Wooden Cat

[discovery999]

I'm starting on a project to build a 50 foot catamaran. All with wood. I'm concerned about every facet of doing this considering I've never built a boat before. But I've been thinking a lot about connecting the hulls lately. I've got a lot of ideas, but until I get into the design, I am bouncing back and forth. Has anyone done this?
My ideas are:

1. Connect the bow of course ( with mahogany)
2. The area in front of the mast. ( and the area around ). probably 2 cross beams
3. The saloon will have 4 cross beams
4. The rear deck area will have 3.

Sorry I can't provide details because It's all in my head so far. The boat will have 4 bathrooms and 4 Bedrooms. The saloon area will be 12 by 12, or there abouts.

Dimensions are 50-55 feet long with a beam of 25-27 feet.

I want to make it light, but not adverse to strength and stability.

I've built a 1/10 the scale boat already. I am hunting for land to build on currently.

Any and all help in brainstorming this is appreciated.

Thank you, Gary

[David G]

Gary,

I do have one thought.

I'd strongly recommend, esp. since you've not built a boat before, that you start with a proven design. If you want a catamaran, there are several designers who've made a specialty of them. Usually, building a boat this large is challenging enough. Designing and engineering it also is an almost sure recipe for failure.

Whatever you decide... good luck!

[donald branscom]

Photos of the model please????
The 1/10 scale model you mentioned.

[BBSebens]

Definitely share pics. And maybe some drawings if you've got them.

Closely study the other designs out there. They offer a lot of insight. We can't say that designing your own boat is guaranteed to fail, but the odds are not in your favor. That said, we don't want you to fail.

Where are you located?

[xsboats]

Gary,

I do have one thought.

I'd strongly recommend, esp. since you've not built a boat before, that you start with a proven design. If you want a catamaran, there are several designers who've made a specialty of them. Usually, building a boat this large is challenging enough. Designing and engineering it also is an almost sure recipe for failure.

Whatever you decide... good luck!
I agree with David G. , but if you are set on having a go with your own design, then I would recommend paying for consultation with someone like John Marples or Richard Woods.

[johngsandusky]

Or study some books on design, and books of designs.

[rbgarr]

The stresses and forces acting on the hulls and connecting beams of multihulled boats are some of the most complex in the fields of yacht design and building. As a result, they can be the least capable of being understood easily and addressed adequately by us as amateurs.

This designer has many designs which have been built, tested and proven, and several that meet your criteria. The challenges of building a large multihull are sufficient enough that introducing the unknowns of an amateur design are almost a guarantee of disappointment and wasted resources.

My two cents anyway and I sincerely wish you luck as well: http://www.chriswhitedesigns.com/

[Woxbox]

...and then there's a thread in the archives here about the guy who built a Wharram (http://wharram.com/index.php) cat but didn't follow the plans for the connecting beams. And the boat broke in half.

But I agree with the above observations. You'll be putting thousands of dollars and years of sweat equity into this boat. At least have a naval architect review the design to make sure it will hold up and perform well.

And good luck with the project and by all means keep us posted. Nothing nicer to follow here than a build thread (with lots of photos).

[andrewe]

As with the others,I wish you good luck and an happy build, but with the same cautions. It sounds as if you have little experience of design and by your own admission, non of building. A 50ft cat is a huge undertaking, what are you going to use it for? world cruising?
I am looking for a new keeper for a 40ft cat. Built, so far, with strip planked underbodys glassed both sides. All bulkheads in place, rudders built some interior work done (heads in place and tanks. A professional looked at it and reconed a year with two people full time. He was impressed by the build standard, this is all epoxy. The owner/builder( a qualified engineer ) has been at it for 8+ yrs, but his age and health have forced him to stop. It has some interesting but unusual features, these are not helping the sales talk.
One of the problems is the regulation system here, obviousl not aplicable where you live(?) that have a whole special set of rules for multihulls due to the complex stresses involved and the stability calculations.
The reality is: we will probably have to cut it up and land-fill it.
So, my advice is to look to your needs and then buy a set of plans that suit them. They may sound expensive, but will be a minimal expense compared to the what might (probably) happen if you go it alone. There is another aspect. One needs confidence in the long build, a good design and support can help over the dark times.
I am not trying to put you off, but the odds are not with you. (so, to be honest, I am putting you off self design.)
Good luck, which ever way you go. And KEEP US POSTED
A

[Matthew L]

Sorry to add to the cautioning chorus, but a 50' catamaran is an awfully big first project. For example, it's possible to design and build your own house alone, but it's a lot easier if you have already designed a built the shed, barn, etc. first or if you're going with a proved kit or stock design. The same goes for boats, and then some.

If you have a dream of building a big catamaran, I would identify the type of construction that interests you most (stitch-and-glue, strip plank, plywood-on-frame, etc.) and then try your hand at a MUCH smaller design to gain some experience and skills. You could choose a design to serve as the tender to your eventual big cat, or you could build a beach cat to play with while you're tackling the larger project.

A project this size is a very, very large undertaking even if you are building to a proven design. Add to that a first-time, amateur designer AND first-time, amateur builder and you have a recipe that usually ends in disaster.

I am curious, too, as to why you would choose to tackle such a big project right out of the gate? A 50' cat is a LOT of boat. James Wharram says this about his Tiki 46 (http://wharram.com/tiki46.html), "The Tiki 46 is a boat designed for Blue Water sailing, with live aboard space for a crew of up to 10. She also makes an excellent charter vessel with 4 private double cabins and an extra double in the deckpod." That's quite close to the specs you mentioned, but do you really need a boat that big?

[Tumzara]

Is that the sound of reels spooling out at a rapid rate?

[paladin]

Lessee...a year of designing, 6-10 months to assemble tools, materials etc...then 8-10- years in a build, 200K in materials........plus living expenses for 11 years....this could be an expensive first time boondoggle.

[donald branscom]

Lessee...a year of designing, 6-10 months to assemble tools, materials etc...then 8-10- years in a build, 200K in materials........plus living expenses for 11 years....this could be an expensive first time boondoggle.

Paladin....you are slipping, you left out the the divorce!

[xsboats]

Not to mention the excessive drinking and subsequent rehab.

[Yeadon]

Go for it! I like this fellow's thinking. Why go small when the ocean is so damn big?

[Woxbox]

I like this fellow's thinking.

What happened to this fellow? Did we already scare him off?

[Tumzara]

What happened to this fellow? Did we already scare him off?

Those strikes probably straightened out the hooks or he didn't have enough line on.

[john welsford]

Paladin....you are slipping, you left out the the divorce!

A good freind of mine designed a 55ft centerboard schooner, sold his 30 footer and got started.
Much much later I was sitting on the afterdeck with him, enjoying a drink and the view, when he commented that "Y'know, this boat cost me two wives, my business, my home, every dollar that I made for a decade, and 12 years of my life. While this is wonderful, I often wonder what life might have been like if I'd chosen to build something more modest".

Take care with big projects. The cost is more than the dollars.

John Welsford

[wizbang 13]

4 bedrooms and 4 bathrooms, heh heh.

[discovery999]

I'm still here. Where I live doesn't have I-net. I knew the worms would come out of the woodwork on this one. Hahaha. Yes, I want to cruise. I looked at Wharrams design. They seem sound enough, but I don't like the look. Yes, I have thought about all the possibilities ( launch and sink to split in half). Thats why I'm so immersed in the connection right now. I will work on my designs and get them uploaded at some point. I live in the South Pacific. The materials here are very reasonable. The cost of the designs that I've seen on the internet will cost more than the materials to build the frigging boat. I'm not married, so the divorce thing is out of the question. Drinking could happen though, and will in my estimation ( daily ). 12 years seems a little excessive. I was thinking more like 1 /12 to 2. This will be a plywood over wood frame by the way.

Having said all this, if the dang thing sinks so be it. What else do I have to do? I'm retired and am looking at this project as fun and wouldn't it be something if I actually did it. Didn't Kon Tiki go all the way across the Pacific? Made of reeds. ( I know it wasn't a cat ).

I'm not downplaying the complexities, don't get me wrong. Thanks for all the comments, they have been most helpful. Keep 'em coming.

[wizbang 13]

design costs more than materials?

[BBSebens]

All we are concerned with for the most part is that you understand what you are getting into. We do wish you the greatest success.

I have to agree with Wizbang... how on earth could the design be more than the materials? Don't forget, the rig can represent a large portion of the cost. Winches, rigging, blocks, the sails, its all very expensive.

Good luck!

[discovery999]

Of course not rigging ( mast, rudders, winches, lines, anchors, ropes, etc. ) and nav gear ( GPS, radios, radar, etc. ), but yes, the cost of the materials here is less than most design plans I've seen. And all of this excludes labor.

[discovery999]

Yes, sorry should have said cost of materials for building hulls, connection, saloon, decks. Plans are anywhere from 10-15K USD. Materials for what I'm doing are 5-10K USD. Believe me, I've priced it. Again, I don't live in the U.S.

[discovery999]

Let me word this another way. I'm not asking for a critique. I need info or if possible provide location of info , mainly on the internet. My sources are limited here. None of the book stores have this kind of material. The lack of resources here may keep me from building the boat more than fear of failure.
I have much more to be concerned with.

Where to build , launch platform, how to get it in the water. What if I spring a leak, Where to do maintainence, How to sail it, how to navigate it, communicate, avoid terrorists.

Thanks again.

[andrewe]

Helps that you filled us in the whys and where. I still think that you should buy plans, are they really that expensive? 10/15k $? Wharram's are (much)less. Also, as said above, build something small like a beach cat. It would be a very good experience as training and management. Plus fun on your days off from the big project. Get lots of books, the builder I mentioned had a a small library. Specificly one on designing cats. I will be over at his shed this w/e and will get some titles. Google 'Rustic Schooner' This is a 64ft ply on frame cat built for day charter out of the Turks & Cacoes Is. Designed by Nigel Irens. I was asked (family friend) to look for a space and facilites to build her and help with the organisation, but the build went to Florida and ran into financial trouble, which is why she is in another charter fleet. There was a site covering the build, would have been very informative for you, but the last time I looked, not visible.

The site I found to build her was just being vacated by a 38ft cat. He drove it down to the beach on a scrap truck chassis, then waited for the tide to come in.

Your materials sound ridiculously cheap, wish I could get stuff like ply cheaply.
Andrew

Just checked the site and there are build photos. Ignore the luxury bit, it was designed for day trips with the guests on deck. The owner had been running a wharram for such trips and arranged finance for a much bigger boat, as it would be nearly as cheap to run, crew wise, but carry many more px.

[wizbang 13]

Next time I wreck a boat, I'll do it where you live. Build a 50'cat for $5000. I spend that much just to maintain my 34'er.
Your concerns,springing a leak,how to sail it, avoiding terrorists, make it hard to take you seriously.

[Cogeniac]

Go for it! I like this fellow's thinking. Why go small when the ocean is so damn big?

That tears it.. I am going to scale up my Marsh Cat plans to 150 feet. Should be impressive! 150 feet long, 60 feet wide, will displace 1.3M pounds. Not sure if I can afford all that planking, not to mention the 4K gallons of West Epoxy, and 25K gallons of Epifanes, but I guess I'll deal with that when I get there.

[Cogeniac]

Next time I wreck a boat, I'll do it where you live. Build a 50'cat for $5000. I spend that much just to maintain my 34'er.
Your concerns,springing a leak,how to sail it, avoiding terrorists, make it hard to take you seriously.

I think I'd be most concerned about the damn thing falling apart in a rough sea. I spent 4 days in a storm between Bermuda and Newport on a 43 foot cat, and believe me, she took a hell of a pounding (15-20 foot waves)...I have a pic of a green water wave breaking over the bow(s) of the boat...literally 2-3 tons of water breaking sideways across the bow.... Just the torsional stresses of something like that would, without proper design, cause the boat to literally break into pieces.. better hope you're on one that floats...

This boat survived just fine (we were a mess!), but on this boat, each winch probably cost $3K...For a 50 foot boat the rigging and support hardware (winches, blocks, lines, SAILS, etc) alone will cost you $25K. Before you take her out, I'd at least invest in a good lifeboat and an EPIRB.. you are going to need it...

S

[Woxbox]

I you want to be sure of success in this venture, the smartest thing you can do is to pick the Wharram design that's closest to your needs and build it to the plan. There's a huge community of people out there to answer questions about these boats, and they were designed from the start to be built on beaches in far away places with simple tools. And when it's done, you'll have something that will have real market value. Lots of boats, some big ones, have been designed and built by amateurs with no professional training. But the rate of success is not very high at all, and these boats are usually so quirky that they can't be sold.

If you want to learn all you need to know to produce a solid design, you'll have to commit quite a bit of time to the study of naval architecture -- easily as many hours as it would take to build a proven design. This would be that resource: http://www.westlawn.edu/ -- to my knowledge, the only school available for "distance learning" of naval architecture.

[discovery999]

ok, thanks for the concern. You've opened my eyes. I've decided to build a canoe.

[discovery999]

Yes very cheap. Marine ply for around $6-7 USD a sheet. Thanks for your help much appreciated.