Power trimaran

During the phase of conception of our actual boat we think
'power trimaran' but for example this type of boat designed by Nigel Irens are 'too light' displacement for us, we saw on 'boat design' one built in Asia also too light for our type of cruise .
We found also one project made by Kasten 'Penny wise'.
But until now we don't find what we are scearching .
Did you know desigs made for 'passagemaking' ?
Because actualy we are trying to sold our 'long-cours 62' and 'in case' the next one could be a power tri for check if it is god or not.

My limited understanding of tri's over cat's is that they have a greater load capacity....and the structure to the amas can be less robust than the structure holding a cat together...but those are some gross generalizations.

Other than beating the length to beam ratio for speed while adding some stability...and possibly more deck space.....I'm not sure all the complexity and building costs are worth it.

But I'm open to learning more about the adavntages/disadvantages...

Sure the volume

will be ridiculous compared with the lenght !
But in another hand the 'efficiency' could be very god (if not too heavy)
And the weight is alway our problems when we make 'projection'
Because we just know the metal work and even in alloy for crossing an ocean the minimum structure and tickness we feel right for this use is 'heavy'
For example full loaded 46000lbs for a lwl of 72 '

I think the future of long distance powerboating is motorsailing if you are concerned about fuel economy.

Long thin hull verses wide, masts on tabernacles, active fins and or daggerboards....think fast sailboat bloated just enough to satisfy trawler comforts.

Motor Sailer the original hybrid

Surface piercing trimaran , fast wet and economical to run. I saw a aluminum experimental 60' or so on the SF Bay 10 years or so ago. Amazingly fast and very weird. I could never find out anything about it. It didn't strike me as being very livable.

longcours62 said:

During the phase of conception of our actual boat we think
'power trimaran' but for example this type of boat designed by Nigel Irens are 'too light' displacement for us, we saw on 'boat design' one built in Asia also too light for our type of cruise .
We found also one project made by Kasten 'Penny wise'.
But until now we don't find what we are scearching .
Did you know desigs made for 'passagemaking' ?
Because actualy we are trying to sold our 'long-cours 62' and 'in case' the next one could be a power tri for check if it is god or not.

Click to expand...

What is your type of cruising and why do you like the power tri? What brand/model and size? There are pluses and minuses. Passagemaker magazine has some advertized as Tri Trawlers?

I also think mono motorsailors are going to caught on for long distance coastal/open water cruising. A cross hybrid of a trawler and a sail boat that has more space/living area. So have you thought about adding sail to your present boat?

This is going to be another long long discussion.

We use our boat for

living aboard (during the last 37 years we just living 6 years in house)
voyaging (not enought !)
I like the form of the "old" Cables&Wireless photo 1
The second I like the look but not "useful' all this nice slipery design 2
On the third may be not enought use of the surface of the 'arms betwen hulls for exemple you could have a normal sized deck saloon and wheelhouse on a narrow hull if you use the possibility of extend the roof on
the arms (sorry if Iam not clear but explain with limited vocabulary it is not easy )
This drawing , I tinking, lost a part of the benefit of power tri 'too hight' 'too deep' look too much trawler :EXOCET 18 trimaran transocéanique à moteur - EFI Bt conception de bateaux de plaisance et petite servitude
Photos 4 and 5 may be not very elegant
Photos 6 too big roof
For choosing a power tri for voyaging I think we must keept something
elegant, not want a fabulous top speed, clearly understand for a volume of a 13 m motor boat the must moove a too big platform just good for open sea and remote anchorage (not golfe of St Tropez a 15 August)
But it could be interresting to cruise at ,said, 14/15 kts with a range for crossing an ocean,possibility of use something like 'skysail' or one more conventional small mast.
For a couple 21 m lenght beam of the main hull at the deck level 3 m at waterline a small 2m , draft less tha 1 m, beam overall 7/7,5 m air draft betwen 2,5/3m , one single engine 200 hp and the weight ....it is my problem I can doing that at less than 44000 pds

Thanks for the picture as I was not thinking of the tri's in the photo. To few of them and futuristic for me. Have you looked at the Windhorse.

http://dashewoffshore.com/do_paradigm.asp

Some what the same but a mono hull, but low profile, long and narrow beam. However they use fish stabilizers instead of pontoons. There have been past discussion and article written with many featured articles in Passagemaker Magazine.


So if you welded the out rigger/pontoons to your boat you would basically have the same thing? I am not sure how stable they would be for coastal open ocean cruising and being so light. Being old I am stuck with the full displacement mono hull, long, narrow beam and heavy with sails of some kind of sails.

There are a lot of sailing tris out there.

Having raced trimarans and catamarans I find the tris to be easier and safer. Less pitch polling. Many sailing trimarans cruise in the high teens and in the 60' plus size are spacious. Why not build a underpowered sailing tri. There must be many french designs already being built.

58 ft converted motorsailor

This is a picture of the Dorothy June a 58 ft sister boat that sails where added. They also added a command bridge as the original 58 ft did not have. However they did come with a forward mast so the 58 ft is set up. They were planning for cruise down the east side coast, through the Panama Canal and up the west coats. They sold the boat and last I heard it was in the Panama Area. Anyway sales can be added to some trawlers as an option.

The question is are you willing to give up weight to gain higher cruise speeds?

And accept the harder docking requirements (need 20, 25ft wide slip) and limited facilities?

While the long skinney boat will be cheaper at higher speeds , its mostly cheaper than a fat boat at the same speed.

I would contemplate the range required , and the fuel required to go that distance.

If the speed is worth the higher fuel burn , and you have the range , why not?

I had a sailing try built in then British Honduras in the mid 60's.

The ride was grand in the ocean , but as a sail boat the speeds were only marginally better than a lead sled as the wind speed required for better performance (15+K) made the ride fairly uncomfortable .Seldom was 20K of breeze and smooth water seen.

Cats for coastal, Try's for trans ocean is still a good concept.



FF

Over the years I have noticed North American backyards and moorings littered with cats and tris, someone's dream yacht not come true. Last month in Northern NZ I saw the same. The reasons are simple, less seaworthy in big rolling seas (hull tripping, a real unfortunate phenomena) than a mono hull and not cost effective to build or dock. Not to mention who wants a second hand backyard one of a kind cat or tri?

The charter markets are the great advertisers, or better put for the warm water markets. Last summer I noted a lovely 40 something power cat in Shearwater BC and got some interesting insights from the owner. His primary lament was no one builds a power cat for wet, cool weather. Nice boat though and I could certainly see one anchored near St Johns with an umbrella drink.

Perhaps this thread , and noodeling about in the archives will be a help .

There are top designers on this board , the visual display is fantastic of their work.

Some folks have built boats with incredible MPG , but the key is light light light.

Much ungood on a cruiser where some days you raft on a tug,

some days the tug rafts on you!!


Power boat design for economy. - Boat Design Forums

Thanks I have seen that Forum - I am pretty fat with design help and have developed lots of data running the tri. The new boat should have a 400 mile per day range but the SL will be under 2. Been lucky to spend lots of time on light boats (RC44,TP52,RP75)

Talking about lightness and reliability, have you tough about this:

Passagemaker Lite 5602 - Tad Roberts' fast, seaworthy, fuel-efficient long-range passagemaker

Your new building

Boatgm said:

Thanks I have seen that Forum - I am pretty fat with design help and have developed lots of data running the tri. The new boat should have a 400 mile per day range but the SL will be under 2. Been lucky to spend lots of time on light boats (RC44,TP52,RP75)

Click to expand...

is going on ?

Portuguese said:

Talking about lightness and reliability, have you tough about this:

Passagemaker Lite 5602 - Tad Roberts' fast, seaworthy, fuel-efficient long-range passagemaker

Click to expand...

You are right, its a good looking boat.
Chuck Neville helped me with a boat that looked similar to the Passagemaker Lite line.
http://www.nevilleboats.com/stock_plans_jollyman_57.htm
but my boating needs changed so its way back on the burner

The SL 1 of this Boat is 7.,

to run 400miles a day you need to maintain 16,7k 24/7

That is a SL of 2.4 ,right in the middle of wake wallowing , Semi Plaining ,about the poorest efficiency that can be selected.

30GPH? at 17K Might be short on range for blue water?

FF

You lost me _ I was talking about the proa. my tri also does 400/day at less them 1 L/nm