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Ramform hull: +stability, +area, simpler design

Home Forums Research Engineering Ramform hull: +stability, +area, simpler design

This topic contains 4 replies, has 5 voices, and was last updated by Profile photo of shredder7753 shredder7753 4 years, 4 months ago.

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    Profile photo of Jesrad

    I’ve recently found out about a new breed of seismic survey ships that are built upon a special, unusual ‘ramform’ hull to make them more suited to their mission ( it makes them extra-stable, and wider so they can tow 2 to 4 times as many lines/streamers as a traditional ship).
    Example: http://shipoftheday.blogspot.com/2007/04/ramform-explorer.html

    The interesting aspect is extra stability and survivability in ocean without sacrificing much mobility while adding a lot of area, also the wide stern creates a vast planform behind it when anchored which could ease mariculture, diving or fish farming. This hull is being planned for use in the new line of megayachts designed by Wally in partnership with Hermes: http://www.why-yachts.com/

    Those are being marketed as a step closer to artificial (floating!) islands and away from usual powerboats. I think the hull solution they retained could therefore apply to potential seastead design too, as the characteristics and benefits of this hull apparently scale up well.


    Jesrad, good point – TSI is going for ship-shaped seasteads and the ramform is the ship-shape that has been found and tested to be the best suitable shipform for interacting with the ocean and being comfortable in stationary work ambients in open sea.

    The ramform combines a broad stable flat float shape in the stern with a ship bow. Interesting that the comfort zone seems to be exactly the 40m beam area predicted on this forum. So we are speaking of 102 m loa and 40m beam – not exactly a small scale start up – but definitly a possible way to go.

    Part of the discussion how beam influences comfort and how to improve geometric platform shapes like cube shapes are also in the discussion of the ecuatorian coast guard platform and its wave response seen in the following video.

    More about ramform ships in this pdf file.

    All in all structures that are below 40m beam seem to be not comfortable enough due to their wave response. This excludes surface floats below 40m beam very much for seasteading on open ocean and restricts small floats to quiet bays and protected waterspaces.

    Only a partially/fully submerged structure can be small and comfortable at the same time in open ocean.



    Profile photo of shadowmane

    Build a Ramform ship with an Ulstein X-Bow, and you have a very stable ship that won’t slam around in storms.

    Profile photo of OCEANOPOLIS

    There are notable improvments in seakeeping abilities in a Ulstein X-Bow ship. http://www.youtube.com/watch?v=GJsogw9fHE0. A hybrid Ramform – Ulstein X-Bow seastead design will probably deliver the best stability letter in its class (monohulls), IMHO.

    Profile photo of shredder7753

    looks like we were beaten to the massive concrete rectangle… a looooonng loooooooooooooooong time ago!


    My Work II

    “Leadership and do-ership are not the same thing”

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