Desperate to sail 2015

Hi Laukejas.

Congrats on your success!

I wish to post a few theories of my own about why the balance of your boat keeps changing.

1.) Because the dagger board is off to one side and the mast is centered. This could greatly change the force vectors, every time you change tacks. With the dagger board on the lee side, the boat may get more lee helm (want to point down wind) because the board is producing lift on that side, along with considerable drag. On the other tack, the board is on the weather side. There, its lift and drag are concentrated, so the boat might have a weather helm then.

2.) The underwater shape of the hull changes as the boat heels. Typically, boats with wide sterns and sharp bows tend to round up (want to point into the wind) as they heel. This is probably because of an unequal bow wave. The bow wave to lee is greater than that to windward, because there is more hull in the water to leeward than windward. This higher bow wave tends to push the bow upwind.

As for the sail.

I agree with everyone in saying I think you did an excellent job in making the it. The few wrinkles may be impossible to remove. It is probably best to tolerate them, as I doubt they made much of a difference i the sail's performance.

I also think the flat cut of the sail is a main reason it made it through this ordeal with no damage. Being flat, it could be feathered into the wind at a point where it did not flutter, or create much lift. This is an ideal situation to be in, in a blow.

The Super Snark(r) I once owned sailed through similar winds. The tiller bent in my hands and the boat left a rooster tail, as I sailed down wind. Up wind, to get back home, was a much slower process. But I was able to feather the flat cut sail to such an extent that I was able to make frequent stops to bail the water out, that had slopped on board.

 

The camber in the sail will move around with different wind velocities. As the wind increases the camber usually moves aft which effectively moves the center of force.

That is an overly simplistic explanation and just the general idea. There is a lot of complex physics going on with a sail and the parts that hold it upright. For example, the mast generates turbulence and causes the air attachment point to move rather capriciously. Imagine a mini tornado marching around on the lee side of the sail. Those are called vortexes and are an important part of what makes a sail work. All that sort of thing is mind boggling actually. If you can imagine that air approaching the mast as a group of streamlines, the streamlines begin to bend outward before they get to the mast. That is counter intuitive, but a reality none the less.

If you can get you hands on the book; The Art And Science Of Sails, by Tom Whidden, (ISBN 0-312-04417-8) You can delve into that kind of science. Meanwhile just accept that there are all sorts of mysterious things going on at or near the sail surfaces. Just for fun install some "woolies" on the sail. Those are bit of knitting yarn cut into pieces 15 to 20 Cm long. Use a small bit of tape to attach one end of the yarn to the sail. The idea is to let them stream freely. Maybe three of them spaced a little bit behind the luff and a few more farther aft, perhaps a meter in front of the leech. Do that on both sides of the sail. Watch what happens to them when you ease or harden the sail with the sheet. Great fun and also frustrating sometimes. The lee side woolies are the most revealing. If you have not used these things before, try it.

No need to get all technical but the book and similar ones might make interesting reading on those cold winter nights in your part of the world. Meanwhile enjoy what you have done. It should be a comfort to know that a Professionally built sail, the size that you have made, could cost $500 US dollars or more. The spars that you have built might cost another $500. You have done it with little money and instead, used blood, sweat, and tears.

Cheers.

 

Sharpii, messabout, thank you both for thorough explanations. The balance isn't very problematic, except for downwind sailing. I now know that the next upgrade to make is decent rudder. I have several ideas in mind. The only thing I'm worried about - this small boat doesn't have a lot of momentum, and it's impossible to tack without getting caught in irons. With oar as a rudder, I usually raise it in the air and "row" several times to help the bow go through the wind line. I guess this would be impossible with traditional rudder. I could, of course, gybe instead of tacking, but that loses distance and isn't very safe thing to do in heavy winds. What would you suggest in this particular case?

As for wrinkles and leech tension, I noticed that if I move sail a bit forward in respect to the mast, there are less wrinkles and leech is much more straight. However, the mast heights limits what I can do in this case. Also, with the boom so low, it ain't easy to tension the downhaul properly.
So the next upgrade (after the rudder) will be longer mast, I think 300cm instead of 245.


Today, I had a huge responsibility: the passenger I mentioned before, who is, by chance, my girlfriend, arrived at the scene and we took off together in quite rough waters with nice, pretty stable wind of 20+ knots and some considerable waves. She never had any experience with sailing, nor any knowledge of the physics behind it - so it befell me to make a proper first-impression of this wonderful sport, as well as explain enough so she could become a proper crew member. I was afraid that with the boat so small (3m waterline), displacement will be too heavy to point to windward, and in effect the whole ordeal will appear a bit pointless (pun intended).
And indeed, boat produced some horrible leeway, but reached up the wind nonetheless. With her at the tiller and me grabbing the mainsheet, we went through some very high speeds and scary gusts. On the way back, we had several accidental gybes, and almost capsized - but due to quick reactions, got away with only few buckets of water inside the boat. My helmswoman did very well.
And the arrived at the port with no damage to the boat, rigging, and ourselves. While this first experience might have been a bit scary, it was thrilling and memorable. We will surely do this again.

We will ask someone to take pictures - every time I set sail there's no one to hold the camera. Sorry for delay, I will keep my promise

So now I'm thinking to add a clamp-on rudder, and a new mast. With these, I believe this boat will reach it's full potential.

Messabout, you're damn right about blood, sweat and tears! There were a lot of these. Thank you for your kind words. I always wanted to believe (and to prove) that sailing mustn't be entertainment for the rich - that it can be affordable, practical, and no less fun if you're willing to sacrifice some comfort and get creative! And I think I'm getting there.

 

Hi Laukejas.

There is an old trick to avoid getting into irons (where the sail flutters until the boat stops, and fails to change tacks).

I had to learn it when I had my Siren 17.

That boat was very light for its size and had a cabin up forward.

The first day I sailed it, the outboard quit because of a manufacturing defect, and I had to rely on sails alone to keep it off the break wall.

Naturally, I was on a tack that put me on a collision course with the break wall when the motor quit.

I tried changing tacks, but to no avail. She fluttered to a stop on her old tack and sailed right into the break wall.

My brother bravely jumped over board and fended the boat off. I was able to grab him, once the boat was on the new tack, and haul him back on board.

I read about a sailing work boat of a hundred years ago. It had a long keel and turned very s-l-o-w-l-y. Turning the boat alone was not enough to get it onto a new tack. It turned so slowly that it would lose way before it got on a new tack, just like my boat.

The solution was to back wind the forward most sail.

In the case of my boat, it was the jib.

It's amazing how well it works.

The back winded jib acts as a bow thruster, pushing the bow over onto the new tack. (The jib was back winded by by leaving it sheeted on the side that it was on, on the old tack)

This worked so reliably that a friend of nine and I were able to short tack up a 40 ft wide channel. People came out of their cottages to watch.

When the jib was not set, the main itself could be back winded by grabbing the boom and holding it on its old side, as the boat changes tacks. Works just as well.

As for a clamp on rudder. Attached is a drawing I made for a project I was working on.

I wanted a rudder that could kick back, if it hit an under water obstruction. But i wanted the rudder to be one piece. My solution was a false transom that attached to the real one with a set of hinges. This way, the rudder can be tipped out of the water much the same way and out board motor is.

In this drawing, I also have a fore and aft pivoting side board (in the place of a lee board. The narrower appendage is the rudder.

 

Quite a story, sharpii2! I'll try backing the sail. Not sure how that will work with single mainsail which has CE aft of CLR, but worth to try.

The rudder design is very thoughtful, however, I did not understand, how does it attach to the transom of the boat? In my particular case, all I can use are ropes and clamps, because it would be preferable not to drill anything. Is it possible to adjust your design to work with a clamp?

 

For the wrinkles, could it be that your yard is too flexible, or not straight? Since the head of your sail is cut pretty straight, the yard should be too.

 

If you get caught in irons, as you start drifting backwards you might try reversing the rudder and backing into the correct tack. Sort of like backing a car out of a driveway. It is easier than having to gybe to change tack, which you'll probably have to do if you make a rudder and don't have the oar to swing you around.

 

Absolutely.

Replace the rectangular piece, I call the "transom plate", with a board.

Clamp the board to the transom of your boat with a pair of "C" clamps.

The bunji cord which holds the rudder down could be attached to a line, which attaches to the bridle, which holds the dagger board case on.

 

Unless your girlfriend is real adventurous and likes outdoor challenges, I would keep her out of the boat if the weather and wind are not suitable for pleasant sailing.

Most women do not like being out in scary conditions in a small boat (even if many guys find it an exiting challenge). More than a few sailors have lost their girlfriends, and possible life partners, when taking them out in "exiting conditions" for their first sailing experience. If they have a pleasant and enjoyable time on their first sailing trip, and you work up to taker her out in more "challenging" conditions, you will get her hooked for life.

 

How does the tiller and tiller plate engage the stock and rudder?

 

Indeed, although it's not flexible, it ain't straight either. Not much I can do about it except for loose lashing.

Sometimes I do that... Only that it loses a lot of ground when trying to beat to windward.

Thanks. Well, for this year, I think I'll let it go. If I won't get decent sailboat next year, then I'll upgrade rudder for this one.

Very true. And I had the same intention you described, only that I cannot control the weather - neither predict when it changes so rapidly here. What seemed a moderate conditions quickly turned into something more serious. But she always wears a life jacket, I insist on that. And despite that little hiccup, she said it was pleasant experience.
I understand the seriousness of dangers of this sport. I capsized once, and know how things can get out of hand quickly, so I don't fool around. Safety is always a priority for me and those whom I take together.



Today, we had light to moderate south-westerlies, no more than 20 knots at gusts. We took off together for two and a half hour cruise, and made some very nice progress, despite having to deal with very shifty winds. I start to understand how this particular boat works, and with some subtle adjustments, it is now possible to beat upwind with some actual enjoyment and within reasonable time, although frequent tacks with boom so low makes it physically frustrating.

There were no special events this time, but we just had a very pleasant trip. As we went back, my dad took some photos, and, as promised, I deliver them to you. Enjoy

http://static.dyp.im/5WTTaIWdAG/60f658812604832d36abc740af410f95.JPG
http://static.dyp.im/s2eqzs44Lz/9ff23c247e77bb1cf9d9d5c855791111.jpg
http://static.dyp.im/NTraF8eqDl/5fc3ba7afed348c29b76e05789f69cde.jpg
http://static.dyp.im/ldg9ldiPOx/53c66015c9c45f02459d36140d38b72e.JPG
http://static.dyp.im/CDjZecyKoA/8c0e6a18cee24f342891d7552275314e.jpg
http://static.dyp.im/YdHMuhlht0/d0e0e862b361de05b5aa88fbe9c5357e.JPG
http://static.dyp.im/4khZ4zfJWc/471ad1cb33abc675797e6bfa4adeadd5.JPG
http://static.dyp.im/cDsmlkqan4/a5c90290ac499b0abf5c70035688c052.JPG

Some of these photos are large, you can zoom in. There weren't a lot of wind during this last phase, but you can still see the sail at it's shape in some of these images.

 

Simple.

The tiller shown is a yoke tiller. The "tiller plate", "TP", has two pieces of 1 x 2 inch lumber attached to it on its under side. This forms a removable stock, which the rudder slots into. It's held on with two bolts, which pass through both this stock and the rudder.

A continuous line runs from one end of the yoke tiller, to the bow deck of the boat, then back to the other end of the yoke tiller.

To give you a better idea of why this is, here is a drawing of the boat it is intended for (see attachment).

As you see, the sailor sits quite a distance from the rudder.

Not only that, he may have to deal with the main mast while the boat is still under way. He can steer with one hand and deal with the mast with the other.

 

great pictures laukejas, if it was not for the blue tarp, it almost looks like it made to be a sailboat. looks like a pleasant sailing trip.

I hope your girlfriend is suitably impressed, not many people can pull that off.

 

Laukejas; Your tacking difficulties brought to mind a "cranky" little pram like boat called El Toro. It is moderately popular in various places around the US.There are some very good sailors who compete in that class.

The Toro is prone to getting caught in irons. Here is what the shrewd El Toro sailors do..............Begin the tack and just as the boat comes head to wind, pull the board up. The boat will usually pivot far enough to fill the sail on the new tack at which time you put the board back down. Moving your weight aft during this maneuver also helps. Moving weight aft gets the bow up a little bit so that it does not have to plow its way sideways through the water. Bow up tacking is common practice on boats that are not perfectly designed for sailing.

I have seen boats, even owned one way back in time, that likes to have the transom up when tacking. That means getting your weight forward during the tack, of course. Just the opposite of bow up.

Next time out in the boat, spend some time experimenting with weight shifts and pulling the board. At tack time, do not put in too much rudder, just go around in a gentle arc that suits the personality of the boat and its rig. You have to find out what the boat wants. The boat is a mindless thing that has no sympathy for your needs or intentions. You just gotta' work with the boat.

 

Brilliant little project, well done on getting on the water. Una rigs (cat rigs) are always harder to tack than those with a jib so you need to slightly over tack to stop getting in irons. Getting to know the run of the boat will help you feel the ammount of rudder required. Every boat is slightly different, as a general rule, boats with a lot of rocker, tack faster than ones with very little rocker.

Worth recutting the foot of the sail a lot higher at the clew, to get some head clearance!.

Thanks for the photos, she looks pretty good for such a quick build time.