Tabu

Messabout, thanks for the mast tutorial. I was not aware of rotating masts. Does the rotation allow the mast to present minimal frontal areaa to the wind? My mast formula is set in stone for this iteration. To implement a rotating mast would require a MAJOR reconstruction of the boat and since my main objective is no longer speed, I don't feel the time and effort would be justified. No do I intend to split the mast down the middle to incorporate an elegant sail track. I will, however, route a dovetail down the aft side then follow it with a sphirical rasp to achieve the same result - thanks for the hint!

Tabu is getting tight
without and ounce of rum in sight

Physics tells us that triangulation begats strength, ridigity, and a tight physical structure. With all the bamboo triangles going into Tabu it should be as tight as a drunken sailor on his first shore leave after a year at sea. Maybe it could be named birdcage to borrow the nickname of the first tubular frame auto introduced by Maserati. Or just panda, considerring the massive store of bamboo shoots contained within. These bamboo constructions remind me of building silk-covered-balsa-framed airplanes as a kid.

The rudder is almost done and pretty cool looking - this will definately be a cool boat - now if it only floats.

 

Float? Of that I have no doubt. Fast? No doubts there either.

Don't underestimate the speed potential of a well built scow type boat. In flat water inland locations, scows have ruled for many years, as they do not make concessions to sea-keeping in waves.

I would hazard a guess your Tabu will be fast enough to keep up with anything but 505s and Flying Dutchman from it's own era or newer skiff type designs (49ers, I-14s etc.). It should work out about as fast as a Fireball - and that is pretty serious stuff.

 

Now comes, to my mind, the sweetest, most wooden boatish, and coolest part of Tabu yet - the rear appendage. Couldn't even finish it before making it's image. The rudder and traveler are ALL wood. The pintels will even be staked with wooden dowels when finished. How much more fun can it get?

 

Woodwork and craftmanship look fantastic.

Regarding the wooden pintles & gudgeons, you may want to consider a little sleight of hand there, putting a metal sleeve on the pintles and a UHMW plastic insert in the gudgeons. No matter how well finished, wood on wood is going to wear and you can anticipate real trouble with friction wear allowing swelling and rudder trouble. Every performance boat out there uses metal on plastic on this critical point, as excess rudder movement can cause real handling problems - especially at the kinds of speed you can anticipate with this boat. Sometimes you have to put beauty behind utility. You got to plan for failure avoidance.

The raised traveler with horse is a method from history that hasn't stood the test of time in performance dinghies. Simpler, lighter and more controlled travelers can be as simple as a split spectra bridle attached to the boat via two holes in the deck. The point of a traveler is to allow you to set a controlled position of attachment for the main sheet becket block - necessary to control mainsail leech shape while reaching and going upwind.

I hope I'm not sounding negative at all - I just want you to know there are simpler, lighter and technically proven solutions out there that can address the issue. If you wish to use the method shown in the plans, go for it! Don't kid yourself that your Tabu is going to be a quaint and tame craftsman's daysailor - it isn't.

 

Bill, I have never felt that any of your comments or suggestions are negative or discouraging. To the contrary, I always look forward to your replys knowing that my boat will be built better as a result.

Your sleight of hand suggestion for the pintles and gudgeons is a case in point. They will still look very woody yet incorporate modern technology to improve performance.

The plans for Tabu call for a traveler made from galvenized water pipe - butt ugly! My wooden version is an attempt to improve on that. I have further modified that by lowering and reversing the horses to have them sweep to the rear instead of forward. Still they look rather klunky. I have researched your suggestion of using a split spectra bridle and the only thing I can find is in the Hobi-cat assembly manual. There I find a traveler with cars and I envision vast amounts money flying out of my wallet. I have chosen the Tabu because of economy. As an option to a traveler system, would the combination of a leech line in the sail and boom vang accomplish the same result? If not, is there a cost-effective split spectra bridle system that would work?

 

Here's how it is handled on the SwiftSolo.

In your case you might want to tie a block on an inverted "V" of rope that attaches to both sides of your stern. Your mainsheet could route from a becket on the boom block, down through the traveler block and back through the boom block before going forward to the block turning it down to your block/cleating system on deck.

If you want to get fancy, the tails from the inverted "V" could feed to eyes and little cam cleats to adjust the travel available.

Basically, what I'm saying is the wooden horse & traveler can be replaced with a rope version of the same thing.

--
Bill

 

Thanks bill, now I understand. After considering all the alternatives of which I'm aware, I opt for the horsey traveler after all. First, it reflects the era from whence came the all wooden rudder, befitting an all wooden boat. Second, the outer skin will be "planks" of cedar with kind of a cris-crafty look that will further enhance the all wood art-deco look. Third, it will project more of a "quaint and tame craftsman's daysailor" - a sleeper. Reminds me of the ultimate sleeper built by a high school friend who squeezed a corvet motor in a tubular frame under a Volkswagen bug body. The transmission was the drivers right arm rest - a true sleeper! And forth, after looking at the traveler with a whinny for awhile, it has grown on me- plus it is already built. Thanks for the continuing encouragement, comments and suggestions!

David

P.S.

OK,OK I get it that you aren't a Navel architect - so where did you get all of your boat knowledge?

 

David:
In my windy explanation about mast building, in no way did I mean to talk down to you. You are making an art form of building a wooden boat and obviously doing it well. Far be it from me to "tutor" an outstanding wood craftsman.

In answer to your question about rotating masts: No rotation does not reduce frontal area. In fact it will increase static frontal area. The operative word being static. The function of rotation is to more nearly align the leading edge of the mast to the direction that the air is actually moving. There is an area of dead air behind a fixed mast that tends to set up an early seperation of the leeside air. The leeside can be powered up noticeably by working toward reduction of the dead zone. Air in front of a moving body, like the mast, will change course in such a way as to anticipate the path it must take around the object. When nobody is around to question your sanity, try this stunt. Fill the bathtub with a few inches of water. Go to the shop and get a handfull of fine sawdust. Sneak back to the tub and spread the sawdust lightly on the waters surface. Now take a dowel rod and poke into the water vertically. Move the dowel rod slowly in one direction. Observe that the sawdust moves out of the way well ahead of the moving dowel. Try moving the rod at different speeds to study the phenomena. You can also do this with a small model boat and observe what the flow is inclined to do. Move the little boat in slightly yawed attitude and see what happens.

 

Dear friends - Tabu now has the slickest bolt rope slot and an input guide so the rope will not catch. With such a cool slot, I absolutely needed a sail to test the slot. Rummaging about in our garden shed, I found a cheap old blue poly tarp, a hank of 3/8" rope, and some 3/16" cord. A trip to the hardware store for some double sided carpet tape and I had a sail anxious to be made. A few hours later I had a really big triangle with a bolt rope luff and foot ,a leech line, and a Cunningham control. Now battens are being built, a set of 7 full 4" battens that taper in thickness from both ends to the thinest point being 45% of each batten length from the luff to encourage draft at that point. A boom is fashioned that displays greater aesthetic than the plans suggest.

With the mast apart for slotting, I made some images displaying the flexability atainable from a skin over frame wooden mast loaded with two paint cans (13 lbs.) The fore/aft flex is demonstrated with the foot of the mast clamped to the bench and 2 cans suspended from the head. The port/starbord flex has the mast supported center with a can on either end.

 

She is out of the shop for the first time to feel the warmth of the sun on her bones while I check th mast/boom arrangement. Dreaming of sails filled with warm wind on quiet waters.

 

Dude, I don't think thats gonna float!

 

thefuture - If the frame were actually hollow and filled with a substance that was 1000 times lighter than air (new space age stuff) then it would float quite well, maybe even fly. Actually that is not the case and the boat is a work in progress, yet needing an inner skin then an outer skin which i hope will allow it to float.

As a part of this adventurous progress I've developed some oak clamcleats through trial and error to accommodate 1/4" twisted nylon rope of which I have oodles and gobs. Finally have arrived at a channel shape and tooth angle that works quite well.

In wondering where to put these clamcleats, I reflected on most vehicles I've operated and realized that all significant controls were easily at hand. So, the main sheet will enter a fairlead at the center of the thwart and into a cleat. To the left of that will be the jib leech line that comes from a block at the base of a forestay and directly across the bow through a fairlead on the thwart to a cleat. To it's left will be the port jib sheet that will travel through a hooked block fairlead with the hook repositionable at four points on the deck. From that block it will travel an an angle through a fairlead, over a cleat, across the thwart to starboard where it is needed during operation. To the right of the main sheet cleat will be the cleat for the boom vang sheet coming directly from the mast through a fairlead on the thwart. To it's right will be the cunningham control sheet paralell to the boom vang sheet. Finally the starboard jib sheet will angle to port, the reverse arangement of the port jib sheet. Because I'll be sailing singlehanded more often than not, I dont want to be wandering around the boat very much.

Now in the process of waterproofing everything inside with multiple coats of spar poly - pretty shiny inside my shop now.

Still dreaming of sails filled with warm wind on quiet water

 

It looks like its going to be a rocket of a boat. I hope you could sense my sarcasm in the last post i made. As far as advice goes, with a boat this small, (and this is only my opinion) i like to take the KISS(Keep It Simple Stupid) aproach. Try to have as few lines astray in the cockpit as possible or you will never find the right one and be untangling them quit a bit. On a boat this size i would negate the use of a cunningham and the jib leech line. If i where rigging this boat i would use a main halyard, jib halyard, vang, mainsheet, and both of your jib sheets. You shouldn't need either of the halyards at hand so you could keep those separated and away from your control lines. Good luck with the rest of the work!

 

Thanks thefuture - yes i sensed your tongue in cheek hence my intro. As far as sheet number, I anticipated potential entanglement and will have little compartments beneath the thwart to hold each sheet separately, possibly with an automatic spring loaded retreval system similar to what I've seen for clothslines.

 

That would be trick. You have a lot of really good ideas. Keep at it and don't let this be your last boat build project.