Jim Michalak's Boat Designs
118 E Randall, Lebanon, IL 62254
A page of boat designs and essays.
(15January 2011)This issue will be about knockdown recovery. The 1 February issue will continue the topic.
THE BOOK IS OUT!
BOATBUILDING FOR BEGINNERS (AND BEYOND)is out now, written by me and edited by Garth Battista of Breakaway Books. You might find it at your bookstore. If not check it out at the....
ON LINE CATALOG OF MY PLANS...
...which can now be found at Duckworks Magazine. You order with a shopping cart set up and pay with credit cards or by Paypal. Then Duckworks sends me an email about the order and then I send the plans right from me to you.
It's 10 degrees out and all is covered with ice and snow and Walter Platzer sends me this photo of his Mixer on a beach in Thailand. Note the clever use of the surfboard sail.
This is a rerun of the 15sep99 issue which featured a capsize test done by Herb McLeod on his then new AF3. I want to keep this one up front because it demonstrates what you need to do when you capsize a sailboat which is not self righting, but rather is self rescuing. That is you can get it back upright and going again if you are properly prepared and if the boat, like AF3, has ample built in flotation or airboxes to keep it floating high on its side as you recover. A few things I'd like to point out. 1) Herb's tests were done in very benign conditions and if you capsize in really bad conditions recovery could be a lot more difficult or impossible. 2) If you tinker with a design such that you remove flotation or airboxes or enlarge hatches or move them off centerline, etc., the recovery system may not work and the boat may swamp to the point where you cannot recover. 3) If you have a design with no flotation or airboxes at all, such as most any traditional open boat, recovery is about impossible because the boat will swamp completely and be unstable even if it doesn't sink.
And now on to our story...
AF3 CAPSIZE RECOVERY...
Herb McLeod has been sending me some great scans and also some results of capsizing his AF3, both intentional and unintentional. Early this summer he wrote:
I now have 14 days of sailing in on the AF3. Alas, no pictures yet of it sailing on the water for the same reason as ever, no one else around to take a picture. Most days I am the only boat on the lake. Had one sail where we traveled 20 miles in one day. We did a 6.5 mile section that day in 1 hour 10 minutes with the small sail (69 square feet) on a beam to broad reach (lots of wind). Also managed to turn the AF3 on its side that same day. The AF3 floated well was easily uprighted, boarded and bailed out. Everything in the cuddy stayed dry and we managed to not lose any of our gear. But that is not what I am writing about....."
That whetted my appetite and I emailed for more info about the capsize.
"I'd like to hear a bit more about the AF3 capsize. In particular: About what angle did it go over?"
"I do not know because we were not sailing it at the time. We were both standing on the cuddy deck fiddeling with the sail in a good blow and it went over real fast. We have regularly sailed the hull at up to 20 degrees of heel and it does not feel unstable although I like it best at 10 degrees of heal. I have an inclinometer on the boat(overkill I know) so I know that the angle of heel is a real measurement not a guess. When sailing I had one puff that almost caused a knockdown because I had accidently cleated the main sheet. What happened is he boat healed over dramatically and the sail depowered enough that equilibrium was reached and I was able to uncleat the sheet in time to prevent a capsize. Unfortuantly I did not look at the inclinometer, but I was busy at the time.
" How did you right the boat? (Did you use the leeboard?)"
"Gord the fellow I was sailing with uprighted the boat while I swam off after our cooler that was quickly blowing away. The water was shallow so he was standing on the bottom. His comment after was that he was amazed at how easily the boat came back up. The second set of plans for the AF3 that I purchased was for Gord as after that experience he was convinced that he wanted to build himself an AF3 this winter. We will see..."
"How did you reboard the boat?"
"I climbed on from the stern. I have a small step on the stern that also doubles as a support for my mast cradle. Iput my hands on the stern deck and placed my foot on the step and climbed on board. I must take a photo of this step and send it to you. With the step it was easy to reboard and I could walk around in the cockpit with the water in it and bail it out. Gord then reboarded over the side, which was much more difficult and his choice not mine."
"What I will have to do the next time I am out sailing will be to dump the boat in deep water while watching the inclinometer and get you an answer. The water should be warm this week as it is again over 30C today. Unreal for us as it is usually cool, no one has air conditioning here. We were at a folk festival today but came home as it was too hot.
At summer's end he wrote:
I was glad that I caught you in the other night. It was good to talk to you after so many emails.
I did get out "sailing" this Sunday. I rolled the AF3 solo both ways in deep water. The AF3 seemed stable to well over 30 degrees and I had the distinct feeling that I could have pushed it back upright until the point was reached that the water started to come over the combing of the cockpit. I had my large sail on the boat at the time of the test (103 square feet, 24-foot mast). Winds were almost non-existent. When it was rolled with the leeboard down in the water righting the boat was an easy task as all I had to do was put light pressure on the board. When the leeboard was up out of the water I "walked" with my hands along the chine log (it makes a good grip) to the leeboard and then pulled on the board to pop the boat upright. The comment from the yacht club spectators on the dock was that it came up too easy. They wanted to see me struggle for a while. When righted the boat had 6" on water in the cockpit against the center bulkhead. I pulled myself on board via the stern. I found it easiest to board directly in the middle of the stern because the boat would tend to wallow with the water in the cockpit if I was off to one side or the other. I found turning the rudder 90 degrees and using it as a hand hold helped to reboard. For those with limited arm strength a step on the rudder or a rope step on the stern near the midline would be a great help for reboarding. My son was taking photos I hope some of them turned out. Also asked another boat to take a few photos while sailing maybe we will get you a picture of the AF3 sailing.
I am now off for a week to Jasper Alberta with my son for some hiking and canoeing.
WHAT I THINK IT ALL MEANS....
Herb McLeod seems to be the most energetic and organized person I've met.
The scenery of his sailing lake is certainly picture book beautiful. He has warned me that the mosquitoes don't show in the photos.
The capsize with two men on the cuddy deck is no surprise. The boat was not designed for that. In fact the idea behind the slot top cabin is to do all sail handling from inside the slot. You can do that if the snotter attachment is kept within reach of a person with his feet on the boat's bottom. I suspect the high snotter attachment Herb is using is to gain more sail efficiciency. That is true enough but after having snotter tackles fail in one way or another I learned to keep the them well within reach.
Actually the AF3 capsize seems very similar to my experiences with capsizing my old Jinni. Both boats capsize well before they take water over the side. Jinni had less flotation and I think took on more water. I was able to reboard Jinni over the side. It had lower sides and there seemed to be a trick to rolling over the side just as the boat was rolling upright. Then I had to be very careful to not recapsize the boat because of the sloshing cockpit water. And like AF3, Jinni couldn't quite roll upright until I put some weight on the leeboard. The Jinni had three skid/stiffeners on its bottom which I used as a toehold to regain the capsized boat in the same way that Herb used the AF3 external chines as a finger hold. I may add some similar skids to the AF3 drawings.
Herb looks to have gone through all his tests without disturbing any gear because he had it well stowed. Very important.
...More capsize stuff.
DARCYBRYN, Cabin Sailboat, 15' X 6', 800 pounds empty
Darcy Bryn is the new name of the "Billsboat" project that was discussed here a while back (see the November 2009 back issues). The idea was for a solo cruiser with good rough water capabilities. The issue of self righting was explored rather deeply back then. The trouble centers around the fact that a small boat like this can need ballast similar to a larger boat because the critical weight that needs to be counteracted can be that of the crew, and that doesn't scale down with the boat. The number you see all the time for ballast in a small cabin boat is 500 pounds. Then for a small boat the problem becomes getting enough buoyancy in a short hull to just deal with the weight of it all, etc. You usually end up with a boat that sits quite deep in the water both to get the ballast down low and to get the hull volume required to float the ballast. And after you've used a boat that floats in 3" of water you will have little interest in one that grounds out in 18" of water and that is about how it goes.
Darcy Bryn is a compromise here because the builder didn't really want the above solution. So what you have on the drawing is 200 pounds of lead bolted to the bottom of the hull, enough we figured to right the boat from a knockdown as long as the crew has jumped in the water and thus removed his weight from the capsize equation. Then the boat will right on its own and should be free from swamping of any sort since she is decked over all the way. Then the skipper needs to get back up and in somehow. Not always easy and you must be prepared for this both with a ladder of some sort that you can grab while swimming, and also with the sail's sheets released so the boat won't sail away without you, which many rigs like this yawl rig can and will do. If it sounds too risky then you might add another 300 pounds of lead and hopefully it will self right with you still on the deck. If this all sounds pretty wild I can tell you I know of two Bolger box cruisers that behaved exactly this way in real knockdowns. Boat tipped and was stable on its side, crew jumped in the water, boat righted and crew reboarded. I think Darcy draws about 12" of water at full weight partly because the ballast extends about 3" below the bottom.
To make the hull take rough water I shaped it with multichines and a pointy bow. It is pretty curvy. The multichines reduce the internal volume and the pointy bow pushed the effective cabin back to the point where a long floor sleep space is acquired by having the sleeper's feet extend past the main bulkhead and under the aft deck. But even with the pointy bow she may not be too comfortable sleeping anchored in open water.
The rig comes right off a Mikesboat because Bill already has a Mikesboat. It looks a bit large on the drawing but lug sails can reef nicely and quickly with practice. The mast is mounted on a tabernacle but whether it is safe to swing the mast up while afloat is a good question, at least I don't think it can be done safely by standing on the deck. Maybe by standing in the front hatch with your feet on the floor. Best done with the boat on the trailer or beached, I'd say.
Well, I guess I've given you all the negative warnings. In the end it might be a tough little boat capable of staying out in the rough stuff after everyone else has given up. With a cozy cabin.
Construction is taped seam.
Prototype plans for DarcyBryn are $35.
Some of you may know that in addition to the one buck catalog which now contains 20 "done" boats, I offer another catalog of 20 unbuilt prototypes. The buck catalog has on its last page a list and brief description of the boats currently in the Catalog of Prototypes. That catalog also contains some articles that I wrote for Messing About In Boats and Boatbuilder magazines. The Catalog of Prototypes costs $3. The both together amount to 50 pages for $4, an offer you may have seen in Woodenboat ads. Payment must be in US funds. The banks here won't accept anything else. (I've got a little stash of foreign currency that I can admire but not spend.) I'm way too small for credit cards.
I think David Hahn's Out West Picara is the winner of the Picara race. Shown here on its first sail except there was no wind. Hopefully more later. (Not sure if a polytarp sail is suitable for a boat this heavy.
Here is a Musicbox2 I heard about through the grapevine.
This is Ted Arkey's Jukebox2 down in Sydney. Shown with the "ketchooner" rig, featuring his own polytarp sails, that is shown on the plans. Should have a sailing report soon.
And the Vole in New York is Garth Battista's of www.breakawaybooks.com, printer of my book and Max's old outboard book and many other fine sports books. Beautiful job! Garth is using a small lug rig for sail, not the sharpie sprit sail shown on the plans, so I will continue to carry the design as a prototype boat. But he has used it extensively on his Bahamas trip towed behind his Cormorant. Sort of like having a compact car towed behind an RV.
And a Deansbox seen in Texas:
The prototype Twister gets a test sail with three grown men, a big dog and and big motor with its lower unit down. Hmmmmm.....
Jackie and Mike Monies of Sail Oklahoma have two Catboxes underway....
Tom Wolf has completed the first Toon2 that I know of and was waiting for some good testing weather...
AN INDEX OF PAST ISSUES
THE WAY BACK ISSUE ARCHIVES
1feb10, Emergency Flotation, Mayfly16
15feb10,IMB Capsize Test, IMB
1mar10,Wood Vs Aluminum, Blobster
15mar10,Rigging A Lugsail, Laguna
1apr10,Beefing A Mast, Frolic2
15apr10,Rigging Sharpie Sprit Sails, Sportdory
1may10,Small Boat Rudders, Blobster
15may10, AF4 rebottom1, Catbox
1jun10, AF4 rebottom2, Ozarkian
15jun10, Rend Lake 2010, Vector
1jul10, AF4 rebottom3, Wooboto
1aug10,Texas200b, Family Skiff
15oct10,Sail Area Math, Jonsboat
1nov10,Sail Oklahoma a, Piccup
15nov10,Sail Oklahoma b, Caprice
1dec10,Taped Seams, Trilars
15dec10, Bulkhead Bevels, Raider
1jan11, Mast Tabernacles, OliveOyl
Mother of All Boat Links
The Boatbuilding Community
Kilburn's Power Skiff
Bruce Builds Roar
Rich builds AF2
JB Builds AF4
JB Builds Sportdory
Plyboats Demo Download
Brian builds Roar2
Herb builds AF3
Herb builds RB42
Barry Builds Toto
Table of Contents