Anonymous wrote:

Bonjour Jacques

In terms of mecanical efforts, the more burry (height between the mast step and the stuck) the best. A rule of thumb is to have a bury of at least 10% of the mast height. 

In your drawing,  the mast step is positionned quite high in regard to the bottom of the hull. 

I would rather put it as low as possible. 

There are at least two different options. One would be to cut the longitudinal plywood reenforcement to give way to the mast, the other would be to move the mast laterally a few centimeters to position the mast against the longitudinal reinforcement. It could even be possible to build the mast step as a tube (as on the laser) that would be glassed to both longitudinal and transversal reinforcement. 

In this case, you would have at the lower part,against the hull, a few glassed layers of plywould to flatten the hull shape and provide a horizontal support to the mast. 

Eric

Anonymous wrote:

Jacques wrote:

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

Here is how I built the mast step on my Ingeborg. It may not be the quickest way, but it is quite straightforward. My main motive was to create the biggest possible glued area between the mast sole and the hull, to exclude any chance of it ever to come loose. I have used this method on 3-4 boats and they have all worked well.

http://bit.ly/2sf2tsW

Good luck!

Arne

Photos : Inside - stuck & mast step draft - How do you feel about this plan?

Jacques, can I ask you where you buy your lamp post ?

Eric writes: "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