Arne wrote:
Thanks, David for the numbers, most interesting.
I notice that she shares some main dimensions with the Alo 28, Johanna. She have about the same length and beam in the waterline, and almost the same displacement.
The difference is that Johanna has 1400kg finkeel and the SibLim design has about 40cm wider beam over all than the Alo.
From the numbers it appears that the outside keel is 791kg and then there is 400kg inside ballast. Was FanShi actually built this way?
Another thing; the vertical CB of the whole underwater body is given as 0.41m.
Then the vertical (z plane?) COG of the whole boat is 0.761m, or well above the waterline. Does that mean that she is unstable within the first couple of degrees heel? Practical sailing has already shown that this is not a problem. I am just curious if the description ‘corky’ could have something to do with this.
Arne
Now I'm back into Freeship, and I can update these numbers.
The draught of Fanshi is 71cm and the all-external ballast is 1218kg. The vertical CG is given as 58.7cm, but this is measured from the baseline which I've set at the lowest point of the hull, so that actually, it's around 20cm below the DWL.
And another point: this calculation was without the mast, sail, battens, parts of the fitout, equipment, personal items and stores, etc, which will have raised it to be at or just above the DWL, as is normal for sailing vessels. A motor vessel with no rig and no need for stiffness under sail will have its CG designed to be much closer to the metacentric height, so as to slow down the roll and make the motion more comfortable and less 'corky'.