Post your design ideas

Thanks, Brorsan.

The folding mechanism is a variation on the kind that folds along a central spine and at the boat's armpits. The idea is to be able to fold the boat with the rig up, so that it can be berthed in a narrow slip (the slip I use is only 10 feet wide, and the boat is 12 feet at sailing beam.) The geometry is such that as the hulls swing aft in relation to the central spine, the shrouds loosen slightly, but retain enough tension to support the rig (though I wouldn't want to take the folded boat out into a chop without tightening these shrouds-- easily done since instead of turnbuckles, they will use Spectra deadeyes.)

The seating is on the center deck. One of the strategies folks have used to deal with the problems of folding small cats is to make removable center cabins or shelters. It occurred to me that if I combined seating and deck storage, these could be removed for folding a lot easier than such a central shelter. So my seats are deck storage and icebox, and for folding, these can be removed and put below.



I should add that the tillers as shown are not the final arrangement, which will be an adjustable central tiller.

 

Hi Brosan

Yes, the idea was to use garden chairs for outside seating on this boat - how did you guess. There is a clear deck space roughly 3m x 1.7m aft of the wheel, so space for a few chairs and a folding picnic table. This would seem to be more adaptable than fixed furniture and probably lighter as well. Would be nice to be able to cover this area with some kind of awing when in harbour. I like those tubular aluminium chairs you see outside cafes - very light, corrosion resistant, stack away when not needed.

For steering, you could either stand at the wheel with the wheel shelter pushed forward on sliding tracks, or you could sit behind the wheel and pull the shelter aft to cover the steering position. You couldnt stand under the wheel shelter as drawn though, its not high enough. Or you could use an autopilot with a remote control and sit wherever you want! There is a possible fairly sheltered seating position for a watchkeeper in either of the recesses where you gain access into the hulls. Its obviously going to be a bit drafty topsides compared to some of the modern cruising catamarans that have a big lounge in the middle, but thats a penalty you probably have to pay for reduced weight and windage .

I have taken a quick look at your three sketches for a trimaran. These are clearly at a very early concept stage, so I dont want to be too critical. I think that with a trimaran this size you either design to have the crew weight out on the windward float to provide much of the righting moment, in which case you may not need large floats, or alternatively you sit the crew in the middle and provide all the righting moment with the floats in which case most people would think you do need large floats, unless you are going to keep the sail area small. You have smallish floats and the crew in the middle but it looks as though you may have designed the floats and cross beam with a view to sometimes saling with the floats pretty well fully immersed, or even submerged. Could well be a valid concept, although unusual.

Looks like we both have a long way to go before we have enough detail worked out to start building!

John

 

John, I like the look of your new cat-hope you get to build it. I remember the hydrofoil design you were developing and enjoyed reading about it.
Good luck!

 

OK, this is what I have been playing with recently. Its a cruising catamaran, about 10m LOA. Recently I have been doing the structural details as separate models that will later get joined together as a new whole boat model, so the whole boat model in these pics is out of date but the best I have right now.

>This cat is very attractive. Have you engineered the loads yet, or is this more a conceptual level?

Construction: strip planking glass sheathed in and out up to the shallow knuckle in the lower topsides, rest would be plywood with external glass sheath.
Keels would be lifting centreboards, pivoted type, with an arrangment to close the slot behind the lowered board, as I already designed for a dinghy.

>I would like to see a drawing of those boards; do you have a link?

Hulls to provide standing headroom but only over a very limited floor area in the galley, the loo and the space under hatches where you change cloths. Rest of the cabin space would be sitting headroom only.
About 650 clearance under central part of bridgedeck, thats reasonable for this size of boat, but maybe even more would be better. Probably two outboards, not one in the middle as shown here.

>Depending on displacement, two Yamaha high thrust 8's would be reasonable. If one or both could be rotated 90 degrees this vessel would have amazing maneuverability close to a dock, joining a raft or climbing a yard trailer.

Sheltered steering position shown with fabric hood, but could be a lightweight ridgid shelter instead. The whole shelter slides for and aft so as to either provide sitting headroom under the shelter behind the steering position or to allow standing behind the shelter. The shelter folds down, then the mast will lower with a tabernacle, thats quite an important feature for me.

>Don't spend a lot of time on this; design an enclosure for a boat, not a boat for an enclosure. I assume the the tabernacle is meant to get under some bridges? What percentage of your market is behind a bridge and still has room for a big wide cat? How big a mess on deck do you create to lower the mast?

This aft view omits transom hung dinghy style lifting rudders that swing up vertical for beaching. These would be controlled from the wheel by a cable and rod system I have worked out but it is a bit complicated to describe in words. I dont think you can easily beat that type of rudder for damage resistance and accessibility if repair is needed.

>Maintain Akerman geometry; this is critical to getting a light weight cat to tack in light air! With a variety of sail combinations there will be a lot of variation in steering loads so I hope the rudders will have some hydrodynamic balance. Just a thought; this boat is light enough to enjoy tiller steering..

Rig would be conventional multihull style fully battened sloop with roller foresail. Undecided about a rotating mast or not. Doesent seem easy to get the right extrusions in UK these days, any ideas?

>I'm really interested in rotating aluminum masts and haven't found much in the way of suitable end fittings. My old Stiletto 30 had a rotating mast, but I haven't a clue where those fittings came from.

I am wondering whether I can omit trampolines forward since I have shown a ridgid structure extending forward on the centreline which could provide access to the forestay attachment. Trampolines do seem to be a maintainance problem and they can catch wind and waves.

>Trampolines are essential for safe footing when working on the foredeck; Think spinnaker, anchor, and dropping the mast. Then populate that idea with a few bow bunnies. Need I say more?

The part of the bridgdeck structure forward of the cockpit provides lots of locker space for sailing gear, anchors etc.

The two main cross beams connect into sockets in the hulls using an arrangement of wedges to lock them tight in the sockets. It must be fairly easily demountable to transport on a flat bed lorry. OK to make several lorry trips, one for each bit since its only five miles to the marina. Mast would be hardest part to move perhaps.


>If this trip is going to happen frequently, you should consider designing a trailer. For grins, mount the trailer ball over the cab of a small truck, greatly increasing maneuverablilty, and allowing a "goose neck" trailer long enough to carry the mast without trouble. If this trip only happens two or four times a season, let the trucker worry about it!


Quote:

Originally Posted by Brorsan FPRIVATE "TYPE=PICT;ALT=View Post"
John, that is a nice looking cat you've got.
Do you have to stand up to steer it from the wheel? I cant see any where to sit down for the rest of the crew either, is this accomplished with normal moveble garden chairs?
/Brorsan
Hi Brosan

Yes, the idea was to use garden chairs for outside seating on this boat - how did you guess. There is a clear deck space roughly 3m x 1.7m aft of the wheel, so space for a few chairs and a folding picnic table. This would seem to be more adaptable than fixed furniture and probably lighter as well. Would be nice to be able to cover this area with some kind of awing when in harbour. I like those tubular aluminium chairs you see outside cafes - very light, corrosion resistant, stack away when not needed.

>Stack where?

For steering, you could either stand at the wheel with the wheel shelter pushed forward on sliding tracks, or you could sit behind the wheel and pull the shelter aft to cover the steering position. You couldnt stand under the wheel shelter as drawn though, its not high enough. Or you could use an autopilot with a remote control and sit wherever you want! There is a possible fairly sheltered seating position for a watchkeeper in either of the recesses where you gain access into the hulls.

>The stiletto 30 and the Great Barrier Express Sport Deck had tiller steering that could be used from the cover of the cabin. The Tektron 32 had fabric enclosures that made this a reasonable place to stand a rainy night watch.

Its obviously going to be a bit drafty topsides compared to some of the modern cruising catamarans that have a big lounge in the middle, but thats a penalty you probably have to pay for reduced weight and windage .

I have taken a quick look at your three sketches for a trimaran. These are clearly at a very early concept stage, so I dont want to be too critical. I think that with a trimaran this size you either design to have the crew weight out on the windward float to provide much of the righting moment, in which case you may not need large floats, or alternatively you sit the crew in the middle and provide all the righting moment with the floats in which case most people would think you do need large floats, unless you are going to keep the sail area small. You have smallish floats and the crew in the middle but it looks as though you may have designed the floats and cross beam with a view to sometimes saling with the floats pretty well fully immersed, or even submerged. Could well be a valid concept, although unusual.

Looks like we both have a long way to go before we have enough detail worked out to start building!

John

>Sandy (an old fart who has owned a lot of cats from a Hobie 14 to an Atlantic 42.)

 

Thanks for your comments Sandy, I do value comments from someone who has extensive experience of cruising catamarans since I have none. That doesent stop me thinking I can design one though! A friend of mine has designed and home built a 36foot trimaran and a 25 foot trimaran, he only has the smaller boat now but he is going to take me for a sail on it sometime this summer, then I will have at least a little multihull experience.

>This cat is very attractive. Have you engineered the loads yet, or is this more a conceptual level?>

Thanks, I think the plumb bow, highly raked retrousee stern and straight or reverse sheer look has become a bit of a design cliche these days, I was trying to do something a bit different, but still practical I hope.

I have done a structural analysis (FEA) on a highly simplified model of the hull structures and cross beams. That showed that when the structure is subject to torsion in a seaway there are high stresses in vicinity to the outer edges of the openings in the decks where you gain access to the hulls. Those areas will need reinforcement, but should be doable. Apart from that no bad news. Once I have more structural detail worked out I would hope to do more FEA, but would need to beg, borrow or steal suitable software since I have recently altered my work situation to give a lot more time for sailing, a down side is no chance to play with company owned high end software during lunch breaks!

Keels would be lifting centreboards, pivoted type, with an arrangment to close the slot behind the lowered board, as I already designed for a dinghy.

>I would like to see a drawing of those boards; do you have a link?

Crude drawing below. This drawing is for a sailing dinghy that has a hollow fibreglass centreboard with the lower part filled with lead ballast. For the cat there is no need for ballast so no winch, just a line to lift and a line to pull down. The bottoms of the hulls would have stainless steel shod strakes on the centreline for grounding and the centreboard slots would be offsett a few inches in from the hull centrelines to reduce the chance of pebbles getting in. I am guessing that the cat would normally be sailed to windward with one cb fully up and one fully down, but including two centreboards provides redundancy and makes extra keel area available if needed for going to windward in strong winds.

>Depending on displacement, two Yamaha high thrust 8's would be reasonable. If one or both could be rotated 90 degrees this vessel would have amazing maneuverability close to a dock, joining a raft or climbing a yard trailer.>

Yes, as it happens a pair of Yamaha high thrust 8's was exactly what I had in mind. These are not the cheapest small outboards, I think you can buy Chinese ones for about half the price, but they do seem to have a good reputation. The outboards would mount just inboard of each hull and immediately behind the cabin structure. The current iteration has the cockpit deck extending about 400mm behind the rear cross beam to make a bit of a walkway to access the engines, rudders and stern mooring cleats, also to aid access to the tender.

Sheltered steering position shown with fabric hood, but could be a lightweight ridgid shelter instead. The whole shelter slides for and aft so as to either provide sitting headroom under the shelter behind the steering position or to allow standing behind the shelter. The shelter folds down, then the mast will lower with a tabernacle, thats quite an important feature for me.

>Don't spend a lot of time on this; design an enclosure for a boat, not a boat for an enclosure. I assume the the tabernacle is meant to get under some bridges? What percentage of your market is behind a bridge and still has room for a big wide cat? How big a mess on deck do you create to lower the mast?>

I agree with that, the design of the wheel shelter is not on the critical path for this project. The tablernackel would be mainly for bridges, but also for access to the mast without having to climb up it. Have no particular bridge in mind, but we like flexibility to cruise where we fancy, one of the main reasons I am interested in a catamaran is that its shallow water capability could be almost as good as our current sailing dinghy that we cruise with a tent over the boom.

>Maintain Akerman geometry; this is critical to getting a light weight cat to tack in light air! With a variety of sail combinations there will be a lot of variation in steering loads so I hope the rudders will have some hydrodynamic balance. Just a thought; this boat is light enough to enjoy tiller steering..

As a dinghy sailor, tiller steering was the first option I thought of. However, with the cabin structure extending right aft to the rear cross beams (which has a number of advantages) it would not be ergonomic to steer by holding the tillers or holding a cross bar between the tillers, so you would have to steer with a tiller extension. I could imagine the tiller extension getting caught up with the mainsheet, or catching up on some other structure, which could be embarrasing. Then I realised that I could have a fairly simple wheel steering arrangment that would place the wheel in close proximity to all the main sailing controls and that seemed to make sense. There would be
athwartships stub tillers on the rudder stocks, the angled recesses in the stern deck are to provide clearance for those. Fore and aft push/pull bars, four pulleys, steering wheel with rope drums and a loop of cable (spectra rope?) complete the system, reasonably simple and should be fairly friction
free. Can include an adjustable degree of Ackerman effect. For ballancing the rudders I was thinking of doing the same as on my dinghy - the blades can rake slightly forward of vertical, coming up against an adjustable stop to set the degree of balance to what you like. Works well. As with any rudder of that type, the steering does get very heavy when the blade has to lift in shallow water.

Motors rotating 90 degrees, how do you manage that, sounds like complicated motor mounts or something. Would certainly give good manouverability though. What I had in mind for low speed manouvering was to steer with the motor throttles, I know that is done, perhaps someone could coment on how well it works in practice.

>I'm really interested in rotating aluminum masts and haven't found much in the way of suitable end fittings. My old Stiletto 30 had a rotating mast, but I haven't a clue where those fittings came from.

I do have a milling machine and a lath at home and all the associated bits and pieces, so can make things like custom mast fittings. A quick internet search revealed that suitable extrusions for a rotating mast are available in Australia, but I didnt see anything similar available in UK, havent yet looked in detail though.

>Trampolines are essential for safe footing when working on the foredeck; Think spinnaker, anchor, and dropping the mast. Then populate that idea with a few bow bunnies. Need I say more?

This is where your experience is really useful. Those bow bunnies do sound nice, but Josephine might not approve. From what you say, I had better make provision for trampolines in the design, but if I actually build the boat I would still like to try it without them first. I had envisaged working the
anchors from the deck space near the forward deck beam, then pulling the anchor rode to the front extremity with a large snatch block. Alternatively I saw a Jim Brown(Searunner trimaran) in a Utube video with two lines to the anchor, pulling these out to the bows with snatch blocks. Raising/lowering the mast would be controlled from the cockpit. Was hoping that with good
manouverablity under power it would not be essential to go to the hull bows for mooring. Say get the stern in first then pull the boat in with a line.


>If this trip is going to happen frequently, you should consider designing a trailer. For grins, mount the trailer ball over the cab of a small truck, greatly increasing maneuverablilty, and allowing a "goose neck" trailer long enough to carry the mast without trouble. If this trip only happens two or four times a season, let the trucker worry about it!

Wasnt planning doing that trip more than once each way each year, but even if you only ever do it once after building the boat you still need to work out how. I would build wheeled trollies anyway, just to move the hulls around on my own property. Would not be a lot more work to have road wheels on those, but in the UK you could not legally tow them with a private car due to the length, even without the mast. Ten minute trip down a quiet road in the early hours on a Sunday morning?? better not start thinking that way!!. I have even heard horrible rumours that it will soon become illegal to build your own road trailer in the UK! I think the easy legal way to do it would be to hire a big lorry and driver with a HIAB or similar crane on the lorry. Job done. Still need mast in tabernacle because HIAB probably not lift high enough to step mast.

>Stack where?
In the cockpit I think, some of the lockers might be big enough too. Those chairs are so light they would need to be tied down not to blow overboard in a gale.

>The stiletto 30 and the Great Barrier Express Sport Deck had tiller steering that could be used from the cover of the cabin. The Tektron 32 had fabric enclosures that made this a reasonable place to stand a rainy night watch.

could be possible optional extra.

John

>Sandy (an old fart who has owned a lot of cats from a Hobie 14 to an Atlantic 42.)
You must have found something to like about catamarans then!

 

You asked...

my drawing isn't fancy CAD. I'm not a designer, but I'd sure love to have input on the final project. I tried a custom design but discovered that among other things, I didn't have practical experience with what I was asking for. Too much risk so a production boat had to do. Still, there's a dream for building something that I had primary input on while still using a professional to make it all work out.

I want a clear bridgedeck 'living/driving space'
My rig should be free standing and easy to use off the wind. My primary beef with the current boat is not being able to ease the main below a beam/broad reach.
Single outboard (in a well), single daggerboard and single rudder with a single mast in one hull (and maybe a bow thruster for close in work)

One double bunk, one bunk/settee on the bridgedeck.
Patio chair seating otherwise
Nice galley.
Full headroom is not required
Long is good, but keep it light and ultimately a 'small' boat, maybe 8k pounds.

Sketch shows a 41' x 17' cat.
Narrow beam (for a cat, and keep the rig moderate.

Balanced lug, not a junk rig

Biggest questionmark is whether the helm would be able to be balnced on either tack or will there be a tendancy to round up more on one tack.

Leave the option for a second mast in other hull if balance is unacceptable I suppose.

 

<<my drawing isn't fancy CAD. I'm not a designer, but I'd sure love to have input on the final project. I tried a custom design but discovered that among other things, I didn't have practical experience with what I was asking for. Too much risk so a production boat had to do. Still, there's a dream for building something that I had primary input on while still using a professional to make it all work out.>

I know someone who thought he would sketch out a concept then get a professional yacht designer to make it work. He has now gone through two yacht designers, paid quite a lot of money and got absolutely nothing so far. Problem is the yacht designers wont stick with his concept, they want to put there own stamp on it, perhaps concerned for their future reputation. Most clients would be more than happy with that, but this person really does insist on it being true to his concept, yet he does not know how to do his own detailed design work and doesnt seem interested in learning. I even offered to lend him SolidWorks, but hes not interested.
<snip>

<Long is good, but keep it light and ultimately a 'small' boat, maybe 8k pounds.>

I hate to say it, but I suspect you have underestimated the cost, or is it a typo and you left a nought off? I have done some preliminary costs for the smaller boat discussed earlier on this thread. I am not going to say just how much at this early stage, for one thing I am still unsure how much I should allow for the rig, but I can tell you I am thinking of quite a large multiple of your figure - thats just for basic materials and the things you cant realistically make for yourself.

<Sketch shows a 41' x 17' cat>
Wow, I thats a big one. Since it doesnt look to be demountable theres no way I could even consider building something like that, I havent got enough building space and handling such a large structure during the build would be too much for me, let alone getting it to the water. Still, your sketch looks attractive, its nice to see such a big boat that is not over packed with berths, very few private owners need the accomodation that production boat builders cram in.

<Balanced lug, not a junk rig>
Just wonder why?

<Biggest questionmark is whether the helm would be able to be balnced on either tack or will there be a tendancy to round up more on one tack.>

I dont know for sure, but here is one way to look at the problem. People have built catamarans with the mast on the centreline but with a keel on only one of the hulls. I think they may even have built them with a keel and rudder on only one of the hulls. From what I have read (eg John Shuttleworth) such boats handle not a lot different to a fully symetrical boat. I reckon that having the mast on one hull but having keels on both hulls would be comparable in this respect to having keels on only one hull and mast on centreline. You are proposing mast on one hull and keel on one hull, so thats about twice as 'bad', but twice 'not much difference' is still probably 'not much difference'.

 

John, I believe Dryfeet is referring to weight, not pounds sterling.

It's true that a daggerboard in one hull only does not make the boat handle any differently than it would with symmetrical foils. My little cat Slider has such an arrangement and it's the handiest boat I've ever sailed. Additionally, I think a lateral resistance scheme with all its area in one board is inherently more efficient than two smaller boards. (Of course, this is true only for cruising machines, in which a hull will never be intentionally flown.)

I'm less enthusiastic about putting a mast in one hull. This to me is not so much a handling or sailing issue. It's a stability issue.

 

Yes, Ray is correct, that's pounds displacement not sterling.

I am unwilling to make the concessions required for demounting and folding so for me, that is not an issue. The difference in mooring a 25'er or a 40' is only $150/month. Real money for sure but small potatoes in the scheme of things.

Reason for lug is multiple.(at least)
1) Unstayed
2) Maintain CE when reefed
3) Lower CE than perhaps a Wyliecat wishbone rig which would be a fall back
4) Wooden spar (oiled or varnished for aesthetics
5) Self vanging effect of balanced lug may obviate need for a mainsheet traveller especially when on port tack where there is no capability for track
6) Not dependent on hi-tech bits

Thre is truth to the fact that a professional has his reputation riding and may not be willing to associate with something out of the mainstream concept-wise.

btw, the sette is offset to permit the diesel or propane cabin heater on port side.

 

Just a couple more thoughts.

I've been working a 25' version (for proof of concept) more a daysailer, weekender/camper.

Unstayed rig permits deep offwind sailing without rigging chafe.

Ray, everything I've seen when doing stability calcs seems to point toward the fact that there is no difference in stability between mast to windward, mast to leeward or mast on center. The forces all apply the same. It's a bit counter intuitive to our 'logic' but the math seems to not care.

Folks often cringe at such a long type boat as being too big. The fact is that Russell Brown's 37' proa is 'long' but it's really a very small and relatively inexpensive boat. My proposal isn't that cheap but compared to your average cruising cat these days, it's probably not much more expensive than building say, a Richard Woods 25-30' design.

 

Dryfeet, you might find the winnowing process I went through with Slider's rig interesting. I considered a lug rig, as I like this rig a lot, but eventually decided the yard meant too much weight aloft, and would contribute to pitching-- considering the fine hulls of cats. It probably wouldn't work for a bigger boat, but for a tiny one, the sprit rig ended up being the most appealing to me. The weight aloft is the lowest for a low-tech quadrilateral rig, plus I saw a study that gave the rig surprisingly good marks to windward-- a big concern to me because of the location of our slip.

One thing you might consider, from a safety viewpoint, is that on one tack, the boom will be hanging out over the water, and will be more dangerous to work with-- I can see this affecting the decision to reef negatively.

I think it's very sensible to build a long skinny light boat, rather than trying to cram as much as possible into a shorter boat.

The static stability math may be the same, but I wonder if the performance in a seaway is the same. Proas, from all accounts are easier to capsize in certain circumstances than a cat with similar stats.

 

Ray,

You raise a couple valid issues. Here's how I think this concept addresses them.

Weight of yard: The rig is appropriately sized for a much smaller 'normal' cat. Hence, already lower, and yet relative to the length of hulls the combined weight of yard and mast are less than or equivalent to a standard sloop rig for that higher hull length. A carbon fiber yard would also be advantageous here.

Boom extending out over the water: There is no questioin that either a comprehnesive system of reefing from the mast position is req'd or there is certainly a preferred tack to be on when reefing. This issue is the same as a bi-plane rigged cat. I find that even with my current conventionally rigged cat, I have a preferred tack for reefing simply to avoid batten/topping lift interference.

Proa type rig stability issues: I would love to find references to this for my own enlightenment. I just haven't run across any at this point. My 'logic' tells me that there is some credibility to it but I've not seen it addressed beyond those static calculations.

 

It has been discussed before in other threads

The basic question is "Who ultimately takes responsibility for the design"

Usually it is the person who gets paid to do the work, not the customer. So no wonder many amateur ideas are rejected by professionals.

Apart from being trained in naval architecture and yacht design most successful designers also have a wide experience of sailing in all manner of craft. And that helps them design better boats than others with less experience

So my suggestion before you get too far is to sail as many multihulls as you can. I know there aren't many in the PNW, but those who do own them are keen to get more people involved. Try NWMA and BCMS for starters

Richard Woods of Woods Designs

www.sailingcatamarans.com

(travelling to the San Juans in a couple of weeks en route to the Gulf Islands, BC for the summer)

 

Sorry, how silly of me! Although we were taught lbs and ozs at school, I would never these days think of pounds as a unit of mass, I only think in kg and tons for mass. Oddly, I do still think of the overal length of yacht hulls in feet, and the height of people in feet and inches, but when it comes to measuring things its always mm, or possibly m for something very big or microns for fine machining tolerances. I guess this is how many people think in UK now, I suppose its different in the US.

Dryfeet, I agree that if you are not overconcerned about berthing costs, building space etc. , its a nice idea to stretch the hulls of a catamaran without increasing the accommodation, and hence without too much weight increase. I think you have drawn a very nice looking boat. Also agree that offsetting the mast from the centreline makes no difference to the heeling moment of the rig, well it might make a small difference once you start to heel, but not a lot. You would need to keep the CoG on the centreline if you are not to loose righting moment on one tack, so are you going to put heavy weights like engine and batteries in the opposite hull?

Am I right in thinking that the one and only reason you want the mast mounted on a hull is to allow it to extend below deck for structural reasons? If that is the case and you would really rather have it on the centreline, I do wonder whether there is an option to have it cantilevered from the bridge deck with a strong bracket supporting it from beams within the bridgedeck structure? Not at all easy, but perhaps worth looking at. Another possibilty might be to support the lower part of the mast with two props forming a tripod base to the mast, again connecting this into strong structure within the bridge deck. Just thoughts. But if you really like having the mast off centre thats fine!

I was just wondering, are you thinking to have full length battens in your lug sail?

John

 

John,

Thanks for your comments. Yes, I would envision equal distribution of weights as in any catamaran. Yes again, to the reasons for the offset rig. Once the decision is made to go unstayed, I see no easy way to get the necessary depth of bury to the mast. Most solutions require fairly massive supporting structure on the front side of the bridgedeck cabin house. This essentially destroys a key component of what I value, i.e. nice, open, forward visibility from within (including while sailing underway). The tripod concept may be do-able but all I've ever seen was too massive still.

I'm not absolutely committed to assymetry but believe that assymetry in foil and rig placement is entirely permissable. (nope, my viewpoint doesn't show up often on those customer preference focus groups!)

Yes again to the full length battens a la Nigel Irens Roxanne/Romily standing lug rig, but incorporated into the balanced lug. I've really come to enjoy the balanced lug on my sailing dinghy as well as full length battens on my current boat. I have some concerns with how well the balanced lug translates into much larger sizes for small crew, especially once one gets to 500 sq ft (46 sq meters for you! ;-) (This is another reason I've kept the rig smallish although it may be a bit undersized in light airs, oh well, here a compromise, there a compromise...)