May I wish good luck to everybody taking part in th champs~ But . WHY DO WE NOT ALLOW ROTATING MASTS?
I can't answer your question directly but I'm interested in how you would implement a rotating mast. How would you isolate it from to of the forestay, jib halyard and stay the mast back at the hounds to stop the rig falling forward under jib halyard load? Is there a class that has already implemented rotating masts with twop or three sails? how do they do it?
Matt
Ref. Other Classes
The Firefly had a rotating mast and achieved this by having a wire bridle to support a floating jib halyard block.
But I think we might be more interested in over rotating rigs, in which case we might look to Tasars or Tornado's.
I think that rotating rigs would probably be the most interesting and least contraversial avenue to pursue, since this is all about improving the efficiency of the rig rather than attempting to increase sail area or reduce weight, which would tend to outclass the existing fleet.
However I remain to be convinced that the class has the appetite for change.
Regards,
David
N3461
What he said...
Rotating rigs with jibs are proven technology, as David says look to the Tasar, or the NS14. Indeed nip into your local waterstones and sneek a look at Bethwaites 'High Performance Sailing' which covers them in some detail.
The short version is you have a deck stepped mast, and all the usual wires...
I am also in favour of the concept, although the cost of developing a new mast, and new sails, and potentially a bit of rearranging about of the boat might quell enthusiasm.
in principle then - if it could be achieved without having to purchase another mast I'd be happy to vote for a change in the rules. its really the cost involved because I wouldn't want ot encourage an arms race that excules all but the financially secure.
For those of us who don't know about these things, could someone explain how a rotating rig would be more efficiant?
Thanks...
Using an appropriate wing section mast, the airflow coming off the mast is much cleaner, reducing the turbulence at the front of the sail thus increasing efficiency. A wingsection mast doesn't necessarily have to be an enormous thing from the boeing spare parts bin, as exemplified by the short squareback design seen on the tasar. This increase in efficiency comes with an alteration of the centre of effort for the rig, so if you used the same sized rig in the same place you would probably have to move the centreboard forward, hence my earlier comments about rearranging the boat.
I reserve the right to be shot down in flames though... ;)
I think there would be a significant areodynamic benefit of rotating a normal superspars round section mast. Although most of the rotating mast you see have a elipsoid shape at least you would effectively hide the mast track if the standard superspar rotated with the sail.
The problem with circular fixed masts is that when you are off wind the mast becomes much broader and asymetrical in the direction of the wind flow. That causes significant vortices and turbulence over the lifting part of the sail. If you let the mast rotate then it keeps its neat narrow profile to the wind at all points of sail.
Check your bethwaite book Matt, wing masts have to be a fairly critical shape to give any benefit. If simply rotating a standard rig was more efficient then toppers and lasers would go a lot more quickly!!
Tim,
quite right, also the main has to be a totally different shape.
I looked into it hard with 3444, Linton was going to make the mast, Frankie the sails,the boat was built for a deck stepped mast and there had been a rules dispensation to allow the development to take place, however as with all things when I wanted to take it up it had become 'time expired'! :'(
John
why do you use an Angell mast then Tim? Surely you didnt pay all that extra money for a narrow mast for aesthetic reasons?!
I'm with Matt, it will improve performance on a standard rig, but a proper section has to be the way to go to do it properly...
How do we go about proposing this to the committee? The only way we will find out if the class is willing to move forward or not is to ask them - up untill now we have just thrust more weight reduction under their noses instead of actually making the boat better.
Cheers all
Mike C
Well it seems Tim is right in pointing out that circular section masts don't make good wingmasts. I still maintain that rotating my current mast would make some improvement in drag - but making this rule change would allow the next mast commision to have the 'correct' faired shape. That brings with it substantial benefits in lift - primarily in the luff region of the sail. That drives the boat much faster and brings the centre of effort of the sail forward. Consequently all those implementing a rotating mast would indeed have to move their centrebords forward or the mast back by almost a foot. Bouncing Ben is - I think - the only N12 desiged with that sort of radical flexibility in mind.
Consequently the advantage lies with the commisioners of new N12's and that is why - I suspect - that we don't allow them. Its a pity but we can't have the fleet split between the haves and have-nots just as we've learned to race equitably between the db/admirals cup boats.
I think a foot might be a little bit over the top! Bearing in mind that the jib efficiency would not change, the only movement will be in the chord of the mainsail + mast area - probably more like inches, and im sure most people have inches of mast position adjustment available, and if not then a little more rake will compensate.
Mailsail will need to be a bit flatter, but at the end of the day people buy new sails anyway - certainly the sort of people that worry about this sort of thing have a new set at least once every two years...
all boats could be converted pretty easily to a deck stepped mast with a stump to deck level for negligable cost - the likelyhood of the front end of the fleet throwing money at new masts until a new solution has been proven is pretty small, leaving it with the tinkerers to come up with cheap ways of experimenting... Balsa/foam fairings on top of round masts etc etc...
As David says, this is probably the best option for improving the performance without completely burning the rule book, and the class needs to avoid its previous mistakes of sitting on change for too long and avoid single big rule changes
Cheers
Mike
I think that the centreboard position could be a bit of a red herring, there is still scope to play about with mast rake, jib area and the ability to swing the tip of the centreboard forward, without having to hack the boat about.
My memories about aerohydro make me think that this is about removing the separation bubble aft of the leeward side of the mast and improving attachment on the leeward side of the mainsail.
With regard to moving this on, the fast track route would be to put a proposal to the agm, however it is unlikely to get through without a thorough campaign and class consultation, i.e. article in ratchet, geting the class and committee behind it, and possibly carrying out a trial.
Apart from the initial development costs (which you might be able to pass off onto the sail and sparmakers) I cannot see that the hardware costs woukd be a lot different to now. The difficulty you might have is persuading people with old boaats and rigs that it is worth voting for a rule which MIGHT limit their competitiveness.
Also if you are going down the route of removing the controls on rotating rigs, it would only make sense to also be considering removing any restrictions on battens.
All the best,
David
3461
I have just spent the weekend in Salcombe sailing my 12. I guess that most of you spent the weekend on your PCs.
I am very unlikely to vote in favour of even permitting a trial of rotating rigs in the future. I am pretty likely to campaign against it. I am also pretty likely to leave the class if it is approved, after 16 years of active 12 sailiing.
Salcombe is one of many great 12 venues that are completely unsuitable to a boat with a rotating rig that I enjoy going to.
Antony
N3484.. for sale if this gets any support.
Antony, I am not doubting your argument in any way, but as I am not as technically minded as some please could you explain why a rotating rig would be unsuitable at Salcombe? I understand the benefits now, but would like to understand the downside...
Thanks
PS...wish I hadn't spent the whole weekend at my computer but unfortunately the typical student lifestyle is put into question at this time of year! :-/
Ok so I am now totally confused, having spent ages trying to work out why a rotating rig would provide any real benifit to a twelve other than to keep us all amused trying I now need to work out what is so unique about Salcombe to make it less suitable for a interesting rig than Trent Valley
For those that may have no clue what Terry is on about, there was a load of experiments with 12's with big (Fireball) rigs at Trent Valley in the 80's by Mr Peebles amongst others...
I have the pictures somewhere - will put them in Ratchet if people are interested
Its funny Antony, I was thinking exactly the same thing the other night but the other way around! Frankly were are running out of things to try in the 12's and resorting to increasingly outlandish attempts to do different things, and while I see that hull and foil design is still to be worked on, the rigs havent done anything but get lighter since the 70's and look particularly old fashioned. I feel something needs to be done to keep interest levels up to stop other people drifting out of the class - I also feel that modernising the rig will make it a more attractive to outsiders which is where the 12s are particularly weak.
Cheers
Mike
PS - one way or the other, the 12's need good secondhand boats!
;D
As the owner of the only Bethwaite wing mast in the Northern hemisphere (Tasars excepted) on the vintage Cherub some of you might have seen at sailboat a few years back maybe I have something to offer.
1) When you get it right its an awsome bit of kit, especially in lighter conditions. You can really feel the power kick in
2) It makes for a tweaky rig
3) Number of sailmakers world wide who know who to cut a sail for one probably one
4) Not reallymuch like a tornado rig at all!
5) If you're going to get all radical and change the mast rotation rule it probably makes sense to freeup the rest of the rules and just measure area. This meansall existing rigs are throwaways. If you do change just the mast and not the rest then there'll be pressure to free up the other rules soon.
6) Have you really got a problem that this will address? I get very excited about low drag highly efficient full battened rigs with wing masts, but judging by the way many popular SMODS have less efficient but easier to use semi soft rigs I'm a tiny minority. I reallly see few sailors who are interested in developing rigs at all, and those that are mostly seem to think the more rag the better and just want to put big rags on, which is scarcely the N12 ethos.
On how it works:-
1) Overrotating masts bend differently, you get really good twist control
2) lower drag with a thinner mast
3) better airflow over the sail with much less mast interference
4) more control on sail shape
5) mast acts as extra sail area (but you'd probably measure it in with the sail)
Incidentally on a related topic, Bethwaite makes someinteresting claims about the "mast cuff": the bit that covers kicker area on 29er etc. He claims that this makes the bottom of the jib much more efficient, which of course gives extra power with very little heeling moment. There's stuff aboutthis on the Tasar Yahoo group. If its legal to make a N12 main with that sort of downward extension it could be something for those interested in rigs to explore without the sort of complictaions of a rule change.
No, its definitely a Big Issue - I remember sending Phil the cheque!
It wouldn't kill the class to allow a dispensation to try it...then we really would know what the pros and cons would be instead of merely speculating.
I still don't understand why some venues are better suited than others...please, someone, explain
Ted,
Fear not, it is a tradition in the class that every year in the run up to the forms for the agm being sent out there is a spate of navel gazing, at which point a whole range of often revisited items such as reducing weight, d*****boards, fully battened rigs get flown in Ratchet or on this board.
This is good and is what sets us apart from the one design classes. Even if we do not adopt the changes, it means that there are sailors trying to push the envelope and explore what makes a dinghy faster. This is how former National 12 sailors like Phil Morrison and Jo Richards learnt their craft.
Occassionally something gets proposed that is of real value and has been passed through, moving on from clinker hulls and cotton sails spring to mind (though some may disagree!).
However you can sleep safely in the knowledge that it has to be a very good idea for enough people at an AGM to accept change, they, like you wish to protect their investment.
However this doesn't mean that a bit of chat about rotating rigs won't get us thinking about how to improve the flow around the mast, already Cherub man has suggested that we should try to improve flow around the kicking strap, which migh be worth exploring.
Finally, I don't think that the suggestion is to adopt full on deep chorded wing masts, I would think that the chord length would be limited allowing existing masts to be converted in order to rotate (I guess that the spreaders would be converted to diamonds).
Regards,
David
N3461
I think my main problem is that the 12's have no development path laid out - I remember finding a copy of an old one in my old mans chairman era stuff - it had ideas for future possibilities and timescales.
At the moment we seem to get shot at for even suggesting any movement forwards. The rule changes of a few years back hit too many people, too hard, and all at once and it has apparently scared a lot of people off of future change.
We need to make sure that when the next ideas for change come in, they are not so late as to make them drastic in a big catching up measure like the last one.
I am planning on making a new boat towards the end of the year, and propose almost making a concept 12 as a testbed for any future changes - that way people might actually get to sail with/use the ideas before putting verdicts in.
The problem is, what are they going to be if any or am i wasting my time?
Cheers
Mike
Ben,
You make a valid point and remember our conversation pretty well. There are, however, very important differences between the changes that get implemented and/or discussed by the class. This is why my views are different on these two issues.
1. Changes that keep the boats 'current' without changing the character of the boat or altering the niche in which the class fits. Our boats are far more 'modern' than RS200s a very few years after that class was invented.
2. Changes that 'change' the class into something different.
It is my view that double-bottoms and lower weight fit into 1. and that spinnakers and rotating masts fit into 2. I know that others will disagree with me about this view.
Mike, the biggest issue with a 'plan' has always been the problem that in advance of any change there is a freeze on new boat building, something that has hurt the class in the past. I agree with you to the extent that the committee should continue to review such things (I am sure that they do), but any changes should be voted on in that year and not be part of a grand longer-term plan.
Ultimately the class will be more fun for all if there are more strong club fleets, and lots of competitive second-hand boats being sold to enable people to get to the front of the fleet more cheaply. Building new boats in a stable rules environment is probably the main way that we can all influence this. Merlins and even Larks seem to be thriving with rather dated looks.
Antony
[quote by=Mikey_C link=Blah.cgi?b=Cool,m=1114709070,s=24 date=1115377936]I think my main problem is that the 12's have no development path laid out - I remember finding a copy of an old one in my old mans chairman era stuff - it had ideas for future possibilities and timescales. [/quote]
Don't you think though that changing rules is the opposite of development? The process of development within a restricted class boat is that one is seeking to get the optimum racing boat within the box defined by the rules. As soon as you change the box though then basically the process starts again and you have to an extent (depending on how major the change is) thrown away pevious development and have to start afresh.
Although I confess that I am not in favour of rotating masts as they seem likely to unecessarily increase the cost of a new boat, I (like Emma) still do not understand why some venues are better suited to them than others. PLEASE WILL SOMEONE EXPLAIN?
In my opinion, rule changes should be considered (a) when current boats have overtaken the rules, e.g. all new boats of "standard" (not exotic) construction are coming out significantly under weight then look at a weight reduction; (b) to simplify unnecessarily complicated rules that add to the cost of construction through either increased time required to build or increased cost of materials to comply with the rules; or (c) to reflect a change in the generally accepted standards of construction, e.g. introduction of metal masts.
I accept that there are grey areas at some point in time with all of the above, but we should continue to foster the concept of maintaining development through evolution, not revolution.
I look forward to seeing the explanation requested above.
Kevin
EXPLANATION
Katy and I sailed an NS14 when we were in Australia. Essential characteristics were 14ft long, 2 sails, daggerboard, fully battened main on rotating rig. The rig was an overrotating rig, with an aerofoil section.
What is the problem with the rig?
The rig is excellent when you dont have to fiddle with it. Every time you have to tack (eg short tacking up the bank at Salcombe) you have to physically tack the mast (it has a handle on it). This did not make the crew happy as too little/too much leach tension caused problems. A bit like a very dodgy top batten.
If your crew is big enough no problem.
This is my view - hope it helps - there may no doubt be others.
Now,
What a hornets nest has been opened up.....The Blaze fleet ae consideing rotating masts..to encourage more members..Maybee the 12 fleet should try the same. As I Have sailed boats with a rotating mast, maybe you should try it first.before commenting..........
The Merlins tried wingmasts over 15 years ago (approx). The boat was called "Wing and a prayer", he soon got rid of the mast - because he could not depower it....
While I'm not convinced that open rigs and wing masts would be right for your class let me just correct a couple of preconceptions.
> he soon got rid of the mast - because he coulkd not depower it
Then the design was no good (all UK bult ones I ever came across were rubbish). My wood Bethwaite mast has excellent gust response for its era (1972). Its just a question of building in the right fore and aft and sideways taper.
> you have to physically tack the mast
When I was racing with one regularly ( crew in my boats) I got into the swing of uncleat jib, grab handle, use it to swing across boat (which tacked the mast at the same time) sheet jib other side. Once I was used to it it just wasn't a problem, and this included using it for cruising up and down rivers on the Norfolk broads with no shortage of tacking (yes, a Cherub!)
One exercise if you wanted to let a few people try a freer design rig might be to force them to have say 5 sq ft less rag. That way the new more sophisticated rigs wouldn't be any quicker than the old style ones and you wouldn't compromise your racing.
Wow rotating rigs, great topic
Havn't paid much attention to the discussion group lately as it was getting a little stale but love this buried little thread.
I just happen to have a couple of extremely competitive 27 year old Tasars. Plan to sail this years nationals with a six year old main 5 year old jib and will probally be expected to get at least one bullet in the week.
The rigs last forever
Tacking is easy after a few practises
The sails are a lot smaller than a 12's and the PY..... suggests that the Tasar is quicker.
Talking from experience sailing a week of 25 kts+ in a Tasar I would expect little or no damage compared with saiingl one race in a modern 12 over 25kts where half the fleet would stay ashore. The 12 would be terrifying. The Tasar I would just depower and have a lot of fun with no worries about the rig.
I never understand where the majority of people who make comments about soft rigs and there ability to depower get there Knowledge from. Where is this magical intermediate setting that a soft sail has that a fully battened sail doesn't have. As for Salcombe I could not imagine a better place to have a rotating rig with all those reaches and short tacking up banks. Max acceleration out of a tack or in a new puff and max speed down a reach
Being a bit of a coward I get psyched out by a slipway full of soft flapping sails. Give me a slipway full silent fully battened sails in a breeze any day.
Just as you can rotate a mast to dramatically increase power you can rotate the mast to depower. Though most Tasar sailors just wind on the cunningham and play the kicker. With only diamonds the rig responds a lot more to gusts and the controls than a conventional mast with swept spreaders.
If anyone wants a go my boats are in Lymington.
I'm currently sailing the 12 with eldest daughter Mariko as we are too light to sail a Tasar. (minimum crew weight rule 20.5st)* and Mayumi has been away.
I think I have sorted out the rig for light winds now and am looking forward to seeing some of you in the summer. Bucket and spade in hand.
Tim
Bouncing Ben
*what a good idea
Noone mentioned the fact that the sails wouldnt flap when rigging...I'm all in!! ;)
Sorry Emma, that probably goes more with the fully battened main than the rotating mast. But since I don't really understand this very well maybe the two would go hand in hand?
If they do there's an intermediate stage to be had, we're all for gradual changes it gives people time to save for any new kit they may want.
Wing masts have been tried much more recently in the Merlins. Linton built several carbon sections a few years ago and several of our top helms tried them, including mutiple national champs winner Phil King. However, despite some serious development (and expenditure!!!), none of these rigs proved to have any noticeable edge over conventional carbon spars, and in fact often seemed to be slower....Not sure about all the issues, but often an quoted problem was the difficulty of depowering the rig upwind in a breeze, or flattening the main for performance in light airs.
Overall, there seemed to be a fairly narrow band of wind strength where the wing masts would perform well, and performance was often poor outside of this. This has been reflected in my own experience of racing against Tasars in my conventionally rigged Merlin (about the same PY) - upwind in force 3-4 they can be hard to beat, but in wind strengths around this, the Merlin is generally quicker.
Why not open up the rules? Most likely a few people will try it, then quietly go back to conventional rigs after encountering a dramatic loss of form.....Even if they develop something workable, it seems unlikely the wing mast enthusiasts will have something which will render conventional rigs obsolete across all wind strengths. These things tend to go in cycles - note that the 1947 vintage Merlin No. 1 sports a deck stepped rotating rig!
it seems to me that merlin bloke has a point. its not often that the class has a member with the imagination for innovation, technical skills to carry out the changes and the sailing skill to try them out with the prejudice of incompetence. these charactereistics are all essential if we are to accurately evaluate any innovations or rule changes before putting them to the vote to the wider membership.
We can't keep on rejecting ideas becausae they MIGHT be too successful becauase we won't make any progress at all. lets give out some dispensations to individuals or to everyone for a limited time so that we can get some accurate evaulations of these dieas.
if you are taking a stand on rotating masts you might just be proved right. if not then at least we've learned something
Ask for a dispensation to try it. Write to the chairman with your proposal. Bitching on the website will just make you angry.
fair point I suppose. I don't actually want a dispensation. I was just making the point that all this speculation doesn't get us very far if no one gets/wants to try it out.
bitching on the website doesn't make me angry - does it make you angry? Perhaps you'd prefer it if I stopped posting.
Bitching! Where? I miust have missed it, not even a vigorous discussion by the standards of the Iles household. This is the best discussion we have had for ages. Keep posting Matt, but next time try and think of something really contentious, but new!
Kevin
Some thoughts:
- 2 foot longer with a smaller rig, of course it'll be easier in 25kts. All very well in Oz but a bit limiting in a country where 9-10kts is the norm...
- Burton week - twice as many entryies as the Tasar champs so it's fairly likely that there are more inexperienced teams and people sailing with small children (a crew weight rule would exclude a huge majority of 12 sailors who sail with their kids - a bit stupid...) who won't complete races.
-Metal 12 rigs last forever too, suspect carbon rigs wil too for the most part (especially the Angells... famous last words...).
-The only places you find wingmasts are on a couple of not that popular dinghy classes and at the no expense spared end of the sport IMOCA and ORMA 60s suggesting that
a) the average dinghy sailor isn't that bothered with wingmasts (so it won't bring people into 12s),
b)that the performance gain is very small relative to the expense, the guy who just won the vendee had a conventional mast as he reckoned it was more rliable and the performance gain didn't justify a wing.
-There are probably plenty of ideas that can be developed/refined within the present rules, ripping off ideas from other classes/ things you've seen in sailing magazines and then wanting the rules changed to to suit seems like lack of imagination...
-If you're that desperate to try wingmasts and you've got too much time/money that you need using up then go make one anyway, why do you need dispensation you can still go try it out without it.
I'm quite happy with the boat and racing as it is. If we had to have expensive development then a masthead assy and all the lead out would be rather more bang for your buck... Wingmasts - yawn... :P
T
N3497
And Tasars really llook their age, very 70s, not pretty... :P
And Tasars really look their age, very 70s, not pretty... :P
This discussion has touched on a couple of interesting points. I have a couple of thoughts to add, though this really doesn't make much odds to me as my boat is too old to be competitive anyway!
1. Tim L said "The only places you find wingmasts are on a couple of not that popular dinghy classes". I would suggest taking a look at the high performance catamaran scene - they are not uncommon with the fast classes.
2. Perhaps going fully battened (mentioned at some point) would be an interesting starting point for further development. I believe (though correct me if I am talking out of my ar$e) that this would enable more sail area as the battens would help support the leech further out. Would also improve efficiency and (as mentioned) stop the sail flapping!
I used to crew on a Hurricane 5.9 which was awesomely quick and had a wing section mast and fully battened main. Controlling the mast was something that we never really worried too much about it - it tended to get set at the start of the leg (with a line led from the handle onto the boom so you controlled the maximum twist relative to the boom position) and left. For club racing I seem to remember we didn't even worry about it that much - just set it when we launched and left it!
I have no idea how much difference these two changes would make, but it would be interesting to find out. OK, the cost of the mast and associated deck changes are perhaps prohibitive, but buying a fully battened main would not be quite so serious as I guess a lot of you serious guys have new sails on a fairly regular basis.
Just my thoughts, hope no-one is offended or put out! Healthy discussion has to be good for the class.
To Mr If you want it,
The great thing about this is that by having a nice friendly (Well, it would be if I knew who you were...) discussion on this topic, is that we can establish what is likely to be acceptable to the fleet in general - while no one in particular has been that fussed either way about rotating masts, there have been a few people plussing on maybe aiming for a battened rig.
No one wants to waste their time and money at the end of the day, and the class has to have a bit of interest in the topic to even consider moving in that direction.
So - next topic. Full batttens? Keep the sail area the same, move to measuring actual area, free up the cross widths and allow 3 full length battens. Performance is likely to increase, sail lives are likely to increase, and less kids will be scared out of their minds before launching on a nice F4+ because of all the flapping! (I know, I've been there too....)
Cheers
Mike C
3489 Radical Edward
In the spirit of this website discussion, I'd go for experimenting with three full length battens on a conventional rig - which seems to be in the tradition of the 12s (taking further the loose foot and full length top batten changes of years ago) while I would not welcome, after all my recent expense, rotating masts which would seem to take us nowhere.
Mike D
N3496 (hopefully will be legal after measuring tomorrow)
If we are going to solve a 'problem' lets solve one that maybe exists!
I would suggest that building sails out of 'modern' materials compared to dacron has some longetivity risks that we should address. As sails get older creases appear from the clew towards the inboard end of the bottom batten. This gets worse and worse.
In the photo at the top of this page you can see the crease starting to develop on the white and blue boats sailing off on port tack. You can also see another couple of examples in the centre spread of the 2004 annual newsletter in the photos at the top of each page (yes one of them is my boat, so there is a vested interest). Another example on page 52!
I think that the problem could be eliminated and the sail last longer by
- considering the current restrictions on the number of batten and/or batten lengths
- consider changing cross height measurement limits on the sails
I would not advocate changing the overall area but redistributing it, maybe an extra batten. As a starting point take 200mm off the bottom measurements and redistribute.
I do not believe that this would attract people to our class, but sail life is very important to everyone in the Class so we should consider. Rule changes should however not be externally focussed, they should be primarily good for the people who are around today. The sail measurement calculations were last considered before the advent of the modern rigs we have today. I think that this would be a decent opportunity to allow some new ideas into the rigs based on the existing spars. Were I to be sailing enough to justify it, I would ask for a dispensation.
A potential rule change caused by other popular developments that have happened, rather than a rule change which might give rise to unpopular developments.
Probably needs a response from a sailmaker...... Kevan, Tom ?
John Meadowcroft
N3473
Can you not keep the 8 sq m of sail based on the main and jib triangles and say anything else is free? Have all the roach you can eat and as many battens for pudding!
After a couple of years the optimum shape would evolve (which I suspect would not be radically different, just a bit roachier) and the 12 would look a bit different and be a bit quicker in certain wind strengths (and probably a bit slower in others) and you could all go back to worrying about wingmasts.
Ted
No N as yet.
PS this is a lot more interesting than the Wanderer website where they are agonising about allowing centre mains and slot gaskets!
[quote by=James_McC link=Blah.cgi?b=Cool,m=1114709070,s=43 date=1116011401]
I would suggest taking a look at the high performance catamaran scene - they are not uncommon with the fast classes.
[/quote]
Good point James, I did think of that after I posted the last bit but I think it further indicates you probably only get a significant benefit from a wingmasts efficiency if you're moving pretty fast in the first place! Also many of the cat classes still have ally wingmasts which maybe suggest that engineering in carbon is still rather expensive??
Another thing that makes wingmasts nonsensical is that we'd essentially be writing off our perfectly good (and not cheap) carbon rigs. Despite being 'old fashioned' according to Mr C and Mr Knight they are still too futuristic for most other dinghy classes so there wouldn't be any secondhand market for them. Might make a nice garden ornament I guess :) but a rather expensive one...
Fully battened rigs would make much more sense for most of the reasons already covered in other posts, definitely a more positive avenue and more in keeping with past 'rule change' development in the class (i.e. taking on good tried and tested ideas while not changing the racing unduly - e.g. adoption of 4 plankers came after the advent of many similarly produced ODs in the 60s). While there are possible handling issues with moving area higher on the rig I suspect it would actually affect the perception of the class in a positive way, marking us out from the more traditional rigs of grads, fireflies and ents? And with sails being 'perishables' as it were, the trickledown of secondhand kit would make the change accessible to those on more limited budgets much more quickly than wingmasts ever would.
T
N3497
As the first person to mention battens although it wasn't to suggest changing the rules I thought I'd make a second set of comments.
Re Meds message, as Dad is at Derwent I'll say it first the sails on his boat in the 2004 newsletter were less than a month old when that photo was taken, I think they were measured that weekend. Since the creases Med's describes seem to be a problem pretty much from the first time we pull up the sails does this suggest that we've developed sails that aren't well supported by our current battens. Again I'd like to hear a sailmakers pov on this one
I'm not a big enough anorack to know when we last examined the batten rules but even in relitively short time I've owned a 12 I've noticed that sails have changed shape, so again maybe the batten rules need adjusting.
Whilst thinking about fully battened sails, why do boats with fully battened sails seem to have more batterns anyway? ??)
What happened to the fully battened main that Kevan made in the early/mid 90s?
Finally, it won't just be kids that are less scared about getting into the boat on a windy day.
Right thats it from me, better go do some revision
cheerio
Graham
Yes to fully batten masts
I also had the extra crease with my new sails though Tom Stewart says its due to trying to squeeze too much area in.
Personal stuff
Unless im not mistaken I did not count 70 boats at Burton week 'Mr L'
I also only referred to 12s in my writing as modern 'Mr L' and did not make derogatory remarks.
Please check your facts before making caustic comments. I own and sail both a 12 and a Tasar. I feel able to add to a conversation about rotating rigs based on real experience not personal bias.
Yes the Tasar is a very out of date looking hull and rig, hence the new rig currently being trialled.
But check out the longevity, yardstick and hull weight. Mine carries 4.5 kg of lead to make a racing weight of 64kg. (oh and its 27years old). The light hull weight makes a crew weight rule essential.
Did I say 12 sailors shouldn't sail with children? Were you at Burton week last year?
My 9 year old daughter weighs in at 21 kg and will be sailing with me at Abersoch, if the forecast is light. I think this family aspect of 12 sailing i have witnessed at previous Burton weeks is one of the attractions..... don't you?
Classes need to look at each other to see what is happening the other side of the fence and cherry pick the good bits.
Stop being so defensive. 12s are unlikely to grow at the expense of Tasars and vice versa.
Lets keep it friendly and move forward. I hope someone puts up a fully battened proposal
Tim Knight
Bouncing Ben
Fully battened masts?! Mines quite stiff enough as it is, i suppose it is one way of stiffining a floppy mast.
:P
Always can rely on Tim to think out the box.
Graham ;)
[quote by=tim knight (Guest) link=Blah.cgi?b=Cool,m=1114709070,s=50 date=1116232073]
I hope someone puts up a fully battened proposal
[/quote]
Just for interest (maybe)this is approximately based on my recent NZ made Cherub rig, but scaled to approximately 8m2. (and the jib made a bit shorter in the foot as seems to be your norm). Its also not unlike a NS14 rig, so its not impossible that an unrestricted N12 rig would go in that sort of direction.
(http://www.devboats.co.uk/nrig.gif)
Have a look at the RS700 sails (www.rssailing.com/fleets.asp?fleet=RS700). They aren't as radical as the image above and in fact are quite similar in shape to your current sails. Because they have 3/4 battens they don't flap in the wind but have a soft enough luff to allow you to do just that - luff. It makes them a joy to sail (badly in my case!).
Light wind sailing is so much harder with fully battened sails (bad workman etc) and sitting quietly on the start line is also difficult because the sail keeps generating lift even when you dump the sheet.
TC
correction
fully battened sails.
oops out of box or out of tree....
as many or as few battens as you like might be a good idea, ie proposed deletion of the rule rather than ammend it
Tim
Quick reply!
I would not support fully battened right now. Too much change. Would support an experiment / dispensation regarding the rig, but would more strongly support a minor rig change rather than a major rig change. We should be clear that change will not generally attract more people to the class than it will deter within it. If we want more numbers on the water then we should continue to concentrate on what we know we are good at rather than taking punts so that we hope we end up somewhere that we might like to be. Changes that support the value of secondhand boats are good as they inspire confidence.
john
n3473
This thread is following a philosophical arguement that has embroiled the class throughout its life.
Removal of the batten rule would no doubt promote some rig development, but I suspect it would polarise to softer rigs for inland and fully battened rigs for Burton Week, I don't see that this would be good for the class, since inland sailors won't want to fork out for a rig that is only useful for Burton Week, therefore they won't turn up.
This is not a disimilar arguement to the D*****board debate, where although I know that our boats would be much better on the sea with daggerboards, we have to accept that some of the apeal would be lost at Henley or Trent Valley.
I wonder if changing the description of the class to a Development Class in the 70's has done the class a disservice, it has given the impression that the class promotes development, whilst the reality is that many of us would prefer the tighter constraints of a Restricted Class. It is interesting that the Merlins seem to be quite successful at a club level because of the relative competitiveness of older boats.
Regards,
David
3461
Contributing from a position of relative ignorance:
I would have thought that any improvement to the aerodynamics which reduced drag without reducing lift would make the boat faster AND easier to sail.
Has anyone tried putting a turbulator on the front of a N12 mast? Something like a strip of tape with golf ball type texture could only improve things (though possibly by an un-measurable amount).
Having a diamond arrangement for the spreaders which can rotate around the mast (a bit) might have some potential.
Can anyone explain why a soft sail would be better inland than a fully battened one. Surely the effects of having a fully battened main would be the same on the sea and inland?
I'm struggling to see how it relates to the DB debate - its been a very long time since I've seen anyone with their mast pointing the right way up sail their rig into anything. It's much more common to see a centerboard sailed into something.
Meds, can I push you for a slightly longer reply - since it was you who pointed out an existing problem and suggested we solve it. As you've said you wouldn't support the most obvious solution to the problem. What would be your suggestion for a "minor" rig change?
Surely any rule change would immediately mean new mainsails for those at the front of the fleet, because its fairly pointless unless it makes the boats faster, cheaper or longer lasting. In this case the two will probably go hand in hand. Even in the middle of the fleet new sails come every few years and surely fully battened sails would mean these guys buy sails less often too.
Only possible problem is the cost of the sails, do fully battened sails cost more than our current ones? Since a RS200 main is cheaper than a 12 one at the moment I don't see the difference being much.
It's true club sailors probably won't bother but then most can't keep up with the open meeting people anyway, so would it really make any difference?
I'm not sure a change would have much effect on 2nd hand boat prices in the medium term - the change would take a lot less time to reach second hand boats than allowing double bottoms did. It may even promote growth in the area of the fleet who can't afford new sails with a mass dump of good condition second hand mains around.
If only I had that many thoughts about my degree I'd probably get a much higher mark. Never mind time to carry on. Hey its only brain science...
Yours,
Confused of Cardiff
As long as it isnt rocket science hey Mr iiles....
I think the light wind thing is one of those nice myths fired around from time to time. I got soundly beaten by a well sailed 200 on Boxing Day at Nottingham, and it wasnt using its spinnaker! Its not something I admit to, but if a big roached fully battened sailed boat can go faster than my 'river boat' (in the broadest sense of the word, Edward is anything but...) in a light airs roll tacking race, then I'm all for it...
Thing is we all look at a skiff's poor light airs performance and say it must be rubbish, whereas it is actually the whole skiff package that is a bit pants in light airs, not just the rig.
Pros - longer sail life, less noisy and offputting for the kids, less silly creases from sticking silly area in silly places, more attractive looking rig (SELLING PONT = MORE PEEPS INTERESTED),
Cons - possible expense, but as a Moth mainsail is cheaper by a long shot, and not much smaller I doubt it...
Can someone who knows how, measure the actual area of one of our sets of sails (inc 'unmeasured') and tell us what it really is. We then say that is our sail area, we must have two sails, and they must stay within the rig height rule, and not extend over the transom/bow, allow three battens, in any arrangement, I will shut up and go sailing, all is peachy!
Mikey C
PS - I was the last person to sail with the Alverbank fully battened sail - it was fine, although it was made to fit existing cross width measurements, so defeated the object - I had no problems sailing with it on the river at Nottingham at the time.
Does the Solo not have a fully battened main? Searching my 12 sailing memory they were'nt that easy to shake off in the light stuff on puddles.
Not sure how much a fully battened main for a twelve would be but it might be worth getting an estimate to compare with soft sails. Comparing RS200 sails may not be that conclusive, for all we know they might be made in China by children . Same goes for Ka moth sails!
What about battens in the jib too they will last longer too. And they're easier to role up.
Ben B
[quote by=tim knight (Guest) link=Blah.cgi?b=Cool,m=1114709070,s=50 date=1116232073]
Personal stuff
Unless im not mistaken I did not count 70 boats at Burton week 'Mr L'
I also only referred to 12s in my writing as modern 'Mr L' and did not make derogatory remarks.
Please check your facts before making caustic comments. I own and sail both a 12 and a Tasar. I feel able to add to a conversation about rotating rigs based on real experience not personal bias.
[/quote]
Tim,
curse of long term memory.... I'm pretty sure you referred to 12 rigs being 'old fashioned' in your first bit in ratchet a few years back.
Y&Y would seem to vouch for my facts being correct on Nationals turnouts, worlds are a different kettle of fish both in numbers and the fleet ability to survive bad weather...
Your insight is appreciated, however I think almost everyone in the fleet has discussed comparisons of 12s and Tasars with you at some point and we're well versed in your views ;) ( I'm counting three times in under two years!!) Good fun, but some more technical insight into your experience with rotating rigs and fully battened sails would be good...?
Tim
I rather think the only thing that needs saying about tall fully battened rigs, rivers and light airs is this picture.
(http://www.thamessailingclub.org.uk/images/LadyJane.jpg)
See http://www.thamessailingclub.org.uk/ for more about the A Raters, surely the definitive river & light airs boat!
So I gather rotating masts are out, but every one is talking now about fully battened rigs - fine...But maybe we should try two top full battens first, with three quarter battens lower down.... and see how we get on, if they work, fine, lets try full length battens throught out later. But I still think rotating masts would be fun As for however suggested a kicking strap cover ala 29er/49er (I cann't be bothered looking back to find who this was!!!) try crewing a double bottom twelve in light airs and you will know the reason we don't have one...
Disagree with the rater comment. Come down to Upper Thames Sailing Club and watch them tack. They have to give the rig a right seeing to so that the battens to pop through on a tack. Fortunately they are heavy enough that you are able to put this amount of energy into the rig without cheating. I have sailed one. They are very nice. They are not National 12s.
I was asked to propose the sort of change which I think could be good.
Rule 11.3.6 shows the current allowed heights as
1/4 height 3F/4 + 470mm
1/2 height F/2 + 565mm
3/4 height F/4 + 530mm
Very simply my proposal would be to reallocate some of the mm from the 1/4 height to the 3/4 height. There is probably a mathematical rule that says by shortening the bottom one you need to add more at the top to maintain the same overall area.
To keep is simple, lets assume that 150mm at the 1/4 height is worth 300mm at the 3/4 height. The proposal would be
1/4 height 3F/4 + 320mm
1/2 height F/2 + 565mm
3/4 height F/4 + 830mm
Caveats
1 - I have no idea if this is the magnitude of the problem that can be seen on the mainsail. ie the problem may not be as large as 150mm, it may be more.
2 - I do know as a measurer that few sails are built out to the maximum 1/4 height allowed anyway
3 - I have assumed that the 1/2 height stays the same and the area pivots around it. If a large chunk is taken of the 1/4 height we may need to move the 1/2 height or we will just get the same problem somewhere else.
4 - will a larger 3/4 height require a 4th batten?
Proposal
Dont change the rule now, but have a look instead. I feel the 4th batten could be genuinely speed enhancing as the rest is just a reallocation of area.
I am not intending to submit anything to the AGM as I am not sailing enough to justify this. I do think a change of this ilk would be good if the sailmakers were supportive and they essentially constructed the rule.
John Meadowcroft
N3473