Buccaneer 24 Builders Forum

Buc in the air

I have been busy too- just not as busy as RC It has been too cold to epoxy outside, but not too cold to sand What fun. (I am sanding and fairing the main hull bottom)
B

 

Nice work bb cold is heading our way also with the last wekend of summer officially upon us this weekend one hopes for extended good weather we are going to miss the sun as seen streaming in through the workshop in last photo's the block wall is a heat sinc but will transfer cold in the winter workshop heating is definately in the thought process's. Keep up the good work summer is around the corner for you....

 

Thanks for that rcr appreciate your time taken to reply keep up the great work... The simplicity of the Buc certainly has made us evaluate all aspects of our design process's can't wait to get this one out of the workshop into the roaring forty's down here and test her out in some heavy water.....

 

Reading the John Pizzey article on T rudders

http://www.boatdesign.net/forums/mu...icle-john-pizzey-his-proa-concepts-46396.html

Could a T rudder be an easy(ier) solution to the B24's lack of volume in the transom ?
It may need a sturdier rudder mount but creating a small amount of lift from a T rudder must be way ease than modifying the main hull.
What say you ?

 

RR.
There is no lack of volume in the butt end of the B24.
Lock provided that volume , without dipping the bottom of the transom below the waterline, by angling up the keel line in a rather acute fashion. This unfortunately brings the tangent line of the keel up by 10 deg, rather than the more favoured 5 deg angle, resulting in an ugly and energy wasting rooster tail at high speeds. Bringing that 10 deg down to 5 deg entails extending the keel line by 45 cm (18"), which you so rightly say is an unwanted modification of the main hull. But a simple "Sugar scoop" would cure this.
At low speeds the curvy butt is really no problem, as exhibited by the B24s extraordinary ability to move out in light winds.
I have to wonder , would the addition of a T on the rudder really have a beneficial effect, or would it merely add induced drag. If anyone has got an input on this I would love to hear it.

 

Am interesting subject for sure. My limited experience with t foils on rudders (sailed skiff moths) has me of the belief that a negative foil has the effect of shortening the hull length, a positive angle increases the boat length. The reason I say that is because on the moth without a negative t foil you would most dive. No buoyancy in the nose cause there is basically no hull. The negative t foil pulled the *** down while the nose was being down so you were essentially pulled down into the water evenly, no nosedive. Effectively moving the centre of effort back. I wonder whether a positive t foil on a boat might do the opposite and basically increase hull length because the buc doesn't really seem to have an issue with nose diving so could probably handle the extra lift from the ***. I don't know. Would be interesting hear other thoughts for sure.

 

rudder lift

RC, I think I would not want to add foil lift at the back of a Buc- when I am going fast, like in a gust at over 15kts, we are all huddled at the back of the boat hoping the bow doesn't dive. Yes we do pull up a wake, but not so much at over 12kts as the main hull starts to lift. Any extra lift would put us closer or over the "edge". (See the "Green Death Trap" video for the results) An adjustable foil might help, but we are already pretty busy at speed. Part of the issue with my 24 is weight, I just weighed it accurately, and it is 200-300 lbs heavier than I would prefer. My boat was built with heavy 1/4" plywood, and the floats are even heavier. My sailing weight empty is about 1650 lbs- about 250-300 lbs heavier than 4mm ply would be. I am sure it would be much better without the extra weight.
All that said, if I were building new, I think I would extend the back of the boat enough to reduce the departure angle, and certainly stick to Crowther's 4mm ply specs and build it as light as possible.
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demasted = opportunity

Hi All,
While having a little tree work done this past week, I had an errant tree land on my mast, putting a 30 degree rake about 2 m from the base. Needless to say the mast is toast, and I am coming up with an estimate for the arborist's insurance company for replacement. The current mast is a fixed section as near as I can tell to the designed length. This might be the only opportunity I will have to switch to a rotating rig and use the same sails I have. As there are not many multihull riggers in the area, I have a few questions for the forum.

The current mast (or as close as I can figure) is similar to a Dyer DM450: 2.75” x 4.5” (~ 70x114 mm).

My questions are:
1. Does the section of a rotating mast have to be stronger than for a fixed mast?
2. Does the attachment points of the cap shrouds at the amas have to change?
3. Do the cap shroud and forestay wire diameters have to increase?
4. Is there a source for the step hardware – the ball and socket?

All the best,
Carl

 

The traditional approach for a rotating mast step for home builders is a stainless steel towball but it may be overkill for a light boat like the Bucc 24.

 

I had a towball on my Piver Nugget 24 and it worked just fine.

 

rotate it

HH, Is your rig "stock" size? To answer your points, Usually, a rotating mast only uses a shackle at the head stay to stay it, so the mast section needs to be more "stable"- usually with a larger section with thinner walls, and on boats our size, short spreaders with a diamond stay set up. Look at a Corsair 24-2 mast- it is exactly what you need.
The later 24s moved the chain plates back on the amas, mine work fine with my big rotating rig. I will get you the location tomorrow.
My boat was using the stock 3/16 wire, but the turnbuckles were about to fail- I was very lucky and found the stripped threads. 7/32 would be the best wire size, but I am using heavy 1/4 wire and turnbuckles as the bigger turnbuckles are readily available for 1/4". (and I had them) Synthetic stays are probably the best way to go if you are starting over. Check with Calligo.
My 36' mast and 2" rotating base were stock Stilleto 23/27 parts. I think they are still available. My mast is about 4"x7", uses diamond stays, and I would not want anything smaller with my sail area. I have started using running backs with my masthead spinnaker. My fat head full batten main flexes it a lot.
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stay position

Carl, the single chain plate on the float is 5'6" aft of the forward crossbeam centerline- by the plans and on my boat. The single stay on each side is plenty of support for the mast, even an oversize one. I should have noted that my forestay is still 3/16 wire, but I use a norseman fitting at the top and a special (large) end at the bottom that matches my Harken roller furler.

 

mast replacement

Bruce, thanks for the information and comments above. My chain plates are in the same locations as you mention above (5'6" aft of forward beam). With your modified and rotating rig, do you still have the four intermediate stays? Apparently many mast suppliers are unwilling to supply a mast, that is not specified by the design, i'll need to work around this... i suspect lawyers got involved at some time.

Has anyone considered a Multi-23 rig on a B24?

 

sticks

Carl, I only have the single outer stays, like most all rotating rigs. They make up for the lack of mid-mast support with "diamond" wires and spreaders that are fixed to just the mast and rotate with it. If you have any Hobie 18s around, check one out. My rig, and most multis these days are just scaled up versions- even up to the big offshore boats. For most current designs, the diamonds are wire due to less creep, the side stays are synthetic, and the forestays vary, depending on jib attachment.
Very non-legal advice!!
A mast doesn't know what kind of boat it is mounted on, and a boat doesn't care what mast is mounted on it. You CAN mix and match- but it does need to be properly engineered. Size does matter, and a multi and particularly a tri like the Buc has a LOT of righting moment compared to a mono with equal sail area. A light boat such as the Multi 23 doesn't load up as much as the Buc 24 will, although it might be over-engineered enough to be fine. I have no idea of its mast size/section.
If you are looking to "copy" (not a bad idea), I would use a boat closer to the buc's size and weight for an example- and maybe tell the mast supplier that is what you have. Since there are plenty of C-24s with three different well designed and tested rig set ups, they would be a good place to start. A C-24 Sprint has almost the same rig size as my boat. Funny how that works, my boat was put together 15 years before the first Sprints, but the practical dimensions worked out the same- then and now.
A few things to pay attention to. A tri has relatively low side stay loads due to the wide stay base, but the fitting loads on the mast are quite high. Plan accordingly. Mast sections on both monos and multis that were strong enough when the boats were designed are often marginal when loaded up with full batten and square top mains. Properly sized multi rigs are not particularly light, but the Buc 24 seems to carry them just fine. There are quite a few "over sized" rigs around, and I haven't heard anyone wanting a smaller rig.
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Bruce in the photo at the top of the page have you fitted your folding arrangement?

So far it looks to be successful for you.