Mast calculations -need assistance please.

[TeddyDiver]

I believe this a bit of overcomplicating. IMHO just take shorter masts but the same profile as described originally and same goes with all the standing rigging. Assuming the chainplates are set there's nothing you can screw up this way.
Doing the opposite is risky and needs recalculations..

BR Teddy

[Scrimshaw4]

I SINCERELY hope the reason you picked 64' as the air draft is NOT because you want to be able to transit the ICW. I say this because due to rising sea levels many of the bridges no longer have a 65' MHW clearance. In fact some of the new bridges in the Carolina's were built with only a 64' clearance. We transited a large portion of it last year with 62 1/2' and scraped the antenna several times. JMHO

[Chotu]

Mark, did you say you bought a spar that was not the right one for you? Do you still have it? Do you want to sell it?

[TrentePieds]

Manatee:

As promised I spoke to Mrs. Brewer last night. She tells me that Ted receives dozens of e-mails every day, and that she triages them before taking the ones that IHO merit answering to Ted. Mrs. Brewer is a formidable lady and no-one's fool, so your e-mail may not have passed muster if, as you say, you have not heard back.

Your anecdote which I quote below, may shed some light on the reason. No reputable designer will take kindly to an amateur's proposal for tampering with his existing design in any way. Such a proposal is VERY different from proposals made by a client, however naïve, while discussing a NEW design commissioned by him, while that design is still in the design stage.

As someone said above: IF you complete this project, you will have a "permanently reefed" boat. I will add this: She is likely to be out of balance, but you have enuff data and an existing sail plan to work from, so to design a new sail plan that will work will not be beyond you, given that you have the experience you have, as well as the cited texts on your shelf.

So here is the anecdote you told: "Advice to see a “architect “. Reminds me of the time I visited the studio of a well known designer. I simply wished to extend the bowsprit on his design. I told him that Ben Hall of Hall Spars had graciously checked all calculations. He had the reaction of a petulant child. I withdrew with apologies."

Perhaps your perception that the "well known designer"'s reaction was "petulant" merits revisiting?

All the best.

TrentePieds

[Michael Pope]

Well I can tell you what I know . My Last boat was a Cat-Schooner with a narrow light hull and 40% ballast with 4.5 ft draft an 42 foot wl B max 10 ft. It was fully powered with a 24 inch prop . Designed for trade wind sailing .But had a Dagger board with a 9 ft draft so could go to weather. I settled on two 50 ft spars that I built from S Glass on a hollow woodcore and wishbones . Went that way as my rigging experience indicated a useful life with complete reliability for swage rigging in the tropic trade winds was 24 months!!! The boat "went away" so I do not know all! But the sail control delivered by the wish bones was fantastic I spent a night against the Gulf Stream 35 to 40 knots of wind.
Foresail only with a deep reef (approx 300 sq ft), Flattened like a board . Foot along the deck. speed 7.9 to 8.25 knots heeling 15 to 20 deg . Mast bending off as designed in the gusts. A remarkably gentle and smooth ride, in as bad a short wave system as I have ever encountered. 24 to 1 purchase pulling the boom aft to the mast and a three to one sheet on each side , So you could move the aft end of the boom from side to side without it lifting. I had winches there but did not need them. S glass used as has a lower modulus and will bend off with long long Fatigue life. I would do it again ( S glass ended up more expensive than carbon but much better --- Made the sail look like a "Wind Surfer Sail" This is more than a few years ago but the two spars cost me $25,000 same price as quoted carbon at the time but clearly superior. You might want to look at this option "NO RIGGING" LESS WINDAGE 1/3 less moment of inertia Hopefully much longer life No thunderstorm Worries. Mike Pope

[Manateeman]

Greetings all. I thought it best to add the following as a seperate thread from the discussion on reducing air draft in which I mentioned “ Roaring Bessie”.
I grew up in Dartmouth MA and sailed in my grandfathers boat which might have been a true Block Island Boat or a blend of a design with a No Man’s Land Boat.
I recently found lines of a Block Island boat by John Hyslop in 1883 of a boat named Island Belle. I also found that Mr. Martin C. Erismann had an exact copy of a Block Island boat originally named Lena M.
There is also a nice model in the Providence Library.
My grandparents lived on Martha’s Vinyard and my grandfather knew a lot of people from New York who were yacht owners. The local fishing boats were fast disappearing. He had a drawing of oxen pulling boats up onto No Man’s Land.
His boat had beach stone ballast which we gradually replaced with lead. We had two rigs. One tall for summer, one short for winter. It had a cuddy and a small stove which set it apart from open fishing boats. She was low to the water amidships but I was never frightened even when she was roaring along and you wished she had higher wash boards. Simply a very seaworthy vessel.
She smelled proper down below and the motion would put me fast asleep in minutes after a day cod fishing in weather so cold I thought my hands were attached to the line. Lost in a hurricane.
My point? Maybe two rigs might look too expensive or too complex but anyone who has sailed in these boats will testify as to the security and common sense in the designs. What if one were to apply state of the art materials.
Well, thank you all for past comments.
Kind regards, Mark the manatee

[Manateeman]

Trentepieds . What? Nothing to say? Let’s just show everyone the boats you have built.
Not bought. Built with your own two hands.
You take smarmy cheep shots at people and hide behind the anonymity of the forum. Come out and play. Tell us what you base your expertise upon.
Sincerely.
Be nice and be honest.
Why hide ?
Mark the manatee

[Pelagic]

Originally Posted by Manateeman

.
.
The objective is to open a discussion of alternatives for older sailors who are simply not comfortable with a big rig.

Hi Mark
Just came across this thread . Since you encouraged some brainstorming, what about considering a schooner rig to reduce mast height and sail sizes by having both masts the same height.

Our boat is similar size (corten steel) and both rigs are deck stepped on tabarnackles giving an air draft of 19m (59ft)

Very comfortable for us to handle

[Manateeman]

Special thanks to Pelagic. Old might mean one wishes to keep sailing and sailing.
This is exactly the imput I was looking for and I hope it will provide food for thought for those who never wish to turn into land people.
Once a manatee, always a manatee.
Kindest regards Pelagic
Mark

[Michael Pope]

Just to share thoughts. I like long skinny boats for Ocean Cruising I Having suffered fro I.O.R. Racing yachts with ridiculous beams 1/3 of their lengths that spent all their time trying to do abrupt turns when going down wind. My last endeavour was 44ft (13m )
and had non of those tendencies. It was such a joy. but it was only 10 ft wide. If I do it again I will put a second centreboard farther aft in the Cockpit sole for use when needed such as when hoisting the Main first. and not having to rush to hoist the Foresail.
I would stay with un-stayed Masts and full batten sails with big roaches. And wishbone booms I think there is a lot of development room there. Once sailing I felt this is too simple why did I not do this before . When it really looks like blowing you can lay all the mainsail on the deck with the wishbone and lash it down . Put as much reef as you want in the foresail and the boat will follow it. May be require the development of "Dive brakes" deployed and easily controlled from the cockpit. No 500 to 600 Lbs swinging around up there. I can hardly wait!! Maybe you could just make the twin rudders get Pidgeon Toed to keep the back comming last. Needs more thought, The masts on that boat were 50 ft stepped at the waterline height and weighed 190 Lbs each complete with all gear. Well enough dreaming! what do your spars and rigging weigh "Pelagic" I like the way your boat looks sleek and purposful. Michael Pope

[Pauls]

The OP mentioned interest in a gaff rig. He wants a low air draft. Gaff rig will give a lot of sail area on low masts. In my opinion it has significant virtue for cruising boats. The lower center of area of the rig allows carrying more sail or a reduced heel angle for a given sail area. It will allow the OP to have his low air draft and maintain a good SA/D ratio.

[dfelsent]

Having grown up sailing a gaff rigged schooner I have mixed feeling about the rig.
Yes more sail down low.
With lazy jacks dropping sail is easy.
But
More complex to hoist. Remember peak and throat halyards. With different ratios so you need to hoist carefully.
More weight aloft.
More induced drag so worse upwind performance.

But pretty, and fun too.

But those fathead/square headed mains look like a way around all that.

[Pauls]

I think that a lot of the criticism of gaff is based on old boats with traditionally built rigs, meaning solid wood masts and gaffs, frequently with dead eyes, etc.

Using modern materials, ie aluminum tube spars, internal halyards and modern rigging is straight forward. It reduces the rig weight a lot. And it will reduce the windage a lot too.

The deal with fat head or large roach mains (which doesn't seem to be talked about much) is that the high tension required on the sail to control twist makes for an expensive and heavier sail, especially when you add in battens, cars, etc. Because of the shape of a gaff sail the stresses are more aligned with the sail cloth fibers, which allows for a lighter cloth, or alternatively, with the same weight cloth, a longer lasting sail.

Everything on a sail boat is a compromise. Gaff has plusses and minuses, like everything else. But I think for what the OP is trying to do it is worth a look.

[Pelagic]

Originally Posted by Michael Pope

Jgear.

...... what do your spars and rigging weigh "Pelagic" I like the way your boat looks sleek and purposful. Michael Pope

The Foremast is the heaviest with 2 long back stays furler forestay and stay sail stay. Weighs 800 kilo.

My boat was launched in Holland in 1981 and the masts are still the original Fir wood box so that is certainly adds to the weight aloft.

But at 42 ton she just heels softly and then stays there.

I'm a conservative sailor

[Michael Pope]

Dear Pelagic Re Lower Masts! Thank you for the photo and the spar weight. She looks great! I some times classify yachts as those who's Hull control the rig and the others who's Rig controls the hull. So true of many "modern" Yachts where when off the wind the helmsman's job is to try and keep the Hull under the rig rather than on its side "Resting". Years ago I had a guest aboard who had recently returned from an around the world race. He commented that my hard working 3/4 Ton had broached, in the 30 -40 mile leg from White Islets more times than he had around the world. Ah yes I replied but you see that boat inshore of us who rounded the island just ahead of us. He rates Two Ton and is the best one here. WE have passed Him. He looked at me and said "To each his Own" Quite Poetic for a Sail Maker!! A heavy boat and heavy spars add inertia but also a lot more comfortable motion . All I would need would be a seat, a Blue Blazer a Peaked Cap with Corroded Gold Braid and a Pipe . I envy you! I keep waiting to "GROW UP" Michael Pope 1933.