Car Topable Dinghy.

[Port-Na-Storm]

Hi
I thought I'd start a new thread as I'm sure Frogsider doesn't need a constant reminder about his rudder failure.
A few years ago on the old yahoo forum we had a discussion about designing an ideal car topable dinghy so I thought I'd resurrect it here. Discussions about Ander's next project seemed as though the boat was being designed from the centerboard out which is a novel way of doing things.

As winter draws in it'll maybe give us something to chat about while waiting for the epoxy to go off.

This is about as far as my own efforts got;

 

Probably too heavy, even in 4mm ply it was designed to be self jigging for ease of build. You can see how the slightly modified version went together

here.

Those not raised on a diet of TV programme Blue Peter will miss the references to Val Singleton's knickers.

Cheers Graham

[Anders]

Its a very nice project and it looks to be worth building. What I like is that it´ll be a safe sail with the side tanks.
If the idea was to make a sail and oar dinghy (thats what I´m into) I have some "issues"

1) side decks/tanks on such a small dink are a bit to "racy" l  for me. I will prefer to sit inside the hull and not on top of it. And only when its really necessary I will put the heavy part of my bump a little bit outside the gunnels.

2) storage of the oars. Even though I like you eggbox design (its very rigid) and all your bouyancy, my question is where do you store the 7,5´oars that this little thing´ll need. I strongly dislike when the oars are just lying around and you either sit on them of have them in the bottom. Its one of the really complicated things to deign on small sail/oar dinks and most designer just "forget" it.

3) centerboard or daggerboard and how thick if it was to be a centerboard. Getting off a beach with shallow water and a 15 knot breeze against you is easyer with a centerboard than with a daggerboard. But on the other hand, a daggerboard means some 3 kilos or more extra weight.

My own project is on its way. I´m building the jig. It´ll be a simple 4planks a side clinker ply hull designed by Tom Dunderdale for me. A modified 11´ 3" x 4´5" version of his Iceni 12. I´m designing the interior and sail.
I have a lot of things going on, one of them my wife being very ill, so I dont even know if I´m going to plank the thing. I think it´ll be a fast build. Maybe even ready for next summer. but.....
I will upload some pictures and drawings soon.

[Port-Na-Storm]

Thanks Anders,
Yes you are right it isn't designed to be rowed very far. The concept of sitting facing backwards waggling sticks around was lost on me at the time.
As you've spotted the idea was to stay afloat even when swamped, which was quite probable given the pretty low freeboard. I wouldn't be too quick to dismiss the sailing ability of dagger boards, all those Lasers Toppers Picos and Mirrors can't all be wrong. It just that they don't fold neatly away when not required. I'd been planning a dagger board for the very reason you pointed out originally, it can be removed to keep the weight down.

It would be great to see some drawings and your ideas on rig/foils etc.

Cheers Graham  

[Anders]

Just one thing.
The side tanks as designed are giving "high" bouyancy underneath the deck. This means less water inside in the case of a capsize where you only do a 90 degrees capsize. But if you swamp the dink, the high bouyancy isnt of much help. The lower the better. The mirror is actually pretty good on this leaving little water to be bailed out

[Frogsider]

That's a really nice looking little boat, Graham.  If you ever get round to drawing up some plans I could be very interested in building one.

At the moment I have put all building plans on hold as I've just bought an old GRP boat that will need a little restoration - not much, but it will keep me busy for a couple of months.  It cost me less than the price of the plywood and timber I was about to buy to build the Selway Fisher Kestral.

Patrick  

[Port-Na-Storm]

Thanks both of you,
I'm not sure the boat would be much different from a Mirror in terms of flotation, either way up. The tanks only appear high as the boat doesn't have another plank round the sides.
I hear what you say though, and final positioning of buoyancy V open cave lockers etc would require further R & D i.e. trial and error.
I know how difficult it can be to right a Laser when its fully inverted and the only grip you can get is to curl your big toes round the lip on the gunwale.

Patrick thanks for the vote of confidence, maybe one day......In the meantime this forum also officially includes re-builds, renovations, and re-fits of old GRP boats, otherwise quite a few of our contributors might be excluded, so please keep us posted on progress.
Cheers Graham

[Forthsailoar]

After various trying alternatives I now store my oars along the gunwale, resting in two sets of rowlocks. Held in place by bungy - which can be quickly released.

I can still sit up if I need to as the place I sit is close to a rowlock, so not too much strain on the oar. It's no more uncomfortable than sitting on the coaming! I try and avoid sitting out anyway.

Cheers

Osbert

http://forthsailoar.osbert.org

On Tuesday, 20 September 2011 at 17:12, Anders [via UK HBBR Forum] wrote:

2) storage of the oars. Even though I like you eggbox design (its very rigid) and all your bouyancy, my question is where do you store the 7,5´oars that this little thing´ll need. I strongly dislike when the oars are just lying around and you either sit on them of have them in the bottom. Its one of the really complicated things to deign on small sail/oar dinks and most designer just "forget" it. 

[Anders]

Osbert

What you describe is called the torpedo way. It can be done on relatively long and narrow hulls with long relatively straight loines like your Walkabout. On short tubby things like Grahams 11´dink, most of the oar will be outside the hull.
Grahams dink´ll need oars just 6 - 12" shorter than your walkabout and the hull is 5´6" shorter.

[Port-Na-Storm]

Of course the dink in question didn't really start out to be sail and oar, so the thought of having a pair of long oars didn't come into it. The idea was for more of an old man's Laser with a bit more room and less tendency to fall over. And when did you last see a laser with a pair of oars?
That of course was how it started out, but as is often the case with ill-defined projects the requirements gradually changed as the end user (me) got distracted.
When I started to seriously consider another plank and maybe a cuddy I realised I was now designing a different boat and it was time to stop.

On the subject of oar storage the 7'6" oars on my 11' Coot now seem to have found their place across the thwarts as shown here,



Fine and handy when I need them and not in the way at all.

Graham