Just Trimarans

[beau]

mudnut, if you give me your personal email I will send you details.
I can't post them on this forum just yet. Some aspects to my design are unique and maybe patentable, at least I want to keep that option open for the moment until final testing. If I post them to this forum i lose any potential for possible patent protection.
I will post the details eventually.
The basis of the design is a hull form that produces very little wave drag. No bow wave is formed even up to 20 knots. So effectively the "rule" of displacement speed = the square of waterline length X1.34 is irrelavent.
I have tested the theory in boats up to 15 ft long so far, but now comes the "big" test.

[beau]

Sailing Trimarans is nothing like sailing mono's.

They are a multihull and sail similiar to a cat.
For some reason cruising multihulls used to be mostly trimarans and now cruising multihulls are now cats.
i think we will see a change back to trimarans for cruising over the next few years.
Modern designs of Cruising trimarans, remember i said cruising not racing, are much better from a practical point of view (in my opinion).

I just don't like the two narrow tubes and all the living area limited to the bridgedeck. With a decent tri design the interior layout is similiar to a Mono without have to go "down below"
I think there has been too much emphasis on racing and speed in multihull design which has limited the more practical aspects of a cruising multihull design.

As i have said earlier, to have a practical cruising cat you really must be over 40 ft to get the right balance betwen bridge deck clearance and headroom on the bridge deck. That costs a lot of money.
Plus if you are cruising you do not need the standard layout of 40 ft cats of 4 X double beds??
A 40 ft trimaran with accomodation only in the centre hull can be built far cheaper, and you can go double decker.
My design (beau's boat) is a motor sailor, with a shallow draft (9 inches)
Two Outboards because they are much cheaper and lighter than outboards.
I have owned 14 boats, mono's, cats and tri's and I am totally convinced that for low cost practical cruising for two people, tri's are the best compromise.
Plus I can put mine in a 40 ft shipping container and send it anywhere in the world.

[BillAU]

G'day Mudnut,

I too want to retire to a Tri (hopefully before I cork it) but convincing the wife of that being a great idea...Well mate...I'm still working on it
I'm guessing you're in Queensland...That's where I want to return to, Bundy anyway, as I'm still working on the wife, here are three Tri's that take my fancy, if you like any of them you could go check them out mate.

First is a 38' (almost) Mashford
Boats for Sale - Yachts for Sale - Used & New Boats @ Yacht Hub Australia & New Zealand

Second is a Jim Brown Searunner 38'
Boats for Sale - Yachts for Sale - Used & New Boats @ Yacht Hub Australia & New Zealand

and third is again a Jim Brown but this time a 40'
Boats for Sale - Yachts for Sale - Used & New Boats @ Yacht Hub Australia & New Zealand

After receiving a lot of advice from other members of the forum, these are the type of Tri's that interest me...And they're all in Aus
Cheers mate and good luck with it. Let me know what ya think of these Tri's if ya get to have a looksee

Bill

[farotherside]

Originally Posted by BillAU

Second is a Jim Brown Searunner 38'
Boats for Sale - Yachts for Sale - Used & New Boats @ Yacht Hub Australia & New Zealand

and third is again a Jim Brown but this time a 40'
Boats for Sale - Yachts for Sale - Used & New Boats @ Yacht Hub Australia & New Zealand

Erm - Bill, correct me if I'm wrong, but those two are the same boat.

At least, the only difference I can spot between the boats in any of the photos is the color of the upholstery in the salon.

Maybe they're different boats but somehow the photos got mixed up? I've done a fair amount of "research" on searunners over the past year or so and I've never come across two setup quite so similarly... right down to the same stuff sitting on the bridgedeck windowsills...

[Mark424]

Originally Posted by beau

Modern designs of Cruising trimarans, remember i said cruising not racing, are much better from a practical point of view (in my opinion).

I just don't like the two narrow tubes and all the living area limited to the bridgedeck. With a decent tri design the interior layout is similiar to a Mono without have to go "down below"
I think there has been too much emphasis on racing and speed in multihull design which has limited the more practical aspects of a cruising multihull design.

As i have said earlier, to have a practical cruising cat you really must be over 40 ft to get the right balance betwen bridge deck clearance and headroom on the bridge deck. That costs a lot of money.
Plus if you are cruising you do not need the standard layout of 40 ft cats of 4 X double beds??
A 40 ft trimaran with accomodation only in the centre hull can be built far cheaper, and you can go double decker.
My design (beau's boat) is a motor sailor, with a shallow draft (9 inches)
Two Outboards because they are much cheaper and lighter than outboards.
I have owned 14 boats, mono's, cats and tri's and I am totally convinced that for low cost practical cruising for two people, tri's are the best compromise.
Plus I can put mine in a 40 ft shipping container and send it anywhere in the world.

I wonder if you could point to examples of some designs. Even the cruising designs seem to really skimp on topside living space, unless you go way back to the 45+ footers pre 1980, then you get big 5 bedroom machines that I have a hard time believing are that fast. e.g.
1978 Cross Pilothouse Trimaran Sail Boat For Sale - www.yachtworld.com

I've sailed lots of monos and lots of cats, but never a Tri. In theory the tri could have advantages, as you say, a single hull with more volume and thus elbow room. I'd be happy with one big queen/king berth and one big shower/head. I like the roll stability of a mono (as apposed to the snap rolls of a cat), but prefer the speed of a multi which allows one to sail in harmony with the seas instead of constantly being pushed around by them (on a slow mono). Is the roll stability of a Tri closer to that of a mono or cat? I would guess that that older pivers, browns, and cross' are closer to a cat, and the racers with smaller amas are closer to a mono....? Maybe the answer is an ama with less reserve buoyancy?

Lastly, and perhaps most importantly, I just don't see many Tri designs that have the glorious living space that the cockpit of a cat affords. Pick any 38-42 cat, L380, Privilege 39, Maine Cat 41, and on and on. As Kai Nui pointed out, must people spend <20% underway, and lounging on the nets the rest of the time doesn't really cut it. Maybe one doesn't really need all that space, but many tri's have essentially mono cockpits on them. Hardly a place to spend 80% of your time in any comfort.

I'm not trying beat up Tris, as I said, in theory I think they offer the potential for an optimal combination (especially if as you say they are half the price to build), I just haven't seen that many really good performance cruising designs esp in the 40' range. Do you really need to get closer to 50' (hammerhead, exception, condor) to get something livable?

The Exception 52 is interesting, but is probably bigger than it needs to be. They reference an "Exception 43", but I can't find info about it.
1986 PINTA Trimaran Exception 52 Sail Boat For Sale - www.yachtworld.com

[BillAU]

Originally Posted by drew23

Erm - Bill, correct me if I'm wrong, but those two are the same boat.

At least, the only difference I can spot between the boats in any of the photos is the color of the upholstery in the salon.

Maybe they're different boats but somehow the photos got mixed up? I've done a fair amount of "research" on searunners over the past year or so and I've never come across two setup quite so similarly... right down to the same stuff sitting on the bridgedeck windowsills...

G'day Drew,

I was thinking the same thing about the two SeaRunners but as they are both a few thousand KM away from my place, I have been unable to get away to check on any of them, my wife is not in the best of health so I can-not leave her on her own for any length of time.

If the agent has used the same pictures to promoting the two SeaRunners...Well...That just strengthens my views of agents...Do little but charge big heaps.

Still, it would be nice to know for sure, just which SeaRunner is in the picture

Cheers mate,

Bill

[Maren]

I've sailed lots of monos and lots of cats, but never a Tri. In theory the tri could have advantages, as you say, a single hull with more volume and thus elbow room.

Umm, no. Tris have less interior space (in the vaka) than a mono. And with a Searunner, as much as I like them, this is even more true. Here's why: an aft-cockpit mono (or tri for that matter) has a long sight line which gives an impression of space. You can see from the cockpit (or at least from the companionway) to the v-berth on most boats. So can see say 20-30 feet on a 36' boat. On a Searunner you might get 12' and 10' for the for and aft sections. Things seem smaller. Also, the finer hull of a tri yields less volume. You make up for this partly by have lots of storage in wings and amas but there are a few limitations already mentioned -- relatively light things go in amas.

So a tri will have less volume than a mono, what about a cat? At about 40'+ the volume is about 2x the interior volume of a mono.

You might wonder why you would want a tri since you have the disadvantages of usable volume at the price of width. The answer is threefold as I see it: speed, stability and price. Keep the weight down and you'll fly; this is easier since you don't have the percieved space to fill up with junk. Stability is a cross between a mono and cat. The max righting movement is about 15 degrees, compared with 5 for a cat and 90 for mono. The motion is also as the amas act like a damper. Price is largely a factor of popularity and the fact that many are owner built.

I'd be happy with one big queen/king berth and one big shower/head.
...
Lastly, and perhaps most importantly, I just don't see many Tri designs that have the glorious living space that the cockpit of a cat affords. Pick any 38-42 cat, L380, Privilege 39, Maine Cat 41, and on and on. As Kai Nui pointed out, must people spend <20% underway, and lounging on the nets the rest of the time doesn't really cut it. Maybe one doesn't really need all that space, but many tri's have essentially mono cockpits on them. Hardly a place to spend 80% of your time in any comfort.
...
Do you really need to get closer to 50' (hammerhead, exception, condor) to get something livable?

I excerpted the above because I think it highlights what I am about to address next. I'm going to stick with the Searunner but cross apply whatever elements fit for other makes.

Searunners are classified as cruisers but better classified as Water boats">blue water boats. The king berths and giant cockpits are more like coastal cruisers. 40 years or so ago this wouldn't be an issue as most people lived in smaller houses. But as people have gotten used to having more space, they expect it now in their boats too; there just aren't that many people who have literally grown up on boats and most are lubbers of one sort or another. We see this in all aspects of boats monos are now larger as whole, cats with their tennis-court sized decks are more popular than ever. To a certain degree this is true for tris.

I'm not saying a Searunner is a "real sailor's boat"; I like monos cats and tris, just for different reasons. But tris appeal to sailors who want some speed and are willing to sacrifice a bit of space for it.

Cheap, fast & spacious. Pick two.

[DaveOnCudjoe]

Maren makes a valid point. For me , the quality of life is inversly proportional to the amount of stuff I have. My 31ft Farrier Trimaran is spartan for sure but has everything I need. It can only carry 1500lbs but that's enough. Standing headroom below,16in draft with boards up, ocean capable and fast. Much has been said about the wet ride, at 20knts what boat is dry? If you want to stay dry just slow down. Beam is 22.5ft but these boats fold. Fold 1 side,16ft, fold 2 sides,9ft. Dave

[Mark424]

Originally Posted by Maren

Umm, no. Tris have less interior space (in the vaka) than a mono.

Thanks for the comments, I was not very clear. The point I was trying to make is that one should get more elbow room in the tri than in one of the hulls of a cat. On most cats with 3-4 staterooms in the corners, I can imagine living in one hull and using the second for guests/storage. Thus the theory would be that I'm better off having one hull with more beam (although not as much beam as a mono), than having two narrow hulls on a cat. In some designs it appears that the centerboard trunk and mast can break up the space a bit.

Originally Posted by Maren

40 years or so ago this wouldn't be an issue as most people lived in smaller houses. But as people have gotten used to having more space, they expect it now in their boats too; there just aren't that many people who have literally grown up on boats and most are lubbers of one sort or another. We see this in all aspects of boats monos are now larger as whole, cats with their tennis-court sized decks are more popular than ever. To a certain degree this is true for tris.

I find the vast majority of designs attempt to cram more quantity (berths, heads, etc) at the expense of quality and livability. My theory is since slip costs are so high that's its one of the largest costs of owning a boat, people are trying to pack as much as possible into shorter boats. There is also an obsession with privacy that you didn't see in older boats. e.g. the need for every berth to be in a enclosed space. all those walls, doors, extra heads, sure break up the space. At 6'4 I'd prefer one decent berth and head to 3-4. As for cockpit space, one of the joys of catamarans is the ability to spend most waking hours in the cockpit vs below on a mono.

Apropos of nothing, just ran across this quasi-tri called the Manta Clipper - had never seen this design before. I wonder how it performs or what how a 40' version might do.
http://cgi.ebay.com/ebaymotors/ws/eB...ht_8163wt_1161

[BillAU]

Originally Posted by Mark424

Apropos of nothing, just ran across this quasi-tri called the Manta Clipper - had never seen this design before. I wonder how it performs or what how a 40' version might do.
34' 1992 MANTA CLIPPER TRIMARAN:eBay Motors (item 270456570184 end time Sep-21-09 13:46:24 PDT)

G'day Mark,

As the link you provided seems to be busted or the Tri is no longer listed, have a look at this one:
1992 34' Manta Clipper - Brewer Yacht Sales
It may be the same Tri and at just under $50,000, or best offer, I believe it would be value for money...for someone like myself
But as I reside in Australia, any Tri located in the States is beyond my reach at present.

Cheers,

Bill

[beau]

I have tried to approach boating design keeping in mind the following principles.

There is no rough weather if you don't have a schedule.
Most cruising is downwind.
You don't start out in 25 knots of wind, you wait until the weather is calm, which means you have no wind to sail anywhere anyway.
Which means you motor.
If the wind picks up and it is behind you, you sail.
If it picks up to a point when you are not comfortably sailing, you motor.
If the weather forecast changes significantly from what you expected, have the speed available to get to a safe anchorage or get out to sea and ride it out with a sea anchor.

Keeping these points in mind I will need a fast displacement hull, big motors and a simple sail rig. (downwind only) for comfort at sea, the longer the hull the better.

The next important aspect of a boat design for me is a shallow draft and beachable. It allows me into moorings generally not available and maintenance and allows for safer travelling around sand bars and coral reefs.

Liveaboard with a female partner. Which means headroom, a proper shower with hot water, a separate toilet. Full cooking facilities which include microwave and oven. A decent size fridge and a freezer ( must have ice for sundowners)

I only need space for two, and it must be inexpensive.

As the above items were necessary, I became aware that the boat could not have a keel so it would have to be a multihull either a cat or a tri.?

As I have said before it is difficult to design cruising Catamarans under 40 ft in length. And they are expensive.

I found that I could design a trimaran under 40 ft with everything i need to live aboard and cruise. And it didn't cost a fortune.
My boat is nothing like the earlier "searunner type" or fast sailing Corsair/dragonfly.
It is a motorsailing monohull with stabilizers (trimaran)
"Beaus' Boat", Is still under development (after living aboard for 18months)
I am increasing the size of motors to 2 X 60 Mercury bigfoot fourstroke outboards and replacing the folding outriggers to a permantly fixed 15 ft wide outriggers (monohull with stabilizers) 39 ft X 15ft and it still fits into a monohull berth and inside a 40 ft shipping container.

New photo's and test report soon.

[ramminjammin]

I just spent one week in a 40 ft tri and now I just have to buy one
We passed all monohulls, and a 46 ft warren cat , crusing from sandy hook to atlantic city ,
sailing into ac doing 15 knots on a 40 ft by 24 ft platform was simply exhilirating , it had my attention like doing 150 mph on my R1 yamaha

I'll take a little less "fat" space below to see =20 knots !!!!

I dont think the c&c 39 I crew on could ever provide the same speed thrill

[SailFastTri]

Originally Posted by beau

snip
It is a motorsailing monohull with stabilizers (trimaran)
"Beaus' Boat", Is still under development (after living aboard for 18months)
I am increasing the size of motors to 2 X 60 Mercury bigfoot fourstroke outboards and replacing the folding outriggers to a permantly fixed 15 ft wide outriggers (monohull with stabilizers) 39 ft X 15ft and it still fits into a monohull berth and inside a 40 ft shipping container.

New photo's and test report soon.

Beau I'm very skeptical of the sailing safety of a 39x15ft tri with floats "as stabilizers". No issue with motoring stability, but sailing is the concern.

[DaveOnCudjoe]

Ramminjammin, Welcome to the club,what took you so long? The speed is addicting but there is a dark side, limited ability to heel means that loads can become huge quick. Unfortunately they are just as stable upside down as rightside up and worse of all because you can sail right up to the beach the babes are always wanting to come aboard to relax instead of rowing out to the boat they came on. Dave

[senormechanico]

Originally Posted by SailFastTri

Beau I'm very skeptical of the sailing safety of a 39x15ft tri with floats "as stabilizers". No issue with motoring stability, but sailing is the concern.

Me too.

My Dragonfly 1000 is 33' x 25' but I've been in a few situations where stability was iffy, i.e. a sudden wind increase and shift.

Steve B.