Hinged centerboard

[rick perkins]

[JohnMurrell]

But have you actually seen the damage that can happen when a Twelve bears off mark rounding in a bit of a blow, the crew can't get the board up due to the pressue ,the helm loses it and the boat hits the beach flat out? I hava and the result is the board 6 inches back through solid mahagony and Linton spending 3 months scratching his head working out how to mend it; sure foam might slow the destruction process down a bit but I think the boat bodgers would be kept in beer and crisps for quite a while...............

Possibly we need to talk to Bernie Ecclestone and borrow the FIA crash test rig and do some trials - anyone fance lending their boat for a couple of months? Can't promise its condition on return though!!!!!!!!!!!!!!!!!!!!!

[Derek]

I did not know anyone had ever made a plate with a hinge IN IT.
The rules say a plate must pivot about a single fixed point.
This is because during the dagger-board "debate" a structure was put together that allowed a centre-board to be fitted to a pair of vertical tracks either side of the plate case, thus still complying with the pivoting requirement, but behaving like a daggerboard.
As has already been posted there is also a precedent off an offset pivot or hatchet arrangement where the pivot is as low and as far forward as possible in the boat in order to minimise the required length of the plate case and the carried water. In extreme cases this involved a pair of fabricated arms that passed either side of the mast.
Dave Peacock was at the origin of most of these bits of whacky engineering.

I do not think there is anything to stop you putting trim tabs or foils on you plate if you can get them stowed to allow the plate to house.

[Richard Colley]

Mr Fatman 3135 was an experimental boat that I bought from Rob Peebles originally designed to be fitted with a pivoted dagger board box.

Essentially, this was a "signal arm" that I had made of a stainless steel box for the dagger board to move through up and down and this box was attached to a lever which connected to a pin. Visually, think of an axe with the  head being the dagger box and the bottom of the wooden handle being the pivot point. The board would move up and down through the axe head. The pivot point was low down.

The board could act as a traditional centreboard rotating up and down, or when the box mechanism was left down the wooden board could be retracted up and down when down wind moving the board point forward.

Main issues were the board was a loose fit in the box and you still had the water in the centreboard slot. The mechanism also cut the crew and helm to bits!

Unfortunately, I moved abroad before I could perfect the mechanism. The centreboard was subsequently replaced by a traditional board by the new owner.

I am not sure if it would be legal now.