Alinghi 5

In 2010 Alinghi 5 and Oracle will meet together somewhere for a sort of America Cup follow on.
A lot of pictures are actually published about Alinghi 5.
Just for fun, I tried to draw up something that may be similar to the real one .

Any one interested to continue the design development ?


I’ve started one, well not exactly, but close.

Got a new cat on the go, with inspired sponsons shaped like the mentioned cat above. That and a f-18 cat I saw a while back, with similar bows.
The bridge-deck (after released from molds in blank form), could be cut out to resemble the Alinghi one I suppose.

Maybe for one of the protos will be a wee alinghi.

The flash-mold surface coat, and first glass layer went onto the plug today. When done, the other half will be cast.

The bridge-deck blank molds are done, and I will lay-up one of those very soon.

I will post pics in time.

What about it’s competion… Any takers on that?

Hello men !

Fabulous ! And thanks to Claudio.
But why 1m and no 1.22m (F48 or Mini40 class) or 2m class ?

I try to do it…

you have the choice, this model do not exist yet

See : plenty of video and photos


Look good your plans - maybe I do a 2m version as an additional winter project.


Hi Claudio, nice work and thanks for sharing.

Boat building here has all but halted because of work demands but I might be tempted to have a play. Any chance of the drawings in AutoCAD format so I can tinker?



Yes Ray
it is possible to convert from the CDR but for the DXF file I can send it only via the E-mail - Please send it via PM.

Claudio, you have a PM.



Alinghi 5 RC model
drawing updating and sketch idea for the beams

Claudio, thanks for the update.

Our thinking on beam construction is very similar conceptually, specifically the inclusion of what you’ve included as an I beam - what I think of as a sheer web. My execution is different though and might give you some ideas:

I would start with two foam cores as in your drawing, however, I would wrap these with bi-axial carbon sleeves, like these:

As soon as the epoxy is applied and the sleeving is wetted out, assemble the two halves, then over the whole layup a unidirectional carbon fibre sleeve, then another bi-axial sleeve. Next, either:

(a) place in some heat-shrink sleeving, gently ease the crossbeam over a curved former (to get the arch across the beam) secure and apply heat to the sleeving to pull it all together and get a good external finish.

(b) lay up some peel-ply, release film and some bleed cloth and place in a vacuum bag, secure over the curved former and apply vaccum.

Incidentally, I would have the foam cores cut by an expert with a hot wire. This process provides a useful aid, especially for crossbeams that are curved underneath as these may be difficult to locate on the former. If you have your cores hot-wire cut a by-product is a set of female versions of your crosbeams and you can glue these to the arch former to create a ‘bed’ to accurately locate the beam when you curve it.

Obviously the arch in the beam needs to be a gentle curve and a slow initial cure epoxy helps.


I’m presently working on generating Autocad plans. I’m going to use them to get some of the pieces laser cut.

Steve, Claudio was good enough to send me his drawings in AutoCAD format; I’m sure he’ll be happy to send you a set if you pm him, or pm me and, with Claudio’s endorsement, I’ll forward a set. Might save you some time, it will me.


Of course Ray, you do what you like.

About what you wrote previously, which dimensions have choosen ? According to your description, are you sure to stay inside the weights ?

With the drawing I presented, you get only 493gr displacement per hull, but once tilted, only one hull must supply the full displacement.


PS : I just converted the DXF format in Zip

Claudio, the beam construction I described would be for a 2metre catamaran with an expected displacement of around 12lbs (around 5.5Kgs) - my experiences thus far are that this construction approach will be strong/light enough.

I had forgotton that your drawings were for a cat 1metre in length so yes it would be over the top for a boat that size and you would probably be OK with two light laminations (one uni-directional and one bi-axial and I don’t think you would need the sheer web); the cross section of the beam will be much smaller too so you would consume a lot less material so weight would be much reduced.


A note/reminder to potential builders…

there exists only three sizes of multihull craft that are actively built/raced/recognized. Not that you can’t build to your own scale, but it would make sense to build to a size that is actively sailed and which will draw more builders.

For reference:

1.2 meter (48 inches) Mini40/Formula48 Class
2 meter ( 78.74 inches) 2 Meter Class
1 meter ( 39.37 inches) MultiONE Class

In addition, the following two sizes are currently being promoted, boats are under construction or actually sailing, but number of units still is insignificant. For the 65M Class, 250 plan sets have been sent out to people requesting them - will be interesting to see how many result in boats on the water.

65 centimeters ( 25.59 inches) 65M Class
30.48 centimeters (12 inches) FOOTY Class

For a brief period a 3 Meter class was discussed, line drawings appeared, but lack of interest seems to have taken its toll.

Hi Dick and Ray,
I’m not intending to build a multi hull also because I’m ignorant on these type of models.
Was just fun to draw the Alinghi 5 starting from various pictures collected (more than 50). This occurs to me rather often to draw plans also for various real racing yachts, where the owners like to get a model at home and some time in the water to.
I knows that many are interested on Multihulls, therefore I’v drawn one of 1 meter, easy to be scaled up if required.
Anyhow Alinghi 5 is a complex and sophisticated construction composed of various beams and stays capable to support the enormous mast. Not easy to translate all that at model level.
A model of 1 meter will probably remains a static one…probably I’m wrong, who knows !
Will be nice to see one day an Alinghi5 model on the water .

Claudio, I do wish to thank you for posting drawings - my intent was to try to focus builders on a size of sialing class where there could be competition. Of course they can build to any size, but always better to see photos of many same size r/c boats than only a single one.

It also helps promote the classes, and multihulls need all the help they can to get interested people to build.

thank you again for your volunteer sharing. I appreciate it very much.


Anytimes Dick,
It is a pleasure for me

Which do you think is going to be the most popular class in the US. I was going to give this one a shot and was thinking 1 meter. But it would be nice to build to a class that is growing.

Hi Claudio, are you not even a little tempted to try a multihull? I’m certain that you would produce an excellent result if you turned your hands to one.

I concur with Dick’s sentiments, your openness and willingness to share ideas and experiences are a credit.

I haven’t really worked on the Alinghi drawings you sent me, just rescaled to 2metre overall and had a general look. I really need to calculate the displacement of one a hull at this scale.

Inevitalbly, making a working model will involve compromises.