Vertical Sailing Craft to circumnavigate Antarctica at 1 knot

Discussion in 'Boat Design' started by rwatson, Apr 14, 2019.

  1. fallguy
    Joined: Dec 2016
    Posts: 7,635
    Likes: 1,684, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Sort of funny to hear icebergs are no concern.

    Just sayin...
     
  2. JamesG123
    Joined: Mar 2015
    Posts: 654
    Likes: 76, Points: 28, Legacy Rep: 10
    Location: Columbus, GA

    JamesG123 Senior Member

    Words are hard.
     
  3. Angélique
    Joined: Feb 2009
    Posts: 3,003
    Likes: 336, Points: 83, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    It's hard for two items only moved by the same systems to get in touch hard.
     
  4. Dejay
    Joined: Mar 2018
    Posts: 721
    Likes: 138, Points: 43
    Location: Europe

    Dejay Senior Newbie

    What happens when an unstoppable force and an immovable object don't meet?
     
  5. JosephT
    Joined: Jun 2009
    Posts: 859
    Likes: 107, Points: 43, Legacy Rep: 218
    Location: Roaring Forties

    JosephT Senior Member

    If they stay in the 50's there is usually enough room to maneuver. They'll need to stay well clear of larger icebergs as gale storms sprout on short notice and swirl around. Anxious to see some of their storm video.
     
  6. JamesG123
    Joined: Mar 2015
    Posts: 654
    Likes: 76, Points: 28, Legacy Rep: 10
    Location: Columbus, GA

    JamesG123 Senior Member

    Get a large styrofoam cooler and a wine bottle, put them into the water on a breezy day and see what happens.

    Iceburgs, even small ones, have tremendous mass and this thing, at the scale depicted, will have a lot of momentum that even a seemingly harmless slow speed will crush itself.
     
  7. Ad Hoc
    Joined: Oct 2008
    Posts: 7,788
    Likes: 1,688, Points: 113, Legacy Rep: 2488
    Location: Japan

    Ad Hoc Naval Architect

    Need to be a bit careful here, especially with terminology. Since you're suggesting a multihull has less stability than a pole, in essence.

    Stability, as in statical stability or seakeeping stability - which are you referring to?

    It is not about the scale per se, it is about the waterplane area to displacement ratio - that's a measure of a vessels restoring force.
     
  8. Angélique
    Joined: Feb 2009
    Posts: 3,003
    Likes: 336, Points: 83, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    The used terminology in the post #11 answer has to be seen in the context of the post #9 question, which was a comparison with the flipped FLIP in post #7.
     
    Last edited: Apr 15, 2019
  9. Ad Hoc
    Joined: Oct 2008
    Posts: 7,788
    Likes: 1,688, Points: 113, Legacy Rep: 2488
    Location: Japan

    Ad Hoc Naval Architect

    Thanks, I just wanted clarification.

    So addressing this now, as noted, it is all about the waterplane area to displacement ratio. The FLIP is very low indeed, hence the large decoupling of its motions from wave actions.
    But you also have this same effect on large Oil Platforms, as they do the same with thin struts where the buoyancy is in large caissons deeply submerged.
     
    Dejay and Angélique like this.
  10. Angélique
    Joined: Feb 2009
    Posts: 3,003
    Likes: 336, Points: 83, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    Thanks John, that's far more exact wording, hence it explains the principle much better . . :)
     
  11. Angélique
    Joined: Feb 2009
    Posts: 3,003
    Likes: 336, Points: 83, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    From the above link:
    [​IMG] [​IMG] [​IMG]

    Yes, post #1 also mentioned the spar type oil rigs, saw it's now also used for SeaSteads, will post the link on the appropriate thread and link the post here.
     
    Last edited: Apr 16, 2019
  12. Ad Hoc
    Joined: Oct 2008
    Posts: 7,788
    Likes: 1,688, Points: 113, Legacy Rep: 2488
    Location: Japan

    Ad Hoc Naval Architect

    Taking a few basic assumptions.

    In normal floating mode, the WPA/displacement ratio is roughly 5.3, typical for a heavy for its length vessel, of any kind.
    Yet, when flipped, the ratio drops to around 0.15.

    A Swath is below 2.0....and anything below 1.0 is extreme, like Oil Rigs.

    So when flipped the motions radically change. As natural period of heave is dictated by the waterplane area and its displacement.
     
    Angélique likes this.
  13. rwatson
    Joined: Aug 2007
    Posts: 6,165
    Likes: 495, Points: 83, Legacy Rep: 1749
    Location: Tasmania,Australia

    rwatson Senior Member

    "Crews will be surveyed every 2 months using a ship, offshore supply type, which will be permanently assigned to the mission. It will leave the nearest port to join the POLAR POD on its drift course on the 3 oceans."
    POLAR POD - Jean-Louis Etienne - Explorateur https://www.oceanpolaire.org/en/polar-pod/
     
  14. Angélique
    Joined: Feb 2009
    Posts: 3,003
    Likes: 336, Points: 83, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    One wonders why they don't just take that offshore supply ship to drift around Antarctica by wind and current, and have a sea anchor attached to the bow to keep it upwind during the rough journey.
     
    Last edited: Apr 16, 2019

  15. Angélique
    Joined: Feb 2009
    Posts: 3,003
    Likes: 336, Points: 83, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    I've posted it on the thread: What do you think of SeaSteading ?post #85
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.