The International Canoe

Chris,

The water certainly separates very cleany from the hull between the mast and the stem but in the limited testing I have had and also without having a Morrison 1 to compare against it is difficult to tell how much is due to the hull shape and the chine rails. The boat does lift very easily onto a plane but that could be just down to weight. More testing required......

For 2014 I think there could be quite a large British contingent and we are building boats now in readiness to come over and give you lot a good thrashing.....hopefully . I have two more boats in build based on my latest Sapphire design and so we will start our training campaign next summer.....

I will put a picture of the new Hyde on the gallery under the M2 section. Rob Michael is developing this with Hyde and I will be testing the prototype with the Llandegfedd boys soon.

Hyde new square top picture may be found at http://www.intcanoe.org.uk/gallery/displayimage.php?album=21&pos=0

Hi,
this year we want to build at least three new ICs in Germany. This is how they will look like:





and this is the actual status of the mould:







all pictures here:
http://photobucket.com/arnes-ic-design

Hi Arne
Any updates on the build? Will you make it to Plymouth with a new boat?
Alistair

hi alistair,

there is some progress, but I will not make it to plymouth with the new boat. but I will come with my ac anyway.

moulds are finished and starbord hull side is done, it came out of the mould at 6 kg:





port side outer skin done today:



all pictures here:
http://photobucket.com/arnes-ic-design

in two weeks we will build another two halves for frederik. after that ecki takes the moulds for another hull and i can use the space for the deck mould.

so things are moving

do you have any advice on new masts? my brother and frederik are looking for a new one.

Hi Arne
Looking really good! So we might have 3 of your designs at Loch Lomond next year? That would be good!
My mast is from Superspars, Rob Michael here is the man to talk to, he has lots of info on the position of hounds spreaders etc. Some of the others in the fleet have Selden, but there are lots of other makers, Aardvark from the UK, C-tech from NZ, some home built, some people have got tubes and fitted them out, a whole lot of options from lots of £££££££££ to less.

Hi Arne, most of us in the UK are using Superspars rigs & are well proven. They are very profesionally built, finished & fitted out & seem to be as fast as anything on the market. A fully fitted IC mast is £1056 + tax & delivery. I know they currently have one in stock for me at the moment. If you require one or more I could always deliver them to you free at the Europeans in Plymouth. If you do require more than one I'd need to put in an order ASAP to garantee the other would be done in time. If interested or need more details you can contact me directly most evenings on (UK) 01243 430253 or email razorbackboats@supanet.com.
Cheers, Rob.

Some news from Arne on all the stuff going down in Germany:

http://clarksail.com/2012/12/18/the-low ... rne-stahl/

Best,
Willy

I seem to be having a problem uploading an image. Anyone know if its just me or a general problem?

Best to post pictures to a hosting website and copy the bb code into the forum post

Chris,

thanks for the advice, but not very techy and don't really know what you mean.

OK now found out what it means.

Hope the info was worth it!

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100 years of canoe design.


I have done some theoretical comparisons of various designs, using the added mass theory. This theory seems to be used commonly for aiding the design of planing power boats. There are a lot of limitations, listed below, but hull profiles are taken into account to some extent. The two features that are key to the model are the rocker and the beam, and the way these vary along the boat.
The limitations of my model are:
1) deadrise assumed to be zero.
2) clean breakaway of flow at the stern of the boat
3) only forces acting are the dynamic lift and static buoyancy forces.
4) models shapes estimated from very little information, except small line drawings. Hopefully the main features were successfully captured.
5) Hulls modelled using a triple chine design.
6) the driving force assumed to be acting through the centre of mass, so producing no moment constraining the trim angle of the canoe.
7) sailing weights assumed to be he same as for the Nethercot. (except for Mayhem, assumed at 286 lbs)
The results shown for Mayhem are those reported by Steve Clark in about 2012 (Jan) on Dinghy Anarchy. My calculations fitted the data extremely well.
Haze, and Wake are the only canoes which didnot have a chined stern and so it could be expected that they would have more transom drag than the others.
Haze was reportedly the first canoe to plane.
Tritonelle outclassed all the other 'B' class canoes and stopped racing.
Iota ( number 1 on the British numbering system for B and International canoes) was a very simple cheap canoe. designed primarily for ease of building.
Wake was one of the first of the International canoes in the UK. In tests at the National Physics Laboratory they considered her to be a non planing hull!

I would like to have better data for comparison, to see if the theory is really worth using as a design aid for canoes. Any tables of offsets and towing tests would be of extreme value, so I'm looking for people to volunteer some.

I have modified the theory in a very simplistic way to try and account to some extend for deadrise. For chine canoes this can make a big difference, as they will exhibit very small lift close to the bow where the deadrise is approaching 90o Accounting for the driving force not acting through the Centre of gravity will have the effect of scaling the speed axis, although I haven't made estimates of this. For the designs considered, a 10% increase in sailing weight would increase the drag between 3% and 7%.
There are many features which have been incorporated into modern design which improve performance. Gear has improved enormously, so that new boats always outperform old ones. The similarity of Wake and Nethercot, perhaps shows the limitations of the theory but also shows how similar the underwater hulls are.
Finally when I modelled Gaijin, I found drag results well below any of those shown here, due probably to a reduction in the rocker.

More data, this time estimates for new boats. Again I have tried to model the salient features of the various design, but without offsets the approximations can only capture large variations in shape. I cannot say whether the data has any real value but would be interested in any comments.



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Hi Andrew
Which boat is Gaijin? was that one of Steve Clarks ply boats he had for Germany? They certaintly were fast but very differant design to Dragonfly and the Morrison, not that they are very similar...

Steve posted the attached lines to Dinghy Anarchy about a year ago. Seems to have very little rocker which is, I think, the reason that the added mass theory predicts a low value for wave drag. My gut feeling is that the drag will be above that predicted, however, as I greatly lack data it is impossible to say with any certainty.


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