need 40-65' tugboat plans.

Discussion in 'Boatbuilding' started by SRSS, Aug 16, 2011.

  1. SRSS
    Joined: Aug 2011
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    SRSS Junior Member

    Thanks for all the info guys!!
    Yeah the larger volume isn't really an issue for me i plan on running a coal powered steam boiler and engine of my own design... but i do agree finding a tug hull that isn't totally rotted out and in my area also and for cheap not very likely...
    Right now i'm pretty much in a research phase... been playing around with some hull designs in a CAD program might send one out to a 3d printing place to have a scale model made up to do some testing!!
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    BATAAN Senior Member

    CAD printed model to test. Wow. Keep us informed please.
  3. SRSS
    Joined: Aug 2011
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    SRSS Junior Member

    yeah there's an online company called Shapeways that does 3d printing here is the link
    All you have to do is upload the 3d model to the site and the charge by the amount of material used to make it and shipping and they have tons of different materials to chose from! I figure its a fast way to do some inexpensive R&D
  4. tugboat

    tugboat Previous Member

    Hi-- dont know when this thread started- what size hp and boiler hp are you looking to put into your tug?..for a 50 ft'er you can go with 15-18 hp geared down to 3:1 turning at 500 rpms--that should give you lots of torque but your not going anywhere fast...have you though of a smaller tug- using the small tug as a tender vessel?..mal lows designs are great and i am presently finishing off the frames for a 27 ft'er- i have a choice of hydraulic drive or steam. ..since i really wanted twin screws i thought of using two 9.5 hp singles. but this is more expensive than going with a single 18 hp which i can get for about 2800.00 u.s. delivered by a company in india called tiny tech..
    anyway- the idea is for the smaller tug to push a small barge , thus making mooring costs non existant.simply anchor the houseboat barge and then use the tug as the tender vessel. seems like having an tug and not at least doing a bit of work is a waste but hey thats me...
    I work for a guy that makes steam engines..,adding a boiler will help with ballasting especially if you go with a firetube which is really a marine type since it holds its steam better for longer requiring less tending to feed her.

    im very interested in your project--please keep me posted ...

    i love tugboats and cant wait to finish mine so i can be steaming her..whether diesel or steam...

    Attached Files:

  5. tugboat

    tugboat Previous Member

    also here is a good 45 ft design...great for steam too!

    Attached Files:

  6. tugboat

    tugboat Previous Member

    Data Input
    Waterline length in feet: 45 feet

    Beam at the waterline in feet: 12.5 feet

    Hull draft in feet (excluding keel): 6 feet

    Vessel weight in pounds: 70000 lbs

    Engine Horsepower: 18 HP
    Number of engines: 1
    Total Engine Horsepower: 18 HP

    Engine R.P.M. (max): 500 RPM
    Gear Ratio: 3:1
    Shaft R.P.M. (max): 167 RPM

    Number of shaft bearings (per shaft): 1
    Desired speed in Knots: 7 knots

    Horsepower Calculations
    This will calculate the maximum horsepower and torque available at the prop(s).

    Total available horsepower at the engine(s): 18 HP
    Total available torque ft/lbs at the engine(s): 189 ft/lbs
    Horsepower loss of 3% per gearbox: - 0.5 HP
    Horsepower loss of 1.5% per shaft bearing: - 0.3 HP

    Total horsepower available at the propeller(s): 17.2 HP
    Total torque ft/lbs available at the propeller(s): 542 ft/lbs

    Speed & Power Calculations
    Basic displacement speed and horsepower required
    Displacement hull speed (1.34 X sqrt of waterline length): 8.99 Knots
    Minimum horsepower required at propeller(s) for Hull speed: 138.8 HP

    Calculations based on desired speed and available HP
    HP required at propeller(s) for desired 7 knots speed: 66 HP
    Estimated speed with existing 18 horsepower:
    This is the speed we will use for the propeller size. 4.46 Knots

    At this point it is important to note that all of the calculations above are based on full RPM and HP. Most engines are rated to run at a percentage of thier full RPM. This is what will determine your maximum cruising speed. The propeller sizing calculations below are based on 90% of full RPM, which allows the engine to develop it's maximum power without overloading. The chart below shows typical engine ratings, you can find this information in your engine specifications.
    Recomended RPM for continuous operation
    Type of engine % of max RPM
    Light-duty gasoline and diesel automotive conversions 70 - 80%
    Light-duty or high output marine diesels 80 - 85%
    Intermittent-duty marine diesels 88 - 92%
    Continuous-duty heavy marine diesels 98 - 100%

    Propeller Size
    Number of blades Diameter (inches) Pitch (inches)
    2 Blade 54.5 X 56.7
    3 Blade 51.9 X 56.1
    4 Blade 48.8 X 55.0

    The propeller sizes shown above do not contain calculations for cavitation or blade loading.
    If you find that the recommended propeller is too large to fit your vessel, you can try increasing the shaft speed. Failing this, you can reduce the diameter and increase the pitch at the expense of your propeller efficiency. The rule of thumb is 1 inch of diameter is equal to 1 1/2 to 2 inches of pitch.
  7. SRSS
    Joined: Aug 2011
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    SRSS Junior Member

    I planed on designing and building a engine and boiler. For the engine i was thinking of a uniflow type with a boxster piston configuration. id like to build a small scale version of this engine and see how well it works then if and when i find or design a hull i like i could just scale the motor up! right now iv got a lot of stuff on my plate so i havent had the time to experiment with anything but when i get to ill be sure to post more!!
  8. tugboat

    tugboat Previous Member

    geez--not familiar with a boxster piston? that a piston valve?..much more efficient than -d the project--keep me posted..i think steam is amazing...
  9. SRSS
    Joined: Aug 2011
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    Location: Michigan, USA

    SRSS Junior Member

    A boxster piston configuration have pistons that move in a horizontal plane they have a natural dynamic balance and a low CG because there flat. i figure if the configuration works good as a combustion engine it should work just as good in a steam engine!
    here's a link about boxster combustion engines...

    And here is a link about the Uniflow steam engine...
  10. cthippo
    Joined: Sep 2010
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    cthippo Senior Member

    After reading those two wiki articles I think you're on to something, but I suspect the finished engine will be quite wide. Depending on the power density of the engine and how big it needs to be for the requisite HP, this may not be a problem.

    Maybe you can borrow seabirdship's design for a Tesla turbine for your genset :D
  11. speed50
    Joined: May 2014
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    speed50 Junior Member

    the YTL 45ft tug plan

    Hi Tugboat. This is a great plan. Exactly what I am looking for as I want to build this Army YTL 45ft tug boat as a static display model. Do you happen to have hull section drawings of this boat? With the hull sections and the plan you provided I would be able to re-create the tug in a 3D software as the foundation for the static model. Thank you in advance.:)

    Sorry I cannot send an email to you so I have to reply to this thread.
  12. SamSam
    Joined: Feb 2005
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    SamSam Senior Member

    I saw them somewhere in the Fremont Tugboat site. It was just the hull lines, no cabin or anything, a top, side and end view with no dimensions but all the lines needed.

    This is from there also, with much bigger pictures, about 1/2 inch down the page. It's not what you're looking for, but I just want to document it on this site.


  13. speed50
    Joined: May 2014
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    speed50 Junior Member

    Hi SamSam,

    It is a great lead. Thank you. I have read Fremont's blog before and it has vast information on tug boats:D I will dig it deeper there! Cheers!
  14. Tad
    Joined: Mar 2002
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    Tad Boat Designer

    Here are the other drawings for the YTL

    View attachment __20101101_0001.PDF

    View attachment __20101101_0002.PDF

  15. DCockey
    Joined: Oct 2009
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    DCockey Senior Member

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