The micromultihull rule

[rayaldridge]

Am I wrong or has this design niche fallen out of favor? Most of the material I've seen on the web is a little elderly.

I'm hoping Richard Woods will see this and comment on it, since his Strider catamaran was one of the first successful boats designed to this rule. But even the stuff on his website that address the rule seems fairly old.

I'm interested in knowing if there is still any organized racing under this rule, since I have an idea for a boat that fits it. It struck me as a great set of parameters for those who'd like a small fast cruising boat.

[Richard Woods]

I don't think I can help much as I've not raced in the UK for some years.

Having said that, although the Micro rule may now have served its time, there are still many opportunities to race small trailable multihulls. Just most of them these days are Farrier tris.

When I first started promoting and developing the rule in the UK back in the early 1980's there was basically no inshore racing for multihulls and thus the only racing multihulls were large ones. Now of course there are hardly any offshore multihull races in the UK

As I said at the time, there was a need to run races races for those who can afford a second car, not just those who can afford a second house.

Later I said "some people don't know the price of cars"

I think the New Zealanders are now trying to do something similar.

It will interesting to see what you come up with

Richard Woods of Woods Designs

www.sailingcatamarans.com

[rayaldridge]

It may be that the time is coming again when smallish multihulls will be more appealing, considering the economic situation. I did run across the New Zealanders you mention-- I think they're developing a 8.5 meter box rule, and a number of boats descended from Tennant's cats have already been designed. Good -looking cats, some of them.

[joz]

I like your idea ray but its should not be limited to 8.5 mt loa rather have various sizes and budget restrictions from 6 metres to 30 metres.

[yipster]

is not a handicap to prefer over size and budget ruling :confused:

[rayaldridge]

I think that there aren't enough boats, or for that matter, enough sailors to populate a large number of development classes,

I'd be happy to see just one set of rules that spawned active racing in small multis, so that I could try my ideas out against those of other designers. So far I've drawn two boats, and neither is speed-oriented, in fact they're not much faster than most monohulls of similar length. Now I'd like to take a crack at building a near-shore budget racer with moderately luxurious accomodations-- a difficult thing to achieve in an easily trailerable boat. I have no interest in replowing ground already thoroughly harrowed by better designers, so it has to be something new.

[Richard Woods]

A couple of years ago the UK multihull magazine Multihull Review ran a series on performance multihulls. I wrote a couple of articles as did Erik Lerouge.

I have just put those articles on my website (on the Articles pages) for those who didn't see the original magazine.

They may help any discussion on multihull racing

Richard Woods of Woods Designs

www.sailingcatamarans.com

[rayaldridge]

Thanks, Richard. Very interesting stuff.

It's hard to know what to think about the way the boatbuilding business has gone, with regard to multis. It's a pretty tough way to make a living, apparently. I've reviewed a couple of those "20 Best Sailboats from X to Y feet" books, for Living Aboard Magazine and one of the sad facts that emerges about almost every boat reviewed is that the company that built it has since gone out of business.

Of course, none of those boats were multihulls. Partly, I suppose, that's because the resale value of multis holds up better than monohull cruisers, or so it seems to me-- making them less of a bargain in comparison with these older monohulls. Partly it might be because there aren't as many older multis that are common enough on the market to be good choices.

It would be nice if there were more choices in the small trailerable catamaran market-- something with the speed of a Strider Turbo, but enough cruising luxury to tempt folks to make extended coastwise passages. For the most part, as I think Richard mentioned, the Farrier tris have the small cruising multihull market wrapped up-- not surprising, considering that their accomodations are far more appealing than most of the trailerable cats on the market. Richard has several boats could, I think, compete well against the Farriers, with his demountable center cuddies, but you have to build your own to get one, for the most part.

One of the biggest problems for small trailerable cruising cats, however, is that currently it's so much more difficult to get a small cat from trailer to water than it is to get a Farrier tri set up. I really like Phil's folding cat, but it still limits designers to 4 foot wide cabins-- and those sight lines inside the cabin are going to be a little claustrophobic, compared to a tri.

But on the other hand, once you get a cat assembled and into the water, it's a much more comfortable platform for cruising, in my opinion. Apart from that, it's the cramped interior of small trailerable cats that keeps them from competing on a level playing field. At the dock, where boats are sold, the spouse shoehorns herself into a manhole and then has to slither into a coffin-sized berth. She doesn't have an opportunity to realize how pleasant all that open center deck is underway. She walks across the dock and steps down into a Farrier and it's a proper little yacht, in comparison.

Anyway, the thing I liked so much about the micromultihull rule was the idea that the boat must be multipurpose-- that it should be possible to take it for a cruise between races. I wish the rule were still the center of a lot of development energy, because it would make it easier to sell a more luxurious micro racer.

Just thinking out loud....

[Chris Ostlind]

This boat represents some interesting potential along the lines being discussed.
http://www.rodannyachts.com/content.php?id=4

[bill broome]

ross turner suggested a solution, with a demountable, and palatial, transverse deckhouse on his 'j7'.

not successful because of the schooner rig and size, which made set up hard even without the deckhouse.

but i think a 6m sloop rig with just two sliding crossbeams could provide a fast daysailer/racer that turns into a cruiser with competitive accommodation for long weekends with the family on board.

[Richard Woods]

That is something similar to what we do with our Merlin catamaran.

In race trim the boat has racing sails with a low boom. In cruising trim we raise the boom, fit cruising sails and also a small central cuddy. This fits easily on the back of our pickup truck (sometimes we sleep in it on the truck) and takes only a few minutes to slide onto the Merlin. In fact we did exactly that only yesterday (I have just come back from a night on board). It took less than an hour to motor from our dock to the beach, back the truck into position, slide the cuddy on, lash it down and motor back to our dock. It would be quicker still with two men instead of Jetti and I.

It is way more comfortable than the open deck version, especially as we use the central cuddy for sleeping which means that we can set up a good galley on one hull and a heads in the other without worrying about putting them away to get to the bunks.

You can see more of both Merlin versions on my website (of course!)

Richard Woods of Woods Designs

www.sailingcatamarans.com

[bill broome]

i like the pop-on cuddy plan, as it preserves hull integrity. less total space than a transverse deckhouse, but privacy as compensation. particularly suited to merlin, as it is performance oriented.

but the equally great problem is competing with folding tris for launch/retrieve time. needs something a bit clever to allow the hulls to accordion together. if it were easy, it would be done already, but new gadgets may make progress possible.

till then, a swing mooring is an even faster way to get afloat, than a trailertri.

[rzj7l2]

but the equally great problem is competing with folding tris for launch/retrieve time. needs something a bit clever to allow the hulls to accordion together. if it were easy, it would be done already, but new gadgets may make progress possible.

I have seen two concepts that could do it
http://www.cat2fold.com/
http://www.foldingcats.com/

But they never really took off :( .

The Dandee8m has a hard to beat price tag (2008 prices: From "Sailaway" in China 80.000 USD to 90.000 with some options when delivered to US). But I have yet to see a high quality product from China. Maybe _this_ is the exception, who knows ?

[rzj7l2]

The Dandee8m has a hard to beat price tag (2008 prices: From "Sailaway" in China 80.000 USD to 90.000 with some options when delivered to US). But I have yet to see a high quality product from China. Maybe _this_ is the exception, who knows ?

I Forgot: The Dandee is really a John Shuttleworth design, the Cheetah 8m. I ordered the study plans a couple of years ago. The design is a bit complicated, everything has a compound curve. Some exotic materials was specified

I just took the bridgedeck clearance from the drawings: 75cm under the deck but at the outboard pod only 0,35m :eek:

[rayaldridge]

The Dandee8m has a hard to beat price tag (2008 prices: From "Sailaway" in China 80.000 USD to 90.000 with some options when delivered to US). But I have yet to see a high quality product from China. Maybe _this_ is the exception, who knows ?

Their claims for the boat are extraordinarily modest. I noticed they said a "lightly loaded" boat could reach at 10 knots. My little heavy 16' open cruising cat, with only 8.5 feet of beam and a very modest sprit sloop rig has hit 8.5 knots on several occasions, and I'm pretty sure that I could get her up to 10 in the right conditions.

In any case, this isn't really a trailerable boat in the conventional sense, because it wouldn't be highway legal without a wide-load permit, and putting it in the water would not be a quick job.

[catsketcher]

Gday all

As someone who has designed and built one finished and one partially finished small cats I think I can give some idea of their strengths and weaknesses.

I think a micromultihull rule will not work as long as it is made for fast boats. That is not a typo. I have a big thing about the best race boats being re-usable. Take a Laser, Hobie 16,J24 Etchell or back in the old days a Windsurfer. You could use any of these boats for
-racing the best sailors in the world with a fab new boat.
-racing good sailors in your area
Then when the boat got older
-you could race in the middle of the fleet with your club
-use the boat as an afternoon racer
-cruise the boat
-use it to teach sailing
-hire it out (Laser, Hobie, windsurfer)

So my take on the micro multi rule is to make the boat the very best CRUISER it can be. It has to be able to take people away for a night or two, take newbys out sailing, fit into many different niches and survive well. It has to be tough and long lived and not really very fast. In fact racers actually do not need to be fast as they usually come back to the same spot where they started. Cruisers need to be faster as they actually have to get somewhere.

This is all a bit upside down but I am an ex racer who qualified for the worlds in a Laser - Racing was ALL I did and it was the racing that got me - not the speed. I got heaps more adrenalin from a start of 160 slow Lasers than racing 8 other superfast Tornados.

cheers

Phil

[bill broome]

thx for those two links, rzj. the 'folding cat' is just my ideal size and shape, but the machinery too complex for my taste. "add lightness, and simplicate" as some motorcycle designer put it.

[Raggi_Thor]

Gday all...
This is all a bit upside down ..
Phil

After all you are down under :)

[Richard Woods]

I quite agree with Catsketcher.

When I developed the micromultihull rule I wanted to ensure that boats had a dual purpose and could be used for cruising. In a way it is more important to do that with small boats as they are often bought on a budget and owners cannot afford to have a boat sitting idle or losing money on a boat with a low resale value.

In fact in the original rules I suggested that major regattas had a long race which finished in a different port than it started. That was to force all crews to live on board. At the time it didn't occur to me that crews would stay in hotels. But at least I tried.

I also didn't want the boats to get too extreme, in part because I know that many people aren't as good sailors as they think they are.

So the F28, the racing offshoot from the micro class only lasted a couple of years, as did the F40. Whereas the micros are still being cruised and raced.

My version of the folding cat problem is solved with my 22ft Wizard and 25ft Sango designs, both of which you can see on my website.

And on the Articles pages you can read a history of the Micromultihull rule and some newer thoughts on performance boats.

Richard Woods of Woods Designs

www.sailingcatamarans.com

[rayaldridge]

Right. This is why I found the micromultihull rule so attractive-- the boats were required to have some degree of accomodation, so they could be used for something other than racing.

[catsketcher]

As someone who has designed two small cats - 6 and 7 metres I think one of the reasons that small multis aren't designed much is that they are really hard to do well.

Any idiot can get two hulls and bang em together but if you really try to fit people in a small boat basic problems emerge. People need 3ft above berths that are 6 ft long no matter what the boat length. Also water and stores weigh almost the same no matter what boat you are on. The chance for error is so great on a small cat.

If a designer gets the weights of his large cat wrong it will usually be because the builder added stuff or people added extra comforts. Maybe an extra 15% is added and the boat floats down just a bit, usually at the bum.

Half of those extra comforts on a 800kg cat are catastrophic as they are so much of the total weight of the boat. When the four of us go away in Cats-paw we add almost 400kg to the displacement of the boat and it doesn't weight anything near 800kg. Our 38 footer gets almost the same load and the proportion is not half but 10%. The boat barely notices. If the designer gets it a wrong with a big boat - big deal add a transom extension. If a small one goes wrong the boat needs to be cut in half and rebuilt.

Look at the video of the Shuttleworth cat. If you look at the flare you will see that with the load on it the flare is in the water - light ship. Add water and stores and you have very fat hulls. This wouldn't happen with higher immersion rate large hulls. I would be very unhappy to sail this boat - the lee hull will be high drag in all weather but especially in chop and without major modification (cutting the thing in half and widening) you can't fix it. Lee hulls go down in cats. The Shuttleworth flare type hull is great in large cats but in small cats it is disastrous if the weight is over the designed limit. I use this shape myself and am very aware of its problems.

As to Bill's point about simplicity - this is a hard one. Folding adds complexity straight away. Add floors, keeping the rig up, keeping hulls aligned, stopping hulls rotating, keeping fingers safe and more and you have many very necessary conditions needing fulfilling. There are many complex and reliable machines - cars, computers, clocks, a roller door, kitchen rollers etc. They can be made to work but a small cat has very very little room for error. I like the idea of small cats which is why I am refitting the 38 footer for sale but the amount of design restrictions you get is amazing - especially if you want to trail it.

cheers

Phil

[rayaldridge]

I have to agree with just about everything Phil says. With small cruising cats the difficulty is not in making them sail well-- it's in making them comfortable.

As an example of the severe constraints you encounter in drawing tiny cats, my 16' open cruising cat, Slider, presented me with a difficult choice very early in the process. No matter how I squirmed, I couldn't figure out a way to have both cabins and comfortable seating in a boat that small. This dilemma turned out to be a godsend, because it led to a breakthrough in my thinking that resulted in a boat that as far as I know is unique. And though I don't have cabins, I do have the most comfortable-to-sail boat I've ever been aboard.

Here's a construction pic that shows the perfect ergonomics of Slider's seating.

http://slidercat.com/blog/wordpress/wp-content/gallery/slider1/nancysits.jpg

It's like sitting in an armchair, because the steering lines run around the outside of the cockpits, so you steer with your outside arm lying along the deck at the same height as an armchair's arm rest.

What Phil says about weight is absolutely true. Slider is designed to carry two people and their camping gear. Last summer I took my two teenaged sons cruising, and for the first time ever we got a little spray in the face while crossing a choppy bay. They're both skinny kids, but their weight and the weight of their food, water, and big tent was enough to make Slider a less dry boat.

I think the failure to consider ergonomics is one of the most common reasons that small cat designs can fail. I remember years ago a novice designer showed me drawings of a small trailerable cat. To me, it looked as if his single berths were only about 16 inches wide.

I'm currently struggling with these ergonomic issues on a 23.5 foot cat I'm doodling. To my eye, the cabin looks too high for the hull, but unfortunately, a bunk needs 40 inches above the bunk board if you're using 4 inch foam as a cushion. Unless you have this much headroom, you can't sit up in the bunk, and if you can't sit up, claustrophobia may result, as well as bruises on the head.

http://slidercat.com/blog/wordpress/wp-content/uploads/2009/07/cabincat24sailwebsize.jpg

You can giggle at the rig; I don't mind. I've really enjoyed Slider's sprit rig, and I was curious about what a split rig might look like on the new boat, so I drew one. To use a single stick conventional rig, I'd need a mast slightly over 30 feet. I actually own such a mast, and a good mainsail to go with it, but I'm scratching my head over the problem of getting it stepped at the ramp. I know it could be done with gin poles, but the masts for the divided rig would be a lot easier to handle. I might be willing to lose some windward efficiency to get added convenience; besides, Slider's sprit-sloop rig has proven to be surprisingly weatherly.

[rayaldridge]

Okay, that was just silly.

But here's another idea:

http://slidercat.com/blog/wordpress/wp-content/uploads/2009/07/cabincat24gaff2web.jpg

This is sort of a hybrid sprit rig, with the sprit hung from a snotter that is suspended from the main halyard by a Dyneema line, so that it moves up and down the mast with the throat of the sail. The advantage is to lower the CoE of the rig and approximate an elliptical plan form, but without the expense and hassle of a fully battened sail.

[terhohalme]

I always thought (and experienced) that battens in mainsail were to avoid hassle. Expensive though.

[rayaldridge]

Terho, I guess it depends on which hassle you're talking about.

For a conventional main with a lot of roach that must be supported by battens, there are some hassles involved: chafe, weight aloft, difficulty of reefing or lowering sail off the wind in strong conditions.

Folks differ on whether these are outweighed by the many advantages of battened sails.