Dinghy Cruiser /Racer Design

[Matthew]

Briefly, to go back to the lug rig thing, we (Swallowboats) have tried them a lot, and still can't get them to be quite as close winded as the standard bermudan sail. For some reason boat speed drops off dramatically when you pinch up that extra 5 degrees or so.
I can see the advantages to the boomless standing lug (fewer spars) but in my opinion, it is always best to have a boom and so make it a balanced sail.
Reasons are the huge sheeting load of the boomless sail, the fact that sheet angle is so important, the difficulties in tacking and sheeting arrangement, and most importantly, that it twists massively when off the wind, setting up horrible rythmic rolling, the only cure being to sheet in.
I noticed that Nigel Irens added a boom to his Roxanne and Romily designs. It just makes sense.
If anyone can figure out a dipping lug system that is comparable in tacking time and ease, to the bermudan, then lets have it! The dipping lug is an incredibly powerful sail for its size, and for spar length, but it's a real pain to short tack. A great auxilary sail though for motor sailors, though only Bolger seems to use it that I know of.

To go back to the daysailor/racer idea, we are working on a 17ft daysailor to be finished in the next few weeks, that will satisfy part of the brief. (Becuase she is a double ender, she has no planing ability, but may give racing boats a run for their money when the wind is light and they can't plane).
We were also worried about CB and rudder area, though our previous designs have indicated that the rudder area can vary hugely depending on hull design, and still be effective. Our double ended hulls have a small (1" by 2") keel running full length, plus smaller bilge-runners, which give the hull a lot of directional stability. In a following sea or driven hard, they never feel on the edge of control, despite a relatively small rudder area. The downside to this is that they take longer to go about, and for us, this is the governing factor on rudder size.
With regard to CB size, the smaller, the worse the performance in light airs. Im sure most of you know that anyway.
Anyway here's a pictue of her:


And you can see more at

http://www.swallowboats.com/storm17.htm

By the way - interested in your revolving T keel idea Stephen.... Have you done any further work on it?
Also, what is the kFOIL system exactly? Is it just a canting keel?
Best Wishes
Matt

Beautiful boat!
The kFOIL™ is a(patent applied for) lateral resistance solution for canting keels and low aspect fixed keels. It is probably not going to be as high performance as CBTF(upwind) but takes up no room inside while allowing a single wing or dual wings to be deployed from a slot in the bulb. The foil(s) are deployed as the keel cants to make up for lost keel area. Variations can allow a single pivoting wing or dual pivoting wings. The idea is to provide the lateral resistance needed upwind when the keel cants(or as a fixed keel heels) and then for the foil to disappear downwind and in light air.It is particularly suitable with a canting keel that retracts....
Check out these retracted and deployed illustrations:
http://www.rcsailing.net/forum1/data...9_kFOIL102.jpg

http://www.rcsailing.net/forum1/data...1_kFOIL201.jpg

[Ian]

[If anyone can figure out a dipping lug system that is comparable in tacking time and ease, to the bermudan, then lets have it! The dipping lug is an incredibly powerful sail for its size, and for spar length, but it's a real pain to short tack. A great auxilary sail though for motor sailors, though only Bolger seems to use it that I know of.]

I read an article in a British magazine on a local type of dipping-lug that is tacked by pulling the clew right around the luff with the sheet (the lazy sheet is lead forward of everything). It occurs to me that the hardest part about tacking in this manner is the difficulty of getting the heel of the yard around the mast. It would seem to me that if you had a second halyard that was attached to the yard near or just above the ballance point and was set up with a little slack in it after the yard was hoisted, it would be possible, when tacking, to slacken the primary halyard untill the yard hung almost verticaly from the secondary halyard and would thus swing easily around the mast. If the primary halyard was rigged like the throat halyard of a large gaffer with a two part purchase, the dead-end of which returned down to deck to finish on the upper block of a 'jig'--it might be possible to lower and re-hoist the yard sufficiently with the jig-purchase. If I had a boat rigged with a dipping-lug lying around, I would love to give this a try--unfortunately I don't.

[Sean Herron]

Heaven...

You peeps have re-lit my fire - so nice to see so much mental activity where it is so difficult to apply it - the small scale - built around a full size human form - power - speed - upwind performance - beach ability, discussions - AHHH - so it's not all about prostituting myself to the 'Who Wants to be a Millionaire' winners...

Many thanks - I almost bought a McDonalds franchise - now I will fight on...

SH.

[Nate]

In response to Matthews Comment... "If anyone can figure out a dipping lug system that is comparable in tacking time and ease, to the bermudan, then lets have it! "

I've been wondering if the following rig has been tried:
The sail, yard, and boom would be the usual size and shape. The traditional mast would be replaced with an A-frame type. The sides of the A would be attached near the gunwales, and the the yard would hoist up into the vertex of the A. The sail would be free to tack inside the A, and could rotate nearly 90 degrees for downwind sailing.

The mast could be bowed out slightly to clear the sail. The yard wouldn't be hoisted up tight into the vertex, allowing it to rotate. It may seem like the yard could jam & break if the sheet were eased too far. I don't think that would be a problem if the mast sections were connected but free to twist at the top.

[CT 249]

Re Matthew's comment "Becuase she is a double ender, she has no planing ability, but may give racing boats a run for their money when the wind is light and they can't plane)."

Is the fact that she's a double ender a problem, per se? International Canoes (pictured), the Swedish cruising canoes, the German Taifun cruising canoes, and Norfolk Punts are all double ended and they all plane. The Moths are basically double ended and can blow off a Flying Dutchman down a fast reach.

Lovely looking boat, by the way.

Originally Posted by a stevo

really if you are just after a cruising dinght grab and old FD,505 or light weight sharpie and reduce the rig by 30%. give it a little keet if you wish then roberts your fathers brother.

Ya, at a recent regatta a guy turned up with a Lightweight Sharpie (light version of the old 12 sq m Sharpie but with a 190lb hull instead of the 510 lb traditional hull) with a rig about 100 ft2 and an alloy centreboard. It was fast, stable and cheap. A Flying Dutchman is also incredibly stable and with a cut-down rig would be a placid machine; it was designed from the outset to be a cruiser/racer and live on moorings. You can easily stand on the gunwale of an FD without rolling it, even with the normal centreboard.

Down in South Australia, there are classes of "Tagis" and "Usual 20s", which are based on the Flying Dutchmen and Sharpie respectively. They just have a bit more freeboard and little cabins with bunks etc. They just show what you can do with these old racing boats in the cruising role.

[Bob Ames]

Self promotion aside, your requirements sounds similar to the Vanguard Nomad.
Nomad at Bob Ames NA (here)
Designer's Comments (here)

This was a great thread a while ago. The Nomad and this boat-among others-really caught my attention. Has any body run into any new variations on the theme in the last few years?
Colson 5
Address:http://www.colsonyachtdesign.com/des...erSailer55.htm

[Claus Riepe]

Doug,
since you asked,

'Matthew' has since designed and built some new boats that have been successful in Raid races, and especially in tough conditions.
For them, he has gone away from his previous double-ender design.

These discussions here do bear tangible results, sometimes.