new Blue Riband liner

Discussion in 'Boat Design' started by OceanLinerFan, Aug 21, 2012.

  1. OceanLinerFan
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    OceanLinerFan Junior Member

    Hey guys,

    I've been thinking of designing a new ship to strip the Blue Riband of the Atlantic from the SS United States after all these years that she has held the award. Doing some research of my own I've realized that the displacement hull has to many limitations at the higher speed range I'm looking at (above 40 knots). I'm been starting to look at semi-displacement hulls to go faster for my new design. Since I don't know much about them can someone enlightenment as to how they differ from displacement hulls and how it could be used for my new speedy liner design? I'm thinking of a ship in the 600 ft range capable of doing 46 knots to smash the Big U's speed record which currently stands at 34.51 knots. What are the main points I need to think about designing a semi-displacement Blue Riband Liner?
     
  2. WestVanHan
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    WestVanHan Not a Senior Member

    This is the most basic and first thing anyone should know-how about just searching the forum? Or using google?
     
  3. DCockey
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    DCockey Senior Member

  4. Willallison
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    Willallison Senior Member

  5. Ad Hoc
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    Ad Hoc Naval Architect

    Is this on a whim, or have you been contracted to do this?
     
  6. OceanLinerFan
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    OceanLinerFan Junior Member

    Well I want to design this ship in the future...right now I guess you can call it a "pipe dream"...actually I did do some research about semi-displacement hulls just now...so I understand how they work.

    Is it possible to push a displacement hull past "hull speed" if you have enough power to do so? Or is going to another hull design a better idea?
     
  7. WestVanHan
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    WestVanHan Not a Senior Member

    Well that's just wonderful.

    You can a little bit,if you multiply the hp by 10,but you just make bigger waves AFAIK.

    Put foils on it.


    Years and years ago when I was a little kid on the BC Coast,some guy put a turbine out of a Chinook (I think) into his fishing boat. Lots of noise,huge wake.
     
  8. OceanLinerFan
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    OceanLinerFan Junior Member

    power calcs

    Thanks for the info guys :)

    Related to this discussion, I have a liner named SS Canada designed to do 38 kts on the smallest hull possible, which I calculated to be 860' lwl x 92.5' bwl x 28.4' (normal draft). Her displacement is 34,017 tons with a block coefficient of 0.527. What I'm stuck on is how much HP to get her up to speed? Her service speed is 30 kts. Can anyone give me a rough estimate of how much power I'm gonna need? The propulsion setup is to be diesel-electric generators coupled to electric motors driving four propellers. Range is 5,000 nautical miles @ 30 kts. Also fuel capacity?

    This is my dream liner. National flagship for the Canadian nation. Inspired by the SS United States.
     
  9. Ad Hoc
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    Ad Hoc Naval Architect

    Sure??

    This statement says you don't understand. :(

    You need to understand a lot more than one line statements and browsing "bits" on the web.

    If you really want to understand i suggest you read some very informative text books or take a course in naval architecture.

    Otherwise your pipe dream shall remain so I'm afraid.
     
  10. OceanLinerFan
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    OceanLinerFan Junior Member


    Actually I do understand displacement hulls quite well. I understand their limitations as far as speed is concerned. I was trying to get my head around a semi-displacement liner to go for the Blue Riband, but perhaps sticking with what I know is best for the moment. I'll wait till I start doing some naval arch. courses to better understand semi-displacement and planing hulls. Sorry for my inexperience guys.

    For my SS Canada from the previous post, I actually do know a lot already about ship design and construction, especially concerning ocean liners. Perhaps what didn't convey well is my questions about semi-displacement hulls. I did about 2 hrs research last night and now *mostly* understand how semi-displacement and planing hulls work, at least in theory. I have yet to gain one-bit of experience with designing and building them although I have read a lot about some. (ie. Charle Parsons's Turbinia, Blount's Destriero, etc)
     
  11. Ad Hoc
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    Ad Hoc Naval Architect

    It takes more than a couple of hours browsing.! However, if you really do understand, then you'll never use the misnomer term "hull speed" ever again!"

    Couldn't agree more :p
     

  12. gonzo
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    gonzo Senior Member

    You don't display much understanding of a "displacement hull". There isn't such a thing. Some hulls attain a certain speed easily and then the power to accelerate increases exponentially. Others have different behavior and can accelerate to a higher speed measured in hull lengths. The prismatic coefficient, for example, has a huge impact on that behavior. There isn't a consensus as to what "hull speed" exactly is. The rule of thumb is between 1.2 and 1.4 times the speed in knots equal to the square root of the waterline. The waterline on the hull underway may be shorter or longer than the static one.
     
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