chine too high?

Discussion in 'Boat Design' started by tugboat, Oct 6, 2013.

  1. tugboat

    tugboat Previous Member

    I have to completely agree. It is the "v" its too deep and some knowledgeable people were questioning it. so I examined it and the light bulb came on - so I went back to what I know works such as the Godzilla. and the Mal Lows tugs-which are all flat bottomed with generous rocker. Mal and Devlin claim they are quite able in a moderate sea conditions.

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  2. tugboat

    tugboat Previous Member

    Par true.

    its not a large displacement tug...MAl Lows Pintle- a 25 ft'er is 25000 to 28000 lbs. displacement my 30 ft'er was 17 000 but the chine did not drop far enough into the water to make it a seaworthy. the actual hull of a tug -I've learned is like an ice berg- most of it is beneath the water. see my attached pics above. it is much like the porker design....
  3. tugboat

    tugboat Previous Member

    Guys- thanks for the help- I realized I want more of a toy that can do occasional work...

    so the flat bottom suits me fine. the rocker gives it a smoother ride in a seaway- and - the slight "v"- who knows!
    Actually PAR- I think we discussed the stability on one of Mal's designs from one of my threads and I used that to help me redesign mine. thanks.
    you were talking about the stability of the flat bottomed boat. I reread it a few times...

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  4. Easy Rider
    Joined: Oct 2009
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    Easy Rider Senior Member


    Now that's a design change ... one extreme to another.

    Have you considered Sampan multi-chine forms?
  5. SamSam
    Joined: Feb 2005
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    Location: Coastal Georgia

    SamSam Senior Member

    What happened with the C-Flex?
  6. tugboat

    tugboat Previous Member

    Hi Samsam - I decided it was too much trouble- and im a steel it needed to be steel- even with my back issues.
    So it came down to three designs.

    1. the Porker (Mal Low) which was originally what I was going to build but kept getting negative feedback on flat hulls. But I see it much differently now. it had the flat bottom and no "v".
    2. redesign the vessel with an N.A. probably a great idea, but im on a limited budget.
    3. the Fred Murphy Glen-l design. I loved everything about this design except one thing I couldn't live with- flared sides. no tug to my knowledge should have flared sides. also the plate was only 11 ga. and its a ******* to try to weld up without distortion. Im not going out and buying a mig unit for 1000.00 just to weld up the plate and probably still have distortion-

    so that's my reasoning in case your interested.
    so I have what I NEED and kept my "look' that made the vessel mine- the compromise is its not a deep "v" hull. it does have some "v" in it- but someone on this thread suggested making it flatter in the midsections so this makes the build very easy...

    I believe Im done!! I built my first frame today- ill post pics when it is on the strongback...thanks for all your help...
  7. tugboat

    tugboat Previous Member

    you bet! I love being able to radically alter plans if need be to suit a build...

    being "design bipolar" is a huge asset!-

    as for the other mentioned designs- never heard of them..:confused: but my SOR has to be a tugboat- that means counter sterned, low freeboard, curved sheer, plumb bow and plumb sides to name a few. Ill check it out though for curiosity sake.

  8. nzboy
    Joined: Apr 2011
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    Location: nz

    nzboy Senior Member

    benford designs

    Jay Benford has plans for tugs very similar to your wishes
  9. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder


    Agreed Benford's designs are so salty, they make your eyes rust . . .

    I vaguely remember the thread Tug, though I do remember the discussion. I think you can do this either way, but a SOR focus will refine the choices. Of course a flat bottom design will work, though she'll be a light weight puppy, which is good for material cost and build effort, but not so much for work. If working is only an occasion thing, this would be the wise design route.

    On the other hand, if you do want to work her, she'll need the mass and internal volume for her equipment, which is why tugs have seemingly distorted underwater shapes. Most working tugs have a lot more boat in the water, than out, which is representative of the shear volume necessary in this role.
  10. tugboat

    tugboat Previous Member

    I love Jay Bedford's designs and looked at them too...
    he has a 31 Ft'er I really liked, and a 38 ft'er I loved. but his plans are expensive. the larger models are 3000.00 for the 38 ft version. and 1500.00(?) for the 31 ft'er and in the end I didn't like the layout.

    I am towing a accommodations barge- so I need two boats. one - the tug- which is the work vessel and the acc. barge which is the tow vessel. you get
    eleventeen times more space in a barge than a tugboat.

    the other problem that needed to be worked out was space for a boiler. benfords design didn't leave much(after acc. space) for a boiler- mine has the space. albeit its not for the decrepit.

    thanks NZ boy.

    got two frames welded up- strongback in place now and an engine for it (diesel) until the steam set-up gets purchased in a couple years.
  11. tugboat

    tugboat Previous Member

    Par- yea- I looked at his designs-- ogled them for a long time in the last couple years while trying to sort out all my blunders and ping ponging.

    however- have you seen the layout for these? I have been aboard the smaller of the two - about two years ago. at "Tugfest" in Parry sound Ontario. its nice inside...but not a working vessel either. good tug scantlings, though, but its a yacht disguised as a tug.

    the larger tug in that pic has a cored hull...this is the reason I stayed away from the c-flex and the core- it would be extremely expensive to use thick enough core and thick skins to make a good solid tugboat- the larger of the two in those pics is 38 ft. it is airex cored. has a round bilge too...its is a thing of beauty- but not a true workboat. Mal Low's designs ARE!

    and they are flat bottomed.

    I highly suggest reading his white paper. (What! a seaworthy flat bottomed boat!? Impossible!) his site is www.small when it comes to tugboats in the 20-30 ft range he is the go-to guy! his Pintle is a work of art but too heavy a displacement for my needs.(25000-28000).

    the 21 ft'er Pelikan has done tandem tows and been in seas with green water o'er the pilothouse.

    It has won awards too. It was designed for work. heavy plate. and tough...

    He has influenced my design thinking and one of his designs would have been my next choice.

    The bow on his tugs are absolutely working tug bows. Very full.

    almost as full as the counterstern.

    Benford's are not-in my op.

    and nor is mine. mine is designed with a very sharp entry for steam propulsion and to give it a period feel.

    its only going to be used for OCCASIONAL light duty work . maybe pulling the odd yacht off the ground and working my own barge...
    but its designed for 3/16th plate. 1/8th inch checker plate deck.

    I added a bilge keel that houses a reduction gear so the output of the shaft is almost straight.

    anyway- I tip my hat to you. I've learned a lot from you and the others on here...

    im happy with my new design changes.:)
  12. pdwiley
    Joined: Jun 2008
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    pdwiley Senior Member

    $3000 is absolute chicken feed in the overall cost if the design is what you want. It's going to cost you more than that just to paint the hull so you need to keep a sense of proportion here.

    As for not buying a MIG, I'd suggest you get over *that* as well. Yeah, you can do it all with a stick welder if you're good enough. You can do it a lot faster and with less distortion with a MIG once it comes to welding the hull seams etc. I currently have a big stick welder, a MIG and 1 of the cheap caddy DC stick/TIG welders and I use all of them. Well, I did. Fortunately I'm pretty much past that stage of the project nowadays.

    Hope you've lined up a good source for blasted & primed plate, or pickled & oiled plate. If you tell me you're going to just use some other way of dealing with the mill scale, we've been through that and I'm afraid I'll put you back into my ignore list....

  13. rwatson
    Joined: Aug 2007
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    rwatson Senior Member

    I cant believe that you think $3000 is 'expensive' either !!!! :eek:

    If you earned $2 an hour for all the time you spent on design palaver, typing, etc on this forum, you could pay $10,000 for plans by now.

    MacDonalds pay $6 an hour I think. :D
  14. El_Guero

    El_Guero Previous Member

    In Ukraine, McDonald's pays $2/hour, I think ....


  15. tugboat

    tugboat Previous Member

    for stock plans I pay around 300.00 to 600.00 so yea its expensive for plans. in my op.

    how many McDonald's workers have their own yacht?
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