Catamaran plans, who have I forgotten ?

Just to be clear, I wasn’t suggesting it’s the same boat, just that of all the designs I could find, it seems to have the most similarities to the Turissmo 9 based on the photos I found of that one with the stripes.

A lot of the other similar sized Tennant boats that I came across have flat transoms and different hull shapes, and most photos are of boats in the water, so I loaded up similar vantage point photos of each boat on land just to make it easier to compare them.

To me, it looks likely that it is at least based on that design, and was either modified for a more modern look by reshaping the transom scoop lines, perhaps to better compliment the custom pod cabin as they have a curve leading down to the waterline rather than a straight angle.

Then if you study each closely, you’ll notice the hulls have just a slight bump up for more interior space compared to the photos of the striped boat which has the typical cabin bump ups the way most Turissmos are configured.

At first I thought maybe someone had heavily modified the boat, especially given its age and modern lines, but after finding photos of the striped boat, I think it’s has had some massaging, and not a totally radical makeover and reshape like some boats get, a great example being this photo I came across while searching using “custom” as one search term descriptor.

 

You are much much better at finding stuff online than I am.

I can work around the rest of the boat, assuming there is a way to get into the hulls and I can fit out some stuff in there. The big concern is payload. Those boats were never great load carriers.

Today I am trying to reacquaint myself with computer modelling to see what scaling up the Saturn hulls will yield. As usual poor sight and being unable to read is hindering progress.

 

Got a response. Hulls are GBE. They don't carry a load well. It'd be fine for twilight racing but not cruising.

 

Bummer. But, it sure was fun to think you'd get a boat that doesn't take you 6000-12000 hours to build.

 

I got a reply from the person who placed the ad not the actual seller. Apparently there have been a lot of enquiries but the owner is difficult to catch.

So: even if the chap who replied is wrong, even if the owner gets back to me and even if it's a tourismo there is a queue of people in front of me after it...

Probably not worth waiting and hoping...

 

Don’t get discouraged, I wouldn’t give up just yet.

Definitely talk to the owner and get the real scoop.

Lots of people are quick to express interest before they’ve figured out the questions, and in the end, end up wasting a sellers time.

Sometimes in situations like these persistence really pays off, and if the seller is hard to contact, it might work to your advantage.

You know what you want, and know what questions you need to ask, so at least have the conversation with the seller if you can, that way you won’t have to wonder.

At one point I was going to suggest maybe it was an updated GBE, but it’s much more similar to the Turissmo based on photos I’ve found of both, and the overall look and construction.

But anything is possible.

Now I know one of the things you would like is some functional cabin space.

Have a look at the interior layout on this wing deck Turissmo 10:

MALCOLM TENNANT http://www.cpyachtsales.com/malcolm-tennant.html

 

My virus program blocked that link.

Thank you for your thoughts.

I've been thinking about Scorpio. Vertical strip planking foam, that's the thing that scares me. I can just see it making a hull unfair. Horizontal strip is slower but less risky. I think I'll ask if I can upgrade to Scorpio. I could get some scrap ply and plank the mold with that to support the foam, glass the outside turn it over and glass the inside. The ply wouldn't need to be smooth like a hull skin just enough structure to prevent the foam bending.

The Saturn rig is about the same size and I could fit the Saturn cuddy to it. Saturn mast is stepped further forward.

I've always wondered about the 3 30' boats. Scorpio Javelin and Sagitta all use the same hulls. He suggests the same empty weight for the 3 despite Sagitta having a bridgedeck cabin but their load weight are different. I assume Scorpio's waterline is drawn higher..

25-30' catamarans by Woods Designs https://www.sailingcatamarans.com/25_30.htm

It'd be nice to buy something really nice but in my experience they are either massively overpriced or sell incredibly fast. I guess it's being pessimistic but even when I could drive I struggled to get to things in time, now it's hopeless. There was a 45' Beach Marine hull $7k a while back. Gone in no time.

Anyway...

 

guzzis3 , I had planed to use pvc pipe instead of battens and strip them with 1/8" masonite to support the foam . My logic was and still is that using a round 1" pvc pipe would eliminate flat spots of a square cut batten and save on fairing . I was going to make a male mold and drill 1"+ holes 1/8" from the outside of batten locations and allow the 1/8" masonite flush up to the station molds . At the bow I was going to use a small dia hot water pvc pipe spaced closer .

 

I took some screen shots of the photos, as there were a lot in the listing. Hopefully you can zoom in.

For reference, the boat was listed for $60K and looks to have sold recently as the registration was up this year.

Interior photos of boats are hard to find sometimes.

Thankfully there are a lot of old listings still archived on the internet that often include pa variety of photos.

 

Again thank you very much. I assume you spotted the galley and bed include extensions inboard. The shot of the head gives a good idea of hull space. And the double diagonal planking!

rberrey: Putting strips on the mold isn't the issue. I can buy 16mm "cover sheets" for $10-20 each and sometimes free. I'd just need enough to roughly plank the mold, speaking of which I think Mr Woods material list might be wrong. He suggests 30 sqm of cedar to plank the hulls. I would have thought that would do 1 hull not 2 ?

Horizontal foam strip is slow but I am sure I can do it. It's that vertical strip foam that scares me.

 

Does anyone have an opinion on the Waller 880 ?

https://www.mikewalleryachts.com/waller-880-catamaran

Yes it's a bridgedeck cat and it's designed for timber, but most if not all the timber can be substituted, and it has a big carrying capacity.

MW puts fairly fat hulls on some of his cats, but I've noticed a trend among many designers for fatter hulls over time.

The athwart ships double forward should satisfy the boss. It'd be nicer in rain or cold than a cuddy cabin boat.

Getting forward is of course a problem like all full width cabins, but nothing is perfect.

It's a sort of semi monocoque like Ed Horstman's boats. It uses double bulkheads under the mast and aft end of the cockpit.

I figure 15mm foam with 600 gsm would be a reasonable substitute for 12mm WRC and 450 gsm. I'm poking around on ali baba to see if I can import 1 - 1.5 cubic meters of paulownia at a sensible price.

Design displacement is 1000kg but MW allows overloading to 2000kg and handily gives immersion by added weight figures. His plans are very good, and remarkabley cheap.

The hull isn't cheap. I calculate somewhere north of 10k for materials, probably similar to Romany for example.

Does anyone have any thoughts ?

 

Guzzi3. An excellent cat and a foam glass version would be an easy conversion, I would speak to Mr Waller, he is approachable. 15 mm foam 600 gsm cloth would do it. Read about the sailing of a Waller 880 on the following 2 web pages at Frecheville Heaney Boatbuilders http://www.fhboats.com.au/page.php?p=410
and also at Frecheville Heaney Boatbuilders http://www.fhboats.com.au/page.php?p=346

 

Likely 30sqm per hull.

If, 30' long, call it 9M
If, 12' of planking all around, call it 4M

That is 36...but not 4M all around ??

I think your strip to foam conversion is a bit off. The 600g laminate is pretty light is all. I'm just offering a gutcheck, but 600g glass is really easy to puncture with foam behind it. If Oldmulti says its good, who am I to argue? But the flex comparison between 12mm wrc 450 and 15mm 60/80 kg foam and 600 is not gonna be equal...

I don't know the hull speeds, so perhaps it is enough and the wrc is way more than needed..or maybe a touch more glass on the bottom?

 

Instead of WRC or paulownia look at macrocarpa (cupressus macrocarpa, aka, monterey cypress, golden cypress). The wood is domestically grown in Australia, not very expensive, stronger and only a little less durable then WRC. For your application the weight difference is not really big, we are talking about a plus of 100-130kg per cubic meter.
This way you can stay with the specified 12mm wood and 450gsm glass, and drive the cost down.

 

Thank you very much for the replies.

I have been reading everything I could find on the boat before asking here. I have the study plans and have studied them carefully.

The materials list suggests 92 sqm of WRC or Paulownia. Even if I buy larger sections of rough sawn and resaw, dress and profile it myself the cheapest I've managed is $3600, compared to foam I can get for $2200. Ok it's $1500 in a 12k hull BOM 10%. Not life changing but it's a significant expense and it annoys me. And all that extra work. Maybe I can find cheaper.

12mm in a boat this size is heavy but I think as it's aimed at family coastal cruising he overengineered it a bit. Typically in cats this size you see 10mm WRC or 12mm foam. 15mm foam would stiffen it up a tad but as said point loads are a vulnerability.

cupressus macrocarpa: Thank you for that I will endeavor to look into it but rot resistance is paramount for me.

Oldmulti: Mr Waller is busy with other things and not interested in getting involved in redesign. If my brain was still ok I could do the engineering. I think if you substituted a solid glass layup of uni and 45/45 for the timber in the main bulkheads same width but thinner to match the timber weight that should carry the loads. 8mm foam plus 600gsm 45/45 either side should substitute for the ply/timber but I'd need to find a healthy engineer to run the numbers. If they couldn't do it in 2 hours there is something wrong so @ say $200/hr...

Be aware though it has LAR keels. Designed in timber but I know how to make those in solid glass. Keels don't protect from everything (jetskis, logs: not sure which are smarter) but they do keep the hulls off the bottom pretty well.

Plans are $750AU which are among the cheapest around as far as I know. His sample sheets are impressive.

A lot of boat designers come to it from other things, or just practical experience. Mr Waller and Mr Woods are both formally trained marine architects. I expect others are but they are the only ones I KNOW are.

I need to talk to the boss next week and see what she thinks...

I do think it's funny it has a chart table. Relic from a bygone era...