Hull Offsets for SS United States

Discussion in 'Boat Design' started by johnhazel, Jul 9, 2014.

  1. TANSL
    Joined: Sep 2011
    Posts: 6,485
    Likes: 387, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    OK, but be aware that I need to draw cross sections, based on the plane of your figure, smooth forms, according to my personal opinion and then get the table of offsets. I mean, I need smooth shapes my way.
    This is what I have for now.
     

    Attached Files:

  2. johnhazel
    Joined: Jun 2008
    Posts: 250
    Likes: 5, Points: 18, Legacy Rep: 60
    Location: Michigan

    johnhazel Senior Member

    So all we have to do is lay your lines over the lines shown in the attachments of my post #15 in this thread. It will be easy to see how close they are that way.
     
  3. TANSL
    Joined: Sep 2011
    Posts: 6,485
    Likes: 387, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    What information you wish me to send, to do that. I mean, a pdf, dwg, dxf??
    Keep in mind that the lines of your pdf can not be taken as an article of faith. They come from a paper drawing which have been made photocopied. These photocopies were made with an apparatus that generated much heat and although little but distorted the drawing. Subsequently, a deformed copy is scanned to move them to a pdf format, etc.., etc.. All these processes get distorted versions of the original drawing.
    What I've gotten so far is the model that enclose. It would be more correct:
    -get a sufficiently smoothed forms. I think the current ones are smoothed.
    - Check that the hydrostatic values ​​of this model reasonably match those of the original ship.
    - Get the offsets table cross sections where you tell me.
     

    Attached Files:

  4. SukiSolo
    Joined: Dec 2012
    Posts: 1,270
    Likes: 25, Points: 0, Legacy Rep: 271
    Location: Hampshire UK

    SukiSolo Senior Member

    Even paper 'moves' as in shrinks and expands with moisture and heat. Tracing is pretty bad for it, only film (mylar) tends to retain reasonable accuracy other than CAD drawings and models. As you say TANSL, photocopying etc and other reproduction means ie dyelines also tend to distort things.

    For all that, there is no reason you should not achieve a very, very good model of her lines. Once she is in the computer of course, the lines can be reproduced with identical precision....;)
     
  5. johnhazel
    Joined: Jun 2008
    Posts: 250
    Likes: 5, Points: 18, Legacy Rep: 60
    Location: Michigan

    johnhazel Senior Member

    2 items:

    (1) The view that shows your version the lines in the attached screenshot. This as you know is just a page from the reference report we are using. PDF format is fine. I am happy that you are just making the unappended hull (without rudder, props, bilge keels etc)

    (2) The table of section offsets output from your program with as many water planes as you can get. (well up to say, 200 or so)
     

    Attached Files:

  6. johnhazel
    Joined: Jun 2008
    Posts: 250
    Likes: 5, Points: 18, Legacy Rep: 60
    Location: Michigan

    johnhazel Senior Member

    This may be intresting for a lot of people. In 1952 the SS United States captured and still owns The Blue Ribband (Atlantic 2-way crossing record). The ship was also know for being able to maintain high speed in rough water.
     
  7. TANSL
    Joined: Sep 2011
    Posts: 6,485
    Likes: 387, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    Please take a look at the table below. Hope this helps for something.
    Dimensions in millimeters.
     

    Attached Files:

    Last edited: Jul 13, 2014
  8. johnhazel
    Joined: Jun 2008
    Posts: 250
    Likes: 5, Points: 18, Legacy Rep: 60
    Location: Michigan

    johnhazel Senior Member

    Great! I am in a canoe race tomorrow and getting ready tonight. Then I drive home. So it will be Sunday to get it put into a graphic and ready to test. This is very cool TANS.
     
  9. TANSL
    Joined: Sep 2011
    Posts: 6,485
    Likes: 387, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    Thanks, johnhazel. You may have to make modifications in the table, so do not hesitate to ask me for what you need.
    The attachments show some results obtained with the current hull.
    I have the hull lines plan and 3D solid model, in CAD. Are you interested in them for something?
     

    Attached Files:

  10. johnhazel
    Joined: Jun 2008
    Posts: 250
    Likes: 5, Points: 18, Legacy Rep: 60
    Location: Michigan

    johnhazel Senior Member

    I had some downloading issues but it's ok now. Back with you soon.

    Froude number @ 39knots (20m/s) and 290m waterline = .375

    This is just before the drag starts to climb from rapidly increasing wave influence.
     
  11. johnhazel
    Joined: Jun 2008
    Posts: 250
    Likes: 5, Points: 18, Legacy Rep: 60
    Location: Michigan

    johnhazel Senior Member

    OK it looks like we need to have more stations to capture the details of the bulbous bow. Since there are 20 stations and some additional intermediate stations 1/4, 1/2, and 3/4 between some stations it makes the most sense to go to 80 stations. Also doubling water planes (0, 0.25, 0.5, .... 9.0, 9.25, 9.5) or even better, also quadrupling them.

    Is it too much to ask for you to pull the additional stations shown on the drawing into your 3d model and then specify a table of offset output of 81 stations and 81 waterlines including the station of all zeros representing the forward perpendicular. If not, I understand and will do this by hand on a spreadsheet.

    I have another canoe race this weekend and then will be going to Grayling, MI to compete in my big goal and "bucket list" item, the AuSable Canoe Marathon(120 miles non-stop), next weekend, after that and a few days vacation I will be back here.
     

    Attached Files:

  12. SukiSolo
    Joined: Dec 2012
    Posts: 1,270
    Likes: 25, Points: 0, Legacy Rep: 271
    Location: Hampshire UK

    SukiSolo Senior Member

    Coming on nicely. The curve of areas looks pretty sweet, nice work TANSL and John. Model is a lot 'cleaner' now, very convincing.
     
  13. TANSL
    Joined: Sep 2011
    Posts: 6,485
    Likes: 387, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    Johnhazel, ships forms are now on my computer, therefore, it will be much easier and more accurate if I get the data of the frames you need.
    I have never used Michlet not know what it does, so, please direct me clearly what you need. For example, you say that the forward perpendicular values ​​are all zero, but this is not so.
    I set up the aft perpendicular to the rudderstock. From that point, I have traced 20 sections so that section 20 is at a distance equal to the length between perpendiculars. Both end sections have nonzero breadths. So where do I draw the sections that you need?. Tell me, please, the point of origin, the distance to the end point and the separation between sections.
    Otherwise, I can get values ​​for as many frames and water lines you need
     
  14. TANSL
    Joined: Sep 2011
    Posts: 6,485
    Likes: 387, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    Thanks a lot. If you take a look at hydrostatic values​​, you'll see that the results agree well (errors less than 0.5%) with those given in the pdf file attached for johnhazel in youhisr post # 3.
    The models are made in AutoCAD. This software is not rendering and therefore does not hide the irregularities that may be on the hull. What you see is what you get. This, for the fairing, is very interesting.
    Other programs have tricks to render precisely hides lumps that may have the hull.
     

  15. SukiSolo
    Joined: Dec 2012
    Posts: 1,270
    Likes: 25, Points: 0, Legacy Rep: 271
    Location: Hampshire UK

    SukiSolo Senior Member

    Agreed TANSL, the values are incredibly close. Quite interesting seeing how 'accurate' the lines plans and hyrdrostatics either agree or not from the data we have left us.

    Some years back, I saw the Normandy being towed up the Channel (English) to Norway to be scrapped. These large liners are like nothing else, although of course we do have the odd new one....;)

    On the modelling side, any accurate 3D package for engineering such as Autocad, Rhino, Pro E, SolidWorks etc should show all the little warts/blemishes if they exist in the original data. Only the 'illustrative' 3D renderers like Studio Max and Blender (free) can easily 'fudge' the shape and give a smooth sweet image with relatively little work!.
     
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.