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Old Oct 21, 2015, 06:51 PM
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Victorian Plank on edge cutter...ballasting?

Hi,
I am working on a model in 1/16th scale of a boat I used to live on.
It was a Class C cutter of 1885 called Vanity (Mary at the time).
It runs out to 48" on the LOA.
Being a typical "plank-on-edger" she is deep drafted, about 8" and narrow beamed, about 6 1/2".

Would I need much external keel/ballast? She would be a similar shape under the water to say a 12 Metre only the keel would go all the way to the plumb stem.

She is plank on bulkhead construction, a gaffer, of course, with a huge rig.

Cheers,
Martin
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Old Oct 22, 2015, 07:17 AM
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An image of the hull lines would help give informed responses. Without that, I'd say use her internal ballast to bring her down to the waterline. I also suggest the ability to reef or bend on reefed/smaller sails based on wind conditions.
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Old Oct 22, 2015, 08:11 AM
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Is this the girl we're talking about? Golden Vanity

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Old Oct 22, 2015, 09:14 AM
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No Jerry, that's a fair bit smaller than "my" Vanity.

I'm trying to find my pictures of her, but they're on a memory stick following a new PC.

I'm using the lines of Clara as published in "Memories and Traditions of American Yachting, which has a lot of British craft illustrated.

She is very similar to Marigold, but 18 feet shorter.

Alas, I have no way of scanning Clara's lines in.

Cheers,
Martin
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Old Oct 22, 2015, 09:41 AM
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Ah, I have finally found some lines of a real plank-on-edge cutter.

Galatea, the upper one on this lines drawing. About as close as i can find to Mary(Vanity)'s lines


Martin
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Old Oct 22, 2015, 05:05 PM
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Your plank-on-edge cutter hull is similar to the hulls of Victorian-era model sailboats in England. You might contact British sailing groups for information on such hulls:
http://www.vmyg.org.uk/
US similar group:
http://pages.swcp.com/usvmyg/

The problem with limiting yourself to internal ballast is one of scale effects: both wind and water don't scale down for a model-sized hull. For example, the wind our models operate in is much "stronger" than the wind felt by real sailboats. Thus, models heel more than real sailboats for the same wind velocity. To resist the heel, and keep the model operating at a realistic heel angle, requires, in my experience, external ballast on a finkeel. No boat with internal ballast has as great a righting moment as the same boat with external ballast. That is simply due to geometry & physics.

Heeling increases leeway for all boats. The internal-ballast-only models I've seen don't work well to windward (by my measures). They may point up correctly, but they don't make good progress to windward; the hull skids off to leeward, even though the boat is pointing upwind. In addition to excess heel, a model's hull does not make as good a "water wing" as the real ship's hull. The water wing is what keeps a ship from simply drifting sideways (i.e.downwind) while trying to sail upwind. We sail to windward using the same physics (underwater) as an airplane uses to fly. A finkeel is a more efficient water wing than a hull, particularly at model scales. This explains why all modern racing model yachts have finkeels (for efficiency) and external ballast (for reduced heeling). Even if one does not want to race models, a skipper still benefits from enhancing efficiency in his model's operation. But, beauty is in the eye of the beholder - if windward progress is not of interest to you, then eschew the external finkeel with it's external ballast. If your sailing pond has access to all sides, and you don't mind walking to retrieve your model, then windward performance is not mandatory.

If I were building a plank-on-edge cutter model, I'd make the hull as light as possible, and put *All* the ballast in a bulb at the base of a fin keel. I'd also be sure, as Gammon Iron has suggested, to have a sail reduction scheme designed into the boat. A narrow hull won't like being over-canvased - you will have to practice micro seamanship and reduce sail area when the wind picks up, just like the real boats do in a gale. For a model, 10kt winds are strong, and 20kt winds are gales.

I sail model squareriggers, sloops, and schooners. All my boats have a finkeel with external ballast. At sea, no one notices the finkeel (waves+refraction, and glare off the water, hide them). My finkeels are removable for transport, and for ease of storage of the models at home. If you are interested in details, my Pamir and Aldebaran threads have explanations and pictures that would allow you to design your own finkeel/ballast system.
http://www.rcgroups.com/forums/showthread.php?t=743611
http://www.rcgroups.com/forums/showthread.php?t=1096365

Jimmy James, an excellent modeler, now sadly deceased, developed schemes for reefing fore&aft sails on his RC boats. I've not used his method because the material I use for sails, Tyvek, is not amenable to reefing. I just remove sails, and replace them with smaller versions, when I need to reduce sail. But if your sails are to be made of cloth, then give Jimmy's method a look:
http://www.modelboatmayhem.co.uk/for...?topic=11955.0
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Old Oct 22, 2015, 06:14 PM
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At 48" (hull length?), I'd say your boat will be almost big enough to eschew the finkeel, if not the external ballast. I base this comment on the operation of 6' model schooners I've seen on the web. They have no finkeel, but do have an external ballast bulb. I know that a 3' hull is not big enough for my models to operate w/o a finkeel.

Be that as it may, I still think even the 6' models would sail better with a finkeel, though. My 16' Snipe used a daggerboard, afterall :-)
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Old Oct 22, 2015, 06:47 PM
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Ok, a bit more like this one: http://www.joliebrisemodels.co.uk/
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Old Oct 22, 2015, 06:58 PM
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Brooks,
it seems only a few months ago that I sailed Jimmy James' pirate boats on a fishing lake in the next village. I live very close to Kings Lynn and PM'd him for a meet up. A real old Jolly Jack Tar of a man. His boats were indeed rough as he says himself, but I never saw a model by a real sailor that wasn't, BUT, they were true if not accurate (see Malcolm Muggerage). I'm so sorry to hear he has died. He did mention some health problems at the time.

I am fine about external ballast as it would never be seen once afloat. I suppose that the amounts would need simple experiment. Fortunately my son made a charcoal furnace which can melt aluminium, so I'm sure he can melt me some lead weights from my patterns.

I'll be sure to build waterproof fixings into a strengthened keel in readiness for the experiments.

Can't follow Jimmy's rigging diagrams, especially the reefing. But I know nothing of square sails and can't see how that system would work on fore and aft sails. I think I'd just bring the boat in and hand tie them! I thought I knew boaty terms, but boy his posts are dense with them, many of which I don't know.

I loved Jimmy's motor driven windlasses. I see no point in spending a fortune on fancy servos when I can make motor driven winches with ease.
Having sailed Jimmy's boats I can vouch for the speed and effectiveness of his windlasses!

Cheers,
Martin
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Old Oct 22, 2015, 07:08 PM
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Jerry,
yes, a lot more like Jolie Brise, but there are so many of those around and I wouldn't touch those silly scales, although I suppose she was built to a metric measurement system, so metric scales make sense. I do have a rule with tenths of an inch on it, but I use that side for cutting against and scraping!<G>

I have a vague memory of Vanity's previous owner (who had researched her thoroughly) telling me she had a 128 foot rig! That makes the model 8 feet above decks. My shed isn't that tall, so I guess the topsails will have to go on at the pondside! I know her bowsprit was 32 feet and the main boom overhung aft by about 7 feet. And she was considered a "small C class Gentleman's yacht" in 1886!

Cheers,
Martin


Edited to say that'l make her 6 feet long overall. Oh dear!
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Old Oct 22, 2015, 11:25 PM
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Martin, you might find this series of posts, starting with #31, helpful in deciding where to put your fin keel:
http://www.modelboatmayhem.co.uk/for...html#msg432694

I also discussed how to decide if your standing rigging is strong enough in post #25 here:
http://www.rcgroups.com/forums/showt...1096365&page=2

The required strength of the shrouds and backstays is dependent on how much righting force your boat has, which depends on the weight and location of your ballast. Internal ballast, with a small lever arm, allows the boat to heel in light wind. Standing rigging would not need to be very strong since the boat would heel easily and shed wind load. In contrast, putting all the ballast at the base of a finkeel would make the hull stiff. This would increase the force on the standing rigging, forcing the need for stronger line. My boats get by with backstays (I don't use shrouds) of 20# spectra line (non-stretch fishing line). Racing sailboat models use 80# wire. In general terms, my fin keels are about a foot to 20" deep, and the ballast is about 2-4kg of lead shot. Before you cast a lead keel weight, you might experiment with lead shot in PVC pipe with a removable cap. The pipe is attached to the base of the finkeel. Then, you can adjust the ratio of internal to external ballast to achieve the sailing qualities you are looking for.

The minimum righting force is that necessary to lift the sails out of the water after a knock down. They will be wet and heavy, of course. W/o this much righting force, you risk loss of control (can't steer when the rudder is horizontal), and even sinking if the hull takes on water while stuck in a knockdown position.

Whatever you decide on internal ballast Don't Glue It to your hull! If you keep your yacht a number of years, you will likely add stuff to it that increases it's weight. If the internal ballast is glued in, this can pose a problem...been there done that :-(
----------------------------
The Jimmy James url I gave you did not cover his "lazy jacks" method of reefing fore&aft sails, sorry, my mistake.
https://en.wikipedia.org/wiki/Lazy_jack
The Jimmy James post I should have listed, post#4:
http://www.modelboatmayhem.co.uk/for...?topic=29228.0

To quote Jimmy (edited for clarity): "Lazy jacks are very useful for reducing sail on fore & aft rigs. Instead of having to tie loads of reef points you just lower the sail between two sets of ropes (Like a suspension bridge). Then you only have to haul in the tack and leech pendants"

If you still wanted to reef the sail, you might consider putting holes in the sail in place of reef points. Then, you could simply spiral lace the loose cloth, rather than trying to tie a bunch of model-scale reef points whipping in the wind. I seem to remember this method used for real sailboats, but can't remember where, exactly.
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Old Oct 23, 2015, 07:39 AM
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Blimey, a load to consider there! Many thanks for taking the time, Brooks.

I'm assuming Jimmy didn't have the Lazy jacks under R/C, but simply put them to work by hand at the pondside?
He's certainly right about the surprising speed of a Zulu. I did an exhibition model of one years ago and the research showed them to be very fast boats.

The thought of a "knock down" scares me to death! I hadn't considered that as a possibility, or the standing rigging strength. Shows how little I've done in actual sailing. My experience has been almost entirely static modelmaking rather than working stuff, at which I never seem to have much luck. I think the rig may have to be subtly reduced from scale proportions.
I've ordered a book on the subject of R/C sailing scale boats, so I can curl up with info in the cumfy chair too.
But your posts are very informative and thought provoking.
Again thanks,
Martin
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Old Oct 23, 2015, 08:05 AM
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Oh dear, I'm sure your post you linked to about fin keel position is very right 'n' proper, but I'm afraid I don't understand a word of it!
Clearly I will have to just slap a fin on somewhere likely looking and suck it 'n' see. I know CE is Centre of Effort, but CLR?? Nope All beyond me. Unlike you, I don't either like or do maths, beyond calculating scale measurements.

Cheers,
Martin
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Old Oct 23, 2015, 08:12 AM
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" If the internal ballast is glued in, this can pose a problem...been there done that :-"(Brooks)

I strongly second that statement. I just renovated a 25 year old RC model that had internal lead shot glued in. What a PAIN it was to fix the hull leaks. I'll add two more options... 1) Place a liner between the internal ballast and the hull before glueing...to be able to take it out again. 2) Like real boats, form the lead ballast as the keel shape and bolt that on and off.
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Old Oct 23, 2015, 08:36 AM
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Brooks,
you and Jimmy often mention(ed) "wear". This is not a term I have ever seen before. What does it mean?

Cheers,
Martin
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