This is my last design
I called FDS - “Ferro Da Stiro” in Italian and “Steam Iron” in English

Here are both but only one is floating !!

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Uploaded with ImageShack.us

Notice the Main boom pivot point and the related effect on Main , hoping it will work !


Claudio -

the offset boom connect is typical on big multihulls, and it does cause added fullness in the mainsail when sailing off-wind and still removes camber when sheeted in. On the 60 foot multihulls, the difference between the deck mounted mast and the deck mounted boom can be several feet. A few have tried it on the smaller scale, but have attached boom to deck - I don’t recall any being mounted to the mast itself… but have not heard of any noticiable results. Works better when the trailing edge of the mast is allowed to rotate so the luff groove of the mast can stay in line witht he end of the boom - otherwise you get a strange sailshape direectly behind the mast.

I do like the side profile of your boat … Hmmmm - I’m thinking RG65 !!! :cool: :stuck_out_tongue: :slight_smile:
Although our recent US RG-65 Nationals saw “narrow” boats at the top of the finishing list… (Light to medium winds were encountered).

Hi Dick,
in fact I was looking a one of the modern rigging with the boom fixed on the deck, that I decided to do something like that on this experimental model. I wonder if is still possible to control the leech .
Discussing with a famous architect, I learn that the purpose to tilt back the bow is to gain weight first and new fashion second. Since gaining weight is a good thing above water line, I decided tu cut also at the stern as was the case on Studio3 (avatar), years ago.

Hi Claudio

Looks great /like all your work/ Hope to see it on watter soon…


Thanks Damjan,
it will take some time , but soon any how.
First I need to draw each single shadows and then … the file will be published also here

Hi Claudio,

NICE BOAT! I have just one thing to add - I would be a little concerned with 80mm freeboard at the bow.
I built an Open 60 style yacht that had 100mm high stem (990mm LOA & 290mm beam) and I wished I made it with a bit more freeboard. Its a very wet machine when its windy!.. I played with spray rails and all sorts to fix the problem.
Just thought I’d drop off some experience in case you wanted … you can see it sailing on my You Tube account.

Cheers, Jim

HI Jim
I will take in due consideration your advice.
Just for better understanding , on your Open60 , where is located the CB ? What ratio exist betewen jib and main ? What is the Prismatic Coeficient ? What is the bulb/boat ratio ?


This one really is looking great. This will be a threat I’m going to follow!
With respect,

Hi Claudio,

As I design things a little different to you the numbers for the Cp and Cb do not exist on paper…
The yacht is a canting keel and canard design. 60 degree cant and a 1000g bulb on a 600mm fin. Total weight was 2.7kg I think. The sails were a no.1 suit for a IOM because I needed to have a performance constant as there are too many variables when putting an untested design on the water.
One ingenious feature of this yacht is that it is actually a flat sheet of carbon, cut and formed into a yacht hull. No mould was used at all!
I made model fast electric boats like this when I was aged 12 from thin ply…
Good luck with your skimming dish!!

Hi Jim,

I put togheter in a sketch the data of the two model boats according to what you says for comparaison.
You will notice big differences for what concern :

  • the displacement,
  • the righting moment
  • the bulb/boat ratio
  • fin wet surface
  • same sail area of 6000cm

The total bow height is 100mm and 85mm from lwl

Too early to pull conclusions, but I think that the FDS has better chances on paper in spite of the canting keel, for the time being


Hi claudio,

Are you sure the cant angle is correct? It is 60 degrees either side of centre… and when its heeled to 30 degrees it flys the bulb! I have a chined hull too and twin rudders. The foils are 40mm wide for all. I know the wetted surface is up there but none the less it sails just as fast as a Standard IOM upwind, but once you free off - Ciao !!

Here she is…