Bow Shape

Discussion in 'Sailboats' started by SuperPiper, Aug 23, 2013.

  1. tugboat

    tugboat Previous Member

    Mike you are quite correct- maybe I should have specified harbor tugs or ship assists...many of the offshore supply tugs and salvage tugs have raked stems... but I personally don't consider them classical tugs- they are butt ugly! had opportunities to work on them and refused...
     
  2. MikeJohns
    Joined: Aug 2004
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    MikeJohns Senior Member


    Most ship assist harbour tugs these days have a raked stem with flare up to a pronounced knuckle which provides the bow fender mount. It's clearer if you look at a profile drawing. This has some advantages.
     

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  3. tugboat

    tugboat Previous Member

    it does allow for more "set" into the push... as long as the fendering is adequate. some of the newer tugs even have almost a rounded bow, similar to the counterstern. If the tugs duties were largely ship assist- I would design in a plumb bow though- but that's me...and I personally like the plumb bow on a tug and the classic tug look.

    sigh...sadly most new tugs wont ever have those beautiful classic lines to them, such as the steam tugs did...my 30 ft'er's lines are much like a steam tugs not short and squat but lean and thin...( I broke my own rules too!)
    this is so beautiful...(see pic) they were and are still quite functional work boats ...but obsolete as a design...
     

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  4. Milehog
    Joined: Aug 2006
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    Milehog Clever Quip

    I wonder if steel gives the designers more latitude in designing hulls vs wood.
    No doubt those oldies are beauties compared to some of the new tractors.
    Speaking of latitude, are you going to toughen the bow for limited ice service?
     
  5. tugboat

    tugboat Previous Member

    not sure if your question is directed at me, but for my tug yes, the extra material is going to be used at the bow. and keel area.

    Steel is much harder to work than wood- -with wood you can create beautiful round hulls using plank on frame carvel etc. not so in steel--used to be good designers and builders could build round bilge tugs in steel-as seen by the ARMY st tugs by John Alden.

    But today its all about how fast the vessel can be built -cost effectively and put into service. so usually the boat is limited to a hard chine developable type which is- arguably- not as efficient.

    im in love with that Wallace Foss...one of the top 5 most beautiful tugs ever built- period!
     
  6. Milehog
    Joined: Aug 2006
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    Milehog Clever Quip

  7. tugboat

    tugboat Previous Member

    does it still have the steam plant?? nice!


    what's interesting is I've worked on 90 ft tugs that were built around early 1900's and they are still working strong. Usually to do barge work. and the shape of some tugs up till around the 1960's or so haven't changed much - back in the late 80's early 90's tug hulls and configurations started to change due to modernized propulsions systems such as the voith -Schneider vane propulsions and the z-drives.
     
  8. Milehog
    Joined: Aug 2006
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    Milehog Clever Quip

    No, the vessel now has a direct-reversing Washington Estep diesel engine.
    If you missed it click the Clickey in my previous post, or here.
    Click this Linkey as well. It gives a good account of the machinery, construction and history.
     
  9. tomas
    Joined: Nov 2012
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    Location: California

    tomas Senior Member

    What is the proper name and design intent of this bow shape please?
    Is it a "piercer" with added reserve buoyancy for when the waves become larger?

    According to the Flickr description, it is a Samoan fishing canoe.
    To my untrained eye it is hydrodynamically sophisticated and beautiful.

    from Francis Pimmel's Flickr

    [​IMG]
     
    Last edited: Sep 1, 2013

  10. MikeJohns
    Joined: Aug 2004
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    Location: Australia

    MikeJohns Senior Member

    It's practical to extend the forefoot as the one piece keel runs right under the stem and is sown to it, it needs a decent length of attachment to keep the stempiece well attached. And to keep the weight out of the stempiece it was shaped back as they realised that the lighter the canoe the faster is was to paddle. They were specifically a fast light weight craft for catching bonito and were paddled out to seabird feeding frenzy attacks on the driven up bait fish .

    It would have been a bit impractical for catching when sliding the canoe over obstructions and it has no great hydrodynamic advantage so close to the surface. But it's a nice carving and they were artistically minded and as influenced by style as most humans tend to be.
     
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