Eris write: "The vertical effort is very low. The only effort is lateral..."

Yes and no. I agree, Jaques' strengthening in that area is probably more than adequate - provided the mast is fixed firmly in position at the heel.

Pitching in a seaway does create quite a lot of downward momentum to the mast. We had a famous case many years ago of David Lewis last voyage, in a junk rigged boat. He never got out of the Hauraki Gulf. The mast "jumped" out of the mast step, in a choppy sea - and then fairly quickly punched its way through the hull.  End of voyage. He was rescued.

Anonymous wrote:

Jacques,
Now, in the hope that the mast position can be accepted, I have drawn  a taller sail, taken from The Johanna 60 series of master sails, with AR = 1.98 (instead of the previous 1.89).This is about the tallest sail I dare to suggest. In case you will do most of your sailing, crossing oceans, I suggest you go for the lower version.

Arne

(..full size diagram under Arne's Sketches, Section 8 - 36...)

Arne,

Some News :

Mast : In september , I get back a street lamp in aluminium ( 10 m , diameter At the bottom  : 16 cm At the top : 10 cm )

Questions :

What thickness for mast floor ? 

What thickness for " étambrai " (in french) : 60 mm 6 x 10 mm ?  for reinforcement deck ?  Omega ou Porque 

PS : Bermudian Ring For sale  !!!

Have a good day 

Jacques

Jacques,
Now, in the hope that the mast position can be accepted, I have drawn  a taller sail, taken from The Johanna 60 series of master sails, with AR = 1.98 (instead of the previous 1.89).This is about the tallest sail I dare to suggest. In case you will do most of your sailing, crossing oceans, I suggest you go for the lower version.

Arne

(..full size diagram under Arne's Sketches, Section 8 - 36...)

Now I had a go.
Unfortunately, to get the CE where it was in the Bermudan rig, The mast had to move a bit further forward.
The alternative would be to shorten the battens and make a taller sail, or even rake the mast forward.

If you can live with the shown mast position, then this sail will be good. A slightly bigger version (B=4.90m) (almost the same...) of this sail is already in use on two other boats, Boudicca, and Ylvi.

https://bit.ly/3GSvilq

Arne

(..full size sailplan in my album; Arne's Sketches, section 8 -35...)

Arne , Sorry