24ft Trimaran in Oz

Well if all your materials and hardware are garnered from Gumtree and eBay you can call it Gumbay !

 

LOL...rwatson....I got the stick and two sets of sails already, off a TT720. OK, not a modern fathead, large roach main, but it will do to get it mobile until I can afford more...if I need it...its for cruising the coast, not racing!

The beams are already part made - Roger modified the Paolo Bisol design which is a swinging horizontal folder - to fixed beams as per the CAD sketch above.

I'm not sure whether to make them "demountable" or invent a different kind of folding system. May do the demountable thing first and then later have a go at the folding rig.

 

Buzz,
The way the beams meet the hull pod looks pretty ideal for a plug and socket type connection ?

 

Yeah, that's kinda what I was thinking, but seeing the beams are elliptical (not NACA) in cross-section, I'm wondering how to make them demountable.....

Glassing them in with a bit of CF is fine - even I can figure that one out - but making them removable......tricky....

Ideas?

 

Male female

You need to add on a plug end to the beams that will self locate in a socket. I would go for some sort of elongated rectagonal or diamond shape that roughly matches the beam shape. Put a taper on it. When finished, coat in release agent and poke the through the cabin side and glass up the socket end in situ, then brace the sockets vertically and to nearby bulkheads.
I say this with no qualification but I would go for a bury of one third the crossbeam length.

 

Oooopps...

Doh. Looks like I was lead astray by the finding of a set of plans for Paolo's 720 in the workshop.

I've just received a USB from the builder's son and it's clear that the builder DID in fact, design it himself, but perhaps used Paolo's 720 as a reference early on...??

I have several documents which show he did all the hydrodynamic calcs and offsets himself and an unfinished article/book on the build in which he refers to the software he used (and/or) created to design the boat.

So unless someone knows how to change the title of this thread, I don't quite know what to do.....

 

Just contact Jeff the boatdesign moderator and request that he change the thread title.

 

Thanks -- PM received and thread title updated.

 

that looks like a fantastic find. That is really nice looking tri. I will be following this thread to hopefully see it launched some day. Good luck mate!

 

Thanks mate, it was certainly a 'find' - but it just about broke me (and I think did my car) getting it back here from South Oz.

Now I need to recharge the bank balance and generate some more 'fun money' so I can get working on it.

First I need to get it into the yard......working on that one.....

 

I have heard from sailboat owners that sometimes the boat you can afford the least is the free one.

 

LOL....yeah, but that's usually in relation to a hulk or 'mooring minder' that someone has given away to save on cost of disposal to landfill.....

This 'freebie' was a totally different ballgame....brand new hull, all good quality marine ply, FGI epoxy and good quality glass fabrics....

Nah. I'm content. It's going to cost me, but way less than if I'd built the 18fter I was planning to build, and gives me WAY more space and a much more comfortable boat for local cruising.

It won't be a fast build, but it will be steady, as the cash flows in, I'll do a bit more....

 

Sounds like with all the info you have you have a bit of homework to do working out what the original builder had in mind.
Have you been able to ascertain the differences between the original design and what you have ?

 

I have dozens of CAD views that he's done, but I am not 'literate' in CAD.....

It's clear he was intending to support the attachment points of the beams ot the hull with ally angles inside the hull, as the hull sides and the adjacent frames have been pre-drilled in a pattern that suggests this was his intention.

I'm not going to go that way.....

 

Jeez Buzzman, having seen the last lot of pics, it looks as though the Tri might get into the yard, but I'm not sure about you!

Congrats anyway - looks like a lovely boat and you will have a lot of fun sorting it out

Alan