea very moved. other advantage is that it completely eliminates the effect of sea waves against the bow. the experience made so far shows that these ships can save from 4 to 7% fuel per year, depending on how they are used. the characteristics of the inverted bow allow the ships with x-bow bow to fender the waves softer" . By analyzing the forms, it seems clear that the slamming has less effects since the wave does not hang with the mascone, but is "accompanied".
to this it adds another effect. those who know a little the ships know that there is a simple regulation for which by adopting a “inverse” bow, maintaining equal internal volume of the hull and weight, increases the length to the float and therefore longitudinal stability. It is a very well-known rule to the old axe masters who made Ligurian gozzi with a bow so exaggeratedly pronounced and a vertical aft straight with the aim of extending to the maximum the water line.
always according to the builders, the “new” concept of bow has improved comfort and therefore safety for the crew. confirming this, in 2006 the “ulstein ax 104 bourbon orca” received the prize of “ship of the year” after the previous year had already won the “prowess of engineering”. meanwhile, alternating ships were made inspired by this concept. the blohm & voss has built the megayacht "sigma" that I attach while also the navy us has to the study hulls with pros that were no longer seen from the times of jutland.
some personal consideration. Although the shape indisputably resembles that of an iron... well, I like it even though as I said at first, it is not a real novelty, but rather a modern revisitation of ideas already expressed. We talked about it in the discussion “laodice project” when I proposed a hull with a “unusual” project explaining that this choice was dictated by the search for a length to the float greater than a more traditional solution (at equal length outside everything). It must be pointed out that the Norwegian shipyards have been able to react to a period of crisis by investing and specializing in the construction of ships, platforms and equipment for oil research in the northern seas.
seas that, it is good to remember, have climatic characteristics very different from those found in our Mediterranean.

 

[XAM]

I generally agree with your analysis, especially share what you wrote about the intelligent ulstein initiative that in crisis period chose to invest in r&d rather than cut all the cutout (as it happens here).

the new forms eliminate the bow flare slamming and surely decrease what effects of slamming.
I would be curious to see a building plan somewhere I read that the forms take back those of a wave piercing, in fact the most interesting part of the matter should be the living work. I believe that from this point of view the hulls equipped with xbow are quite different from those of the ancient units you mentioned.

 

[Fulvio Romano]

But why lose all that bridge?
once the length of the float is established, a bow not quite straight, but not at 45° it would recover a few meters of "liveable" bridge, wouldn't it?

 

[Exatem]

I generally agree with your analysis, especially share what you wrote about the intelligent ulstein initiative that in crisis period chose to invest in r&d rather than cut all the cutout (as it happens here).

the new forms eliminate the bow flare slamming and surely decrease what effects of slamming.
I would be curious to see a building plan somewhere I read that the forms take back those of a wave piercing, in fact the most interesting part of the matter should be the living work. I believe that from this point of view the hulls equipped with xbow are quite different from those of the ancient units you mentioned.

It would certainly be interesting to see a building plan.

But why lose all that bridge?
once the length of the float is established, a bow not quite straight, but not at 45° it would recover a few meters of "liveable" bridge, wouldn't it?

but what you lose on it, you get it under...
It's just a joke.
evidently the evidence in the tub convinced of the best entry into the wave.