New member here interested in rowboats

Discussion in 'Boat Design' started by SailorDon, Apr 8, 2013.

  1. SailorDon
    Joined: Apr 2013
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    Location: Livingston, TX

    SailorDon Senior Member

    I just joined this web forum on boat design to get information on rowboat designs and performance. At first glance, I'm a bit disppointed that there is no catagory for "human powered" vessels. That would be rowboats and canoes.

    Where do I post on this forum for discussions on rowboat designs? I hope that "Boat Design" is OK.

    I didn't do much research before buying a Selway-Fisher Mandarin 17 from the builder, PicniK Yachts, in Sugarland, TX. It is a one man operation and he builds boats as a hobby. The reason for buying was I wanted an upgrade from my Achilles inflatable dinghy that I rowed about 100 miles last year (not all at once).

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    For a video of my "new to me" Mandarin 17, I posted a video clip to youTube.


    http://youtu.be/FcIaKiu6qmI
     
  2. michael pierzga
    Joined: Dec 2008
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    Location: spain

    michael pierzga Senior Member

    Yup...nice looking boat.


    If you search Boatdesign net there are many, many threads by row boat aficionados.
     
  3. Leo Lazauskas
    Joined: Jan 2002
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    Location: Adelaide, South Australia

    Leo Lazauskas Senior Member

    As already mentioned, search for "rowing" on this site and you will find a lot
    of threads.

    Unfortunately all my work on rowing is for olympic sliding-seat boats. See:
    http://www.cyberiad.net/rowing.htm
    There is a note on kayaks that might be of interest too:
    http://www.cyberiad.net/kayak.htm
     
  4. viking north
    Joined: Dec 2010
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    Location: Newfoundland & Nova Scotia

    viking north VINLAND

    Sailordon, first welcome to the forum,second my compliments on a well presented first post: I am a builder and avid rower but of grand bank dorys. The model shown is a modified grand banker known as the Shelburne. Two photos during build one afloat. It's designed evolved to be launched off the beach rather than from a mothership, thus the surfboat style bow. It is my favourite rowing dory and after experimenting and fine tuning the rowing position and a little trim ballast I can hold her at 4.5 kts. for miles on end. I row between 10 and 20 miles per week from May thru to Oct. I viewed your video and noticed a couple of negatives that is robbing rowing efficiency. On your power stroke the stern is just barely lifting out of the water while she is burying her bow and forward sections just a little too much. This indicates too much weight forward which is often a factor of who is sitting in the rowing seat. A rowing boat has to be tuned to where and how much it's load is in relation to it's center of floatation. Because they are generally small craft they are most sensitive to this. Since it is impraticle to move a fixed rowing seat we can offset this by a bag of sand (trim ballast) For the heck of it on a calm day place a 50lb. bag of sand at different distances aft of your rowing position and time her glide distance after your power stroke. The longer her glide the better her balance, the greater her potential speed and less work for you to cover a given distance. Note, if you discover 50lbs does the trick positioned halfway back to the transom then try 25lbs. placed at the transom. Have fun and happy rowing ---Geo.
     

    Attached Files:

    Last edited: Apr 8, 2013
  5. SailorDon
    Joined: Apr 2013
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    Location: Livingston, TX

    SailorDon Senior Member

    Hey viking north,

    This is good stuff! This is what I'm looking for. How to make me and my boat work better together. I've only had it for 4 days and I'm just at the beginning of my learning curve.

    Here is a GPS log of my rowing adventure this morning.

    [​IMG]

    The builder of the my rowboat, PicniK Yachts, (who is also the one who sold it to me) also recommended aft ballast. I searched on YouTube for aft ballast and found this one.

    http://youtu.be/qnotdh8hIfo

    [​IMG]

    Now that ballast would look fine sitting in my aft passenger seat. :D
    Sure beats a 50 pound sack of sand!
     
  6. Tad
    Joined: Mar 2002
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    Location: Flattop Islands

    Tad Boat Designer

  7. SailorDon
    Joined: Apr 2013
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    Location: Livingston, TX

    SailorDon Senior Member

    I skimmed over a lot of stuff in those 94 pages and basically found one suggestion about "stern in the water" at slow speeds. The particular reply said that stern out of the water was preferable. On another post by someone who watched my video, they suggested the aft of my rowboat was too high. They suggested I experiment with aft ballast and time the glide to obtain proper fore/aft trim. That's my plan, but I have to wait for a calmer day. It's blowing 20 mph and there are whitecaps on the lake today.
     
  8. NoEyeDeer
    Joined: Jun 2010
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    Location: Australia

    NoEyeDeer Senior Member

    I think the bow-down look is just an illusion caused by the droopy sheer for'd. You can see the effect in the lines plan and pictures on this page (about 3/4 of the way down). http://www.selway-fisher.com/Rowskiffs.htm
     
  9. viking north
    Joined: Dec 2010
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    Location: Newfoundland & Nova Scotia

    viking north VINLAND

    Ha Ha, ya but she'll sandbag you into expenses that'll force you to sell the boat to raise funding. You made a good trip today -- Rowing is alot like swimming timing and rythm. Don't over do it putting too much energy into your power stroke and allow her to glide lowering the oars for the next power stroke with a smooth non splashing entry. Remember the stroke cycle involves your arms- legs and back muscles as well as proper timing in your breathing. It takes time but you'll develop a natural rythm thats less strenious that walking.Great exercise -- I knocked off 35lbs. three years ago and holding pretty good since. On a typical summer sunday the wife sits and reads in the stern seat I change up to the forward rowing position and do a 10 to 15 mile trip around the bay. I'd much rather row than walk that distance.
     
  10. viking north
    Joined: Dec 2010
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    Location: Newfoundland & Nova Scotia

    viking north VINLAND

    Possible that could be creating some illusion but from experience i'm a firm believer in fine tuning with a bit of moveable ballast. It's very difficult to get the rowing positions dead on to match a large variety of body mass. What works for a 175lb. body does not necessarly work for a 225 lb. Never hurts to play around with it a little.
     
  11. Dirteater
    Joined: Oct 2010
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    Location: Canada

    Dirteater Senior Member

    Hi SailorDon,

    Welcome,
    great looking boat :)
    there's nothing I like more than getting out for a row on a good day/morning/evening.
    I've recieved some really great help here over the years. the lakes are still
    frozen-over up here, but in about a month we should be able to get on the water.
    I would imagine you have a longer rowing season down south. (I wish).
    nice to see another Rowboat on board. :cool:
     
  12. messabout
    Joined: Jan 2006
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    Location: Lakeland Fl USA

    messabout Senior Member

    Scrumptious boat SailorDon. You are going to have a blast with that gentlemans toy. You'll also get into pretty good physical shape if you continue to enjoy the activity.

    VN is right I believe. The video suggests that the weight distribution causes a slight bow down situation. Tinkering with ballast and glide time is going to be a worth while exercise.
     
  13. keith66
    Joined: Sep 2007
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    Location: Essex UK

    keith66 Senior Member

    Any man that can row an inflatable 100 miles even not all at once is a hero!
    As for trim & ballast, i built a Pete Culler designed Whitehall years ago and she was very trim sensitive. Her keel was dead straight & if she was down by the head at all she became a pig to handle.
    Trim her down by the stern an inch & she became a lovely boat to row.
     
  14. SailorDon
    Joined: Apr 2013
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    Location: Livingston, TX

    SailorDon Senior Member

    I am looking forward to calmer weather and some flat water to do some serious glide testing with various aft trims.

    For those of you up north, Lake Livingston never freezes. I row all year round. My sympathies to those who have to take a break for the winter.

    My plan for the glide test to determine optimum aft ballast is to set a "starting line" from the end of my dock. I will approach the start line at a constant speed that I am comfortable with, perhaps 4.5 mph. That will be measureed with the Garmin GPS. As I cross the starting line, I will stop rowing and coast (glide) to 1.0 knots (again with the GPS) and use the stopwatch to time the glide, and a range mark to measure the glide distance.

    I'm a data junkie (retired mechanical engineer) so I will have a great time downloading the GPS data into an EXCEL spreadsheet for detailed analysis.
    As an example, here is a speed graph from EXCEL spreadsheet analysis of GARMIN GPS data:
    [​IMG]

    It's easy to see where I was stroking and where I was slacking. :)

    In addition to the 50 pound sandbag in various fore/aft positions, I plan to repeat the drill with 25 pounds, 75 pounds, and maybe even 100 pounds. I will collect data until my arms give out.

    Here is a link to my inflatable dinghy rowing days. When you row 1 mile per day, 3 or 4 times per week, the 100 miles per year of dinghy rowing isn't all that much of an accomplishment. Notice in the dinghy video, the ability to turn on a dime. Of course when entering the turn at 3 mph, the dinghy will slide sideways for a good 20 feet or more before traveling in the new direction. :D

    http://youtu.be/tI3H7hObJv4
     
    Last edited: Apr 8, 2013
    1 person likes this.

  15. viking north
    Joined: Dec 2010
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    Location: Newfoundland & Nova Scotia

    viking north VINLAND

    Wow! I was thinking of something a little less technical say first without ballast do a power stroke and time the glide 1 one thousand, 2 one thousand until she drops to what you perceive is basically stopped. Next place you ballast say under the aft seat and do it again , then a third time with the ballast set at the transom. This will give you a good idea of any improvement. Once you get a feel for it do a couple of measured runs, say 1/2 mile out with the ballast located where you think it should be, dump the sand and repeat yout time on the return row. Play with it and over a few days rowing your natural feedback will be all the input you'll need. However having seen your GPS graphs why not have fun in the details. I think the 50lb. trim ballast will be all you need for trials. Eventually thru miles of rowing you'll become one with the boat and you'll develop a sense of trim ballast location for Up wind, Down wind, beam wind, and dead calm rowing. About that same time you'll row 5 miles and not remember the last 2, commonly know as "In The Zone". Have fun it's a great sport.
     
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