Best rig for small catamaran circumnavigator?

[rob denney]

Originally Posted by RHough

Now that you have stated that a Ballestron Rig (complete and ready to step) is probably heavier than a conventional rig (also complete and ready to step) I don't disagree with the weight comparison so much. To compare the carbon Ballestron Rig to an untapered alloy spar and rig is hardly fair. The fair comparison is between a tapered carbon mast and carbon boom as part of a stayed rig and the Ballestron. The Ballestron rig will be *much* heavier than its stayed carbon counterpart.

Rob
The rig will be, the boat won't be.

RH I also question your conclusion that the rig loads add that much weight to a conventional design. There is a finite amount of material needed to handle the loads. How does moving it from the boat's structure to the Ballestron boom result in an overall weight savings? I may not understand how you are getting to your conclusion.

Rob Concentrates the loads, the same as the unstayed mast does. To support a forestay, the entire boat needs to be beefed up. It also needs high bows to keep the (heavy) forebeam out of the water. It is a difficult discussion as no one will supply the numbers and there are few, if any cats designed specifically for unstayed rigs, so we only have anecdotal evidence. For instance. The 15m proa weighs 2 tonnes and has similar righting moment and accommodation to Richard's 12m performance cruiser. The proa could sail on both tacks with no structural changes. So the boats are "roughly" equivalent. The 14m cat weighs 3.5 tons. We would need to get the surface area from Richard to compare them exactly, but I bet the cat does not have the 75% of extra area that the weights imply. If you can get accurate weight and surface area numbers for any performance cat round this size we can make a better comparison.

RH Sailing loads are another concern. How does a Ballestron rig maintain forestay tension? If a permanent backstay is used, you lose the performance of a large roached fully battened main. If you have no permanent backstay, the leach load on the main and the longitudinal stiffness of the mast must counter forestay tension. If leach loading is used in to keep the forstay tension, you have to keep the leach tight in heavy air. On a stayed rig with swept spreaders of aft leading cap shrouds the shrouds keep the forestay tight and the jib flat while the mainsheet is eased to allow the roach to twist of and depower the rig. I don't see how the Ballestron handles this very well unless the mast below the hounds is *very* stiff (and heavy).

Rob All correct, (unless the mast is rotating, when mainsheet tension provides the forestay tension), which is why it is not a good full crew racing rig. It is also not the rig that I suggested for the subject of this thread. Nor is it the rig I put on my boats if performance is the requirement. If the last couple of per cent of performance is your goal think how the boat in the video would go with a 3m higher wing mast and no jib.

RH Not having seen the detail of how you are using UHMW for the bearing, they may not be the problem I foresee. I has been by experience that keeping bearing clean and running free on boats is an engineering challenge. If you have come up with a no maintenance solution, that is a feather in your cap. If it can be duplicated by an amateur builder, even better.

Rob The protection is a simple boot around the mast and a raised lip around the bearing. It's primary purpose is to stop water getting into the hull, which it does well, so presumably no contamination is getting in there either..

RH As far as reefing and tacking etc. I'm blessed, my last mate is sailor. She can hand, reef and steer. Being able to do it while not standing on a 20-30 deg deck would be heaven. If my sailing partner had fewer boat handling skills, I would see more value in rigs designed with easy sail handling over performance.

Rob Remind her of that when the rain and squall comes through at 2 am, the furler line has jumped the drum and there is land to leeward, just after she has got into her pj's after a long watch.

RH The "self reefing" feature of a bendy, tapered, carbon spar would not be lost if the rig was stayed. It is the mast tip above the hounds that needs to have good gust response. If you have figured out how to have the entire mast bend and depower without losing forestay tension and powering up the jib you have my attention.

Rob Would not be lost, but is not very good either. Without a jib, the entire rig depowers, not just the top 10%.

RH IMO a good cruising rig can lose any one stay and still stand. The mainsheet serves to back up the backstay, the jib halyard backs up the forestay. If the mast section is a proper choice for cruising, any one stay can fail and the mast should stand, granted the remaining wire(s) may get stressed mast their elastic limit and require replacement after the event, but the mast should be fine.

Rob My opinion about the rigging as well. Not shared by 95% of multihull designers, unfortunately. If the mainsheet has any load on it, the backstay will not break. However, if you have just eased the mainsheet, or done a crash jibe, the mast will go over the front. If the forestay breaks, the jib halyard is unlikely to survive, unless it is stronger than the forestay. You then have the joyous task of going up the mast to install another stay.

RH Although there are many potential points of failure in a conventional rig, the little bits are easy to inspect and easy to replace (if I build the mast). I can see the signs of impending failure. I cannot see the beginning of a delam problem in a composite spar.

Rob That is because, unless you bang it into a bridge, there will not be any, same as there will not be any hull, rudder shaft or daggerboard delam issues unless you bump into something. Think about this next time you are up the mast checking all the little bits.

RH I can see that the Ballestron Rig and a PROA are a good match. In the Harryproa (as I understand it) the longer, leeward hull is the 'light' hull and the windward hull is the heavy hull. There is little need for the leeward hull to be strong enough to support the crew walking around on it. There is also no convenient place for a conventional rig's stays. When you add the requirement that the rig sail both ways, the Ballestron becomes a near perfect answer.

Rob Near perfect, but tossing the jib and the foreboom makes it even more so.

RH On a cruising catamaran, none of the PROA's rig limitations exist, some of the problems a Ballestron Rig solves for a PROA just don't apply to a cruising cat. I'll take the tapered carbon spar, a stayed rig with mast rotation, a big roach main and a long traveler.

The only difference is the proas shunt, so you don't get caught in irons or require slow, easily tacked hull shapes. Still leaves you with the crash jibe, the difficulty of reefing (and sailing) downwind, and the maintenance issues, which are much more relevant to cruisers than performance, particularly when, as Richard points out, that performance requires 100% attention to achieve it.

Your ideal cruising rig is not the one you have described avove. Big roach mains, rotating masts and backstays are a no no, so you will end up with a 3 stay rig with diamonds with the stays wearing away on the hounds, and fatiguing in the breeze as they are not tight, the same as everybody else. I suppose i should be glad, The rigs you describe fall down often enough that there will never be any shortage of business.

regards,

Rob

[RHough]

Originally Posted by rob denney

The only difference is the proas shunt, so you don't get caught in irons or require slow, easily tacked hull shapes. Still leaves you with the crash jibe, the difficulty of reefing (and sailing) downwind, and the maintenance issues, which are much more relevant to cruisers than performance, particularly when, as Richard points out, that performance requires 100% attention to achieve it.

Your ideal cruising rig is not the one you have described avove. Big roach mains, rotating masts and backstays are a no no, so you will end up with a 3 stay rig with diamonds with the stays wearing away on the hounds, and fatiguing in the breeze as they are not tight, the same as everybody else. I suppose i should be glad, The rigs you describe fall down often enough that there will never be any shortage of business.

regards,

Rob

LOL ... I've never seen a rig come down that could not have been prevented.

You have mentioned one of my pet peeves ... the crash gybe. IMO crash gybes fall into the "operator error" folder. I refuse to discuss the ability of any rig to stand while being abused. Faulting a rig for falling down after a crash gybe is like faulting a hull for leaking after being driven at speed onto a rock.

Fast cruising boats should never be sailing deep angles. If the BAW is forward of the beam a crash gybe requires a *huge* deviation from course or an 'act of god' change in wind speed and or direction. If the boat cannot track well enough and yaws enough to be in danger of a crash gybe, the design is poor, the sailor inept, or the speed is too high for conditions. I'm no fan of "idiot proof design", God builds better idiots faster that the best designers can account for.

Not to argue, but a 10mm Spectra Jib halyard will keep a mast up just fine after a 6mm SS wire fails.

As far as 2am reefing drills go ... there should also be enough crew on deck or on call to handle any reasonably foreseeable weather event. In the case of being off a lee shore with squalls possible, she won't be in her PJ's ... she has the choice of napping in her deck gear or reefing naked ... which come to think of it *is* her deck gear ...

I think you have pointed out that a case can be made for more than one rig, and that the requirements and desires of the crew/owner should be considered when making that rig selection. I don't think that there will ever be agreement on what rig is "best" any more than there will ever be agreement on blonds over brunettes or redheads. Different splices for different skippers.

[Alan M.]

Just wondering, how well do these Ballestron rigs go to windward? How high can you point? Can you maintain forestay tension?

What about stayless bi-plane rigs? Would they be able to point as high as a conventional rig on an equivalent boat? Would they go to windward with no headsail?

On both types of (stayless) rig, how does the variable mast bend affect sail shape? Can you predict mast bend for various wind strengths and cut sails accordingly?

Just curious, since nobody seems to mention this stuff much.

[masalai]

Just being cheeky, but if one is cruising (not racing) then why the need to "point high"? - - - - If one is racing then the "rules" will determine what rig....

[rob denney]

Originally Posted by Alan M.

Just wondering, how well do these Ballestron rigs go to windward? How high can you point? Can you maintain forestay tension?

What about stayless bi-plane rigs? Would they be able to point as high as a conventional rig on an equivalent boat? Would they go to windward with no headsail?

On both types of (stayless) rig, how does the variable mast bend affect sail shape? Can you predict mast bend for various wind strengths and cut sails accordingly?

Just curious, since nobody seems to mention this stuff much.

G'day,

According to Richard Woods, they are 25% more efficient than a conventional crusing rig sailed by a set and forget type of sailor (your average cruiser). I think this overstates the case, but they are certainly superior. Windward performance is as good as most cruisers, but as the breeze gets up the rig works the wrong way. That is, the forestay gets slacker, the jib fuller and pointing deteriorates. Some people put a running backstay on (can be attached to the end of the boom) to combat this but it needs tacking, and is not ideal as the mast still bends sideways. A ballestron with a wing mast and no jib (this is the 3rd reef, the first is automatic, the second is removing the jib) points extremely well, better than any cruiser under similar conditions as there is way less windage.

Reaching, running and general usability they are vastly superior to any other main/jib rig.

Biplane rigs get to windward pretty well and are invariably set up to sail without jibs (mast further forward). They would do better if they were wing masts rather than tubes, although Eric Sponberg has had success with oval sections.

Mast bend is highly predictable and the predictability does not vary once the mast is up. The one in the video was within a couple of mms in the static bench tests we performed. The more we build, the better this prediction becomes.

Cutting the sails is a bit trickier as few sailmakers have experience with large rigs, as can be seen in the video. Our sails have big roaches and bigger jibs than the aerorig guys use, which makes it much harder for the sailmaker. However, most sails I have seen are pretty good after the sailmaker has had a look and made any adjustments required. Lesson is to ensure the final payment is not made until the sailmaker has been for a sail in 10 knots and 20 knots and the sail looks like the picture on his computer. This is quite easy to check using a camera and standard sail photo techniques.

masalai,
The famous lee shore in 40 knots scenario requires good pointing, but otherwise I agree.

Rhough,
I wish my sailing was as predictable as yours obviously is.

regards,

Rob

[sharpii2]

Exactly what is a 'Ballestron rig'?

I've tried looking it up without success.

[rob denney]

Originally Posted by sharpii2

Exactly what is a 'Ballestron rig'?

I've tried looking it up without success.

Otherwise known as an aerorig or an easy rig. The boom extends past the mast and has the jib attached to the front end and sheeted to a track in front of the mast. Sheet loads are reduced and no vang is required. A very easy rig to use.

regards,

Rob

[Gary Baigent]

I may be mistaken but I thought the first spelling of this rig I saw, it was actually spelled baelstron - is it Scandinavian? - and then more commonly - balestron - and I see Rob uses ballestron. The French used the term with Paul Lucas 5.5 metre planing monohull designs back in the 1980's and later of course with Elf Aquitaine 11. Anyone spread more light?

[Alan M.]

Originally Posted by masalai

Just being cheeky, but if one is cruising (not racing) then why the need to "point high"? - - - - If one is racing then the "rules" will determine what rig....

Even cruising you still have to go to windward sometimes. And the higher you can point the less distance you have to sail. When it's choppy it's better to sail high and slow rather than low and fast.

Rob, can you give some examples of pointing angles and speeds in various windspeeds? "As good as most cruisers" doesn't really say much to me.

[rob denney]

Originally Posted by Alan M.

Rob, can you give some examples of pointing angles and speeds in various windspeeds? "As good as most cruisers" doesn't really say much to me.

G'day,

Not really as I have never had wind gear on my boats, nor the necessary cables to download the tracks from gps to the computer for analysis. But even less helpful is they all been on proas, so it is difficult to know how much is boat and how much rig. All my boats have easily tacked through 90 degrees, if that is any help.

The 15m proa in the video has just been sold (previous owner died) to someone who looks like he will use it a lot, so we should get some numbers from him this summer.

regards,

Rob

[sharpii2]

Originally Posted by rob denney

Otherwise known as an aerorig or an easy rig. The boom extends past the mast and has the jib attached to the front end and sheeted to a track in front of the mast. Sheet loads are reduced and no vang is required. A very easy rig to use.

regards,

Rob

Thanks, Rob.

I thought the 'Ballestron' rig was different to the aerorig.

BTW- why do you call your boats 'Harry Proas'. Why aren't they called 'Rob Proas'

[brian eiland]

Originally Posted by RHough

..I do expect them (marinas) to be full of lower maintenance, more bang for the buck boats. I expect more cruising multi's, maybe not for the reasons I would choose, but more of them. The small catamaran circumnavigate is a type that has more potential than most. Once the mass producers of sailboats figure out a way to build and sell small 30-40 cruising cats to the folk that now buy 30-40 cruising mono's (Benetaeu, Catalina, Hunter, Etc.) they will take off like nothing we have seen before. The hint is to watch mother at the boat show. Compare her expression when looking at the accommodation of a 40 ft mono compared to a 40 ft Multi. She sees a kitchen (not a galley) and bedrooms (not oddly shaped closets with "Guest Cabin" on the door), she steps on the edge of the boat (what the hell is a gunwale?) and it does not tip alarmingly, she has seen father watching the AC boats tilted at 30deg in a light breeze and hears every word when the factory rep talks about sailing all day and not spilling your wine.

We (Chesapeake Catamarans) used to sell a lot of Stiletto 27 foot catamarans. And the factory guys would come visit us at the Annapolis Boat Show every year. For several years they were contemplating new models...what to do in a new model and/or how to modify their existing one to have more appeal to the market. I forget now how many times I told them to watch the woman's reactions, expressions, etc as you talked to her husband about the catamaran product you were trying to sell them. And then later on see if you can find this same couple looking over other boats. Watch the difference in the woman's reaction between those long slim hulls of the cat with the trampoline in between, and that cozy little monohull they would likely end up buying.

I finally discovered the 25 foot Dragonfly trimaran over in Denmark, and immediately recognized I could sell this product to the woman. It was like a small monohull with 'training wheels'. I began to import them, but ran into a serious problem with supply. The acceptance of the vessel was indeed excellent, so I had to set about designing our own variation, the Firefly 26'. I am firmly convinced that in the under-30 category the trimaran configuration is superior to the the cat for all-around usability. In the 30-40 size range its open territory, and over 40 its a catamaran world unless you are single-handed racing.

My point is I agree with this need to address the woman part of the buying decision...very important

..Things like UHMW bearings inside a hole in the deck of a cruiser's sailboat sound like a horror story waiting to be written

I considered this material as a possibility everytime I get a chance. On the Firefly tri we actually utilized it as a rudder stock material rather than conventional alum casting or stainless bracket. We just sawed a block of thick UHMW into the trapezoidal shape we needed for the slot in the hull's transom, cut out some lightening holes, and drilled a big whole thru for the SS rudder shaft....simple to construct, self-lubricating, non-fouling, inexpensive....

I even suggested it as a potential bearing material for a rotating mast, but the potential problem is its 'static friction coeff' as opposed to the dynamic coeff.

[rob denney]

Originally Posted by sharpii2

Thanks, Rob.

I thought the 'Ballestron' rig was different to the aerorig.

BTW- why do you call your boats 'Harry Proas'. Why aren't they called 'Rob Proas'

G'day,

Wife's suggestion, she has no idea why she said it. ( I blame alcohol, perhaps an old boyfriend, or harrsion Ford). It is a lousy marketing choice, but we have had a lot of fun coming up with names. harrigami for the folding one, solitarry for the solo one, harriette and elementarry for the little ones, visionarry for the one for taking blind people sailing, etc. A little bit more imaginative than the usual run of model names.

The visionarry in the video has just sold. New owner is a keen and knowledgable cruiser, wants to sail it round Australia in the near future, maybe do the Brisbane Gladstone race next year, as well as lots of local cruising.

Brian,

Static friction of UHMWPE for unstayed rigs is usually not a problem as the lever arm is so big.

[BigCat]

Originally Posted by Alan M.

Just wondering, how well do these Ballestron rigs go to windward? How high can you point? Can you maintain forestay tension?

What about stayless bi-plane rigs? Would they be able to point as high as a conventional rig on an equivalent boat? Would they go to windward with no headsail?

On both types of (stayless) rig, how does the variable mast bend affect sail shape? Can you predict mast bend for various wind strengths and cut sails accordingly?

Just curious, since nobody seems to mention this stuff much.

Chris White likes unstayed rigs, but gave up on them because of the effect of bending on sail draft. I have overcome this problem by inducing sail draft by a different means than curvature of the luff. Sail draft in my rig design is via one method used in the modern junk rig, that is with hinging stiff battens, and a sheet with sheetlets that cause the leech to bend to windward. I didn't invent this-it is common on junk rigs these days. Cutting rounds in the sail along the battens is another method used in modern junk rigged boats, as well, and this method of putting camber in the sail is also immune to the effect of mast bend.

I have overcome the problem of the un-reefable wing mast by inducing the wing shape in a wrap around sail with battens, as in the Gallant rig. Using battens to induce the wing shape makes the shape more predictable, and eliminates the clinginess of the sail to the mast, which has made reefing and furling a problem in fairing sleeves in the past. This method of shaping the sleeve also allows a smaller diameter leading edge, thereby making it possible to use an optimum foil shape.

Going to windward with no headsail is no problem-simply consider the Laser sailing dingy. You can see my wingsail rig at:

http://www.dunnanddunnrealtors.com/Catamaran.html .

[waterbird]

Hi, does anyone out there now anything about corinthian Trimarans?
Like windward ability, Resin used and so on.
Would be grateful for any comments.