Here
is a good centerboard idea that is not too well known. This configuration
originated on the International 14 class boats. It was
probably an Uffa Fox idea and a darned good one at that. Sandy
Douglas used it on the Thistle, the Highlander
and the Flying Scott.
Because I haven't done plans on this 70-lb. Blivit 12,
I thought that some sketches & photos to document the technique
might be worth while.
The
troublesome hinge pin is not required. . . the board simply drops
down in the slot and rests on rollers that run on a curved track.
There are matching radii on the forward bottom of the trunk and
the forward end of the board. This configuration provides an action
similar to rotating on a pin.
The
result of all of this is that leaks are eliminated and the board
is easily removed. It still retains all of the swing board characteristics
and needs to be weighted. Therefore quite a bit of force is needed
to raise the board so some kind of tackle is required. The simple
lift out feature makes it ideal for car-top boats, especially
on my Geodesic Airolites.
NOTE:
If this looks too complicated it probably is - and you had best
forget the whole idea.
NOTE:
Seal inside trunk and top surface of roller tracks with double
epoxy coat.
SUGGESTION:
Make a fullsize cardboard pattern mockup of trunk side and board.
Use a 2 1/2" diameter bottle/jar cap for a roller pined to
the board. Now check the actual shape by rolling it against teh
2" radius of item 4.
RIGGING:
The line for a four part tackle starts at an eye at the mast step.
It goes back and forth from board to step with three truning blocks
located ath teh step. Adjust and secure it to a cleat monted on
the top ot the thwart (as seen in the first photo.)