Folding trimaran

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Neil

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As part of my self-education in the world of yachts, I have been trying to understand the pro's and con's of the various makes and style of boats. The monohull/catamaran debate that surfaces now and again seems to polarise around the stability (up to a point?), speed and accommodation of the cat vs expense of mooring (and maintenance?). What was the monohull advantage again? Well, potentially more seaworthy in v. heavy seas, easier to tack, I suppose. I'm sure someone could remind me.........

But then I thought about a trimaran. For example, a Dragonfly, which has the advantage of having folding pontoons, making the beam little more than a monohull when withdrawn - similar mooring requirements? No keel, easy for canals?, can be beached. Accommodation is probably that of a narrowish beamed monohull (poor?) so you need the length, getting expensive? (3 'hulls' and longer than the normal requirement).

If they are so good why aren't there more of them?

But a potential 20knts gets the juices flowing......Pop accross the pond in no time!
 
Yes, about Euro 260K +VAT for the 35 footer! How does that compare to the premium brands such as HR or Oyster? (they don't seem to publish prices - if you have to ask, you can't afford it!).

I did ask if there were other considerations apart from price!
 
Neil said:
Yes, about Euro 260K +VAT for the 35 footer! How does that compare to the premium brands such as HR or Oyster? (they don't seem to publish prices - if you have to ask, you can't afford it!).

I did ask if there were other considerations apart from price!
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You can get a HR 34, with loads more space, for a lot less!

But... if you have ANY DOUBT about why a Dragonfly 35 is worth every penny...... watch this... http://sejlsport.tv/dragonfly/pages/df35_ultimate/df35moov/df35mov_full/index.html


I want one.
 
Tony Smith's 26' Telstar model (1970's?) was loads cheaper, but really only a glorified weekender. I had a serious look at them at one time, but never got over my concerns about any joints or hinges in a mixture of seawater & air.

Tri's have limited accomodation in the central hull as the ama's are generally too small for standing headroom & access is likely to be external via a trampoline or the beams - not good in bad weather. Enormous stresses generated by the twisting forces of wave action too.

All multis tend to be very sensitive to overloading as well.
 
Neil said:
If they are so good why aren't there more of them?
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I have owned boats with 1,2 and 3 hulls. The tri was a great sea boat and very fast. A reaching speed of 14 knots made for very quick passages. The downsides are very significant though.

My tri had the same external dimensions as my present cat - 12m LOA, 7m beam but the tri had a displacement of 3.5 tonnes compared to 5.5 for the cat and 14 knots compared to 10 in fresh reaching conditions. The big problems are weight - you can't add much load to a fast tri before it slows right down - and accommodation space.

There is a forumite who still sails an identical tri to mine but has loaded it down with an inboard diesel and a lot of cruising gear and it now goes no faster than my cat but still has only 1/5 of the space below decks I enjoy.

The other big drawbacks with things like the Dragonfly are the astronomical cost and the worry over the reliability of the folding mechanism. If the lee outrigger folded at sea, the boat would flip instantly. It's held out by wire stays and, having had a wire break on me at sea through fatigue, I could never relax.

Having said all that, If I could afford aDF35 for cruising around Britain and the near continent I'd have one like a shot. If you decide to get one though, don't go making passage plans that involve 23 knot averages!
 
We bought one of the last Telstar's from Tony Smith in 1980 and used her on the East Coast, she was ideal for the area , dry out upright at the top of creeks etc. We also towed her to Spain and cruised for three months, so if you want to try out three hulls on the cheap buy a good one, if you do not like it you can sell and maybe not lose money, good luck.
 
We have the old style Dragonfly & I think probably its the most fun we have had on the water - lots of compromises of course (I still have a penchant for something big solid preferably with an aga - pilot cutter or something similar IE the other end of scale)

For coastal cruising ~ & i have been pleasantly surprised by the way a small tri handles both stronger winds & confused sea states (Rolling well spaced swell generally a ball by the way) ~ it suits us well.

We accept comfortable (cramped maybe?) camping, pick the weather to a degree, tuck into 12" of water or park on the beach & can always fold - a bit of a pain - if need to marina.

Daily range expanded by about a 1/3rd & as genuine outboard auxillary you generally sail the boat (same as a dingy) & by the way the later tris sail great balanced, fast & predicatable -

We are not planning on crossing the Atlantic so suits what we do at the moment. For a larger / longer range boat Chris White etc have the designs & a proven record & can make a case for safety / strength.

I have had thoughts/concerns about inherent strength (Standing by to be flamed) but firstly I am generaly converted to the "strong, light stayed / engineered structure" (Some manufacturers do seem to have better systems for this than others - I'm saying no more on that its a sep debate) & secondly I know what I want from our boat (3rd = luck)

- I think in summation I have enjoy the "lateral" -sorry- thinking in the design & use of multis. The sailling is obviously the same pleasure (certainly more of it for me) but there are a host of additional considerations & knowlege to aquire which I think will mean that any future boats we may have are very unlikley to have less than 2 or 3 hulls. Having said that was eying up well priced 30ft 1 off mono the other day.#

Oh & sailing flat is a great wife/child pleaser & much safer. I like life @ 20deg heel & the boat bending with the wind but it doesnt beat the acceleration as the windward float lifts & 8 - 9 - 10 - 15 knts come up on the log with a 7 yr old on the helm.
 
Not all folding tris can be folded on the water. Some fold by tilting the floats inward so they are convenient for trailing but no use for taking a monohull berth in a marina. I have even come across a design where the floats fold inward 90° and have wheels installed at gunwhale level so they can be rolled up a beach when folded!
 
I had assumed that the 25+ kts capability was on flat seas!

I think I would have a concern in heavy seas, at any decent sort of speed, that if one of the outriggers ploughed into a heavy swell it would either snap off or pull the boat round in some sort of alarming fashion. Are you limited to displacement speeds in heavy weather?

However, I'm sure the designer is a better man than me and has addressed the issues? How many are there and what is their real-world experience?

You never know, it could be me! (if I ever did the Lotto!)
 
Neil said:
I had assumed that the 25+ kts capability was on flat seas!

I think I would have a concern in heavy seas, at any decent sort of speed, that if one of the outriggers ploughed into a heavy swell it would either snap off or pull the boat round in some sort of alarming fashion. Are you limited to displacement speeds in heavy weather?
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Far from it. The floats present very little resistance so will plough through anything. The dangers are things like pitchpoling as a result of overtaking the wave in front or stalling on the face of a large wave when close hauled and digging in the lee stern. One large tri actually capsized over the beam when the self-steering put the helm down in a big sea.

A tri can be more comfortable in a chop if you drive it hard rather than slow down to monohull speeds.
 
There are a couple of Telstars locally. They are on river moorings so don't need to fold, but since they are still in regular use there was clearly nothing wrong with the basic construction. One was for sale on ebay several times a few months back but I don't recall what finally happened to it.
 
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