Been playing around with multihulls for some time now; various configurations of cats and tri's. Here is latest effort and was intended to use an old One Metre hull with a "bolt on" conversion to a lightweight trimaran. Not a new idea, I know. Paul Goddard has an excellent version based on the DF95.

Anyway, a few pics of what can be achieved with simply printed floats and a few printed brackets. Boat can be sailed conventionally as a One Metre: remove the fin and ballast, clip on the hulls, connect the longer rudder and just sail as a trimaran (will need a stub fin as a centreboard) Or add foils to the outboard brackets and try foiling. This is Mini40 legal but a bit shorter than the max allowed and a tad more convenient.

Weighs in at just under 2Kg all up sailing weight. I have not sanded the printed floats and they are printed in 4 parts. This set was assembled with thickened epoxy, hence the visible joints. I have printed another pair and joined with clear epoxy and will retro fit these after fully testing.

I do not intend to have this measured or propose any "minor" rule amendments to make this legal. Just a good way to use an old IOM hull and have some fun.

Hi Richard, nice development project!  Few questions.

What 1 metre hull is it based on?

Are you printing the pontoon hulls yourself? If not where are you obtaining them?

Foils and rudder source?

What wind speed do you need to achieve foiling? 

If not foiling how large a fin is required? Any ballast? In this mode how does it perform in comparison to its base IOM hull?

I presume a rescue boat is required when sailing in case of capsize. Glad to see your experimental/development is not diminished. Where are you sailing this yacht?

Are you still playing with the American one Metre?

Eric

Hi Eric, This is an old One Metre development hull. An extreme design idea that never really worked. Any One Metre would be good though. With the displacement reduced to sub 2Kg a typical IOM will only be on about half of it's WL and "sitting on it's rocker" hence a manoeuvrable platform as opposed to a full WL. Added bonus of plenty of reserve buoyancy. I am printing the floats and also the X beam brackets and foil / rudder incidence adjusting clamps. 

Not a lot of wind is required to foil, as proven with the same foils on a heavier cat configuration. Light wind -  remove foils and slot a short, stub fin to act as a centreboard. Fit smaller rudder and sail conventionally. No ballast required = very nippy ! Don't forget that only one float is in the water at any time with a low wetted area.

As pictured with the orange prototype floats, the foils are in the fixed incidence tubes and it was apparent that the high aspect rig moment cancelled the incidence. Next sail will see them fitted in the adjustable, outboard, brackets visible in the shoreside pic. Incidence can be quickly adjusted. The rudder is already mounted in the same bracket on the aft beam.

I have a rescue tug (cheaply made from liteply) and will also fit a floater at the masthead to prevent full inversion.

Sailing at Colwick Park, Nottingham.  US One Metre still available and have pinched the rig for the trip. Might give it a go again.