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Plus Plus

A Single Handed 14 foot dinghy design/development Project.

Dimensions


* LOA 14 feet
* Beam at chines 3ft3" approx
* Hull beam 6ft6"
* Overall beam probably 9ft
* Prismatic Coefficient .68 (at a sort of average trim).
* UK Portsmouth Yardstick Club Trial Number 966
* Sail area something over 130 sq ft
*

Sail Carrying Power to weight ratio
(for Bethwaite readers)

40% approx.

Picture - PlusPlus Racing Dinghy

Photo - Andy Wells

End of a Holiday...

I sold the PlusPlus on around 2005 (I forget exactly when). I spent a good five years on the project, interspersed with a Cherub campaign. It was a lot of fun, and I learnt a lot. There's no substitute for a design/build project if you want to learn about sailboats. Would I do it again? Well perhaps not for a while, but I don't regret doing it. The only thing is that mixing it with the Cherub was not a good move as the Cherub got a lot of work and expenditure that could probably have been used to good effect on better development of the PlusPlus. On the other hand there's a bunch of glass ware in the cupboard 'cos I won more with that Cherub campaign than anything else I've done sailing. To be fair the PlusPlus has an entry in the cupboard too, for a placing in a club series that perhaps owed more to turning up than anything else...

So what should I have done differently? I probably should have done the hull shape tweak mentioned on the sailing pages. There was a bit of unfinished business there. I certainly should have had a much more readily moveable daggerboard. Investigating the effects of daggerboard position on some of the trickier handling quirks would have been rather useful. It might have been useful to move the mast about too, but that's a bigger ask to do structurally! The wings worked well, with the folding: that was good. The stumping mast worked wonderfully, but was almost a complete waste of time because it seems that you virtually never want to reduce sail area in a single sail dinghy because what you gain upwind you more than lose downhill. RS learned that with the 600 too!

What else... Well the basic dimensions. On reflection I probably should have gone to 15 feet long and made the boat just a little bit narrower on the waterline so the stability was much the same. 14feet is one of those traditional standard lengths, and there's something in that, but on the other hand a longer and thinner boat would have been just that bit more slippery in the lighter stuff. Andy Paterson suggested that right at the design stage!

There are things I've learned since. The biggest irritation sailing the PlusPlus was that its fast enough to sail out of the front of a gust, but not fast enough to sail into the back of one. Consequently in gusty inland conditions (just about every time I sailed it) I spent more time sailing downwind in the lulls than the gusts. So you go tearing past a Laser, out of the front of the gust and stop. Meanwhile said Laser is still in the gust and sailing in twice as much wind. So is this unique? No, an IC does it too! That means that the problem is probably not soluble with the state of the art at the moment since the IC is as fast as one could reasonably expect a boat without hydrofoils to get and is more of a handling challenge than I was looking for with this rule set. Does that mean that the search for a manageable high performance singlehander is fruitless? I'm not sure, but I think one needs to be aware that beyond the performance equivalent of say about 1050 in UK terms the extra speed/difficulty of handling balance starts running into diminishing returns.

So, what am I doing now? As hinted, the current boat is an International Canoe - inspired by the IC returning to a box rule for the hull shape. That had a big - and unplanned - rebuild, and the next project should be a new rules IC. I did start one off in Jan 2012, but for various reasons I had to call a halt to that one.


Links - This Site

Sailing the Boat Last Updated 16th Feb 2005
Plus Plus mk1a/2 Last updated 18th October 2001
Hull Surgery in Progress Last Updated 1st January 2002
Building the Hull Last Updated 19/5/1999
Hull Design - Overview of the Hull Design Process - Last Updated 10th July 2001
Rig Design Update on upwind performance with the small rig. Last Updated 12th July 2000
FAQ With a note on the Heatwave 18th Jan 2004
Picture Gallery New shots showing the short rig, 11/5/99
Other People's Comments Andy Paterson tests capsize recovery in adverse conditions... Last Updated 5th July 1999
Class rules. Draft 1.3, 19/3/1998, comments welcome.
Alternative uses There were floods in Leatherhead and I needed to get to the office, 1/4/2000
Main Page

Links - Other Sites

Bloodaxe Boats built the basic shell, and are building the mast and foils.
Island Barn Reservoir Sailing Club is where the beast will mostly be sailed.
International Moths are the major influence on the boat above the waterline.
U.K. Rules Cherubs are the major influence below the waterline.
Norfolk Heritage Fleet Trust The only relationship these magnificent 1930s wooden yachts have to this project is that I like to sail them from time to time. I notably don't have too much time for half-baked updates of old boats to produce something that's neither flesh nor fowl. These, on the other hand, are the real thing, with the only mods from 1930s spec being practical ones - terylene sails and ropes, and a bottled gas cooker instead of a Primus. There's just an oil lamp for light, no electricity, and no engine.
International Skiff Club - Based in Germany, with a variety of skiff related resources.

Links - Other Performance Singlehanders

I'm not going to bother with links to the mass market boats - they're easy to find. These are more obscure and perhaps a bit more interesting...
Bucko This is an asymettric equipped 14 footer based on a 14ft skiff hull. Good sized wings plus trapeze - serious stuff!
NS14 Singlehanders are, of course, a variation on the influential Australian NS14 Class. No trapeze or wings, but a very efficient hull.

Acknowledgements

Andy Paterson of boatbuilders Bloodaxe Boats, Gurnard, Isle of Wight, U.K.
has contributed much helpful advice and information from his experience in the International Moth and Cherub Classes.
Graham Caws of Caws Sails took my crazy ideas, modified them with his experience (notably in the development of very fast Moth Sails) and produced a practical sail.
Charles Crosby, Dept of Mech and Aero Eng, University of Pretoria, South Africa,
has frequently acted as a sounding board for some of my crazier ideas and contributed ideas of his own.
Andy Champ, Bracknell, U.K.
has also acted as a sounding board at times, especially when I've wanted to get a viewpoint that's not steeped in high performance and development classes.
Dave Roe, Winchester, U.K.
designed a revolutionary Cherub, the Italian Bistro, one of which I own and which has influenced this boat significantly.
Mike Bees, Cambridge, U.K.
has given me the benefit of some of his experience with 18 footers in European conditions.
Adrian Kiely, Sydney, Australia
has similarly given me helpful information from the Twelve Footer fleet there.

And Less Directly,
I've bent the ears of many Cherub sailors over the years about what makes boats work. I suppose Dave Roe, Simon Roberts, Chris Forman and Simon Robinson have the sorest ears...
Iain Murray, Sydney, Australia has designed some of the best Cherubs and 18 footers of the last twenty years, and I looked very carefully at some of his dinghy designs.
Mark, Frank and Julian Bethwaite, Sydney, Australia, have had significant roles in the development of the lightweight planing dinghy over the last 25 years or so, and I had a good look at a 49er's bow sections too!
And finally, had it not been for the late Uffa Fox (Cowes, U.K.) and the late John Spencer (New Zealand), I'm not sure that the modern planing dinghy would have developed anything like as far as it has. Mr. Spencer especially is very much a personal hero and was a very influential and underrated designer.

I give the above full credit for all of their ideas that I've plagiarised, but none of the blame for anything that doesn't work because I failed to implement and combine the ideas successfully! Apologies to others who I've missed off!


Why a One Off Boat?

So why does the world need another dinghy class? Well, I don't suppose it does, but after twenty years on and off sailing Cherubs to Open Meeting level (and even winning one three) I came to the conclusion I was getting to old, slow and fat to be forward hand in one any more. This combined with a job that involves a fair amount of unpredictable weekend work, so the option of forward hand in a bigger two handed skiff type wasn't really there. Bearing in mind that my helming skills are such that I long ago took up being forward hand, the obvious solution was to sail some sort of single hander at club level (Open level being too embarrassing). I also figured that I might be more likely to cope with decreasing fitness with a sit out boat than a trapeze boat, simply because in a suitably powerful sit out boat one can just sit on the side and sail it, whereas a trapeze boat always demands a good level of agility. When you're younger of course the decision for the lazy goes the other way, since a trapeze boat is undeniably far less hard work to drive flat out that the "boil your tendons and break your back" school of extreme hiking.
So I bought this old single hander for the hardly excessive sum of £90 (UKP), and proceeded to sail it - or at least break it, which is what you expect when you pay that for a boat, but given a few odd bits of foam and epoxy I managed to get the thing working. This experience has taught me a few things

Given these three points I started to consider a different class. It rapidly became obvious to me that I actually had no choice at all. The only single handed classes available that could possible fit my philosophy of sailing were the International Moth, which doesn't fit my waistline, and the International Canoe, which whilst a boat I admire, has never appealed to me. So I was either going to have to compromise or build a one-off. The available compromises didn't look too clever either, since whatever I picked on was going to be, to a greater or lesser extent, all three of too heavy, too old-fashioned and too slow. So I started sketching, and this site documents the results. It seems to be working out as a diary of the project, and I hope this might be of use to other amateurs considering similar projects.

· Page Last Updated 6th April 2012

· Email Jim Champ (Webmaster)

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