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Old 01-10-2015, 13:38   #1
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(heavy) overloaded Trimarans... where are the limits ?

This thematic "overload" is a common topic within the world of multihulls. I suppose it has been discussed tremendously here and there in this forum.



I am very aware that cruising catamarans over time can become heavy overloaded with all that "memories" the cruisers bring on board during their stop-overs. Quickly come together 4-500 kg per year.... and the speed is gone, sucks the stern heavily.

The potentials (speed + safetyness) which are given by the designer of multihulls are based recently on light displacement building methods (compared to heavily keel-weighted monohulls).

More sensitivly than cats react the three hull compagnons. Trimarans loose their potential speeds quickly if the boat builder is not taking care the materials he is using or and the owner is storing lots of equipment (e.g. heavy diesel engine, big tanks etc. ...).

As I am in midth the process to look for a Trimaran (living + working) I ask herewith:

Does exist a kind of "table" to get an orientation about what the maximum weight/displacement shall be ?

E.g. by experience I can say that 40 Foot trimarans are built round about 3.5-4 tons. A 50 footer estimated at 5-6 tons.

Is there a (more scientifidally proofen) matrix, given by four main parameters to define the max. weight / displacement ? (A kind of table would be helpfully)

- length (water line)
- width (beam)
- mast (length)
- sails area (main sheet + jib/genua)

To give an example: actually I have a sales offer for a 36 foot (LWL) Trimaran (LOA: 37', Beam: 23') with a newer 40' Aluminium mast 20 years after it was built. The mast was designed by one of the most renowned multihull specialists: Lock Crowther.

The Trimaran was built professionally (cold molded) by a boat builder and launched 35 years ago who had built different Trimarans, and some bigger ones in the range of 40-50 feet.

The boat is well proofen (practically) and has an excellent survey... which gives the amas a 180% reserve buoyancy.

It was sailed two handed long distances: e.g. from San Francisco to New Zealand/Australia, from Alaska to Hawaii (and back) etc. ...

It seems a very robust boat. Maybe too robust loosing its potentials of speed ??? - The official papers list a "net tonnage" of 10,000 kg. The discplacement is ~6,000 kg.

It is not to expect, that the boat needs any further equippment as it is fully equipped: from 2x autopilots to 2x anchors incl. parachute anchor, 2x roller furling (Jib, Genua) beside 3 reef main, watermaker / water tank">fresh water tank with 2 water pumps, icecube maker/frigerator, 4 burner stove (with oven), head with sink and vaccuum toilet, solar + wind generator, fully security equipment (life jackets/life belts, automatic Halon fire extinguisher in the engine compoartment of an 18 hp saildrive and others), Radar/Epirb, all navigation electronics (speed/log, VHF, GPS, Deep sounder, compass) and 2.85' inflatable dinghy with 6 hp outborder.

Is such a heavy boat a risk ? Or is it just slow ?

As I dont have urgent need to make a quick decision and will proof some different other trimarans, it would be helpfully to have a kind of "table" available. Kind of "BMI" :-)

Tks in advance...
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Old 02-10-2015, 07:49   #2
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Re: (heavy) overloaded Trimarans... where are the limits ?

sounds like a Kantola that I tried to buy 20 years ago for $35k, fifth fox. I don't remember the sail drive.
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Old 02-10-2015, 10:06   #3
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Re: (heavy) overloaded Trimarans... where are the limits ?

Quote:
Originally Posted by multihuler View Post
sounds like a Kantola that I tried to buy 20 years ago for $35k, fifth fox. I don't remember the sail drive.
It is not relevant the boat type... I target at the generally question to get an understanding what means "overweighted Trimaran" ??

E.g. I have a sales offer for a Formula 40 Foot Trimaran (a Phillippe Cabon design), which was built by an amateur. The 2nd owner demised, and now the boat is for sales. It has 3 tons weight without internal equippment...

Some say, this boat is already on the limit of "being overweighted".



So I like to get an understanding for Trimaran constructions, e.g. having a "matrix" which gives me a clear warning about the risks for safetyness and seaworthyness.
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Old 02-10-2015, 10:30   #4
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Re: (heavy) overloaded Trimarans... where are the limits ?

The architects often describe the displacement.

For example, my 28 foot cat has 3 displacements on the drawings:

Light displacement 1230kg 2703#
Half Load disp 1498kg 3295#
Full Load disp 1767kg 5797#

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Old 02-10-2015, 10:46   #5
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Re: (heavy) overloaded Trimarans... where are the limits ?

"Full load" is the top of the bottom paint level. Guess you're close to "full load" right now on that 28' cat.
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Old 02-10-2015, 11:14   #6
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Re: (heavy) overloaded Trimarans... where are the limits ?

appears to be a great design, the yellow one that
was sold last year flew a hull at the dock, there is more to the story
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Old 02-10-2015, 12:25   #7
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Re: (heavy) overloaded Trimarans... where are the limits ?

Quote:
Originally Posted by paxfish View Post
The architects often describe the displacement.

For example, my 28 foot cat has 3 displacements on the drawings:

Light displacement 1230kg 2703#
Half Load disp 1498kg 3295#
Full Load disp 1767kg 5797#
Paxfish, great... you can be lucky to get and have available such details. Nice boat :-)

What if the designer is no more, has demised... or - as I experienced couple of weeks ago - the architect still lives but has lost his plans and cant remember the details by memories. (Rec.: it was another 40 Foot trimaran at the weight of 4.5 tons which was built in the 90th.)

Indeed it would be helpfully to have such a frame from light to half and full load displacement. In your case: 537 kg.

As you probably know trimarans are not round the corner to find and get, while we have a more easy going with monohulls one can find in nearby every harbour. Especially not in Northern Europe where i live it not easy to find Trimarans.

For now I had 5 boats as offer. One on US West coast (close to Canada), one in Indonesia, one in South America, one in down under and the Green one as the closest on French Atlantic coast.

I cannot fly around the globe over weeks/months... spend thousands of dollars flight tickets and travel expenses and then wait in the marina 1-2 weeks for light and heavy weather conditions to do test sailing and then seeing: The boat is overweighted, bad steering, unsafe in big waves etc. ...

So I have to do a pre-analyses from the datas on my office desk, beside all what I get, e.g. pictures, videos, talks with designers (so far exist).

Its a real challenge to get the right boat with 3 hulls. :-) Nothing to complain about. Its a good learning process. I have learnt over last two months a lot about trimarans.

Just try to do it most efficiently not to trap into something bad.

To give one example: yesterday I got an email from the broker about the green boat. The widdow made some snaps last week... so it looks "from inside" and "on deck" now.... see attachments.

Shiny glamour world of brokers. The pictures in the sales proposal show something very differently.
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Old 02-10-2015, 12:33   #8
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Re: (heavy) overloaded Trimarans... where are the limits ?

call me if you need a devil's advocate in the US. Stephen 775 775 722 5677 pst
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Old 03-10-2015, 06:43   #9
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Re: (heavy) overloaded Trimarans... where are the limits ?

This link might be of help to you. Print your calculations as you go because the calculator readily dumps them.

www.multihulldynamics.com

Let us know what you discover.

Roger


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Old 03-10-2015, 12:33   #10
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Re: (heavy) overloaded Trimarans... where are the limits ?

Boats in general have 2 or more displacement numbers specified: designed empty weight, and designed all-up displacement. The difference between the 2 is the designed payload. These numbers are usually very explicit (at least on the plans & specs) of multihulls, harder to find on monohulls. Sometimes there are additional numbers available, such as racing vs cruising max weight, or coastal vs offshore.
Notice that I explicitly used "designed". Any individual build might be (rarely) lighter or (frequently) heavier than designed. That affects the available payload.
There is (unfortunately) no rough-and-ready guide like you'd like, as the condition on any particular boat is really it's deviation from the design. For example: a 60ft racing tri might have less available payload than a 40ft cruising tri. The 60ft could have less stuff and be overloaded, than the 40ft which still has weight to spare.
But as a rule of thumb starting point: check out the under-wing clearance and the amount of bottom paint showing. And learn whether that designer goes for "immersed" amas (all three hulls are in the water even when light) or not (one ama/outrigger is always out of the water). In the latter, if all three hulls are in the water, it is grossly overloaded. Though you only tend to find those in racers.
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Old 03-10-2015, 13:56   #11
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Re: (heavy) overloaded Trimarans... where are the limits ?

Quote:
Originally Posted by svtrio View Post
This link might be of help to you. Print your calculations as you go because the calculator readily dumps them.
www.multihulldynamics.com
I am enraged... about the bad job of Google Never came across this link my path. :-)

Indeed it opens the door into the direction I am looking for. Many tks svtrio

Quote:
Originally Posted by svtrio View Post
Let us know what you discover.
Will do so...
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Old 04-10-2015, 01:55   #12
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Re: (heavy) overloaded Trimarans... where are the limits ?

Ciao Skip,
I am in the same process of finding a suitable trimaran to liveaboard during few months each year..so I read with pleasure all your posts.
I have been learning a lot too in the last year about trimarans, and I hope this will help me make the choice when i will find the right boat.
So far is difficult, lots of compromises between space, speed, comfort and budget..
I was going to buy a Newick but the owner withdraw from sale
Anyway i have a chart from Crossmultihulls which could be helpful to estimate the weights onboard.
Hope it can help.
P.S. how do you think to solve the batteries problem? Small honda generator (that can run watermaker) and solar panels?

I personally want to keep things as simple as possible, as the more equipment you have, the more money and time will be spent fixing it!
Like the say in Australia...
Keep It Simple Stupid!
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Old 04-10-2015, 06:51   #13
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Re: (heavy) overloaded Trimarans... where are the limits ?

Hi Indodream

There is a Newick echo for sale here in HK just in case you still fancy a Newick. It's 36 feet. Not sure I would want to live aboard it for a few months but it might be OK for 1 or 2.

Finding a Tri with both decent interior space and great performance seems a particularly difficult task!

Good luck with your search.
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Old 04-10-2015, 07:01   #14
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Re: (heavy) overloaded Trimarans... where are the limits ?

Quote:
Originally Posted by indodream View Post
Ciao Skip,
I am in the same process of finding a suitable trimaran to liveaboard during few months each year..so I read with pleasure all your posts.
I have been learning a lot too in the last year about trimarans, and I hope this will help me make the choice when i will find the right boat.
So far is difficult, lots of compromises between space, speed, comfort and budget..
Welcome in the club, hm ? :-) How long you took for this Newick to find it ?

I suppose it depends lot on the right attitude (towards boats generally and "living on a boat" specifically). Some potentially owners who have lots of money dont think a lot about the details, as they have to invest their time in "money making". So they visit 2-3 boat shows... take tons of catalogues home and then make the decision and order the boat within some few meetings with the designer, so long it is not a single built project.

I have a different attitude towards this topic. I suppose it is because I was professional skipper... so you get a different perspective towards boats. Looking for "living on a boat" solution is similarly like to find the right architect for designing the only single house one want let build and live in till pension age. Its relevant to feel well and homely on board.

Third aspect (probably the most important) are the risks... most of us know (beside some naive folks) that "swimming homes" on high seas can be a "deadly traps"... so we have to think seriously about safety aspects first of all and more heavily compared to owners who do weekend sailing for leasure times.
I was involved too often in rescue missions (mostly deadly) seeing owners not caring enough about paying a high prize.

One thing is important as I see it: To make a start.

Probably one can build up a big database, with tons of information about boat types, boat building methods, different warfts etc. ...

I try to find here the balance of good compromise, otherwise I will search still in 10 years for the "perfect boat". This became clear for me over last months. The perfect boat doesnt exist.

Young people here can be very smart, even not having money and not knowing what comes next day... You know this video ? I wish I could have this naivity... and positivism.

In consequences I like to take two pairs of aspects in view:
(A) max. of safetyness (here I take the IMO/Solas standards as orientation) + seaworthyness
(B) a mix of "lower (puristic) comfort + good speed" (otherwise I'd better take a catamaran).

...as I think in 2-3 years I like to sell the boat for a bigger one... and then proably in 10-15 years after being an old pensionist going back and downsize again. *laugh* (knocking on wood)

Quote:
Originally Posted by indodream View Post
I was going to buy a Newick but the owner withdraw from sale
yeah, such things can happen... best is to have 4-5 boats parallel as option. It is more the psychological aspect behind.
Then te broker or owner feels, that you do not have pressure and that you do not want his boat urgently. So he has to come along with, e.g. a good prize offer to make it attractively for you.

As an example:
On Friday I got the email answer of a "broker". A real idiot of sales man. (Sorry, I know not all brokers are yearks.) - He resists to overhand my request to the owner... because he (the broker) likes to pull maximum money / profit (commission rate) out of the selling. So he just pretended to speak in the name of the owner saying manipulating a "fake email" showing it to me and says: "Look here, the owner expects a good prize, so he will not sell it now and want wait till beginning 2016." In other words: The broker likes to push me into action, the prize up and set me under pressure to make the deal now (heavily overprized). - What a fool, isnt ! - Bad habit of seriously business.

Lots of show making and wrong expectations. I know that this boat will loose every month up to 5,000 dollars in value if the owner waits longer. So is the market now. We have entered into the foiling era... and soon we will see foil-assisted and fully foiling cruising Trimarans. Then the "old boats" will become quicker worthless as some owners wish nowadays.

Some brokers have bad knowledge about Trimarans and this very specifically market, so it feels for me. They do not care a lot, e.g. not delivering newest photos, no details about the boat history. Some brokers even do not know the sail area. - Quick money making guys, mostly. But thats a thematic on its own. :-)

So lets come back to the thematic...

Quote:
Originally Posted by indodream View Post
Anyway i have a chart from Crossmultihulls which could be helpful to estimate the weights onboard.
Hope it can help.
Sounds interesting... Do you have a link ? Is it available as excel calculation sheet or as table (PDF or image download) ?

Quote:
Originally Posted by indodream View Post
how do you think to solve the batteries problem? Small honda generator (that can run watermaker) and solar panels?
Yes, that goes through my mind, heavily...

As I have a living + working on the boat, I need lots of "electric energy" to run computers, file server, Internet connection. I cannot afford a "black out". That would ruin my business and me quickly.

Roughly I can sail (and repair/maintain) 14 days per month, the other half I have to work full time on the boat (cultural journalistic work + radio productions).

I have started a thread about this question to get some ideas...
How to calculate a Solar system for a Trimaran ?

I like to have a boat as a kind of "eco friendly one", as much as possible. I dont like the idea of a skinky diesel engine/generator. Thats 20th century. Sailors should not only talk "green" more come into action to "live green".

With a pre-calculation roughly you can get a fully installation at around 3.5-4,000 Euros (pls calculate by currency exchange on your own). Thats the result for now. Yet not calculated a pure "electro motor" (e.g. as exists by OceanVolt (Finland) or Torqueedo (Germany). Another homework on my long, long list. :-)

About the weight I posted a provocative question:
What to do that Amas (Outriggers) aren't "dead space" for a Tri ?

Yet I am not clear about a good solution how to trim the boat with higher weight by battery blocks.

As I use a boat (probably in the size of 35-40 foot) alone, I can compensate it little bit NOT having 2-3 other crew members on board. Only day-sailing for little bit socializing, which is important. But it wont become a "family boat" with a bunch of 3-4 people steadily.

So a Trimaran with regular berth for 4-6 people can handle the bigger battery block more easily, I think. The question more is: "Where" ?

Quote:
Originally Posted by indodream View Post
I personally want to keep things as simple as possible, as the more equipment you have, the more money and time will be spent fixing it!
Like the say in Australia...
Keep It Simple Stupid!
Thats why I like Trimarans... I come from monohull sailing... there the boats became more and more complicated since the 90th... heavily overloaded with lots of stuff on board. I dont like it.

More stuff on board, more work it is...


Trimarans are sensitive because of "overweight", so these boat type forces one to keep an eye onto "simplicity". Indeed it helps to keep self control.

A good video being remembered about the "essence of sailing" is this...

Too quickly we fall into the trap being spoilt in mind by all the consumption goodies we get offered from everywhere. Happens to me, too. Great video to get motivated by others...

Good luck with finding another Newick ! "Down under" its little bit more easy to find Trimarans while I have to search (from my office desk in North Europe) for 3-hull boats like for the needle in the haystack.

What about a Crowther or a Grainger ? These boats are very well known in Australia/New Zealand.
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Old 04-10-2015, 07:12   #15
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Re: (heavy) overloaded Trimarans... where are the limits ?

Quote:
Originally Posted by nalinjay1974 View Post
Hi Indodream

There is a Newick echo for sale here in HK just in case you still fancy a Newick. It's 36 feet. Not sure I would want to live aboard it for a few months but it might be OK for 1 or 2.

Finding a Tri with both decent interior space and great performance seems a particularly difficult task!

Good luck with your search.
I suppose you mean the Echo 36, right ? I have thought about this boat.. it has a nice interior design. But its 15-20 % overprized at a sales prize of 96 Thousand US dollars; actually a 43 foot cruising-racing Trimaran you get for lower prize (at roughly 80-84 Thousand). - Since longer this boat is in the market.

The owner should demonstrate good will with a prize reduction. :-) (Probably this might disturb his energy balance, the Chi. (The boat name is "Chi Machine")




To keep on the track of the topic... this boat has a weight of 3 tons. With water Tank of 160 Liters (fresh water) and fuel tank of 50 Liters, this and that (e.g. water maker, holding/black water tank) as extras it will be in totally ~3.6-4 tons I suppose.

Is this boat then overweighted ??

No single broker is delivering details about the sails size. Lots of nice sounding Bla, bla, bla... but the relevant datas are missing.

Mainsails : Doyle Dacron Tri Cut Main -Sept 2014
Headsails : Doyle Dacron Tri Cut Genoa –Sept 2014
Spinnaker : UK Sails spinnaker -2010
Screecher / Gennaker : Doyle Carbon Screecher -2009
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