One of our readers recently sent me a link to a trimaran designed by Australian yacht designer Barry Colson. I’d never seen this one and am now able to share a bit more about it, even though it’s not in active production, after hearing back from the designer himself.
I asked Barry a few questions and he sent me the following write-up. The Colson website refers to it as the Colson 580, and below, Barry dubs it the F.A.D. trimaran.
The webpage for this design can be seen here: http://colsonyachtdesign.com.au/colson-trimaran/
Many thanks to Barry for this info! One thing not mentioned in the below is that one of the goals for this boat was to build a cheaper alternative to the Corsair “Pulse” trimaran. Efforts and knowledge gained from designs such as this help others when they conceive new boats now and in the future.
…………………
F.A.D. (From Another Dimension) Trimaran
by Barry Colson
F.A.D. is a 5.80 metre folding Trimaran designed to be built to a budget with simple construction, being fibreglass sheathed plywood built over permanent frames and stringers. The three hulls were basically flat bottomed with vertical topsides and “peaked” foredecks. She had aluminium beams with radiused drops so the beams fit into the ama hulls decks.
Originally built with a swing up centreboard, the lack of buoyancy and drag proved excessive and the swing board was replaced with a vertical centreboard. Various ama boards were tested, initially angled in between the ama and main hulls and installed from outside. Eventually these were replaced with “J” foils slipped in from below and then “Doors’ were built into the inboard side of the ama hulls so they opened up and the ama foils were fitted and the “doors’ closed.
F.A.D. proved an interesting and enlightening test bed for the location, size and attitude of the lifting foils. They worked without a doubt and at times the boat was blisteringly fast and stable, but in low wind speeds the drag was hard to accommodate.
In hindsight the foils were a little big and the hulls a little too heavy. The rig development went straight on to my 550Z “MissUnderstood” being an aluminium Tornado mast with new rectangular UK Halsey mainsail, jib and furling code zero. The folding mechanism was played with and had sliding tubes in pivoting /hinged captive rings set in the edges of the rigid wing deck.
The wing decks were maximum beam (2.49 metres) then trampolines fitted between the wing decks and the amas. The beams slid in until the ama hulls touched the wing deck and then pivoted under the wing deck so the trailering width was 2.49 metres. Opened out she was 4.0 metres beam.
The steering system was innovative with a short tiller on the cassette mounted, swing-up rudder then dyneema cables lead under the full width mainsheet traveller to a separate tiller hinged on the traveller beam at deck height. The cables were tensioned with rigging screws.
In the end, the time to rig was a draw back and it became apparent that whilst I could open her up and set up myself it was not going to be sustainable in my older age with a permanently damaged Achilles tendon on the trampolines and the Farrier folding mechanism is hard to beat.
