My Design - Trifoglio 25' - Suggestions & Opinions

[Doug Halsey]

...can we agree those scows are both rather tiny in comparison to the original drawings here and even the modified?

Sure. Those photos I posted are all Moths (11' long). But I don't see anything wrong with larger ones (the ones with higher freeboard anyway). Here's a 20' scow that my uncle built & sailed frequently in the 1940's.

BobHalsey_20'Scow

• Doug Halsey
• Dec 10, 2020

...As a sailor, do you have a concern about the scow surface area as a percent of mainsail for to the wind and the boats ability to windward?

As noted in other posts, scows are at their best when planing (usually not close-hauled), but many scows still perform nicely going to windward.

...If, for example, the scow is 9 square feet and the main is 200, then the scow is 4.5% dead to wind. I have been head onto the wind many times in my open skiff and once the wind gets you sideways; it keeps you.

I don't understand what you mean by this, but I don't think scows are any more difficult to sail than skiffs, generally speaking.

 

[cracked_ribs]

Pretty amazing that he built that in the 1940s. I would have guessed a few decades later, just because the overwhelming impression is that someone said "hey, what do you want to do with the Volvo 240 that has no engine or running gear?" and he responded, "well, there are vehicles that run without motors...how are we set for sailcloth?"

 

[Doug Halsey]

Pretty amazing that he built that in the 1940s. I would have guessed a few decades later, just because the overwhelming impression is that someone said "hey, what do you want to do with the Volvo 240 that has no engine or running gear?" and he responded, "well, there are vehicles that run without motors...how are we set for sailcloth?"

I've got absolutely no clue what you're saying.

But, nevermind, I did some more digging into family history and it looks like he built the boat in 1939.

 

[cracked_ribs]

It's just funny that this unique boat of 1939 looks so much like a 1980 sedan.

It must have seemed incredibly futuristic at the time.

 

[DVV]

This is a Colvin design, quite extreme, but I like it. Based on an old chinese junk (hanshaw bay fisher/trader). The bottom side of the bow seems to be curved (sides lower than center)

 

[DVV]

Update:
Lots of work done. Added details, added dimensions and offsets.
Almost ready to start building the balsa model, just need to design a Jig to use.
Here some details of the internal structure.

DVV

 

[DVV]

 

[gonzo]

This is the hull heeled at 20 degrees (max stability angle)

Is 20 degrees where you have the highest righting moment or where you don't have any more positive stability?

 

[DVV]

Is 20 degrees where you have the highest righting moment or where you don't have any more positive stability?

I hope that's where I have the highest righting moment. If it was where I dont have any more positive stability I'm afraid I would capsize the boat just by jumping into her!

Anyway, it was wrong. Max GZ is at 40°, and AVS 126°.

Maximal GZ : 0.686 m
Heeling angle for GZ maximum : 40.0 degr
Heeling angle at which righting lever=0 again : 126.2 degr

I'm afraid that's a bit too much, I think I'll have to go back to add some weight or depth to the keel...

EDIT: No. I think I over reacted. 40° is quite fine, I dont think I need to modify any keel, its fine like this.

 

[DVV]

Hello everyone. An update about the design.

Many things changed again. At the end I have been able to workout a single chine version that seems fine to me.
Moreover, there is no more keel, I switched to an internal ballast with leeboards. I used a bigger cabin top, and this gives me standing headroom inside, and enough buoyancy to compensate to the missing keel. Stability Curves are still fine, with an AVS of 130°. Max GZ is now at 20°, so she will be quite stiff, but I think I can live with that.
She's may be a bit less good looking, but that's not my main driver. The objective is to build the boat, so the simpler the better.

DVV

 

[Dolfiman]

Your project reminds me of the Caragogne, a 4,6 m with small cabin sailboat with such "tender like" shape and bow. The cabin version itself derived from the popular Caravelle used by a lot of sailing schools in France since the 60's and still a very active class. Here photos of a Caragogne recently refit (in 2019) and a video of sailing in costal waters. As long as the waves are moderated, the bow does not prevent an easy sailing including upwind :
Mise à l'eau de la Caragogne (amarrage-asso.fr)
Les abers en caragogne - YouTube

 

[fallguy]

Your project reminds me of the Caragogne, a 4,6 m with small cabin sailboat with such "tender like" shape and bow. The cabin version itself derived from the popular Caravelle used by a lot of sailing schools in France since the 60's and still a very active class. Here photos of a Caragogne recently refit (in 2019) and a video of sailing in costal waters. As long as the waves are moderated, the bow does not prevent an easy sailing including upwind :
Mise à l'eau de la Caragogne (amarrage-asso.fr)
Les abers en caragogne - YouTube

It should be noted the beautiful boat you linked does not appear to have standing headroom.

It was cruising along quite well I'd say.

 

[ExileMoon]

I think we should consider the design of this boat based on actual needs.

For example, if you are just trying to get a houseboat floating on the water under your limited budget, then you don't have to think too much about things that deviate from habitability such as 2% faster.

 

[DVV]

Your project reminds me of the Caragogne, a 4,6 m with small cabin sailboat with such "tender like" shape and bow. The cabin version itself derived from the popular Caravelle used by a lot of sailing schools in France since the 60's and still a very active class. Here photos of a Caragogne recently refit (in 2019) and a video of sailing in costal waters. As long as the waves are moderated, the bow does not prevent an easy sailing including upwind :
Mise à l'eau de la Caragogne (amarrage-asso.fr)
Les abers en caragogne - YouTube

Beautiful vessel!

 

[DVV]

Current state of the design.
Trying to make it simpler and simpler..