Hi, New to these forums =D.

Getting started on a design for a small catamaran and was looking for some advice on where I should go forward. I used to do some sailing as a kid and my wife actually had a catamaran for a while previous marriage. I have been building and designing some small boats before mainly kayaks. we recently moved to a new location that will make a sail boat possible near Lake washington in seattle.

Now that you got the background. I have some design questions. I am building with an old friend of mine and we want a boat for his wife mine and us to cruise on a lake with. Lake washington is a big lake and opens out to the sea and can have a variety of wind and wave conditions but not nearly like the sea. tad bit tamer.

first question to boom or not to boom?

what type of sail should I use? there seem to be a large variety out there have not hit the library yet on that but plan to this week. Also dependent on the question above/

Size. We planned on a smaller 14' for transportation but with 4 people on it 16' might be wiser. Could we have a stable maneuverable boat at 14' or should we go bigger.

Speed is not a main concern how tall should the mast be?

Thanks for any help. still in the design phase and looking to start construction next month

We will also be taking some courses to =D safety first

I highly suggest you buy an old cat first, and use the knowledge you gain from it to assist you.

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Rob
OKC
Pile of Nacra parts..
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Buy used first, and build down the road after you learn the subtle differences that you'll want to include in your design.
For 4 people to have fun, get an 18 or bigger. If you are going to sail two people at a time, then you will have fun with a 16. Smaller cats (Hobie 14) are designed for one person, and are slow and hard to tack with two or more people on board.

Building one from scratch is going to cost more than buying a good used one (or two) and learning the variables from it. Positive flotation in a punctured hull, forced mast rotation, sail fabric and what downhaul ratio to use are just some of the thousands of details you want to at least think about before you build your own catamaran.

My $0.02

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Sheet In!
Bob
_/)_____/)_/)____/)____/)_____/)/)__________/)__
Prindle 18-2 #244 "Wakizashi"
Prindle 16 #3690 "Pegasus" Sold (sigh)
AZ Multihull Fleet 42 member
(Way) Past Commodore of Prindle Fleet 14
Arizona, USA
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I understand your concerns yurdle and Klozhald. The Idea of constructing my own is not to save money but to enjoy the build process. I have been building up to this for years and it is finally coming to a head. I have been working with wood and metal fabrication for 8 years. We will also be documenting the project for those interested =D I also have an understanding of many of the variables of hydrodynamics and boat and hull construction.

I was hoping to cheat length through design but you are all likely right I was hoping not to go 18 but that seems the likely case. As most of my research has proved.


My wife has cat sailing experience and owned a cat not less than two years ago hence the reason we are building one now. (well technically she still owns it but her ex and her have been fighting over it for years even though he lives in South Africa and just wants to sell it.) Construction is not an issue as I have all the tools resources construction knowledge and experience to do this. I would take courses with my friend and his wife to re-learn sailing and teach him and his wife. My wife is plenty capable with cats and we would follow her lead. As far as the design questions I came here to get more information from a third party source or sources.

Essentially my wife wants me to do my research and put skin in the game as the phrase goes. This means gaining and earning my own knowledge. She has no construction and woodworking experience so Design and construction Ideas will come from me.

Before Any construction project it is best to have all information before hand So every element of the design fits the end goal.

The questions listed above are more questions about your own personal tastes and or preferential experience to cruising on a lake. We are not racing Just going out on the water for a summer day with very light wind.

When I start a project. Every detail must be mapped out perfectly before any construction can begin. I am not a hobby woodworker I do this professionally and have been building my own personal woodshop for some time now.

Have you considered building a Tornado? Although it is bigger than what you want for transport, it is the size you need to deal with 4 adults especially with less than smooth conditions you describe. Plans are available and the design is well tested. You will also be able to purchase rigging and sails instead of having to custom make everything.
You will also have a much easier time selling an actual fleet designed vessel than a one of a kind creation if you ever grow tired of it.

I have been looking at some similar designs to that. I think That will be pretty close to the finished piece probably wont be designed to be so speedy but I think you are right with rigging and sails. Customizing those parts tend to be way more troublesome than the hulls themselves.

mrjabberwochy

I have been looking at some similar designs to that. I think That will be pretty close to the finished piece probably wont be designed to be so speedy but I think you are right with rigging and sails. Customizing those parts tend to be way more troublesome than the hulls themselves.

Mr. Jabber,

Welcome to TheBeachcats.com forums, I look forward to following your progress with the build, should be an interesting discussion.

In case you didn't know, as a member of the site you are able to create your own photo album and upload photos and descriptions of your ideas, drawings, photos etc. as you build to document your progress.

Also, Rider mentioned the Tornado, the hull shape of the Tornado is well proven and has good load carrying capacity. With your experience you could probably scale it, there have been some production beachcats (Prindle 19 and Prindle 18-2) that were pretty much scaled tornados with 8 foot beams for trailering.

If you built Tornado hulls and put something like a Hobie 18 or even Hobie 16 rig on it you would have great space and carrying capacity without too much power.

Have you found the Tornado plans that are here on the site? Should give some food for thought.
http://www.thebeachcats.c…ictures/?g2_itemId=11015

Here's someone starting there project from old C-Class hulls
http://www.thebeachcats.c…ictures/?g2_itemId=81540

Plans are available for the F16 class catamarans but they are lightweight low capacity cats.
http://www.thebeachcats.c…ictures/?g2_itemId=11955

So is the A-Class which plans are also available
http://www.thebeachcats.c…catamaran?Article49.html

What type build are you planning? Strips? Plywood?
Ian Lindahl is using an inovative foam strip method to build really nice lightweight hulls, he is concentrating on building A-Class cats but the method could be used on more substantial craft.
http://lindahlcompositede…eebly.com/lr4-build.html

Anyway, should help your research.

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Damon Linkous
1992 Hobie 18
Memphis, TN

How To Create Your Signature

How To Create Your Own Cool Avatar

How To Display Pictures In The Forums.
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I think you should buy a used cat. If you want to cruise with 4 people you will need at least an 18 footer, 14 or 16 would be crazy if you always had 4 people.

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ALLEY CAT 1984 RED LINE HOBIE 18 MAGNUM
Sail # 10505 or 277
San Diego, Ca
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Thanks a ton for the input Damon that will really help =D

I'll toss in one other reason to buy a used cat, especially if you plan to build one:

I've looked at building a cat for years (the last few years were spent leaning toward the Tornado design.) There are some excellent plans out there, and if you have the skills, the tools, and the copious workshop space required, it's entirely within reach.

In the end you will have two hulls and possibly two rudders. The rest of what makes a boat a boat typically isn't woodworking. It's castings, extrusions, forgings, etc. If you're rolling your own boat, the choice of mast, sheets, sails, tiller assembly, etc. either means you also take on a bunch of metalwork and sewing or you pick up parts off another boat, as Damon mentioned.

Get a used boat now, and you have a donor rig waiting for your hulls to be done. Meanwhile you're picking up sailing skills. This also gives you an opportunity to pick another designer's brains, so to speak, by seeing what works for you and what you'd rather change. When you do move your rig to your new hulls, the hulls off your old boat will be just what someone else is looking for after a crash, or after realizing their soft hulls couldn't be fixed with a drill 'n fill.

I didn't wind up making my own boat. I'm simply not a good enough woodworker. Instead I picked up what's considered to be an extinct cat. No class association, no fleet races. No rules, essentially. If I want to change something on my boat, there's nothing stopping me. There's a lot of freedom there. Not as much freedom as you'll have building one from scratch, but I can certainly see the appeal.

Best of luck to you! And yes, please post pictures. Looking forward to it!

Tom

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Tom Benedict
Island of Hawaii
P-Cat 18 / Sail# 361 / HA 7633 H / "Smilodon"
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Oh I plan a whole big write up and ill have the final plans posted free for those to use including instructions.
With the above posts I have done my fair share of metalworking too including welding, machining, casting (mainly aluminum and bronze). Trust me you dont need to worry. Part of the point of this is to make a well documented guide. Yes donor rigs will be handy and I might have a few lined up. thanks for your concerns though I can see where they come from =D This will be a strip built hull for those interested and i'll provide documentation on that process as well. As I am teaching my friend all of these techniques as well It will be sort of a learning guide for a hobbyist.

Aaaaah... Makes me happy just reading that. I'm looking forward to your write-up!

Tom

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Tom Benedict
Island of Hawaii
P-Cat 18 / Sail# 361 / HA 7633 H / "Smilodon"
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Curious choice of alias. http://en.wikipedia.org/wiki/Jabberwocky

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'life is too short to drink cheap beer'
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build a SHARK!!!....check it out!

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Check out "Prindle Sailors" on Facebook!
bill harris
hattiesburg, mississippi
prindle 16- "BLUE RIBBON"
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Quote

The Idea of constructing my own is not to save money but to enjoy the build process.

Now I understand.
Best advice is to find plans that already have the details pounded out. Tornado and Shark have already been mentioned. Another:
http://www.sailingcatamarans.com/
The web seems to offer even more.
The bonus for you in using plans is that the engineering is already done for you. You will not have to learn how to choose a sail plan that will give you the center of effort that matches your hull design, or decide what mast rake range will be appropriate or where your jib leads must go for heavy air and choppy seas. Tornados are hot rods, and are a significant step up from a beachcat, so building one of these may be too complex as a first effort. Anything over 8 feet wide gets hard to trailer, too.
Good luck. You have courage to take this on.

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Sheet In!
Bob
_/)_____/)_/)____/)____/)_____/)/)__________/)__
Prindle 18-2 #244 "Wakizashi"
Prindle 16 #3690 "Pegasus" Sold (sigh)
AZ Multihull Fleet 42 member
(Way) Past Commodore of Prindle Fleet 14
Arizona, USA
--

mrjabberwochy

Oh I plan a whole big write up and ill have the final plans posted free for those to use including instructions.
With the above posts I have done my fair share of metalworking too including welding, machining, casting (mainly aluminum and bronze). Trust me you dont need to worry. Part of the point of this is to make a well documented guide. Yes donor rigs will be handy and I might have a few lined up. thanks for your concerns though I can see where they come from =D This will be a strip built hull for those interested and i'll provide documentation on that process as well. As I am teaching my friend all of these techniques as well It will be sort of a learning guide for a hobbyist.

The problem is that you are asking VERY basic design questions. You want to get started in a month but don't even know your hull length yet? You really need to try a few designs and see what you like and don't like about them. Don't just read others opinions about designs. That way you will build something you really like. The last thing you would want to do after taking the time to build your boat is to try out another boat or design and realize you have a tank.

What are you thinking about using for beams? How will your tramp(s) mount? Where will your your stays mount? How will your DS be designed? How much free board and volume do you want? Skegs or Daggers? I think all of those questions need to be answered before you can tackle such a project.

--
Greenville SC

Offering sails and other go fast parts for A-class catamarans
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even if you build your own hulls

presumably you will be wanting the rig from an old beachcat

and if not the rig the sails

look around for a cheap local donor boat with iffy hulls

and that should help you settle on hull size

plus you may be able to sail something with soft spots etc for a season to see what you might want to improve

how far are you willing to go for a 10mtr mast?



Edited by erice on May 16, 2012 - 06:33 PM.

Jabberwocky if you think you can "plan" your way of the problems you are delusional. No offence intended, but you are completely overlooking the value of experience. It is essential. No way around it. Most of the advice posted so far is just fine, but I see your resistance to it. That's fine, it's your right and I won't complain if you go right ahead. But in my view, the best bit of sailing, and probably the fastest you will do, is into a complete, full qualified black belt disaster. The full enchilada.
At a minimum, buy a used boat and learn to sail, and not just how to tack and jibe. Learn what makes a boat go. Learn what mast height affects, and luff tension and pre-bend and core materials and epoxies and new fangled fibres. Your brilliant workshop will generate brilliant crap if you don't know what you are doing. As I see it, and with respect, you have little idea of just how little you know. If you want a happy end to this wonderful project, learn a lot more first, PLEASE!

Jab,
Too many experienced guys have tread this path ahead of you. Unless you have access to testing labs and have the design experience, you are far better off restoring an existing boat (of which there are plenty, in all states of disrepair). Plus, you'd save a ton in time and money over fabricating your own parts. There's lots of boats from 12' on up that could fill pretty much any conceivable gap -and could accommodate any custom mods you'd like, such as wing seats or a taller rig or the like.



Edited by RSabast on Jul 08, 2012 - 10:23 AM.

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Hobie 16
Hobie 18
G-Cat 5.7
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Lots of home built cats out there. Tornados, Sharks and a few others (can't remember what the smaller shark type was).

Noah's marine has a plan and supplies for a 16' cat here:

http://www.noahsboatbuild…c=GLP%2DLACHATTE&eq=&Tp=

Paper tigers are popular in australia. Plans here:

http://www.papertigercata…=article&id=70&Itemid=85

The Tiger shark is a scaled up version.

So it is not unheard of to build your own. But it will be a steep learning curve, probably not much harder than building 2 wooden kayaks. Sounds like fun to me.

Regards,
Dave

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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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Building your own is a far cry from designing and building your own.

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Rob
OKC
Pile of Nacra parts..
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That's true, better to pick a design and scale it to your liking. Or pickup 3-4 plans, measure a couple of fiberglass boats and figure out what you like best for each. The best idea I can see is to pick up an old boat (say an H16 or N5.2) for nearly free, throw away the hulls and make your own. That way if it sucks you are just out several hundred dollars in wood and resin, instead of thousands of dollars for the entire rig. And if it doesn't suck, you can slowly customize it the way you like after the basic boat is together.

God help me, but I'd love to build a cedar strip Tornado!!

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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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I sail a strip wood Tornado & played a dirty trick on my neighbor who has a Corsair 24' tri. Gave him my other woodie to sail for the summer (in exchange for storing both for the winter) and now the Corsair is up for sale. He couldn't stand the livliness of the 375# boat compared to the Corsair & relishes raising the hull 8' in the air. Pete

I can't remember the guys name but for comfortable cruising, have you looked at "Slider" catamaran? I think the guys name is Ray? just google "slider cat".

yurdle

I highly suggest you buy an old cat first, and use the knowledge you gain from it to assist you.

Thats poor advice. An old cat will offer him no further insight than a new cat he built himself and at 1quite the saving compared to a new Hobie. My first kayak I built myself. An old one would have offered nothing that I didnt learn from mine built from plans - and at a third of the cost of a new kayak commercialy made.

I highly suggest the original poster at least considers Rich Woods Catamaran designs for which he offers plans. Ive built several boats - none of which required someones used and abused heap to help me make a better decision. Sail what you make and go from there.
The Quattro 16 is lighter and FASTER than a Hobie 16 as well as a Dart. The lightness comes from the fact that okoume and fiberglass composite is stronger than gelcoated fiberglass pound for pound. Woods also employs skegs in his designs that are agreed [internationaly] to assist in upwind sailing and tacking. I started cutting bulkheads last night. Im looking forward to this craft hitting the water.

LOL, and I didnt need anyones banged up yard junk to make the choice.

Pete

bacho

mrjabberwochy

Oh I plan a whole big write up and ill have the final plans posted free for those to use including instructions.
With the above posts I have done my fair share of metalworking too including welding, machining, casting (mainly aluminum and bronze). Trust me you dont need to worry. Part of the point of this is to make a well documented guide. Yes donor rigs will be handy and I might have a few lined up. thanks for your concerns though I can see where they come from =D This will be a strip built hull for those interested and i'll provide documentation on that process as well. As I am teaching my friend all of these techniques as well It will be sort of a learning guide for a hobbyist.

The problem is that you are asking VERY basic design questions. You want to get started in a month but don't even know your hull length yet? You really need to try a few designs and see what you like and don't like about them. Don't just read others opinions about designs. That way you will build something you really like. The last thing you would want to do after taking the time to build your boat is to try out another boat or design and realize you have a tank.

What are you thinking about using for beams? How will your tramp(s) mount? Where will your your stays mount? How will your DS be designed? How much free board and volume do you want? Skegs or Daggers? I think all of those questions need to be answered before you can tackle such a project.

I think he needs to do some reading on some well established cats that the top designers offer plans for. The best arent tanks and they answer a lot of the questions you rightly asked. Designing it himself at this stage is awsomely uphill, and frankly, virtusally impossible to really achieve a great craft. The plus side here is that his strip building almost guaruntees a lower wetted surface than tortured plywood might, though there are exceptions. Id look up the top designers - like Woods - and go from there. The questions of where stays mount, freeboard and beam structuring and so on is already answered for him. Ive followed the Quattro16 for the last... wow... 13 years as well as the designers progress on other multihull craft. No one boat is EVERYTHING ever, but he could chose a lot worse.

Pete

What do you sail again? A kayak? Or a bulkhead?

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Rob
OKC
Pile of Nacra parts..
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yurdle

What do you sail again? A kayak? Or a bulkhead?

A kayak, a sailrigged kayak, a tacking proa and a trimaran is under construction. Nearly done. The cat is a gnawing interest of mine Im finally moving on. Your avatar looks like you sail and anchor.

Pete

tifdal r.....

Which tri did you build? self designed or plan set? any pictures?

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'life is too short to drink cheap beer'
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havliii

tifdal r.....

Which tri did you build? self designed or plan set? any pictures?

I want to say "self designed" but its actually a composite of other designs. The trouble with all other Trimaran plans is that they - and Im totally serious - wont fit through my basement condominiums window. There is lays the *stretching* and such of established designs in order to facilitate the shop window exit. Its a "sitontop" as opposed to the cockpit style which aggrevatingly can fill with water and forever be a bilge pump issue. If it werer lake sailing alone itd be a cockpit deal. With the 3 to 5 foot waves in Long Island Sound it HAS to be a closed body sitontop. Room for storage to be sure, but above decks. My finishing touches will be a sliding seat ontop to move the CG forweard and backward depending on conditions and sail loading. IM still keeping options open for an inboard drop keel as opposed to a leeboard. The leeboard is a little ungainly but it has the distinct advantage of adjusting lateral pressure on a reach to dial out weather helm in the most efficient manner. Its also lighter for tghe craft overall. You can dial out weatherhelm with the rudder of course but at the cost of drag.

There is no plan set. I merely *adjusted* the dimensions to accomodate my needs.

Its going to be nice. Im looking to get a hundred sq. ft. of sail at the least - maybe 150 max. The bouyancy of the amas have a lot to say in the regard and I wont know until its sailed. Its robust enough for a full 200 sq. ft. rig but I havent designed amas to carry that loading. Theres a lot to be said for ease of carry and setup with lighter components.

No pics yet. Ill post when done.

Pete

hey some body have a 10 feet cat or construction plan or someting to help me

email me im new here jean_r_@hotmail.com