Thread: Best 12' dinghy

Jummy!!!



Yep, the UK National 12 has some very interesting and beautiful lines. This one is done in strip.

You guys are really worrying me! If I link to some N12 videos will you be even keener or perhaps want just a bit more waterplane!!!!!

[ame="http://www.youtube.com/watch?v=vgU4LA52ngg&feature=related"]YouTube- Broadcast Yourself.[/ame]

make sure you watch till 1.55 sec.
[ame="http://www.youtube.com/watch?v=aJNuox54Nzc"]YouTube- Broadcast Yourself.[/ame]

Ian Proctor designed a 12' with a flat bottom, and intersting build









SigneT Dinghy Building

Brian

Well, those videos only make me keener! What a performance packed in 12 ft length whilst not making things overly complicated. Pitty I live in the Netherlands where this is a national UK class and for this boat not being a single hander.

So we depend on MIK designing a 12 ft beauty with some spirited DNA for fast solo cruising and occasional racing.

Joost

here's a 17 page PDF on building a wooden Nationa12 from the class web site


Brian

Originally Posted by keyhavenpotter

You guys are really worrying me! If I link to some N12 videos will you be even keener or perhaps want just a bit more waterplane!!!!!

YouTube- Broadcast Yourself.

make sure you watch till 1.55 sec.
YouTube- Broadcast Yourself.

Ian Proctor designed a 12' with a flat bottom, and intersting build









SigneT Dinghy Building

Brian

60 Hours for the build is quite some going for the SigneT, even if it was a kit Nice and simple method though. I like the National 12's performance, and it would make a nice project for the more experienced builder which has a bit more complexity. The rig and fitout would cost a bomb, so it's not a cheap boat by any means. Thanks for the links and pics

The N12 is much sexier than the SigneT but it is nice to see a flat bottomed 12' dinghy designed by a master such as Ian Proctor which proves the approach can work.

I always like to see a dinghy heeled over a fair way with a comfortable crew and a balanced central helm - kind of points to a well balanced dinghy.





looks a bit familar,





Brian

I have been churning over this for a while and I think the only solution is to draw up two boats that use the same method. One a family sailing version, a bit like the Penguin above, but completely Goatish, and a second high performance one for single handed racers minded types. So the builder can choose one of the two.

G'day Michael,

Would the easiest way of solving this problem be to just keep the hull shape the same but offer different rigs for different uses. This is the approach Dudley Dix has taken with his Paper Jet 14 and the late Chris Koper with his lovely Sonatina scow. I think there is a real opening for a 12' single handed racing dinghy which can still be sailed by two. Realistically something like that would suit the little bloke and me better than the Goat now that my daughters are growing up and moving away. A boat like this would be great in the future for the little bloke if he wants to race in the Combined High Schools regattas.

cheers,
clay

Originally Posted by seajak

G'day Michael,

Would the easiest way of solving this problem be to just keep the hull shape the same but offer different rigs for different uses. This is the approach Dudley Dix has taken with his Paper Jet 14 and the late Chris Koper with his lovely Sonatina scow. I think there is a real opening for a 12' single handed racing dinghy which can still be sailed by two. Realistically something like that would suit the little bloke and me better than the Goat now that my daughters are growing up and moving away. A boat like this would be great in the future for the little bloke if he wants to race in the Combined High Schools regattas.

cheers,
clay

Now there's a name I instantly recognise Clay....Koper. Chris's father, Gerhard, designed the 12' Dabchick, which started me in sailing (and which is posted earlier in this thread, and is the simplest boat to build, bar none) and the Tempest (scow) which was a 16 foot version of the Dabbie, only with a shallow cockpit and a spinnaker. Both Dabchick and Tempest had superb performance, especially when the breeze was up.

The Dabchick ensured that that the Optimist was never successful in South Africa, as juniors went for a much more exciting boat. The Dabbie also kept juniors away from the Mirror, which was a mums and dad's plodder by comparison, even though the Mirror had a spinnaker, which did nothing for it's performance anyway. Koper's Tempest was pretty much pitted against the Fireball, and while the Tempest sailed rings around the Fireball on all points of sailing, it was the stitch and glue Fireball that eventually won out because of its ease of construction and its Olympic class status at the time.

I haven't been able to find any pictures of Koper's Tempest, but imagine a larger Sonetina and you'll get the idea.

It's really good to see the name Koper is still getting people into boats today.

Howdy,

The different rig approach is flawed I think. Purely because of the range of crew weights expected. That is where the problem is.

If a boat designed to be high performance with one person aboard then it won't be high performance with two aboard and vice versa just because the boat will be floating too light or too deep.

Additionally sailing one up on the wire is very different from having two on the gunwale. Too much volume for really hight speed in all conditions when one up or too overloaded with two aboard. The PJ hull design is very 1980s so won't be as fast or controllable as the smaller hull volume boats with narrower transoms and flatter but narrower sections forward that dominate the skiff classes now.

The Goat is very much in that style - just going faster without really seeming like it is planing.

The Jet already has quite low freeboard, but it does looks like it is struggling when two are aboard in some of the pics.

The National 12 shapes have a lot of that more modern influence - flatter sections well forward so the whole boat lifts, higher freeboard so the flare of the hull is out of the waves, narrower transoms and the narrowest hullwidths possible within rule constraints and stability constraints. This has come from largely the NS14s and Skiff Moths which influenced Julian Bethwaite (that is my guess) to move to this sort of shape in the 18ft skiffs.

The best place to show it is in these line drawings.

A cherub dinghy from about 1980


You see the plan view above. The most curved line is the waterline. The one above that is the chine.

And later ...


Note that the rocker is much reduced, the rocker is flattened right out, the stern is much narrower. This is more like a modern shape. The whole boat is expected to lift very evenly rather than plane on the back end like the paperjet. See how the national 12s accelerate so well in the videos above.. No real change in trim - the bow doesn't come up, they just go way faster.

Also note how close the Paterson shape is to the GIS - except the GIS has more flare because it can't have (or want) wings and a trapeze.

With the Son of Goat (?) the problems are the two distinct purposes of the boat.
A family cruising boat that can carry one or two or maybe handle a third and still sail well.
or
An interesting single hander that can carry a second person but still go OK. More twitchy than the above.

It is just too bigger range and the smaller the boat, the bigger the problem if you add weight.

I don't plan on anything like the top end performance of the Paper Jet, it comes at too much cost and complication.

Best wishes

MIK

G'day Michael,

Thanks for the detailed explanation. Makes a lot of sense when I think about it The rig and hull should be designed together for a desired displacement otherwise you run the risk of ending up with a boat which is 'jack of all trades but master of none.' I'm looking forward to seeing your ideas for the 12 footer.

cheers,
clay

Originally Posted by woodeneye

Now there's a name I instantly recognise Clay....Koper. Chris's father, Gerhard, designed the 12' Dabchick, which started me in sailing (and which is posted earlier in this thread, and is the simplest boat to build, bar none) and the Tempo (scow) which was a 16 foot version of the Dabbie, only with a shallow cockpit and a spinnaker. Both Dabchick and Tempo had superb performance, especially when the breeze was up.

The Dabchick ensured that that the Optimist was never successful in South Africa, as juniors went for a much more exciting boat. The Dabbie also kept juniors away from the Mirror, which was a mums and dad's plodder by comparison, even though the Mirror had a spinnaker, which did nothing for it's performance anyway. Koper's Tempo was pretty much pitted against the Fireball, and while the Tempo sailed rings around the Fireball on all points of sailing, it was the stitch and glue Fireball that eventually won out because of its ease of construction and its Olympic class status at the time.

I haven't been able to find any pictures of Koper's Tempo, but imagine a larger Sonetina and you'll get the idea.

It's really good to see the name Koper is still getting people into boats today.

Um, Gerhard Koper designed the South African Tempo scow, not Tempest as I stated in my previous post.

Incredibly, I found an article from Australia's "The Age" newspaper in 1967 that mentions the Tempo.
The Age - Google News Archive Search

The Age - Google News Archive Search

Video:
[ame="http://www.youtube.com/watch?v=lxZ2zeYMOH0"]YouTube- Broadcast Yourself.[/ame]

Here are some other pics of the Tempo, some from the Netherlands...









Attachment 124289 Attachment 124290



And Koper's brilliant 12' Dabchick, just to keep the relevance!

Great stuff Woodeneye!

On the water it looks very much like a Fireball, but you can hear the bottom is wider and it is more "plane-y" upwind.

It had me looking on the net to see which was designed first. The fireball was in '62 and the Newspaper articles for some Tempests being built in OZ were in '67.

Interestingly the Fireball was originally designed to be a trapezeless and spinnakerless boat for couples to sail.

That makes the two concepts very similar.

I'm not suggesting at all that one was taken from the other. But you can certainly see why so many good Fireball sailors came from South Africa.

MIK

I noticed those big images above came from flickr. If you look at the pic on flickr, there is a "all sizes" menu item immediatedly about the pic.

If you click on it yougo to the biggest image but you also have the choice of some smaller ones.

Great post!

MIK

Originally Posted by Boatmik

I noticed those big images above came from flickr. If you look at the pic on flickr, there is a "all sizes" menu item immediatedly about the pic.

If you click on it yougo to the biggest image but you also have the choice of some smaller ones.

Great post!

MIK

Oops, I've fixed the size of the images up.

The Tempo is like a lot of boats that need to be sailed flat. In that video, it is not being sailed to its potential a the crew isn't even using the wire, but you get the idea of its possibility.

Mick, you picked up the sound of that wide, flat hull (narrowish transome tho) correctly! When a Tempo comes up on a slower boat, it doesn't sneak up by any means. That scow washing machine sound is very loud and intimidating.

I loved to take my dad's friend's Tempo out when the wind was up. It could really fly. It certainly was faster than the Fireball which I raced while at university (University club boats). However, the Fireball always guaranteed good fleets, which the Tempo didn't always deliver, and that's what sadly killed off the Tempo. However, it seems to have migrated to the Netherlands somehow, but then those Dutchmen will sail just about anything that floats.