Constanzi Stern of the Queen Mary 2

Discussion in 'Boat Design' started by Surfer Naval Architect, Jul 22, 2018.

  1. TANSL
    Joined: Sep 2011
    Posts: 7,369
    Likes: 699, Points: 123, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    What advantages can that "thing" have from the point of view of marketing ?. And it occurs to me to think, should naval architects design the submerged volume of their projects from the point of view of marketing?
     
  2. Mr Efficiency
    Joined: Oct 2010
    Posts: 10,386
    Likes: 1,042, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    It's clearly an example of that important design principle, "whatever floats your boat". :D
     
  3. alan craig
    Joined: Jul 2012
    Posts: 380
    Likes: 131, Points: 53, Legacy Rep: 14
    Location: s.e. england

    alan craig Senior Member

    The answers seem obvious to me, a bungling amateur. The reason for the curved shape was answered fully in my post copied from Wikipedia; it has the look of a traditional ocean liner. As for the transom/azipod thing; it is not specifically the transom which is required but the flat or nearly flat hull beneath it - suitable for mounting azipods. Without that flat hull the azipods would have to be mounted on long columns extending down from the steeply sloping sides of a traditional liner stern.
    And I bet the transom is completely dry at the 35mph/30kts that the QM2 is capable of.
     
    Last edited: Jul 24, 2018
  4. Mr Efficiency
    Joined: Oct 2010
    Posts: 10,386
    Likes: 1,042, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    Yep, they didn't want the stern looking like a container ship.
     
  5. bhnautika
    Joined: Feb 2006
    Posts: 852
    Likes: 57, Points: 38, Legacy Rep: 571
    Location: australia

    bhnautika Senior Member

    Tansl while the picture is nice you didn’t mention anything about shape and speed, which one would be more efficient as speed increased ? This lightly immersed transom can be seen on a lot of other vessels which include military .So I kind’ a think there is something to it. To me it looks like a refinement the D-series fast monohulls which has been around a while now. Then again if you think a team of naval architects working for one of the oldest shipping companies have stuffed up!
     
  6. TANSL
    Joined: Sep 2011
    Posts: 7,369
    Likes: 699, Points: 123, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    We are not talking, obviously, about planing speed. We are talking, I suppose, of a displacement ship at 22 or 24 knots. The shapes of the water line in one case or another are totally different.
    Sometimes, although some may deny it, the naval architects are also wrong. What I say is that, in my opinion, it is due to an error in the project, error that could be the lack of buoyancy aft or, for example, to project the ship for a type of propulsion that, later, it was seen that it was not the most adequate to get the benefits (and I do not only speak of speed) required.
    In this there is, without a doubt, something strange that neither you nor I can explain.
     
  7. MikeJohns
    Joined: Aug 2004
    Posts: 3,192
    Likes: 208, Points: 63, Legacy Rep: 2054
    Location: Australia

    MikeJohns Senior Member

    It's designed from scratch to look like that. It's supposed to give better separation than a full cruiser stern and can supposedly reduce pitching moment in heavy following seas, It is wider than earlier versions it's based on because of the stern pods. Look up the now scrapped Italian liner "Eugenio" and look at her wake. There was a good write up on this in one of the Naval Architecture pubs last year.
     
  8. bhnautika
    Joined: Feb 2006
    Posts: 852
    Likes: 57, Points: 38, Legacy Rep: 571
    Location: australia

    bhnautika Senior Member

    Mike thanks for the tip. I was probably a little flippant when I used the term at “best a cosmetic touch”. Another thing I have lean't is that there are Naval Architecture Pub’s, the ones in my area seem to be based around football.
     
  9. Surfer Naval Architect
    Joined: Feb 2018
    Posts: 46
    Likes: 1, Points: 8
    Location: Amsterdam, The Netherlands

    Surfer Naval Architect Naval Architect

    Thanks a lot Mike for your description, it is the one in my opinion make more sense.

    So first you say:

    1) It is suppose to give a full cruiser stern (so aesthetic purpose to have the shape more elegant)

    2) Can reduce pitch? yes... I would say because has more buoyancy below the waterline and less volume above the waterline (so less inertia) compared with modern cruise vessel that have a straight aft part of the vessel, where the suite are now located.

    The classic cruise vessel had before a swimming pool which it was closing the aft part of her, that in my opinion it was much more elegant and sophisticate.

    @MikeJohns you made the example of Eugenio, I give you a more extreme example, like the cruise vessel ex name "Italia Prima", how do you consider that aft design of the vessel?

    I would like to challenge you to discover what that vessel was before to become a cruise vessel...

    Thanks a lot and regards,

    Raffaele
     

    Attached Files:

  10. MikeJohns
    Joined: Aug 2004
    Posts: 3,192
    Likes: 208, Points: 63, Legacy Rep: 2054
    Location: Australia

    MikeJohns Senior Member

    Hi Raffaele
    It looks like that was repurposed to a passenger ship, what was she designed as a fleet tender ?
     
  11. Rurudyne
    Joined: Mar 2014
    Posts: 1,170
    Likes: 40, Points: 48, Legacy Rep: 155
    Location: North Texas

    Rurudyne Senior Member

    I must confess that my reaction to the stern was too much like my reaction to the first super yacht A when I finally saw her transom. I would point out that I did in fact like that boat. Still do.

    But when I finally saw a picture of her transom I posted: "Sadly, this is the end."

    I felt it was like the designer just ran out of ideas and muddled on through.

    (Been plenty of cars and buildings that look like that too)

    At least Italia Prima's designer seems to have tried.
     
  12. Surfer Naval Architect
    Joined: Feb 2018
    Posts: 46
    Likes: 1, Points: 8
    Location: Amsterdam, The Netherlands

    Surfer Naval Architect Naval Architect

    Dear @MikeJohns

    thanks for your reply, she was before the MS Stockholm famous for her collision with the Andrea Doria. MS Stockholm was also a passenger vessel but later on when Star Lauro bought her, they basically made a huge dry dock expensive job, changing all the superstructure and the interior, she became a luxury cruise vessel. Star Lauro kept only the hull, but they added a “Duck Tail” to her stern, giving more stability..

    Apparently this vessel had to much rolling in her past, installing on the vessel the “Denny Brown” Stabilizers.

    I saw that more info you can find on this website MS Stockholm of 1948 http://www.ssmaritime.com/Stockholm.htm, and as you can see in the picture attached, the writer mentions that the hydrodynamic went to improve for this vessel.

    But I am quite wondering about this, because basically the hull didn't change below the waterline, any idea about it?

    Thanks a lot,

    Raffaele
     

    Attached Files:

  13. TANSL
    Joined: Sep 2011
    Posts: 7,369
    Likes: 699, Points: 123, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    If that was the case, it was simply a question of placing an ornament, very expensive indeed, on the ship.
    At some point, I'm sure, the ornament is submerged and improves some feature of the boat.
     
  14. Surfer Naval Architect
    Joined: Feb 2018
    Posts: 46
    Likes: 1, Points: 8
    Location: Amsterdam, The Netherlands

    Surfer Naval Architect Naval Architect

    Hello Tansl!

    exactly fully agree with you.

    But still I don't get it how hydro-dynamically talking that shape can gives an improvements. Italia Prima I think as just one classical propeller, so not azipod where the question of the Queen Mary 2 can more or less been considerable..

    Do you have any idea?

    thanks a lot,

    Raffaele
     

  15. TANSL
    Joined: Sep 2011
    Posts: 7,369
    Likes: 699, Points: 123, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    No idea, what's more, I am convinced that, from the point of view of the general hydrodynamics of the hull, it is not good.
    I have said before that my idea is that these modifications have had to be made to get more volume aft.
     
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.