John Hesp 12 Skiff, new CNC S+T version.

[keyhavenpotterer]

John designed this sweet skiff as a tender to his own designed and built 28' Gaffer "Hope". She has served him well.



She is remarkably good looking for a flat bottomed two plank skiff.

Recently John was asked to cut a CNC kit for the design, so he took all the measurements off his own boat, and refined the design in CAD with outputs to his own CNC cutting machine. Jeremy Burnett is just now building this new kit. Lets hope we can coax some pictures from him.

Here's some 3D renderings John sent me to admire. Very sweet indeed.

[rbgarr]

It looks like a 10' version of the Francis Kinney dory as drawn in 'Skene's Elements of Yacht Design'. http://www.portlandyacht.com/sail_boats.php

[Duncan Gibbs]

Beautiful, and looks dead simple to build.

[Hesp]

Well spotted rbgarr. I bought a boat in the 1980s which the builder said was built from the Francis Kinney design. I lost that boat and in 1991 or 92 built the boat in the photo above. Not sure how close in shape it is to the Skene design. Jeremy had seen me rowing in Falmouth Harbour and asked for the drawings. I've redrawn it; partly because I haven't got the 1992 drawing any more; partly because redrawing gives a chance for improvement to the boat; and partly because modern 3D CAD allows a better shape to be produced and viewed, allows the panel shapes to be calculated, and is in a form for input into a CNC machine.

Thanks Duncan. Being of a lazy nature I hope it is easy to build. I'm hoping the CAD and CNC have done their share.

A 3D pdf file (should be viewable on any computer with an up to date version of Adobe Reader) can be found here. For those not used to 3D pdf's you can rotate the model with the left mouse button and zoom in and out with the mouse wheel. The "Toggle Model Tree" icon lists the layers used when drawing the model - you can turn items grouped on one layer off and on. As with any web page you can view full screen by pressing F11 on the keyboard. F11 to exit full screen too.

John

[rbgarr]

I like your version. It looks more ' burdensome' somehow. The Kinney dory I had a chance to row was pretty low-sided, 'tiddly' and heavily constructed. which seemed like a contradiction in a sleek pulling boat.

[Hesp]

Thanks. I've often used it with four adults in. I'm hoping that Jeremy's will turn out at less than 70 lbs weight. I seem to remember the boat I built in the early nineties weighed 65 lbs.


John

[Songololo]

Very nice! I remember seeing this skiff in another thread. How easily could she be fitted out for sailing e.g. with a balanced lug rig? Or would she need a bit more beam ...

Lance

[keyhavenpotterer]

Good question, I had also been thinking of asking. Rig should be kept small in view of ease of being driven. Perhaps, a small sprit might suit her best. Here's IO's 12' Pike skiff



Perhaps she is best kept as a handy fun good looking workhorse. Tender, regatta racer, beach cruiser.

[Clinton B Chase]

I like your version. It looks more ' burdensome' somehow. The Kinney dory I had a chance to row was pretty low-sided, 'tiddly' and heavily constructed. which seemed like a contradiction in a sleek pulling boat.

I also like Hesp's version better than the Portland Yacht Services version. They widened the original, but I don't think the results are very beautiful. Why would anyone want a boat that is not beautiful?

Cheers

[keyhavenpotterer]

I love the work that PT Watercraft are doing with their 11' Skiff. Very fine minimalist engineering. Their rig, board and rudder set up is just as neat and well thought through as the boat. Perhaps something like this which gives a very small packed size to store on the boat when rowing could work for John's skiff as well. I just happen to have a fantastic carbon two piece windsurfing mast in my garage.



Sitting on the floor makes a lot of sense in a small skiff, and John has mentioned just how comfortable the hull shape of the skiff might be to sit against when sailing.

Brian

[Hesp]

Wow! How is that boat moving? There doesn't seem to be any wind.

Brian, I know you've a lot of experience with windsurfers, do you see any problems in using a mast which was used for a different application? It does seem to be the easiest way to get a very lightweight mast.

John

[keyhavenpotterer]

Windsurf masts are pretty tough and resilient. Being two piece is great as well. I noticed that Swallow boats use them for various mizzen masts and gunter top yards, and on their new sailing canoes with a neat thin boom that also stores inside the half mast.

I think in a very lightweight easily driven skiff loads are not going to be high, and in stronger winds you would probably just row. I think the mast would take anything you could give it when sailing sitting on the floor.

I have two in my garage, one all carbon and one 50:50 carbon glass. A nice little 5m sail like the Hobie copy Swallow Boats have done for their sailing canoes - very high angle top batten which makes for a fat head sail with good gust response and will still roll up around the mast. Use a boom though.

[Dan St Gean]

The raptor 16 makes for a simple rig like the hobie but uses a boom.

Out of production, but the idea is still good.

Dan

[keyhavenpotterer]

A 5.0 sq m fat head sail cut be cut and produced very simply,

here's a quick example of what can be drawn

https://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid=0B4Bi31i xDF93ODA1YzdmOTEtMWMzYy00ZTFjLWFkMDMtOGFmMWMzOWJjM DBk&hl=en_US

and the panel development plotted as xy shapes to mark out on the sailcloth, cut and sew.

https://docs.google.com/viewer?a=v&p...iNjFj&hl=en_US

[Hesp]

Well Brian, the fat head sail does make sense because of its ability to de-power in a gust, but you'd rather sold me the idea of lug sails

This boat is 10' 3" LWL and 32" waterline beam, and after 20 years of owning this boat and thinking about a sail the main reason I haven't stuck one on is because of the boat's lack of stability. Apart from keeping a 50 sq ft sail from blowing it over there's the problem of moving about in the boat to ship the rudder of hoist the sail. If I get into the stern of this boat for some reason I find myself on a boat with a triangular waterplane maybe 5' LWL and average 12" waterline beam (assuming I'm on my own). So I think it needs a rig that can be lowered easily without much moving about. The rudder can just have a pull up blade.

In any case, I do like the look of the lug or sprit rig better on this boat.

I think any rig would work better on a scaled up version though - say 15' because of ply lengths. A person could move about more confidently on a boat of this size, which would allow a rig that lifts in and out.

John

[keyhavenpotterer]

Lot of sense in what you say John. I do think a proper rowing hull needs a pretty small sail area to keep things enjoyable, just like a sailing canoe does.

I have owned a couple of rowing boats with rigs and had a similar stability problem with both. On the wind is ok, you sit against the heel of the sail and everything is good, just needs watching. Off the wind on a broad reach was very uncomfortable in gusty conditions. Sit out to hold the boat up, and as a gust eased, I would have to sit in quickly, then out then back in. Felt very uncomfortable and unstable. Swing around back upwind and it was fine just taking the amount of power I wanted to, luffing slightly or bearing away.

Back down river and just the same again. The Skerrieskiff with a 5m was very unstable I found off the wind. I know CVlint sails his Drake off the wind and loves it. Perhaps it was just the conditions, with moored yachts causing gusts and eddies as I sailed down the River.

Here's the 15' Skerrieskiff with rig





Here's the very small waterplane you mention.



I know with sailing canoes, that if you can really get your weight connected to the hull then everything feels much better. Your description of sailing sitting on the floor, back settled well into the curve of the hull would help loads in keeping her steady. I think my experience with "oar with added sail" designs lead me to be very wary if it was really possible. Perhaps it's to do with the relationship between sail area, hull stability and weight and the sailors weight. The Tammie Norrie worked beautifully as an "oar and sail" design, bigger and heavier so more reserves of stabilty, and then the larger Oughtred's are fine but not the lightest of rowers.

So, a 15' Skiff could be very interesting and also challenging to get right. The Skerrieskiff was nice to row, perhaps more weight in her when in sailing mode might have been better. Water ballast could be a very fruitful area to examine to create a super rower and also a good sailor. One "rowing" waterplane with empty tanks and a deeper more stable hull form when tanks were full and she settled into a more "sailing" hull lines.

Look forward to seeing the 15' Skiff.

[keyhavenpotterer]

Jeremy has been having fun stitching up the Skiff hull.

[Tim Marchetti]

Nice! Simple and clean design. Is there a build thread for this boat.

[Tim Marchetti]

Jeremy has been having fun stitching up the Skiff hull.

Any updates on this build???

[Jeremy Burnett]

Any updates on this build???

Yes, its finished. I've been fiddling about modifying some oars to suit. We could launch tomorrow but the weather is good and I have been working on our cruising boat (35ft Buchanan) its a question of priorities.I will take some more photos as soon as I can.

[Tim Marchetti]

Grazie