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Thread: Air rudder for a big rowboat?

  1. #1
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    Default Air rudder for a big rowboat?

    My Welsford Walkabout is set up as a camp aboard rowboat. It's pretty big for a solo rowboat, stretched to 18' length with 5' beam, weight can be 500 - 600 lbs with me and camp gear aboard.

    Primary cruising ground is the Sacramento Delta and Suisun Marsh near San Francisco Bay. There are many sloughs and channels, very little fetch to build big waves but the wind is strong and constant in the summer. The channels tend to capture the wind, so if one is oriented close to the wind direction it will be blowing straight down the channel.

    My persistent challenge when cruising here is rowing up a channel into the wind. If I can hold the bow right into the wind I can claw my way up to the next bend and some shelter, but always the boat tends to turn away from the wind. If it gets much past 20 degrees off then I have to drop one oar and pull like crazy on the other to get her back, which is more tiring than a steady slog.

    Over the years I've tried several potential solutions:

    1) Weight shifting in the boat (the dory stone approach). Weight shifted forward helps some by putting the bow down and the stern up, but with a full camping load the stuff needs to be distributed. Now that I added a forward dodger it really does not work, too much forward windage. I like having the protective dodger, so need a solution that works with it.

    2) A regular rudder. I made the rudder per Welsford's design. It's fine, works as intended, but is worse than useless for this problem. A rudder only works when the boat is making headway, rowing into wind is very slow and sometimes the boat stops or goes backwards in a gust. Then the boat pivots on the rudder, bearing off much worse and impossible to turn by oar. The rudder also needs active human control, not really feasible while rowing. Maybe I could have rigged some kind of foot control, but that still does not help when the boat stops.

    Here's the kick-up rudder. The rudder cheeks are supposed to be immersed, says JW, as a sort of mini-rudder when the main blade is raised.:


    3) Yawl sailors like their mizzen sail, not so much for any power but because it helps point the boat. With the main dropped, the mizzen can be sheeted straight and hold the bow to wind. That sounded great, so a few years ago I tried making a furling sail and mounting it on the stern, like this:



    This did not work well at all and it added a lot of drag. If I stopped rowing in strong wind the boat would accelerate backwards, then turn sideways. I think it pivots on the skeg, and there is no centerboard to stop the turn.

  2. #2
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    Default Re: Air rudder for a big rowboat?

    Did you try the mizzen mast without the sail? I
    -Dave

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    Default Re: Air rudder for a big rowboat?

    With the sail furled it was not enough Dave. What I was leading up to was seeing an old post of Clarkey's on Boatdesign.net. He was musing on how a solid wing shaped mizzen might work, would it offer high lift force for low drag and no flogging: https://www.boatdesign.net/threads/s...-mizzen.34647/

    The thread died off without the idea being tried. Sooo, I got a cheap piece of half sheet ply and made a wing-ish shape by bolting to that mast and clipping the trailing edge flat, like this:





  4. #4

    Default Re: Air rudder for a big rowboat?

    extension of your idea: kickup rudder with hinge up near sheer ht so blade [longish] is above sheer-shadow when retracted up vertically. Keep cutting back blade length until works but is not bulky.
    bcmarinetrails.org - an attempt, by volunteers, to protect and enable 27,000 km of continuous camping and accesses along and around the whole Wild West Coast of British Columbia - for small beachable craft

  5. #5
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    Default Re: Air rudder for a big rowboat?

    I gave this a try on Suisun Slough today. Winds were only 10-15, gusting maybe to 20, but at that level it worked quite well. I could row into the wind, release the oars, and the boat continued into the wind as long as it had even a little headway. It no longer tried to bear off in the gusts, instead would head up if I was a little off.

    The wing was controlled by the rope steering I was using with the regular rudder, so it was steerable. I could set it so the boat was angled to the wind, it held course this way also. Here are pictures from my rowing seat, with the wing amidships and with it angled:




  6. #6
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    Default Re: Air rudder for a big rowboat?

    C'mon, Rick == I know you row a lot faster than me, but an airplane's rear tail fin is taking it MUCH TOO FAR! What's next, wings and landing gear?

    Most of us in sail and oar boats just lower the centerboard a little bit -- some drag but vastly improved lateral stability. If the airplane-style vertical stabilizer and rudder thingie creates too much drag or heeling in gusts, you could always try a light leeboard.

    "The enemies of reason have a certain blind look."
    Doctor Jacquin to Lieutenant D'Hubert, in Ridley Scott's first major film _The Duellists_.

  7. #7
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    Default Re: Air rudder for a big rowboat?

    You'll be amazed at how easily you can row upwind if you "tack" up in a zig zag two to three points off the wind on each side. But it only works if you can beat the leeway and your boat is not really suited for a centerboard.

    Since you don't sail, a pair of leeboards is not needed. Just one board on one side. As wide as the shear strake and next strake combined. Build up on the strake under the shear to give a flat for it to land on, pivoting at the seam between the two planks so build up inside as well. Big washers and a nut with a handle built around a socket wrench will give enough friction to keep the board down but you might need a little line to secure it up.

    The pic below shows the very much smaller rig I have on my dink. This dink has a very gentle round from sides to a flat bottom so it skitters a lot. If you row fast and then hold one oar in the water, the dink will turn till the oar is trailing but will keep moving in the original direction, now just sideways. In the pic, Susan has adjusted the angle of the board to let the boat row easily across and downwind with even oar pressure. For 'tacking' upwind in a stronger wind, the board would be more nearly vertical. For your boat, a wider board.


  8. #8
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    Default Re: Air rudder for a big rowboat?

    That air rudder is a hoot! Paint it bright orange so any jetskis or drunkards careening around the bends of the sloughs have a chance to see you before you get run down!!

    Correction: Drunkards ON jetskis https://www.youtube.com/watch?v=_3pmO39wBDA

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    Default Re: Air rudder for a big rowboat?

    I knew there would be some abuse from you lot . If this was a 4 sq ft salty looking actual sail, it might not be so aesthetically offensive.

    Ian - thanks for reminding me about trying a leeboard. We had this discussion a few years ago, I remember. Since the leeboard is not there to balance sail force, it could be smaller and possibly more forward. Someone had suggested a bow mounted drop down skeg, if I recall.

    Still, the wing thing is working better than I expected. It lets me go directly upwind with no increase in draft in the shallow sloughs, and no flapping from a sail. I will try this ugly one in some stronger wind, and think about how to do a smaller, lower one that can be folded onto the deck or just easily removed.

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    Default Re: Air rudder for a big rowboat?

    I might think about a small foot controlled rudder.
    Windage is hell.

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    Default Re: Air rudder for a big rowboat?

    Quote Originally Posted by Canoeyawl View Post
    I might think about a small foot controlled rudder.
    Windage is hell.
    But so is a dragging rudder. A small rigid foil section should have much less drag than a bare pole and could provide some drive in the right circumstances.

  12. #12
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    Default Re: Air rudder for a big rowboat?

    About fifty years or so ago there was a cool sail/rudder gizmo. Basically a triangular sail with a sleeve luff over a round mast that was a continuation of the forward edge of the rudder. A sprit boom clew higher than tack so self-vanging. The sheet went to a plank that was a continuation of the tiller.

    With the sail right above the rudder, it was easy to get things in balance and no centerboard was needed. It took a little practice to get past the weirdness and coordinate sheet handling with steering. One nice feature was that in a gust, adding weather helm to count er rounding up also, unless you trimmed the sheet, put the sail a bit more alee. It was a hoot.

    If you make a sideboard, first put the rudder down and pull the boat sideways to find the center of lateral resistance. Locate the pin of the board right there. That way when the board is about vertical it will provide resistance you want tacking up wind. When off the wind, various angles will get the resistance moving aft for easy rowing across or down wind. This will usually put the board about at the widest point, allowing the board to remain parallel to the keel at any angle of immersion. If the center of resistance is away from the point of widest beam, go with the latter and fix the balance with experiments of best blade angle for a given wind.

    You may need to experiment with different boards to get it right.

    My dink's board is on her starboard side allowing me to always land on the starboard side of any boat I visit.

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    Default Re: Air rudder for a big rowboat?

    Ian - Thanks for the advice. I still have on my to-do list making a leeboard for sailing. For now I'm going to play around with this wingy thing for a bit.

    Jake - The water rudder gets less effective as the wind gets stronger and the boat goes slower. In a gust that stops the boat the rudder makes it worse, pivoting the boat and preventing turning with oars.

    Clarkey - This is all your doing, I would not have thought of it without your old post.

    Today I am cutting down, lowering, and cleaning up the cheap ply wing. Testing to come...

  14. #14
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    Default Re: Air rudder for a big rowboat?

    It is a pleasure to see it being put into practice and apparently having some promise. I really need to get my work/life balance sorted out and work on my latest contrary ideas - a rowing boat with an upwind only rig and shelter for the oarsman that can provide drive rather than drag....

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    Default Re: Air rudder for a big rowboat?

    I hear you on the life balance, work has become all consuming recently.

    The wingy is reduced and lowered to just above deck. Now it is about 40" by 15":



    The profile is cleaned up a bit, got to be cleaner air flow than the clamps and bolts:



    Maybe get a test in tomorrow.

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    Default Re: Air rudder for a big rowboat?

    RG, would something like a drogue sleeve work ? A light, cylindrical tapered sleeve open at both ends and attached to the top of the mizzen mast ...

    Rick

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    Default Re: Air rudder for a big rowboat?

    Looks like a good start to some old school self-steering gear.
    -Dave

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    Default Re: Air rudder for a big rowboat?

    Quote Originally Posted by hawkeye54 View Post
    RG, would something like a drogue sleeve work ? A light, cylindrical tapered sleeve open at both ends and attached to the top of the mizzen mast ...

    Rick
    Hmm, probably not. The first try at a mizzen sail had too much drag. I was intrigued by Clarkey's plan to use a rigid foil for minimum drag when pointed into the wind, but a strong righting force when the boat tries to bear off.

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    Default Re: Air rudder for a big rowboat?

    The theoretically most efficient shape would be a tall slender foil. Like the extrusions Duckworks sells.
    https://s3.amazonaws.com/duckbbs/sup...nife-cover.jpg
    -Dave

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    Default Re: Air rudder for a big rowboat?

    Duckworks used to sell just the nose as an extrusion, you could use ply or other lighter material to make up the full foil. IF this test works (not enough wind last weekend), then I will probably try to make one like a model plane wing, shaped thin wood sections with fabric. A skin-on-frame rigid mizzen.

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    Default Re: Air rudder for a big rowboat?

    Can you please explain this to me?

    If you are rowing into the wind, and the bow gets blown off....an air rudder will always point the rudder into the wind, so will accentuate your course error.

    I'm sure I'm missing something, but I can't see how this helps you keep track into the wind, if it is direct and not opposing.

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    Default Re: Air rudder for a big rowboat?

    Quote Originally Posted by lupussonic View Post
    Can you please explain this to me?

    If you are rowing into the wind, and the bow gets blown off....an air rudder will always point the rudder into the wind, so will accentuate your course error.

    I'm sure I'm missing something, but I can't see how this helps you keep track into the wind, if it is direct and not opposing.
    There's no water rudder, it's just the air rudder. Like a mizzen sail, but "sheeted" with the rudder steering line.

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    Default Re: Air rudder for a big rowboat?

    Much obliged.

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    Default Re: Air rudder for a big rowboat?

    Quote Originally Posted by rgthom View Post
    Duckworks used to sell just the nose as an extrusion, you could use ply or other lighter material to make up the full foil. IF this test works (not enough wind last weekend), then I will probably try to make one like a model plane wing, shaped thin wood sections with fabric. A skin-on-frame rigid mizzen.
    Nice idea. You also can use some polystyrene core with ultra thin wood spray-glued. Hot wire to cut the polystyrene... maybe faster than SOF...

  25. #25
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    Default Re: Air rudder for a big rowboat?

    Sounds like you need a sail. Even tacking up channel it will be a lot faster than rowing.

    Rowing is for when the wind dies if you ask me...

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    Default Re: Air rudder for a big rowboat?

    Such a beautiful little sailboat, that

    (I still have that sail for you)

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    Default Re: Air rudder for a big rowboat?

    Quote Originally Posted by J.Madison View Post
    Sounds like you need a sail. Even tacking up channel it will be a lot faster than rowing.

    Rowing is for when the wind dies if you ask me...
    Well.... even if a person did prefer sailing, on these sloughs the sailboats and the rowboat cover similar ground at similar speed on a week long cruise. Going upwind the rowboat is often ahead, while the sailboats are motoring (if they have a motor ).


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    Default Re: Air rudder for a big rowboat?

    Quote Originally Posted by rgthom View Post
    Duckworks used to sell just the nose as an extrusion, you could use ply or other lighter material to make up the full foil. IF this test works (not enough wind last weekend), then I will probably try to make one like a model plane wing, shaped thin wood sections with fabric. A skin-on-frame rigid mizzen.
    I hesitated to mention sof, but I thought of it immediately...

    Peace,
    Robert

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    Default Re: Air rudder for a big rowboat?

    Quote Originally Posted by rgthom View Post
    Well.... even if a person did prefer sailing, on these sloughs the sailboats and the rowboat cover similar ground at similar speed on a week long cruise. Going upwind the rowboat is often ahead, while the sailboats are motoring (if they have a motor ).

    Great shot, where are we?

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    Default Re: Air rudder for a big rowboat?

    Quote Originally Posted by J.Madison View Post
    Sounds like you need a sail. Even tacking up channel it will be a lot faster than rowing.

    Rowing is for when the wind dies if you ask me...
    That isn't the case in my experience.

  31. #31
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    Default Re: Air rudder for a big rowboat?

    Yeah, I was out rowing my Tammie Norrie the other day, I was doing 3 knots while the yachties out racing would have been lucky to do half a knot!

  32. #32
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    Default Re: Air rudder for a big rowboat?

    On my Tammie I have found myself recently having to row toward windward in light conditions due to strong tides and an undersized lug sail.This worked quite well leaving the tiller unattended while rowing with the sail sheeted in tight (row sailing ) at around 25 degrees of the wind.
    I did however occasionally have to use just one oar on the windward side as the wind increased in order to maintain my heading with the rudder free wheeling.
    Not sure how well that would work in some of your narrow channels up the Delta, however in broader waterways row sailing combined with regular tacks and possibly using just using one oar might get you to your destination a little easier.

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    Default Re: Air rudder for a big rowboat?

    Quote Originally Posted by Canoeyawl View Post
    Great shot, where are we?
    Jake - looks like the Orwood Bascule on Middle River.
    "The enemies of reason have a certain blind look."
    Doctor Jacquin to Lieutenant D'Hubert, in Ridley Scott's first major film _The Duellists_.

  34. #34
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    Default Re: Air rudder for a big rowboat?

    Thorne is right on the location.

    A shallow draft rowboat can have an advantage in crosswinds on the Delta as well. Many times I am rowing along the side of a levee, one oar almost touching the rip-rap, while the wind howls overhead. Deeper draft boats are out in the channel, with the lee shore (also rip-rap) only a few hundred yards away. You don't see many sailboats out here, maybe some in the wider rivers. Our band of sturdy TSCA sailors are the exception.

  35. #35
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    Default Re: Air rudder for a big rowboat?

    The forecast for the Carquinez Strait today was a small craft advisory for winds 15-18, gusting 26 kts. Great! I took the lowered and reduced hard mizzen for a test.

    On the dock:



    Out on the strait:


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