My Cat Design..

[EEO1]

I've sailed my 'rents cat around the apostles and norther lake surerior, it's time to have my own. I've had luck with cedar strips in my kayak, I think it would make a solid hull, maybe 1/4" strips glass inside and out, maybe two layers out and under.

I'm doing a 36' cruising cat, safe/comfortable on the great lakes yet solid enough to cross the ocean one day.

a 36' foot cat makes a nice grid. For ribs, I am reusing section cut outs (where I can) of 3/4" marine plywood spaced every 3' (12 total) (essentially 4-6 inches ply running around the hull); every foot between the major ribs are a strip or two of cedar coating the hull 1' OC (26 total)

It's gonna have a comfortable deck based off other designs that google has brought my way. I am pretty confident in my balanced levels of excitement, determiniation, craftsmanship, sailing experience, and ignorance to make this happen. I see that many of you out there are/have done similar projects. I hope I can attach my schematic drawings. Any comments would be wonderful. Some parallel project would also be invaluable.. Any other crazies out there?

Still working out the frame (hardest part). Thinking aluminum tubes such as my 'rents reynolds 21' cat, maybe 3-4 across.

[chowdan]

Well i can already picture what she looks like. Did you come up with these plans?

it looks like your already on your way! i can't think of anything other than shes going to be beautiful!

[Tad]

In a 36' cat I would expect a skin of at least 3/4" cedar strips with glass either side. Three foot spacing is too great for fair planking, therefore to build the hulls you would need temp molds between your ply frames.

Dissimilar materials are always awkward, a strip or ply box could be simpler than aluminum tubes.

[Manie B]

Sorry

nothing new - nothing different - nothing cheaper
just more of the same thing - again and again

do yourself a HUGE favour and buy a set of plans from a designer that has got the experience

my recommendation is

http://www.sailingcatamarans.com/

read what the man (Richard Woods) has written
it will save your life
it will save you money

you are very fortunate to be in a first world country where you can still get the things you are going to need

[chowdan]

you are very fortunate to be in a first world country where you can still get the things you are going to need



I feel ya there! It's such a pain living in a 3rd world country sometimes! Beautiful land but yet such a pain to get things done!

[uncookedlentil]

Take Manie's advice, your boat doesn't break any new ground in looks or performance and it will be worth a heck of a lot more at resale time if you purchase plans from a reputable designer

It's not worth taking the chance on blowing some critical scantling area. That and the ''coasties'' are going to be very interested if you plan on chartering in US waters.

[pdw]

You're maybe right, but I understand EOO1 if he want to be proud of a boat that he design and build. It's only matter of point of view and I congratulate EOO1 for his effort, time, work and money he involve in his project. So go on and believe me that your boat will be the best of the world for your eyes. I´m sure that a little bit of support will help him, and also positive comment.

Patrick

[EEO1]

It's great to hear from you all! I read one book and I give it all up, but than another (kontiki perhaps?) and get the motivation to do another iteration.

I did realize I wasn't having much fun with my design. I am redoing everything from the hulls up, it's gonna look crazy but great.

Especially in architecture, I have found that there is always more than one way to do things. Wood floats, guys. I won't be the first to tell you that you could design a perfectly good house, you don't always need an architect. Boats, sure, are a little different. The seas are beyond me. I'm getting pretty deep in this stuff, I'll do it and see what happens.

Thanks for the support!

[BWD]

"VERY HIGH," huh?
ok, playing it straight anyway:

Did the kayaks you built come from plans or did you design them?

If you haven't done a design yet, you should probably at least design, build and sail something with sails and a motor, before you saddle yourself with a project that could easily cost $250,000.

Even if you think yourself rich, it's money and years that you won't get back. It's not like building a house.
A nice grid will sit on level footers, nicely.

Or, at least get a consultant naval engineer, and good luck.

Edit: oops. those things are called footings aren't they? I should know, I think I have dug some once or twice? Doh.
Anyway, sorry if I sounded harsh, but, if the awesomeness is "VERY HIGH" I figured you wouldn't mind....

[rayaldridge]

I'm also of the opinion that one should start small, but that need not be unambitious.

Here's a snapshot of a little beachcruising cat that I designed and built. I am not a naval architect. Despite this, the boat has continually surprised me with how well she sails.



http://slidercat.com/smsailjul3.jpg



On the other hand, I've been a sailor for over 30 years, built several small boats, and been a student of boat design for most of that time (the first boat I built was an adaptation of a scow described by Chappelle. It was a disaster. It was not Howard's fault.)

I spent several years thinking about Slider before I began to build and 19 months scratching my head over every detail.

The reason for the whole exercise was that I wanted a boat for which no designs existed. Had I been able to find a design by a trustworthy designer for a tiny beachcruising cat with comfortable in-hull seating and a low-tech sail plan, I'd have been a fool to spend so much time trying to duplicate the work of a more gifted and experienced designer. But the kind of boat I wanted did not exist, so far as I could tell, and I looked pretty hard.

That to me is the most rational of reasons for attempting a design as an amateur-- that it's something new. The pioneers of multihull design were rarely trained naval architects; they were breaking new ground.

On the other hand, there are those who find boatbuilding more interesting than sailing, and more power to them. If you aren't one of these, and you're not breaking new ground, get plans from a good designer. You'll be sailing a lot sooner.

Ray

http://slidercat.com

[Trevlyns]

I think there's merit in most of these replies. But there is also some non-constructive criticism too.

Just poo-pooing a design because it doesn't break new ground, doesn't hold water for me (pardon the pun ;) ) After all, aren't all boats just variations on a theme? I think what really matters is the satisfaction one gets from knowing that the design was generated by YOURSELF. It is unique. There is nothing else quite like it.

But speaking from my own experience, you must realize that there is NO one perfect design. Every one is a compromise. I've lost count of the rubbished plans I've drawn in my quest for "my perfect boat". You just get one design right, and further reading and research reveals "a better mousetrap". You scrap it all and begin again...

Even my own 24 foot proa design elsewhere in this forum (too embarrassed to find it :p) has now been scrapped - even after I finished constructing all the bulkheads. I've now just finished drawing another 24 foot proa with an asymmetric main hull. And I'm sticking with this design!!! You see, I finally realized that if I don't go ahead and commit to a design - no matter how imperfect, I'll spend the rest of my life dabbling in new theories and never get to sea. :mad:

EEO1 - don't be swayed by criticism! Just DO IT!!

By the way Ray, absolutely love your Slider design and have followed it in this forum and the Proa File (http://www.proafile.com/). Well done lad :p

[rayaldridge]

Thanks, Trev. I really appreciate the kind words.

I don't mean to say that there's anything wrong with designing a boat that doesn't break new ground. My point is that a person should decide what is more important to him -- designing for the sake of designing (nothing wrong with that) or going sailing.

Designing a boat is like putting together a puzzle from scratch-- not just fitting the pieces together, but making the pieces, too. There's a great deal of fascination in that, even if the boat is like a thousand other boats.

If one is designing for the pleasure of designing, it seems to me that pleasure might be more intense if the boat being designed is different in some significant way from other designs. Of course, this is a riskier form of entertainment, as there may be some very good reason why no one is building boats of that unique sort. Failure is definitely an option when breaking new ground-- but it's also possible when one is re-inventing the wheel.

There are thousands of designs for open skiffs in the 14-18 foot range. Some are brilliant, like Dobler's 16 footer, or Michael Storer's Goat Island Skiff. I wouldn't be tempted to draw a similar design, for several reasons. For one, it is very unlikely that I, an untutored amateur, would be able to design a boat as good as the boats designed by gifted and experienced professionals with a lifetime of experience in both design and sailing. Why cheat myself out of a superior boat, just so I can say, "It's my own design. It's much like a thousand others, but not as good as the best of them."

In a way, I suppose this is like the dilemma of the art lover who, late in life, takes up oil painting. He naturally prefers to decorate his living room wall with his own daubs, rather than prints of great paintings. There is absolutely nothing wrong with this, and this attitude is much more admirable than the mindset of some Philistine who buys a painting because the colors match his couch. Still, for every Grandma Moses, there will be a million painters whose work never rises to the level of art.

However, copies of great boats, unlike prints of great paintings, become living works of art themselves, given a little creative input by their builders. They take on that mantle of originality because of the way they are used and maintained and loved.

I'm maundering, so I'll stop. I'm just making a plea for a rational cost/benefit analysis when it comes to designing one's own boat. Like sailing around the world alone, designing one's own boat has an undeniable romantic appeal. But just as so many would-be sailors cheat themselves out of the pleasure of small voyages by holding out for great ones, it may be that some would-be designers cheat themselves out of the pleasure of building a boat of their own, by taking on the ambitious job of designing it themselves.

Ray

http://slidercat.com

[TeddyDiver]

I think what really matters is the satisfaction one gets from knowing that the design was generated by YOURSELF. It is unique. There is nothing else quite like it.

Amen!

[Spiv]

With 30y of both power and sailing cats experience and after having built several small boats and one big 42' sailing charter cat, there is no way I would design my next cat myself.

Sure, I would tell the designer what I want in it if I cannot find a design already on the market, but if there is already one tested, I'd just go for it.

There is a lot more satisfaction is saying "I built it myself" to a boat designed by an expert that sails well and doesn't crack after being hit by a storm than regretting the many small and big mistakes one can make in designing it.

One might save a little money designing it, but the resale value, the additional insurance costs etc will probably offset the saving.
I would never even consider buying a second hand boat designed and built by an amateur, regardless on how pretty it might look.

EEO1, if you cannot find an existing plan that you can adapt to your liking, it would be a lot more prudent if now you took your beautiful drawings to an experienced CAT designer and got him to work out the scantlings and the sail plan for you.

[pdw]

Ok, back to the subject of this post.
EE01. Just a simple question, which software do you use to design your cat?
pATRICK

[EEO1]

You got me realllly excited!

Why must it be Port/Stern symmetrical? NowI am changing everything above the water line. I am continuing the outside port hull lines up and over the deck, reinforcement and aesthetics. This opens the deck to have glazing on three sides thus allowing for better view from the cockpit and a much more pleasant bridge deck. Image, a couch that stretches inside and out yet closes like a bottle. Aesthetics are now being INJECTED into the design. To close the bridge deck, I am pulling the inside stern hull lines up.

You really have to see the sketch in front of me, the drawings need way more work than I have the sober ability for right now (buzzing with excitement, but drawings are attached nonetheless).

It could like a floating oasis, open and "loungy." I will install vertical 4" blinds (silicone solar panels of course) to keep it cool and productive. I am relying heavily on those aluminum supports now that the deck has gotten asymmetrical. The new design does allow for some heavier framing, maybe get some hardwood upin there? I am concerned about dissimilar materials with the hull being cedar, ply, and glass.. aluminum.. any ideas?

I am going to model this in Rhino/MAYA/CAD this afternoon, maybe even render it nicely.. maybe a movie, too.. I absolutely love the conversations..

FYI: I am using autocad 2008, tracing over images I borrow* online and image from my own fleet.

[EEO1]

Libraries, Barnes and Nobles, even my schools libraries.. there's not a lot of info on cats out there..

[rayaldridge]

One might save a little money designing it, but the resale value, the additional insurance costs etc will probably offset the saving.



If one's time is worth anything, designing your own boat is a lot more expensive than buying plans. I believe it took me approximately 4 times as long to design and build Slider than it would have taken me to build a similar boat from plans.

Ray

http://slidercat.com

[rwatson]

God - thats awfull! Try doing some side views to see how that is going to look- its horrible!

Take a hint and get some decent design from a professional

[BWD]

Sorry to be a bit direct but that "thing" looks like a hare-brain pomo joke house.

And in a storm you ship water into that assymetrical cockpit and have 1.5-2t of water ballast on the wrong side of the boat. Brilliant.
Go sailing!
Absorb some more knowledge.
There are reasons that even "cutting edge" designs stick to some basic principles....