New design, 15' cat ketch

Discussion in 'Boat Design' started by 176inches, Apr 24, 2012.

  1. 176inches
    Joined: Apr 2012
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    Location: NW Ohio

    176inches Junior Member

    First launch was today. Lots of work, mistakes, problems and some good, fast cruising with wind speeds between 15 and 20 miles. Worst were a (relatively slow) leak and an inability to tack (flat out stalled). That last one would have been a real killer, but it was fixed simply by pulling down tight on the mizzen downhaul. Main points:

    - After retrieval I found the leak, and it's through the joint between CB trunk and garboard. Nothing that some nails, epoxy compound and caulk won't fix. Unfortunately the supposedly watertight buoyancy compartments also took on some water, so I have to dry them out and seal them with caulk this time. Clearly epoxy compound leaves invisible holes for water to come through.
    - Rigging her is a pain, and a lot of things can go wrong. It takes two people to do it. On a calm day she could be rigged at the dock, but since the mizzen partner is also the rowing thwart, I would need a motor, which I don't intend to get (yet, anyway).
    - She rows very well, but the high sides and nine-foot oars mean she is not a real row boat.
    - She is very dry (well, except the leak anyway :)), weatherly, stable and stiff. She has very little leeway. Also a slight weather helm, which is exactly how I designed her.
    - She can really fly on a moderate breeze.
    - The tacks, and especially the mizzen one, need to be tightly hauled down. I had been warned many times in books and web articles, but I didn't realize that the consequence would be inability to tack.
    - The masts, although slender, performed perfectly well, with no perceptible bend. I can't vouch for them in a much stronger wind, but I am very pleased with them.
    - I need to clearly label yards and sprits so I don't repeat stupid mistakes like I made today.

    For more details and a couple of measly photos (too busy and worried, and no friend to take them from another boat) check out
  2. philSweet
    Joined: May 2008
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    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

    Now all you need to do is repeat the process once a week for the next twenty years and all that little stuff with sort itself out. I put my little skiff in storage for a year once and felt like a total idiot down at the ramp tring to sort it out a year later.

    Nice boat. Sail it like you hate it and keep some paint handy. I give you six months until you get a little kicker:p
  3. sharpii2
    Joined: May 2004
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    Location: Michigan, USA

    sharpii2 Senior Member

    What do you mean by 'failed to tack'? Do you mean failed to point sufficiently up wind? Or do you mean failed to come about?

    The Siren 17 I used to own, routinely failed to come about. especially if there was any chop in the water. On her maiden voyage, she got two nice gouges in her gel coat for failing to come about, at the last moment and sailing, instead, into the stone breakwater.

    The problem was fixed by using traditional boat handling techniques from the 19th century. I learned to always back wind the jib, using it to force the bow onto the other tack. It worked perfectly. She never again failed to come about, even in seven foot waves and 30 kt winds.

    I suggest painting the tips of your yards and sprits. Paint the tips of the yards one color and the tips of the sprits another.
  4. 176inches
    Joined: Apr 2012
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    Location: NW Ohio

    176inches Junior Member

    She failed to come about. With the helm to the lee, she came up fairly close to the wind, then stalled before it even started luffing. As I said, the problem was solved when I tightened the mizzen tack downhaul. The problem was only on one tack: the mizzen was too far out from the mast and full of wind so it resisted getting closer. Lug sails lie on one side of the mast. Each of the two of them are on different sides so they generally balance each other but the mizzen is critical for tacking. I was pleasantly surprised at how pulling on the tack downhaul solved the problem. Nothing like hands-on experience to figure out traditional sails.

    Thanks for the paint suggestion. I was going to mark them M (main) and Z (mizzen), but I do have blue and white paint.
  5. Tad
    Joined: Mar 2002
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    Location: Flattop Islands

    Tad Boat Designer

    Sounds like she turned out great, the whole learning to use her and getting everything sorted the way you want is another adventure........

    Besides downhaul/halyard tension, there's another trick for tacking a cat-ketch in challenging conditions. Say there's little wind and a lumpy chop so the boat has little speed. As you go into the tack ease the main sheet and push the mizzen boom into the wind, she'll come right round.........split rigs are great.....
  6. 176inches
    Joined: Apr 2012
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    Location: NW Ohio

    176inches Junior Member

    Thanks Tad. I tried turning the main boom into the wind but it made no difference. Never having sailed a split rig before, I didn't know that the mizzen is the one that controls the tack.

  7. 176inches
    Joined: Apr 2012
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    Location: NW Ohio

    176inches Junior Member

    Today I dried out the boat and inspected the underside more carefully. I can actually see the tiny gaps between the garboard and the centerboard trunk along the slot, on one side only it seems. I can't believe I could be so careless. Anyway, the leak will be fixed (hopefully) this week.

    I painted the forward tips of the mizzen yard and sprit blue so I could tell them apart from the main ones, which I left alone. It will be easy to remember: Blue at the Mizzen is the last of Patrick O'Brian's series of nautical novels of Master and Commander fame. The naval lore that they are packed with has proven handy more than once.
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