BIPOLAR

Build logs from members building catamarans, trimarans and other multi-hull variants.
mahnamahna
Posts: 580
Joined: Wed Aug 02, 2006 4:48 pm
Location: Gosford NSW

Re: BIPOLAR

Post by mahnamahna » Mon May 26, 2014 7:35 pm

Not sure its simpler red. I think the new hollow wings would be easier for someone with little or no interest in sailing (yes there are cruisers that only sail because its cheap and have no interest in being able to sail well/better) so therefore limited knowledge or ability to be able to achieve a more efficient wing shape. After reading about both it seems that whilst the initial mechanics seems simpler, sailing of advanced wings systems rig does not seem as simple.

And also it would seem that their alternative is designed for stayed masts. I want unstayed masts with as few adjustments (ropes to pull on) as possible. If its designed for stayed rigs, it wont have the one feature of all of them that attracted me to the bi-rig in the first place, the ability to completely dump the load by releasing or cutting the sheets.

But its great that more and more options are opening up so builders have options and competition drives prices down.

mahnamahna
Posts: 580
Joined: Wed Aug 02, 2006 4:48 pm
Location: Gosford NSW

Re: BIPOLAR

Post by mahnamahna » Wed May 28, 2014 3:40 pm

(Mods maybe this might be skewing into a thread of its own, please feel free to move this post if necessary).

http://soft-wing.ch/en/

http://soft-wing.ch/en/235/

Here is another variation of the soft wing sail. Its mounted to hobie type cats and seems stayed, but that would seem to be a function of the ability to rig a free standing rig on that platform so I would assume that a free standing (unstayed) mast would still be an option with this rig.

The sail wing shape forming and camber articulation seems more complicated than the first link i posted in my earlier post but what I like about this one is that the mast is fixed and the boom and sail rotate around it rather than the mast rotating.

Having a fixed mast solves a number of problems, for example, wind reading transducer can be fixed to the top of mast, as can nav lights.

There would also be no need for a mast post, the mast could be buried in the hull and glassed in, and not need massive bearing surfaces etc.

These ideas are very promising. Hopefully I can find one that ticks most if not all of my boxes. I will need to find out a little more and how much tweaking the reverse camber wing adjustments are and how often they need to be tweaked, but if the benetau thinking is that the rig is much simpler in order to attract more people to sailing then a minimal tweaking version of a wing sail might be available.

I would assume that such a mast would not be tapered, just a carbon tube same diameter top to bottom so that the bearings of each batten fit at any point along the height, which facilitates reefing to any point of its height.

Mike (Whimsical) or Sean (not sure of your handle here Sean is it SeaMad), what do you think of wings?

Darren
Posts: 58
Joined: Thu May 29, 2008 8:37 am
Location: Launceston, TAS

Re: BIPOLAR

Post by Darren » Thu May 29, 2014 8:15 am

Have you considered a rig like the Atlantic 47 Mastfoil. Still have 2 complex masts, but I suspect you might be able to compromise on the 'foil' part. It's essentially a ketch rig, but with 2 roller furling jibs. A few on the water (ie bugs are sorted mnostly), and pretty effective by all means. The foil rotates, but mast is fixed (I think)

Another interesting option is similar, but uses an a-frame mast. Bernd Kohler at k-designs has drawn a design based on this recently. The main disadvantage is the radical look is a re-sale issue, and extra drag from the a-frame, althogh no more than any other ketch design. mastfoil is self feathering, and less drag than a conventional mast.

If I were building, I'd be seriously considering something like the mastfoil, but I'm not (yet), so I'm free to dream up anything...sigh

Redreuben
Posts: 27
Joined: Sun Dec 18, 2011 11:19 am
Location: Fremantle W.A.

Re: BIPOLAR

Post by Redreuben » Thu May 29, 2014 4:04 pm

That soft wing sure looks powerful !

But to my eye, the internal view upwards looks complex and fragile, not sure if that fits well with cruising offshore away from a parts supply.

Early days, I think future developments may simplify things.

While the wingsail I posted does use a stayed rig, two luff grooves and a mast rotator are pretty simple. The key with that rig imho is simply getting the leading edge profile (mast shape) in the same groove as the boat and its sailing objectives. High potential for a string puller, or more flexible but less potential power for a cruiser.

mahnamahna
Posts: 580
Joined: Wed Aug 02, 2006 4:48 pm
Location: Gosford NSW

Re: BIPOLAR

Post by mahnamahna » Fri May 30, 2014 1:59 am

Hi Darren,

Yes I have seen that Chris White design before. It does look more complicated and also does not address my most recent concern, that of the wing masts driving the boat on their own in a blow or at anchor or even just the motion of the boat at anchor in a blow with the various drives one way then the other as the wind matches the angle the wing masts are secured at and suddenly the boat takes off in that direction until the anchor line restrains it and the process starts over. My fear is hat constant straining could eventually lead to the boat breaking free.

And this far into my build I am not sure I can convert from bi rig masts mounted in each hull to fore and aft configuration, at least not easily. Having said that, I still have not completely ruled out a single unstayed mast mounted through the cabin roof into the saloon to accommodate the benetau style ballestron rig albeit with a single wing sail rather than a main and furling jib on the double sided boom.

At the end of the day I am looking to make the sailing as simple as possible. I dont mind making the building more complex so long as once its up and running, sailing is simple to do. Otherwise, I know what will happen. The boat wont ever be sailed. Complex whilst in the shed is fine, its a once off then simplicity takes over for the rest of the time we own it. Thats what we are looking for. That simplicity extends to not having to worry about a boat left on a mooring in a blow. And it seems that wing masts are just adding a layer of anchoring complexity that a round fixed mast does not seem to have.

Speaking of A frame rigs, there is a design called the Omer wing sail designed by a keen sailing ex fighter pilot that recognised 20 odd years ago that wings are more efficient that sails. Looks very complicated, consists of 3 seperate sales and 2 booms both of which look to be articulated rather than fixed to the mast and hydraulic rams adjust the wing camber. Push button is nice and easy but its just something else that can fail on a cruising boat. Great for weekend racing not so sure for a lazy ass cruiser.

I wonder if a combination of the benetau simplicity in the way it creates the wing shape around the mast and then adjusts the camber of the wing with hinged battens and a simple trailing sail edge and the soft wing sail and the fact the sail rotates around a fixed mast and the clever way the shape of the cambered wing is created, it would seem it should be a more efficient foil than the benetau.

As Red said, the soft wing beach cat seemed to smoke the bermuda rigged hobie like it was dragging warps, and if its true that a wing is that far more efficient than a standard sail plan, then it should mean that a smaller wing (smaller mast too) can be employed to achieve a sensible cruising boat sail plan and that means a shorter safer rig, and probably much cheaper to produce, especially if the mast is fixed, the bearings not being needed.

What I am thinking is that the battens have a hoop in them that slides up the mast similar to the way the soft wing but minus the more elaborate shaping mechanisms. I think benetaus take on it is much simpler and therefore much less likely to fail.

Take a look at the benetau pic:

http://i62.tinypic.com/rjfrbk.jpg

And imagine the rings in place in their connected to the battens as the method for keeping the wing in place on the mast and rotating around the mast on them rather than the whole mast and everything rotating as it does in the benetau design. I guess the issue is having the boom mechanism rotate around the mast with the rest of the wing. That is probably the engineering issue to be resolved and probably why there is so much structure inside the soft wing.

On another note, I cant imagine benetau group ever releasing or selling their version of the rig on anything but on their boats (lagoon cats).

Again I agree with Red, as a cruiser, the concern would be how would you maintain and or repair the batten structure.

Just a thought. It certainly an exiting development.

he b gb
Posts: 34
Joined: Wed Mar 20, 2013 11:05 am

Re: BIPOLAR

Post by he b gb » Fri May 30, 2014 10:49 am

Hi Mahna Mahna, You might be interested in this site,google "Tystie's rig update" I found it quite interesting,not so much as a junk rig,but as a soft wingmast/wingsail way. It looks far more robust and uncomplicated than the beneteau,omer and other systems I have seen so far and this site also shows how he constructed his rigs quite simply(although I'm sure you could easily cut some weight out of it).How's your boat progressing and have you heard anything about Ozone recently? Cheers he b gb.

mahnamahna
Posts: 580
Joined: Wed Aug 02, 2006 4:48 pm
Location: Gosford NSW

Re: BIPOLAR

Post by mahnamahna » Sat May 31, 2014 12:13 pm

Hi Hebe thanks for that link I found it very interesting. It does make me think I could build my own set up around a round non rotating unstayed mast. However, I know nothing about foil profiles. Perhaps if I had the profiles and a set of plans.....probably best left to those that understand what they are doing.

In the meantime, I found this one, also seems quite simple and robust, appears from the vid to be an unstayed non rotating, constant radius (not tapering) carbon mast and it appears that the spar at the top rotates with the wing around the mast.



http://www.onesails.com/wingsails.php

These guys have a loft in Sydney so I might give them a call and see if they think it would scale to a 40ft cruising cat or even twin mast bi rig.

Disappointingly, all of the various versions that mention the rig is reef-able, none of them show it in their short vids. This one makes me suspicious that although they say "possible reefing" I suspect they have only got as far as designing a racing rig for 18 footers that usually only sail sheltered waters and dont need to reef, they either race or they dont.

Work is progressing, albeit very slowly, some weeks I barely get a few hours work done. Unfortunately we had to close our business due to technology making our products redundant, so I have to work for a living again. It sucks.

This week TerryK came over to help me install my outboard raising and lowering system, and we discovered a problem I didnt know I had that I had already spent about $400 fixing the problem I thought I did have! I was originally using sail tracks and cars attached to a transom shaped cars that Dean the boat builder in my shed made for me on a mold out of solid glass. The original aluminium cars would bind on the ally track, (4 cars 4 tracks, cost $300) so I had plastic bearing cars made (cost $200) these also bind up. So finally I bought 70mm aluminium C section and another set of plastic bearings (ally cost about $100 I cant remember and the new bearings $300) and these bound too! But we also had trouble getting the ally c section mounted properly, so we measured everything again and in the process Terry discovered that the solid glass cars/trucks (I call them trucks so as not to confuse with the cars that ran on the tracks that I was originally using) were slightly sprung and that the flanges that the bearings attach to are just a touch off exactly flush to each other, causing.....yep you guessed it. Binding. Had I discovered this I have no doubt the original tracks and cars would have worked fine. Anyway, the solution is $20 worth of 316 s/s M8 threaded rod to tension that spring out again and all should work fine. The newer tracks should be more robust than the original sail tracks and cars so theres that.

Once the outboard system is installed I can finish glassing in the rear steps and apart from deck hardware pads and a couple of other fittings (davits already made but not glassed into boat and doors for my catwalk and over the bath/outboard storage well), and finally stanchions I am pretty much finished the building construction and I move on to fairing for the next 6 months or so, then painting.

I cant fit the deck hardware pads until I have a better idea of the rig and where I need to fit the various hardware, so options such as wing sails are still open to me.

I also have a shipload of internal finishing and linings but I plan on doing them after launch. I just have to get this boat out of the shed. Some weeks I work too many hours in the real job that I cant get any work done on the boat, just so I can pay the rent on the shed. Talk about a catch 22. Nevermind. The dream is still alive and well, I am still fit and healthy and progress is being made.

Redreuben
Posts: 27
Joined: Sun Dec 18, 2011 11:19 am
Location: Fremantle W.A.

Re: BIPOLAR

Post by Redreuben » Sat May 31, 2014 1:06 pm

mahnamahna,

This thread may interest you;

http://www.boatdesign.net/forums/boat-d ... 49425.html

The more I see and read, the more I think this is the way forward for cruisers.

groper
Posts: 239
Joined: Sun Nov 18, 2012 11:23 am
Location: cairns

Re: BIPOLAR

Post by groper » Sun Jun 01, 2014 8:16 am

Why?

The more I look at them the more complicated they seem. They also look extremely expensive once you consider a full size cruising sail for a +40ft cruising cat instead of a toy day sailer...

mahnamahna
Posts: 580
Joined: Wed Aug 02, 2006 4:48 pm
Location: Gosford NSW

Re: BIPOLAR

Post by mahnamahna » Sun Jun 01, 2014 1:19 pm

More complicated construction for sure, certainly not more complicated to sail. Read comments on just about every forum or review on them and the overwhelming majority say "ease of sailing" is the main selling feature despite nearly all also agreeing that they are about 20% more powerful for a given sail area.

It would seem they need some learning to sail (or unlearning of conventional sailing technique which fortunately I have none), keeping the angle of attack right is more important for a wing than a sail and it seems they are less forgiving in that regard than sails, it seems they are either on or off or at least can fall off power more easily and dont have the same warning signs than a conventional rig, but from all reports, once mastered are far easier to sail than a conventional rig, easier to tack, easier to gybe, there is no violent swing of the boom over then a crash when the boom reaches the end of the sheet length, in fact I saw in a benetau video review, the wing slows and stops itself on the other side of the gybe, silently, no crashing noises, nothing.

But yes I think cost is going to be a pretty big factor, especially early on before competition and abundance of choice or companies offering brings pricing back down. If you were in my position and had made up your mind to go with an unstayed rig of some kind, then cost difference might not be quite so great. What it might cost me in higher sail cloth and sail making cost I may save in lighter/shorter, not wing just round and probably not even tapering and probably even non rotating carbon mast or masts if I continue on the bi-rig path which is my preference.

I will report on this as I find out more. I already know what the current wing mast set up will cost (ball park of about $65k broken down into $5k each for the posts with bearings, $5k each for the main sails, $2k each for the booms and assorted hardware and $25K each for the wing masts possibly less to about $20k each as Michael has taken 3 meters of the original length or about 20%, so lets say $20k each.

I would guess that the sails alone would cost somewhat more than double our current quote because they are in effect 2 sails and some hardware inside. But I could make up some of that (if not all) extra cost in much cheaper masts. It may even be that I can make them myself. Currently each one is about $27k each including posts, booms and hardware.

If round, non tapering, non rotating masts could be made for say $20k each I have $14k more in sail budget and still break even ,(depending on the system, the boom may or may not be part of the batten system).

If cost were the same, wings in my opinion seem a superior system. Or I should say, they alleviate concerns I have about other systems.

I wont have wings to worry about tweaking angles to sails on, I wont have wings I have to worry about tethering just right at anchor that are going to make my cat at anchor into a bucking bronco as each gust plays on a different wing angle and drives it off in that direction until the bridle pulls it violently back again until the next gust sends it off again (Michael perhaps you could comment on this as you are the only one with a practical example).

All said and done, this is about exploring options that fill wants and needs. Perhaps my new concerns about wing masts is unfounded, as unfounded as my attraction to the bi rig in the first place, but new designs are created to fill these concerns about shortfalls in the old, otherwise why bother? And for me it seems that wing sails tick boxes that wing masts on a bi rig did not, and certainly the bi rig ticked boxes for me that a conventional rig did not. (and having a rig in the first place ticks boxes that a power cat does not, and having a cat ticks boxes that a mono did not).

Ironically, should I proceed down the wing sail path (and that is no certainty, at the moment I am still on the wing mast/sail path) there will be 4 bi rig 1230 Schionning's launch, each with a different sail plan, Mike (whimsical) and Michael with very similar wing masts, Sean with round carbon masts and sails and me with a wing sail. All of us looking to improve on the status quo.

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