planning cs20 capsize test

[JeffM]

Planning to capsize Beatrice Ann in shallow water tomorrow to find out how long it takes mast tops to sink, whether a noodle at mizzenmast head will prevent that, where water comes on seat tops, etc. Most importantly, I want to see how I might right her when I'm shoulder deep in water. Suddenly occured to me to ask what other info people (those building or thinking of building, and maybe Graham) would like me to collect.

One issue is whether I can even REACH the cb in a boat this big. A line hanging the high side would give me something to haul on, but I don't know how to make it practical --rig them without dragging them in the water all the time.

Ideas on capsize testing? Righting?

[Tom Williams]

Good luck with the test. I'll be interested in hearing the results. I want to add some buoyancy to my masts when I build them.

As an idea for reaching the CB when flipped: You could tie a ~ 12" piece of line to the bottom of the CB leading edge. The line would cause extra drag when sailing but would hopefully be hanging down when horizontal. I believe the water forces would tend to push the line to the right side of the board during the capsize. Just a thought.

Tom

[Designer]

I think that everyone should perform this test.

You will need some buoyancy at the top of the mast to prevent the masthead from slowly sinking. You also need to make sure that your mast does not leak.

I am planning on a knotted line attached to the underside of the deck on each side. I can throw over the high side line to help in righting the boat.

I am not keen on dragging a line from the centerboard. Beside the drag, I would hate it to get caught between the board and the trunk and jamb.

Good luck with the test.

[JeffM]

Thanks, Graham. I wasn't thinking of a line from the cb, but lines dragging from each side--I wasn't sure if I would have time to toss a line over if capsize were unavoidable. I've plugged both ends of each 8' top mast section for buoyancy, and I could use my staysl halyard to raise a pool "noodle" to the masthead, roughly doubling the floatation over mast tops alone. This would be ugly, but not mess up the air flow too much I hope. I'll post results tomorrow.

[JeffM]

Did a short test on Saturday. Wind about 5kts. Boat almost totally empty. Put boat in thigh-deep water, pulled over using halyard. Masts were nearly horizontal before boat went over on its own. Note from photos where water comes on seats. Masts appear to have had just barely enough bouyancy to prevent complete overturning (I don't think they touched bottom). I took about a minute to get around to the bottom and begin pulling on line over coaming (tied to gusset). It took hauling nearly all of my body out of the water to get the boat upright, and I had to prevent my feet slipping off the bottom to lever myself out of the water. (In the end, it might have come upright with more patience and less weight.) One important error on my part: I should have released the mainsheet as soon as the boat came up--it tried to sail off with me as I tried to pull myself up on the boarding step. Cockpit had a lot of water and took several minutes of fast bailing. Finally, lockers proved to be substantially flooded: a couple gallons or more in each seat locker even though they were only submerged for a few minutes at most.

In my judgement, righting the boat --at least in light air--is easier than boarding it! I may have to keep the boarding ladder handy in stiff winds. I find even the boarding ladder difficult to use, though--there just isn't much on the deck to hold on to. Graham's idea of keeping a knotted line to throw over is a good one. I might even toss it over in heavy winds as a precaution.

[JeffM]

the rest...

[JeffM]

A new thought: the mainmast is held in place by the snotter run to a block on the fordeck, then aft. But unless I remember to pin it in the step (I keep the reefed mizzen from turning by running a pin through the side of the step and into the wooden plug), the mizzen could, theoretically, come un-stepped in a capsize. Another new thought: I need a handle of some kind on the aft deck. Something strong but low profile.

[Noklin]

I have been hoping someone would test the CS 20. I was concerned that one person might not be able to right the boat after a capsize.

If I might ask, how much weight did it take to right the boat? How much difference would a 20 knot wind with the associated waves have made? Do you think that the boat would have finally turned completely upside down and how long do you think it would have taken? Would a full load of gear made much of a difference?

Anyway, that is a fine looking boat.

[Tom Williams]

Nice job with the experiment. I will definately plan the same with mine (next year ).

You mention in your text a boarding step. I've been thinking about one for my CS17 and would love to see a picture of another. I was envisioning a step attached to the transom between the rudder and one side. The step would be ~10" long X ~5 inches wide located just above the WL. Enough to get a foot or knee on as you pull yourself out of the water. Anyone have thoughts on this?

Tom

[JeffM]

I weigh about 200lb. I mountaineered myself almost out of the water with my feet on the bottom, but my sense is that it didn't need quite so much of a pull--I was just a little impatient. I can't imagine a good breeze being anything other than a hindrance, especially with associated waves. And of course I'm unlikely to capsize in "5kt seas <1ft." But I haven't enough experience to say how difficult it would be. May be others will chime in. Note that my upper mast sections are plugged at both ends for buoyancy, and 8' long (plans call for 5 1/2'). I don't think the boat was in any hurry to turn over completely, but in a stiff wind I'd probably be on the safe side by running a float (pool noodle) up the mizzenstaysl halyard. I can't see gear making much difference. If it were enough to push the hull down a bit more it might slow the turtling a tiny bit by reducing the angle of the masts to the water.

The boarding step--available from Duckworks--was someone else's brilliant suggestion. I fixed it low on the transom beside the rudder, through-bolted to a big piece of 5/4 pine stair tread for strength. It isn't easy to use--too high up to get my foot on. The one time I actually had to climb into the boat in earnest I needed the boarding ladder as well (also Duckworks) and still looked pretty foolish. I plan to put a low-profile handle on the aft deck just this side of the tiller and as far forward as I can reach. Otherwise I have nothing to hold onto but a cleat that's off to one side.

[Rob Blackburn]

Try sailing on a big day with some ballast... To my mind this is the issue. Shackleton filled the James Caird with rocks to sail to Sth Georgia and at the end of the day the CS 20 with full sail and one person on board is not going to be easy to sail. Nor relaxing going to weather.

Our boat is great fun with some wind about IF it has plenty of weight on board for the whippy unstayed masts to whip and flex against.

Then you run into our problem of actually bending the masts if you have too much of all of the above.

R

[Bruce Leonard]

I sail my CS 20 #51 singlehanded most of the time. In fact I've had crew on board only 5 or six times.

If overpowered, I have learned to feather the main up wind in a breeze to keep her on her feet. Sailing off the wind singlehanded makes it all worth it. The boat planes so easily and is so fast.

We have some serious wind here on Narragansett bay most of the time.

In sailing my CS 20, I've learned to shorten sail early. When I see white caps or heavy gusts, I immediately take a reef, often before leaving the ramp. The CS 20 sails extremely well with reduced sail. Well balanced and fast. It's a lot more fun to sail under control.

The sail tracks we installed make reefing fast and easy.

[JeffM]

Dunno, Brad. I'm an old Sunfish sailor myself. Even if I could get a 20' boat around into the wind and still have time to get to the cb before she went belly-up, I'm not sure I'd be able to keep it into the wind. Also, I've got to get to the transom to climb aboard--the bow is too high. (I've toyed with the idea of a sea anchor that could be ready at hand...) I'd definitely need to free the sheets, and then make d_ sure I don't let the boat get away from me--even in irons, my boat can drift a whole lot faster than I can swim!

[Designer]

I have to disagree with Brad about bringing the bow into the eye of the wind. I know that all of the textbooks tell you to do just that, and it would be nice if you could.

I have found that the longer the boat is capsized the harder it is to right, because the boat wants to invert and water leaks into unexpected places like masts and fittings, lockers etc.

My technique is to make sure that the sheets are free and the board is down which takes only a moment if you are used to capsizing. I then get to the outside of the boat and on the board as quickly as I can and I don't care which way the boat is pointing. I then start to right the boat even if it is pointing downwind, it will slowly rotate around into the wind by wind pressure on the sails as the boat starts to come up.

I have capsized nearby other identical boats and I am up and gone while they are still trying to get the bow into the wind, in shallow water by this time their masts are stuck in the mud.

[Garry]

I used to capsize a lot singlehanding my 15 footer in stiff winds. As long as the masts have a little flotation, the hull will blow downwind with the masts pointing into the wind. Don't waste any effort trying to fight it. A chop will continue to add the weight of water onto the sails so sometimes it takes patience to get the sails out of the water. When its really rough, sometimes you can't do it.

With a little experience you can learn to clamber over the side of the hull as it rotates under you when the boat is going over. You will already be on the high side. Try to remember to let go the sheets then scramble onto the centerboard if it will take your weight. If you're lucky, you can have her coming back up before she gets all the way over. You can have a righting line ready and grab it as you climb over.

If she starts to go on over (turtle) get your weight off her and hang onto the end of the centerboard or the righting line. That will usually keep her from going on over. If you're unlucky and the wind is pushing squarely on the hull, it will drive the masts and sails down and turtle her. In deep water you can eventually get her righted from the downwind side with the righting line. I've had the mast STUCK in the mud and needed assist from a power boat to get her out.

Be careful when she comes upright again. In strong wind she will tend to continue rolling when the wind fills the sails. Be ready to scramble in and get your weight on the upwind side.

Like others have recommended, reef early asnd ease the sheets in a puff. I doubt you'll have too much trouble with capsizing.

[charlesrider]

Garry,

I'm glad you mentioned this. I guess those who sail unbalasted race boats learn this scramble. As I was reading all I could think of was, "what are you doing in the water?" Sure there are times when the boat, you, and everthing that isn't tied down go swimming, but I got really good at the scramble over the rail and onto the board. This whole discussion put it in my mind that if I get it together to build a CS20 that I will put grabs on the rails, grabs on the transom, and a step on either side of the transom.

The whole idea is to sense when you have overdone it, toss the sheets, scramble onto the rail and get it back up as fast as possible.

Also, I was wondering why the side decks are so narrow. While there is some sacrifice in interior width, another 4" of deck would make a nicer place for large people like me and would decrease the likelyhood of big dollops of water in the cockpit. I suppose moving each of the seat sides in 4" might make it difficult to fit my size 12s between the lockers and the trunk. Hmmm.

[Designer]

Chad,

The reason that I made the side decks narrow was for rowing, you will notice that narrowest part of the side deck is where the oarlocks go. The further the oarlock is from the coaming the less water clearance you have with the oar blade on the backstroke. If rowing is not important to you, you can widen the side decks.

[JeffM]

Actually, my side decks are narrower than plan. After sitting on my nice, deep seats for a couple of months of building, I became dismayed at the depth I lost when I began to dry-fit my carlins. After a little thought and consultation over the structural importance of the side decks, I narrowed them throughout. At the narrowest point, my side decks are about 2 3/4 inches. (Plans call for 3 7/8.) After a half-dozen good rides, the sides still seem quite stiff.