Jim Michalak's Boat Designs
1024 Merrill St, Lebanon, IL 62254
A page of boat designs and essays.
(1 September 2019) We look more at rowing. The 15 September issue will take us on a Scram Pram cruise.
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.
TIME AGAIN FOR THE INDIANA MESSABOUT
Just a quick note to remind you that the 28th annual Lake Monroe Midwest Messabout (near Bloomington, IN) will take place September 13, 14, 15 --- just six weeks away! Mark your calendars for this informal family-oriented gathering. There are no officers, dues, members, discounts, or coupons, but there is one rule -- Enjoy a relaxed weekend of messing about with small boats. All small boats and boaters are welcome, be they sail, oar, paddle, pedal, or motor motivated.
Come join us. We indulge in all things related to having fun with small boats.... boats, boat plans, boat books, construction ideas, photographs, and the telling of tall nautical tales. While many messers are boat builders, being a builder is certainly not a requisite for attendance. It's not even necessary to bring a boat....although we always like to see a new build, an interesting design, or your current project (completed or "in process").
We'll have the usual Saturday evening pitch-in dinner and campfire so bring your favorite dish to share and plan to stick around for the evening's fireside chat fest. Click on this link https://sites.google.com/site/lakemonroemidwestmessabout/home for detailed messabout information. See the "Saturday Pitch-In and Campfire" page for suggestions on food for the pitch-in. If you plan to attend, drop us a line and we'll update the website's "Who's Coming" page.
Paynetown State Recreation Area non-electric campsite P22 will be the messabout "headquarters". Several enthusiastic souls typically arrive on Friday with Saturday being the main day of the event. If you can spare the time, Sunday usually offers quality time on the water as many of the lake's high-horsepower boaters head home early Sunday afternoon leaving a calmer lake for those who can stick around. There is an Indiana University home football game on Saturday September 14, so it would be wise to make your lodging arrangements as soon as possible.
Feel free to contact us if you have any questions or concerns.
We look forward to seeing old friends and making some new ones. Pass the word to your boating friends.
John and Susan McDaniel
Olin in the Czech Republic has posted many many af4 construction photos at https://olin77.rajce.idnes.cz/Moje_stavba_lode_AF4 and a cruise video at https://youtu.be/kYayUUmIJ1Y
1024 Merrill St,
Lebanon, IL 62254
Send $1 for info on 20 boats.
GEAR TO INCREASE POWER
(Before we get too involved in this I should mention that I have never tried any of the following techniques myself. This is just a paper study for me. If you think I've really blown the analysis, let me know with details and I'll rewrite with corrections.)
Increasing power will improve speed. Remember the formula for power is an arrangement of force, time and distance.
One way to increase power is to work out at the gym a lot and increase your muscle size such that you can pull with more force. Then slide the oars out a bit such that the extra force you can develop is converted into extra hull speed.
Another way to increase power is to quicken your stroke, pulling with the same force through the same distance. The increased oar handle speed is instantly converted to increased blade speed. You'd be rowing with lots of short quick strokes. This method works well with short boats that don't carry well between strokes.
You could also lengthen the stroke, keeping the force and stroke frequency the same. With any boat, especially a fixed seat boat with short oars, there are limits on the stroke length. If the oars start sweeping through large angles, efficiency will be lost.
Figure 1 shows the usual sliding seat arrangement. Here the rower sits on a seat that slides on rails, his feet are strapped into shoes which are fastened to the hull. In position A, the start of the stroke, the oarsman has his arms extended and his knees drawn up such that his hands are near his ankles. By extending his legs on the power stroke at the same time as he pulls on the oars, the rower greatly increases the length of his stroke compared to a fixed seat. The seat looks to be sliding about 2' during the stroke. In the diagram he has about 4-1/2' of oar handle stroke, about a 50% increase over a fixed seat. If the cadence of the stroke is the same as for a fixed seat, a 50% increase in horsepower would result. (He might also pull with a lot more force on the handles, but remember all the force he generates will transfer through his arms and hands. So I wouldn't expect a large increase in handle force in a long run.)
All the forces produced on the rower's hands are reacted through his feet alone and the human body is well built for that. None of the force reacts through butt friction.
Here are some arguments against the sliding seat.
For one thing the sliding of the seat may require a long space. (But the boat should be long anyway to take advantage of the extra power.)
The sliding seat can be a hazard in rough conditions. That may be a double hazard because you must strap your feet to the boat for the system to work.
The length of the oars must usually be increased because if you double the length of the stroke you will double the sweep of the blade. The angles the oar will sweep through will become excessive and inefficient if the oar is not lengthened. The lengthening of the oars will usually mean the addition of outriggers to help place the oar handles conveniently.
All these things may be worth the bother if you are the right person in the right boat. But maybe not. As shown in the figure I dreamed up for Roar2, a 50% increase of the power will increase boat speed about 15% . Instead of going 4 knots at full stretch with a fixed seat you might make 4-1/2 or 5 knots with a sliding seat. Normally I advise against it for a shorter boat. A longer narrow boat will probably be needed to take advantage of the sliding seat.
And increasing the speed potential of the boat will do no good if you don't pack the extra horsepower needed to push it to the higher speed. The rowing rig is just a transmission to match your power output to the needs of the boat.
There is another set up - the sliding rigger. In this boat the rower is seated on a fixed seat. The riggers that hold the oarlocks are not secured to the hull but instead are fastened to a sliding car which also contains the foot brace. The rower's feet are tied to the brace as with the sliding seat. But now his feet push the rowlocks aft as he pulls the handles forward. The overall power effect is the same as for the standard sliding seat. But the details are a bit different. For one thing the rower's weight doesn't shift around causing trim changes and hobby horsing. And all the force on the rower's hands reacts through his butt again. I've never seen one of these rigs in action. I read somewhere that when first tried in racing shells decades ago the sliding rigger boats easily beat conventional sliding seat boats and were soon written out of the rule books. Maybe so.
Ron Rantilla developed a rowing system starting with a standard canoe in which you paddle facing forward, (an advantage of paddling as opposed to rowing). To avoid having to transfer the paddle from side to side for directional control (an advantage of rowing and double paddling over single paddling) he mounted two paddles on a pillar in the center of the boat. The paddles attached to the pillar with a springy thingy that carried a lot of the paddle weight while allowing flexibility to paddle. Thus he was able to work each paddle with each hand. Ron lengthened the paddles into oars and thus he was able to row facing forward, (his "oars" were pivoted in the center of the boat in this case, not at any oarlocks, and his hands were outside the pivot). Forward facing push rowing has been used for a long time in certain areas and seems to be an inefficient way of using the human anatomy. Even fancy articulated oars that allow you to pull row while facing forward have never begun to achieved the efficiency of regular pull rowing. But Ron's system does allow forward facing pull rowing without the mechanical losses of an articulated system. Then Ron found he could run lines from foot pedals though pulleys to the oar looms and get his leg power into the equation. Then he found, that by attaching the leg lines just right and adjusting the center pillar springy thingy just right, he could make the oars dip just the proper amount under power and feather the proper amount on retrieval. No hands required in the proper conditions!!
I haven't seen Ron's system in action but there are certainly several advantages. None of the stroke power need be transmitted through the arms and hands - they can just be used to guide the oars if needed. You face forward. You sit in one position. You're feet aren't strapped to the boat.
Clearly there is some complexity of gear involved, but it's all pretty reliable and understandable and efficient. I guess the reaction forces on your body go out through the butt again. I would think a conventional sliding seat boat could boast more "power" because the rowers arm and back movements can add to the length of the stroke.
Ron wrote about his invention and experiences in MESSING ABOUT IN BOATS several times. He's not a racer but has raced the system with some success against sliding seat ocean racers. Like the sliding rigger experience, some of the conventional sliding seat racing organizations won't let him compete.
OLIVEOYL, Cabin Sailboat, 15' X 6', 500 pounds empty
OliveOyl was designed for someone who likeD AF3 but wanted more cabin room and comfort, but not more length. So I actually had some AF4breve drawings handy when I drew the lines for the new boat. Although Olive is the same length as AF3 the cabin is deeper and the bottom a foot wider. One thing the owner did not want, which made the larger cabin possible, was a large cockpit. So I've drawn a bridge deck which extends into the cockpit, reducing foot space there, and also just borrowed length from the cockpit and put it in the cabin. So the floor length in the cabin is over 8'long but you will probably sleep with your feet stuck under the bridge deck. I suppose the downside is that the cockpit is less than 5' long so two adults would fill it. I am guessing an empty weight of 500 pounds but it will take 2000 pounds to put its stem in the water so she should take a fair load.
I suppose I've learned a bit since I drew AF3 a while back. One thing I've learned is that when beached a boat like this is much easier to board if the bow is not too high, thus on this boat I've cut down the bow enough so you can sit on it anD swing your legs around right into the cabin entry in the bulkhead, I hope. The owner did not care about that and I don't think she beaches much in her area.
Now, the owner wanted a conventional cabin with sliding hatches so I drew that. And with it went a mast mounted on a tabernacle. I drew the mast off center as I normally do, attaching it to one of the main cabin deck beams. That moves it out of the center of the boat where you will be sleeping. But this boat could be simpler if it had my usual open slot top with a one piece mast. Such a layout would be a lot better I think for a boat which would be sailed off a beach too since it would allow the skipper to hop on the bow after pushing off, and then run upright back to the cockpit. As is he would have to creep down and tHrough the cabin or go over the cabin but I should warn you that, with AF3 at least, standing on the cabin top is an invitation for capsize. After all, these are not large boats.
The rig shown is pretty much right out of the AF3 experience, in particular with AF3's balanced lug rig. The spars are short and cheap and the mast short enough that the tabernacle won't be required if the open slot top is used.
But I doubt if OliveOyl would stay with an AF3 in a race. She has the same rig but she is wider, deeper and heavier and bound to be slower. On the other hand she is a much better overnighter since the AF3 has a minimal cabin suited for a backpacker.
In a lot of ways I think OliveOyl is more of a shortened Normsboat and if you don't mind the extra length and the weight and cost that go with the extra length, Normsboat would be I think a lot more boat for the buck.
Conventional nail and glue construction. She needs seven sheets of 1/4" plywood, two sheets of 3/8" ply, and four sheets of 1/2" ply.
Herb McLeod completed the first OliveOyl up in Canada. He also made an AF3 long ago and has been sailing them together and noting the pros and cons of both. In the coming weeks I will be presenting his results.
Plans for OliveOyl 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.
We have a Picara finished by Ken Giles, past Mayfly16 master, and into its trials. The hull was built by Vincent Lavender in Massachusetts. There have been other Picaras finished in the past but I never got a sailing report for them...
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:
Another prototype Twister is well along:
A brave soul has started a Robbsboat. He has a builder's blog at http://tomsrobbsboat.blogspot.com. (OOPS! He found a mistake in the side bevels of bulkhead5, says 20 degrees but should be 10 degrees.) This boat has been sailed and is being tested. He has found the sail area a bit much for his area and is putting in serious reef points.
AN INDEX OF PAST ISSUES
THE WAY BACK ISSUES RETURN!
MANY THANKS TO CANADIAN READER GAETAN JETTE WHO NOT ONLY SAVED THEM FROM THE 1997 BEGINNING BUT ALSO PUT TOGETHER AN EXCELLENT INDEX PAGE TO SORT THEM OUT....
THE WAY BACK ISSUES
15sep18, Taped Seams, Philsboat
1oct18, Plywood Butt Joints, Larsboat
15oct18, Small Boat Rudders, Jonsboat
1nov18, Sink Weights, Shanteuse
15nov18, Piccup Spinoffs, Piccup Pram
1dec18, Electric Boats 1, Ladybug
15dec18, Electric Boats 2, Sportdory
1jan19, Sail Area Math, Normsboat
15jan19, AF3Capsize, Robote
1feb19, Bulkhead Bevels, Toto
15feb19, Leeboard Issues, IMB
1mar19, Hollow Spars, AF4 Breve
15mar19, Underwater Board Shape, Harmonica
1apr19, Polytarp Sails 1, River Runner
15apr19, Polytarp Sails 2, Mayfly16
1may19, Sail Shaping, Blobster
15may19, Sail Shaping 2, Laguna
1jun19, Capsize Lessons, QT Skiff
15jun19, Rend Lake 2019, Mixer
1jul19, Scarfing Lumber, Vireo14
15jul19, Rigging Lugsails, Vamp
1aug19, Rigging Sharpie Spritsails, Oracle
15aug19, Rowing1, Cormorant
Mother of All Boat Links
The Boatbuilding Community
Kilburn's Power Skiff
JB Builds AF4
JB Builds Sportdory
Puddle Duck Website
Brian builds Roar2
Herb builds AF3
Herb builds RB42
Barry Builds Toto
Table of Contents