trimaran

[Lem]

Okay, first things first I know very little about boats and I need some kind help please...

I am an engineering student and have been given a brief that basically requires me to know all about the design processes and costs of designing "4-6 birth sea-going sailing yachts", including all the mould costs right the way through to buisness plans etc.

I'd like to put together a trimaran, 4 birth (how many ft? 30? 40? 60?), enfacis on being able to do some sort of endurance cruise. Portsmouth to France to Las Palma to US? That's a fairly hefty trip isn't it?
I Could do with some help as to the most reliable / cheapest hull material (composite?)?
Was thinking of going for a kind of affordable cruiser or something of a kin to that.

Any advice, knowledge or web adresses from any kind members would be welcome.

[stokesdakat]

Let me first tell you that by wanting to build a tri, you are taking the hardest path possible, i should know. i am building one only 14 feet long, and have been for the last 4 years... but i digress. the length doesn't determine the number of berths a boat has, but trimarans are known to have skinny hulls resulting in very little interior space. some notable exceptions are the old piver tris, but there are bulky and not as fast as one would hope. there are a lot of designs out there that use plywood as the hull material that would be relatively cheap and easy to build. other than that, buying a tri is the only other way to go.

my project is a 14 foot sunfish as the main hull with a 12 foot winsurfer sliced in two and jacked out 3 feet off the beam of the sunfish, making it 14 feet long by twelve feet wide. BUT all of my hulls are relatively flat-bottomed in order to try and plane the boat up and out of the water. the loop-hole in my project is not using skinny hulls, rather using almost flat bottomed hulls in order to produce a planing multihull with a lot of room for its size that will not heel in order to power it up to ridiculous speeds. anyways, good luck on the trimaran, if you have any questions. email me.

Stokes, use the search function of this forum and punch in "Small Trimarans"; you'll find a three page thread that may interest you.Maybe you could post more about your project there; I'd be very interested to hear more!
Lem, I would think your best bet right off the bat is to research trimaran designers and builders; many of them have small tutorials on their websites. You can then formulate more specific questions that people here might be able to help you with.

[mackid068]

Trimarans are complicated. Go with a cat and with 40 ft. you can fit 2 2 person bunks, a master stateroom and a guest stateroom (Enough for 6 people). With a monohull I bet you could get the same in with 60-80 ft.

[mattotoole]

You might try the websites of Ian Farrier and John Shuttleworth.

[Lem]

Thank you for all your help.
It has been much appreciated.

I have now completed my project and handed it in. Now I just have to wait for the marks

Thanks again.