A New Beach Trimaran

Scale is an issue

Folding multis is something that has occupied my mind since 2000 when I came up with an idea for a folding cat. Since then it has taken thousands of hours and more money on two prototypes - and yes I am applying for a patent - the process is arduous and costly.

That is not what I am writing this for - it is a scale thing. When I was first making scale models of the little cat my model worked really well. On the 6m prototype a few early folds on wheels in the backyard had me learning that hulls that you hold in your hand don't cooperate like that in full scale.

Cats and tri hulls are thin and want to fall over. They also bind up poorly designed mechanisms and need to be "fed" into their receiving sockets. In Chris's case I have already stated my thoughts on the sockets. Getting two beams to fit into two tight fitting sockets while holding up a float is going to be tricky. I have been caught trying to short cut on the cat and have ended up wrestling with a little 6 metre cat - it was a tussle.

So again I would like to see the tri have quick fit sockets - if you go to a stainless place that sells hinges and stuff for truck tailgates there are even nifty little spring loaded pin systems that click when they line up with a hole. With the simple struts and sockets you lie the float on the beach - attach the struts to the main hull and then lift the float up. The beams then nestle into the sockets and the stainless pins click into place. Lift and click rather than "A bit your way - a bit my way - PUSH!" Otherwise you do what the Windrider does and go really loose and floppy but I don't think that will work so well on this boat.

Fanie - As stated in previous posts I think that there could be some issues with your boat wanting to fall over - especially with a mast up - as it folds. Again the model may not show this up. With a raised mast the main hull could fall to one side, the floats stop this but the mechnanism may bind up and you may have to get ashore to give it a tug. Also the mast raising procedure will have to deal with a big folded rear beam in the way of mast lifting. It may need a temporary brace instead of an installed one - or just use the Farrier system - it is very well proven - you can use alloy - the Tramp did.

cheers

Phil Thompson

 

Fanie,

Here's my take on patents for boat stuff in general. All you guys out there in TV land can have your own take on these things and I encourage you to make your points known. It won't change my opinion on the matter after 25 years of fiddling around producing video programs for start-up companies who blew a large wad on their chase to "get a patent in place" and then fitfully protect the same thing.

Real simple, patents can cost really large amounts of money. The more complex the claims in the patent application, the more money it takes for some patent attorney to make use of his selective knowledge of the arcane language of the patent application.

If patents could be submitted in normal language, there would be many fewer reasons for hiring of an attorney at $300 an hour to write this stuff for you. After all, who knows the way the machine works better than you?

For most patents, the big cost is in the process of the "patent search" so that you can quote many examples of prior art in your submission. Again, this is all part of the game, should you need to pursue some violator of your precious patent in a court of law. Notice how it, once again, comes back to a court scenario so that you need to hire another attorney to stand in for you?

After all, the patent by itself, is nearly worthless, save for the so-called ego boost one might get from being a "patented inventor". It's just a crappy, official looking document on your wall that just might impress your buddies when they come to visit. Without the desire and resources, as in MONEY to pursue the violators, the whole patent process is absolutely worthless as a business enterprise.

My take is that for the average guy, who has developed some really cool thing for the boating industry, the best thing to do is to take all the money that they would otherwise toss at a patent and save it for something else. The intellectual properties attorney, the draftsman who does the nifty and similarly arcane drawings of the invention and the fees at the patent office; Save it for another, more important thing.... That would be to use that money to invent the next best thing for the boating industry, OR... better yet, spend it on the marketing of the first really cool thing they did, so that they can achieve something like market penetration and hopefully, market share.

There is one exception to this patent thing for boaty kinds of things. That being the absolutely inconceivable potential that your patented device can properly be licensed out to a big time boat company for MILLIONS of dollars. Really, MILLIONS... as in the kind of money one might get for inventing a new medicine that cures five kinds of cancer. You know, the kind of cash machine idea that would move the desktop computer industry into the next millenium... Otherwise, it's a huge waste of time and money and it will give you a false sense of confidence that you really have something worth fighting over.

It is just so damn easy to make a ten- percent improvement in an existing invention that, in the words of the Patent Office, moves the invention forward, that it's ridiculous. Want to know how simple in actuality this all is... just go to a big tradeshow for any industry, you pick it, and watch the hordes of guys from Asia running around with digital cameras, taking pictures of everything under the sun that looks even mildly interesting.

Now, what do you suppose those dudes are doing with such a fervent sense of purpose? The answer is, and I hate to dump it on you nice guys who think otherwise, but they are swiping your ideas. They are shooting photos of your stuff so that they can take all that home and reverse engineer it. They will make some very small and virtually irrelevant change in the device and come roaring back next season (or sooner in some cases) with their own brand of your hard-earned super cool, next best thing. Now, don’t get me wrong that it’s only those Asian guys who are doing this. Everyone is doing the same thing, or they will soon find themselves without a job. Well, they will unless their company has a very high degree of ethics and they have their own super smart inventor dudes who don’t need the leg-up.

Think you can stop that? Think that it matters to them if they "might" get sued by you? Think they worry about your limited financial resources that totally inhibit your ability to mount an on-going legal procedure? Hey, my friend, this is modern business which is the civilized equivalent of open warfare without the explosions. If your figurative army is too small, you can only try to make a hasty retreat and lick your ego, literally.

All this boils down to the fact that you should be spending your lovely time, your creative problem solving genius inspiration and going down to the shop and inventing that "next best thing". This will, once again, put you ahead of the market and force the other guys to play catch-up to your glowing capabilities.

Does all this make me sound bitter and hateful? Do you think that maybe I had one of these gotchya experiences myself and have the wounds to prove it? Well, I'm not and I didn’t.

I just worked around hundreds of creative industrial types, making video based marketing presentations for them and their really cool, patented new gizmos. Most of them, if their invention was, in fact, really cool, were unceremoniously shoved to the corner of the big sales floor by a bigger outfit who brazenly nabbed the idea and had the resources to go full-tilt with it…. Within two years!

The good guys had no fall-back position and no fresh ideas, as all their time and money had been spent on chasing that “Hey, I’ve got a patent” concept. Eventually, many of them accepted full-time jobs at the firm which nabbed the invention, where they learned to keep their mouths shut and take that lovely paycheck home.

There isn’t much that would suck more than that.

 

Chris I agree with you fully. Besides everyone looking for ideas, you can go on the internet and get years and years of information on anything.

I'm not a boat builder, but I would rather attempt to give the customer a better deal to buy a great boat than having to rev his pocket to accomodate my legal costs amongst others.

If a courier has to charge me for a packet delivered here, there are two ways. The driver can bring it the shortest route and save time and fuel and make his ounce of bread, I'm happy and they are happy - or he can take the route via Cape town then here in which case the parcel is going to be very expensive. The extra traveling and expense has wasted time, fuel and produced extra cost that didn't contribute any to the value of the item I am getting.

What many people forget is that in many communities people discuss things. If someone is happy with something he got everyone else in that line would be interested too. If the price is right then there is a good chance of selling more.

Big companies won't put out the millions for a little swing arm that you designed. It is far easier for them to just sue you, right or wrong, and keep you in court until you are bankrupt. Old trick. Why do you think it is that fuel is our only source of energy... many has come up with much cheaper alternatives. They will even just let you disappear if you are in their way.

As for my tri, I can see the mast up could topple it over, especially if there are some wind. The idea won't be to launch with the mast up. I will see how well it works once I've got it assembled. Patience...

 

Chris

you are 100% correct

nailed it spot on

 

When to patent?

Guys you're right, the only time to patent is when YOU will manufacture yourself! Otherwise you will not get millions from some Co. for any of the different reasons stated above.

catsketcher if you still would like to patent, use the UK patent office. It is the cheapest and geared towards the backyard inventor, ie. you can write the patent yourself, a copy of NOLO - Patent it yourself, can help but not necessary. They will search the patent databases, periodicals for prior art and advise if your application can stand as worded. Then if you get through all this, less than 6months if you pay app & search fee upon filing 30+70lbs, withdraw and re-file in the US, the biggest market and the one you should own.

That's my take on individual patents and I ain't no lawyer.


Have you seen this folding system? The Exploder 25, I'm working on my own 20ft folding tri! Think I'll use a Farrier like system, not too worried about capsizing.

 

This is my multihull Product.
http://www.youtube.com/watch?v=sGPyl-Ja2Jc

 

What are the expected benefits - and what is new about the concept?

 

folding mechanism

Glad you guys are diving in deep into improving "trailerable" tris. IMHO it's the key to a boat being trailerable. I'm confident I could have cobbled something ugly together that would've killed someone
first time it opened.

Thanks

PS: You must know my younger son. He was the one who discovered Led Zep about one year ago

 

Dear Mr Watson,

The folding arms like in my earlier posts are working. There are some pics in the link below.

http://www.boatdesign.net/forums/boat-design/boxy-fisher-catamaran-idea-20022-18.html

I haven't gone to any troubles to add another hinge or mechanism to keep the centre hull upright while it is partly folded since the tri is only a test boat for some things I have to try before I jump in making the cat. It is however easy to keep it upright if you stand inside the hull and push the arms up or down, I can do it on the lawn. The position of the hinge on the hull determines how high or low the ama's fold in. The folded width is about 1m400. The hull wasn't designed so the ama's would fold in snug as Farrier did, never the less an easily trailable setup.

If one cad a mechanism up and the ratio's work out it is very seldom that it won't work out in real life. I'm visiting a friend at a dam with the tri after Christmas and will do some more testing on the hinging there amongst other things, on the water and not the lawn.

On fixing the beams to the 'housing' I have four bolts. It is a bit of a pain, it takes too long to screw them down and you need a spanner or socket drive.

A far easier and faster way of securing the beams in place would be a cam with an arm on it. You can then just hook the cam and push the arm down and the beam is locked into place.

In the event of a capsize, the cam can be released, the beams folded and the tri can be righted, then folded out again and cam clamped again.

 

I am building a 7m racing tri similar to a multi 23. I started with a old tri cut it up and kept modifying it till it works. (This process was slow but has avoided some design faults and was a huge learning experience) The plug is now complete and I will be making a mold next week. (easier to make a mould than fair several hulls). I now need some advise on beams. I have decided to use a grainger system similar to the new grainger 7 boat. Any advise on material to use and ideas would be greatly appreciated. My original idea was to 3D model a beam, 5axis route a plug make a split mold then layup vacuum infuse 4 carbon beams.
Weight is critical to this boat. My target is 250kg so I have little margin to waste on heavy beams.
I am not a boat designer so I have no idea how to calculate the strength required. Boat details are as follows:
Max sailing weight 500kg
Beam 5.2m
Beam length 1650mm
Main hull max beam 900mm
Underwater stay 800mm (supports beam nearly in the middle)
The tri will be sailed on one float upwind
Distance between underwater stay hull mount and top of beam 350mm
I worked out that breaking strain of one assembly would need to be about 1000kg including safety margin. Would this be correct?
thanks

 

Hi everyone- I have a question on trimaran waterstays- why the heck would anyone use them? as soon as they go through the water the boat slows considerably. Doesnt this extra drag created completely defeat the purpose of a trimaran in the first place?...are they only used in folding designs? they seem to me to be not very intelligent. maybe im missing something?
- i have no idea why they are used and i am designing and building a core cell racing/cruising tri. I refuse to use expensive cross arm systems and also refuse to use waterstays: why could i not just use aluminum tube akas curved slightly at the amas and mounted with sleeve and pins? what about eliptical (tubes), curved akas? or triangular,? even an i-beam or something should be better than waterstays?
it seems that would outperform any tri in the same class that uses waterstays??? hope someone can explain why waterstays are used...
thanks !!

Doug

 

Waterstays are used in various ways, Doug. Typically, you can use a much lighter aka beam with a stay, than you can without one. This may allow an overall lighter structure and ultimately, an overall lighter boat. Many times, it can also be less expensive to build the aka structure with stays, than to build it as a stand alone beam. You can usually build with a smaller diameter beam with stays than without, reducing the aero drag signature.

Let's see... a racing boat design that is not going to use "more expensive" beams (I assume carbon construction here) and also do not want to use waterstays. This means that you are probably limiting the discussion to larger diameter aluminum tubing, or wood/composite box beams designed for the loads of a racing boat. You can use alu tube akas with a curve if the tube wall and diameter are of sufficient strength to handle the job. Finding a good mandrel bending service for tubes of the proper spec may be a bit of a job and it will not be free to have it done. You'll probably need to have them shipped two directions if the bender is not within reasonable driving distance.

Outside of those two solutions, the design of the L7 sliding beam trimaran utilizes pultruded fiberglass I-beams to solve a very similar dilemma to the one you describe. You may want to take a look at how they have integrated that material in their boat.

Using flat beams will probably require you to have taller amas, as sea clearance is a bigger issue for drag than your complaint about waterstay drag problems. If your design regularly immerses the ama end of the beam you'll see drag numbers through the roof compared to wire stays.

Well, yes, properly integrated and designed aka structures can contribute to a faster boat over one that uses waterstays. It all depends on where you are going to sail and in what kinds of typical conditions, as well as a very long list of design brief issues which need to be thought of as a whole if you are going to arrive at a truly fast boat.

In parting, you may want to look at the exceedingly fast SeaCart30 trimaran from Sweden. It uses waterstays as a functional design component to full advantage. Virtually the whole boat is carbon with really strong and slender, low drag carbon aka beams that fit into sockets in the vaka hull. This design solution is done so that the boat can be easily trailered without the added weight penalty of a typical folding system. If fast is what you seek, you may wish to consider how they have completed their design with waterstays. The SeaCart30 apparently suffers no serious problems when it comes to fulfilling the goal of an incredibly fast boat for racing.

 

Thanks Chris! and every one for responding-- i will check out the above mentioned designs- yes i had thought of using large diamater tubes but you have brought issues to my attention regarding that..what i think i will try is using corecell...making large diameter aka halves, epoxing and glassing both sides(composite foam sandwhich)and then joining the halves with epoxy to create light but large and inexpensive akas. Maybe 8 inches in diameter?. lets see thats PI x dia x length say using 8 inch dia akas and 3/4 inch core cell- aprox 200 square ft of core cell...i can get that much core cell for about 500.00 at noahs marine...and the glass and epoxy should not be too much- thats maybe another 300.00 or so to do that amount..looks like i could make my akas for around 800.00 give or take ..that doesnt seem too bad for unstayed akas.? does it? i could make a 45 ft mast in the same way but only 5 inch diameter and eliptical in shape.

peace and thanks to all..any comments positive or constructive are appreciated.

 

Waterstays are generally out of the water (despite their name), so don't add appreciable drag.

I assume you realize that the water stays react both the drag loads on the leeward ama and the forward thrust from the shroud on the windward ama. If you don't have any water stays, the beams have to be stiff in the fore-aft direction to take these loads, and that adds weight to the beams. For example, the structural part of the beams on my Chris White-designed 34' trimaran are only 2" wide. The rest is just a light foam and glass fairing.

Another reason to use waterstays is to have a statically determinant structure. If you depend on the bending of the beams to take the drag and thrust loads, you have a statically indeterminant structure. You have to take into account the elasticity of the structure in order to analyze the strength and stiffness. Finite element methods are great at doing this, of course, but I'll bet most designers of homebuilt beach trimarans don't use FEA. With waterstays you can use pinned joints for the beams that allow you to analyze the structure as a truss - much simpler, and you know where the load paths are.

You can integrate the water stays into the design of the boat so they serve other functions as well. For example, running the stay taking the drag loads from the bow to the outer end of the forward beam makes it a great place to attach the forward net. Otherwise, you'd need to provide lifelines all the way from the bow to the forward beam on boat that was bigger than a beach cat.

 

Ok..ill put myself on the line here: this is the concept of my amateur designed tri- i have the plans dawn and the core cell for it now. i have based it on the premise that the originators of multihulls(the polynesians) did not have autocad or any real modern naval architecture knowledge albiet what they learned over years, may have been of trial and error. of course those boats are probably not as fast as todays but they still have merit in there design concepts. i.e they used only their brains and guts to design their crafts.- now having said that I know i am opening a can of worms here and there will be people who will disapprove of my design and tell me that it wont stand up to heavy weather etc etc blah blah. but i guess i wont know for sure till i try..but try i must so here it is...
the vaka design is essentailly an ama shaped 32 ft loa hull with an area of 256 square feet. it is made form 3/8th core cell lamainted with two layers of cloth inside and out. using a wave cutting bow- rockered at the stern- shape smaller but very very close to the float of an extreme formula forty cat float. but it will be wide enough say about 3 ft at its widest beam amidships, to accomodate one person on a mattress berth to lay down on when i need to rest on extended ocean crossings. the boat will be water tight using an entry hatch on the deck being sealed up in heavy weather. a self draining central cockpit which is built similar to Chris Ostlinds cockpit- which i
sorta-kinda got the idea from a warren design. the mast will be made from core cell in halves having a dia of about 6 inches and about 45 ft high. rotating on a ordinary wheel bearing mounted at the hull keel. and through the deck. with a good sized mast diamater cyclinder mast step protuding up through the outboard deck about about 8 inches or so as added support. the rig will be a large wishbone rig similar to the nonsuch im thinking around 450 square ft.- hopefully jibless!. the sail is attached to the mast using a sleeve. and reefing is done by pulling the sleeve at the bottom and pulling it down. then pushing it back up with a long pole type tool(?) .... (btw how important is a jib anyway if i use a huge wishbone rig??) i would like there to be a mainsail only, if possible.
the akas are made again from core cell- 8 inches dia by 1/2- 3/4 inch thick each 28ft long. WITHOUT using waterstays. as i want no drag when i hit a wave to slow me.
the design is very sleek and made for speed but it will be strong with the foam and epoxy. and i plan on using it for extended passages with bear minimum gear. mostly coastal cruising but i could cross an ocean if needed.-The rest of the boats area will be used for food and water for long crossings. free board about 30 inches plus at the cockpit. i will use dagger boards or even leeboards to prevent dmagae should i hit soemthing- although i have been toying with assymetrical amas to do away with a dagger board. alternately i may or may not use daggerboards in the amas themselves, regardless of what others say about that type of system. amas will be half the size of the hull beam and attached using standard ratchet straps recessed into the amas about a 1/8th inch. so as not to move or cause drag. or perhaps a bolt mechanism. the cross arms are one piece long 28 ft running running THROUGH at the cross arms and step to aid in mast support and help in the rotation without binding. and a cross arm running through the hull at the cockpit aft. the mast will be freestanding rotating type. i have experimented using core cell for masts and let me tell you- they are strong !! in the event of a severe storm and high winds and seas- the boat will be watertight and ill hide below using a sea anchor till its done. or outrun it. The idea is, it is a capsule 32 ft long. with slenderness ratio of about 10:1. the main hull will weight around 250 lbs dry. but no carbon fiber will be used. people have crossed the atlantic in dories and even 10 footers! and Web Chiles crossed oceans in the south pacific in an open standard dory 18 ft long using canvas sails!
ok...i know its what might be called primitive design but to me that is a compliment - because the idea is minimalist and simplistic and cheap!- lol.if not ill just go buy a k design catamaran plans. anyone think the duo 800 would be a good choice for passagemaking if using the right precautions? the idea is to get on the water as fast as possible..btw the sails will be polytarp. im sure the traditional sailors out there will have some objections to the poly, but they also do work well! any positive or nicely communicated constructive ideas are welcome...
thanks-

i wish i knew how to upload my hand drawings for you to see.
Doug