A Day's Work...
Busy putting together a bare hull for a Goat Island Skiff and finishing the kit process.
Busy putting together a bare hull for a Goat Island Skiff and finishing the kit process.
Lying Head to Wind Under Mizzen
Awhile back I wrote about the merits of the yawl rig and posted James McMullen's Instructions on How to Use the Yawl Rig.
Here is a great image showing perhaps the greatest use for the mizzen: lying head-to-wind while the helmsman or crew moves forward to set or strike the sail.
Yawl should know the conundrum of getting a tiller 'round the mizzen mast
The details of how to design a yawl so that the tiller gets around the mizzen is an interesting topic. There are a number of tricks:
Using a line steering system: Here you can see Michael Storer's Beth Sailing Canoe with the tiller forward of the mizzen and the lines connecting to the rudder, which is out of the picture.
I'll add that there are a number of ways to do line steering. My Deblois Street Dory has line steering coming into the boat from a rudder yoke but there is not a remote tiller as in Beth. The Coquina is another example of line steering in which lines are attached directly to the rudder and pass through the transom, via a pulley system, and the steering line goes around the perimeter of the boat.
Using a long push-pull tiller: Here you can see James McMullen's Oughtred's double ender.
Using a curved, laminated tiller or split tiller
Using a normal tiller with an offset mizzen
For the Goat Island Skiff, we go with an offset tiller as in this model by a customer:
The other methods I mentioned just won't fit the situation we have in the Goat Island Skiff, mainly because there is not room for a split tiller and we want to keep the solution simple. We are deciding about just how much to offset the tiller. You can see above that the tiller will hit the mizzen before 45-degrees. The big question is how much room do we want to give the tiller to swing. In the pictures, we decided to test a 45-degree swing. That puts the mizzen a little further off the centerline than I'd like. This boat is very light and pushing a tiller than hard over makes the rudder act like a brake and the risk of losing so much speed that you can't get through the tack is something to consider. Then again, we don't need it so close that things feel claustrophobic. In the picture above of the offset mizzen, notice how little offset the mast is...the tiller must touch the mizzen pretty early. Does that give enough steerage for the helmsman when the push the tiller in the mizzen direction?
We'll have a solution soon after a full-scale mock up. The way we are doing this, collaboratively, is something I do on many projects. It always gets a better result because many thoughts and ideas can be sifted through. The more the merrier. Whatever the solution I draw up, the mizzen can always be moved a little more or less off the centerline according to the skippers preference. The important thing is to maintain the rake of the mizzen, which has been determined. My point is, that collaboration with designers, customers, and other folks with experience through the forums and boat shows can be an advantage in getting many thoughts onto the table and generating the best solution.
Using a line steering system: Here you can see Michael Storer's Beth Sailing Canoe with the tiller forward of the mizzen and the lines connecting to the rudder, which is out of the picture.
I'll add that there are a number of ways to do line steering. My Deblois Street Dory has line steering coming into the boat from a rudder yoke but there is not a remote tiller as in Beth. The Coquina is another example of line steering in which lines are attached directly to the rudder and pass through the transom, via a pulley system, and the steering line goes around the perimeter of the boat.
Using a long push-pull tiller: Here you can see James McMullen's Oughtred's double ender.
Using a curved, laminated tiller or split tiller
Using a normal tiller with an offset mizzen
For the Goat Island Skiff, we go with an offset tiller as in this model by a customer:
The other methods I mentioned just won't fit the situation we have in the Goat Island Skiff, mainly because there is not room for a split tiller and we want to keep the solution simple. We are deciding about just how much to offset the tiller. You can see above that the tiller will hit the mizzen before 45-degrees. The big question is how much room do we want to give the tiller to swing. In the pictures, we decided to test a 45-degree swing. That puts the mizzen a little further off the centerline than I'd like. This boat is very light and pushing a tiller than hard over makes the rudder act like a brake and the risk of losing so much speed that you can't get through the tack is something to consider. Then again, we don't need it so close that things feel claustrophobic. In the picture above of the offset mizzen, notice how little offset the mast is...the tiller must touch the mizzen pretty early. Does that give enough steerage for the helmsman when the push the tiller in the mizzen direction?
We'll have a solution soon after a full-scale mock up. The way we are doing this, collaboratively, is something I do on many projects. It always gets a better result because many thoughts and ideas can be sifted through. The more the merrier. Whatever the solution I draw up, the mizzen can always be moved a little more or less off the centerline according to the skippers preference. The important thing is to maintain the rake of the mizzen, which has been determined. My point is, that collaboration with designers, customers, and other folks with experience through the forums and boat shows can be an advantage in getting many thoughts onto the table and generating the best solution.
Great Boatbuilding Article
NY Times has a great article in its Preoccupations editorial about a writer who builds boats for fun and "describes his work on boats as a 'postgrad seminar in character-building". Please visit my links page to see this wonderful article as well as other good links.
"Building a boat offers no paycheck,
but teaches much about the values of work"
quoted from
"Finding an Answer To Rough Seas" by Lawrence W. Cheek
How do you determine the number and dimensions of staves in a Bird's Mouth Mast or Spar?
Birdsmouth is the word in the shop, lately. We have several orders for birdsmouth masts and spars that are in progress. I have been working hard at nailing down the process to be able to make them efficiently and to a very high standard and feel very excited about how it is all going. The Landing School of Boatbuilding has asked me to to give a talk/demo on making things birdsmouth style, so I've been pressed to improve our webpage on birdsmouth spars as well. On the page is my procedure for determining the number and dimensions of staves in a birdsmouth spar. Gaeten Jette, a featured contributer to Duckworks magazine on the topic of Bird's Mouth Spars, generously helped me customize the online calculator for my use and students' use. I hope you find it helpful, too.
We make two styles of Birdsmouth spar, using symmetrical staves (most common) and asymmetrical staves, which when done correctly will yield a perfect octagon and a spar that is slightly stronger and quicker to make. I decided to apply this type to making an ultralight kayak paddle shaft.
I am pleased with the results. The biggest hold up was fitting the plugs in the scoops that will take a ply-composite or a carbon fiber blade, which is already something we produce for our wood/composite, high performance oars.
With that part of the process ironed out it really is just a matter of setting up the operation to produce these paddles after some testing. This one will go to some paddler friends who will take the design on the seas and really test it out. Hopefully, sometime this summer the results will come in and production will begin. I'll leave you with the best part of making new things: breaking them with a hammer. We test most spars this way to make sure that things break the "right" way. That is, in a proper glued structure, the wood should always break before the glue joint does, otherwise there is a problem. Happily, all our spars have been breaking the "right way" in the shop so we know they won't break out on the water.
