Topic : Rigs

Just been looking at a thread on the N12 web site and read that Jo Richards new 12 which was very dominant at the recent champs had the rig a lot further back than the norm. This leads me to wonder if any recent merlins have experimented in a similar way and maybe the more technical of us might like to share views as to why Jo may have gone this way

Posted: 02/06/2009 11:52:46
By: Dave
Ever thought that Jo could win in nearly any boat / rig combination. You say the rig is further back, what about the centre board position in relation to the mast foot, or is the mast more upright compared to other boats, with the centre board in a similar position to the other boats. Is this why he uses a centreboard as opposed to a dagger board. More than just the rig coming into play here I would suspect. Would like to know his overall design philosophy on this boat.

Posted: 02/06/2009 12:15:25
By: Dave
Reply by a different Dave.

Posted: 02/06/2009 12:16:02
By: Dave
The effect of the winged rudder (to which Jo Richards designed the hull around) is to effectively increase the waterline length of the boat, hence it is more like a National 14. The mast foot and I suspect centreboard therefore needed to be moved further back to the new centre of effort to maintain balance.

Please note there is a proposal by Graham Williamson and seconded by myself to ban winged rudders, details are included in the forthcoming magazine and the proposal will be voted upon at this years AGM at Salcombe.

Posted: 02/06/2009 12:25:45
By: Alex
Mmmm not sure about effectively lengthening the boat, but I will await the presumably detailed descriptions in the next magazine. Personally, since no one has (yet) designed a boat with a T foil, although Mr King had one I think, are we not jumping the gun a little. I cannot see that a T foil is suddenly going to lift a Merlin out of the water like a Moth - afterall the width of the centreboard case precludes a second lifting surface (see Rule 4 (j) (ii) - max. 50mm width).

A T foil might allow more (how can I phrase this) larger helms like myself to lift the transom, but as we all recall, anything that makes the heavy weights more competitive aides the lightweights by a similar amount.

If we are looking at cost, then this has to be questioned too. According to the Aardvark Racing site, a T foil upgrade and stock mod costs about £300 on top of some £480 for a standard daggerboard style rudder. Surely this is a bit of a false economy when you have to spend so much on a new boat anyway. Work a rig out that eliminates the need for the one string and seperate lowers, shrouds, etc. and you have saved well over the £300 mentioned above!

I look forward to hearing and voting on any resolution proposed at the AGM.

To go back to the original posts, the Cowes Online has a couple of good articles describing the boat. I notice that the centre main & traveller connected to the helms toestraps was discarded for a transom mainsheet.


Posted: 02/06/2009 14:24:59
By: Andy Hay - Enchantment 3386
I would not get too focused on the t foil rudder with dead cat bounce. The boat is radical in many respects. It has a lot more rocker, without the traditional deep stem seen as standard in both 12's and Merlins since the 70's. The deep stem is supposed to help with winward lift. The trend has gone to both the rudder and centreboard giving lift, effectively moving the centre of effort back. 
It has minimal waterline width, both will make it fast in the lighter conditions that Jo was particularly devastating in. The trim tab is an interesting development, the board is pretty much normal sized, which according to Bethwaite's experiments with asymmetrical boards should make little difference. Their suggestion was that this should allow you a smaller board, and reduce drag.
No one quite understands the effect of the winged rudder yet. The early non canting rudders were discarded, which suggests the extra length theory is not the answer. Canting the rudder allows greater lift, allegedly changing the balance of the boat, so it will displace on a different part of the hull. Terry from Aardvark feels that the rudder would be more effective if mounted further forward than the stern. It certainly seems to help with weight carrying so far, but wait till the little guys get their rudders working!
There are too many mods on dead cat bounce to know what is making the difference, the winged rudder may even be slowing him down. The one thing that it will do is stimulate another round of development, so I may need to swap my winder one design 12 in the next year.

Posted: 02/06/2009 23:39:46
By: Ectopic 12
If you stick a rudder on a  gantry off the back of the boat and move the centreboard and mastback by the same amount the boat will think it is longer when being pushed sideways. (centre of effort, centre of resisance?)  I presume that this will help the nose stay up when sailing but as wind/speed increases a short hull will still drag off the transom. It occurs to me that this set up could place a T foil rudder into the wave that rises off the stern where the foil would think it was going down hill and push the boat forward. There is more boat in front of the mast to resist nose diving. Dead Cat Bounce seems to have its foil quite high up the board. This is just a personal observation, am I anyway near correct?

Posted: 03/06/2009 07:43:58
By: John Saunders
For what it is worth, my pet theory is that the T foil on a rudder will do two things:

1. generate lift to raise the transom, although how much is open to conjecture - but could have significant trim effect which then increases the running length of the boat (as per a trim tab on a motorboat)
2. modify the transom wave pattern by introducing a "reverse" element to flatten the wave pattern (i.e. the same way that bulbous bows are used on big ships to modify the bow wave)

DCB has the T about mid way down the rudder (from photos I have seen). So probably more likely to act as a transom wave suppressor than generating much lift.

I do agree with a previous post that there are a number of contributing factors and major differences to the defacto N12s so isolating one is going to be tricky. Anyone want to commission Jo to have a new look at a Merlin .....

Posted: 03/06/2009 08:47:25
By: Andy Hay - Enchantment 3386
I believe jo "breathed" on glen's boat,seems pretty quick now,however, Mr truswell would still feature in the results if he rigged an old bath tub,skill being the main factor!

Posted: 03/06/2009 10:19:45
By: D. H
It looked to me as though DCB was particualrly fast in a F1-F2, and about the same speed as the other 12s at other times (but generally a teeny bit quicker round the course than the other 12's overall - I suspect the helmsman might have been the difference most of the time!) 
I think what is more interesting is that most of the 12's with T- foil rudders have the wings pretty high up and they are arranged so that they can lift the rudder blade vertically and the T foils are then clear of the water and neatly swing into the transom cutouts out of harms way.
DCB was devastatingly fast when you would expect the wings to be lifted clear of the water (I don't know whether it was that day - it was too far offshore)

I suspect the T foil thing actually works by adding an additional planing surface at the stern when it is windy - thus allowing the designer to put in much more hull rocker at the stern and narrow the waterline. (Which is what DCB actually has)
So paradoxically the T foils don't make the boat faster when it blows but allow you to "get away" with a highly rockered hull that comes into it's own when the wind drops and the foil is lifted out of the water.

This would brobably mean a T foil rudder blade wouldn't work very well if it was retro-fitted to an normal hull. Well that's my theory ayway !

Ban em quick before someone trys to sell you all three pronged weed sticks for Salcombe!


Posted: 03/06/2009 17:51:49
By: IanL
Ians observations are correct regarding the Paradigm boats, they are able to lift the wings clear of the transom and therefore reduce drag when it is light. DCB had lower set wings which were slightly canted upwards. The rudder was otherwise set off a standardish rudder stock, and lifted by rotation. Jo therefore had to keep his wings wet in all conditions, the canting mechanism was via the pintles/gudgeons. Pre the developement of canting the foil wings were tried  by Graham Camm on his Numinous, which does not have have a 1980's/90's flat planing surface on the stern. He felt they gave him extra stability downwind when it was windy, but overall probably was of no benefit. It should be noted that graham did take the one race off DCB in the week, I think he was having starting issues the rest of the week, given the number of times he had to get past us on the early downwind legs.
The guys with wings were saying they were canting the foils upwind, neutral on the reach, and on, but not fully on the run. We will see if they make any difference on the other designs in the coming year, as people get to experiment. I expect the Chapters may benefit, as they were originally designed to carry a buoyant rudder to induce lift. I am also not convinced on the other designs, but anything that can lift the arse of a baggy upwind and in on the run in sub-planing conditions has to be good.

Posted: 03/06/2009 19:14:22
By: Ectopic 12
Walking round the dinghy park at the Nat 12 nationals I reckoned I saw just about every innovation that Glen Truswell originally had on After Hours MR3585.  Moveable centreboard pivots, shroud bases, mast foots, rudder fittings etc. (except the engineering was more low tech on the 12's - lots of string!) Given that Glen gradually removed the complexity and went faster, it'll be interesting to see how many of those innovations are still there in a year or so!  

Posted: 05/06/2009 00:13:30
By: IanL
All very interesting to techie geeks but another factor in Jo's win was the crew. Sophie Mackley, experienced in 12s and Larks and now part of the Whitstable Merlin fleet, take a bow.

Posted: 09/06/2009 15:55:25
By: Mike Fitz
People have been moving shroud bases for years, some love it others don’t.  Important in a 12 because we run dead with no kite, probably less helpful in a Merlin.

Not aware of any movable mast steps. Movably CB pin is not allowed. Few hatchet boards, always have been. Generally look good.

One thing that has been proved is that if you want wings you must be able to adjust them.

Some comments above about wings allowing you to redesign the hull sound right. Joe’s comment was the boat is designed for the wings, without them it would be no use at all.

Personally I’d ban them while you have the chance. Pain in the arse to launch, pain in the arse in the dinghy park, pain in the arse in the car. But you lot have fixed rudders so you already have the launching problem, at least your boats go in a straight line.

As mentioned above Joe and Sophie sailed fantastically, who knows how much was boat and how much was crew.

Posted: 09/06/2009 16:34:27
By: 12
Bring it on, that's all I can say!

Posted: 09/06/2009 17:58:33
By: .
Kind of odd really people seem quite happy to spend £10/14000 plus on Carbon fibre rocket ships, New sails a couple of times a season but afraid of others playing with winged rudders! No doubt the equalibrium being tipped the wrong way? Or just one they can't understand or buy? Just a thought......

Posted: 10/06/2009 22:52:41
By: Admiral Lord Nelson
It is the interest in the status quo, too much money invested in the static state of the present development class, one of two thimngs will happen, they (these new fangled foiled rudders) will be quicker depspite their complexity but very few will be good enough to get any advantage (Like roll tacking.) or they will show no real advantage. Meanwhile fouil and boat builders will had some welcome extra business which may help tokeep them in business.
Personally I hope the class permits them, that they work and allow a more rockered and thus weight carrying hull to be competative and let real men sail again!

Posted: 10/06/2009 22:58:26
By: ..
I think that it is time that John Dalby got involved in this debate. The top Merlin Sailors were, at one time, all for banning carbon masts but the AGM voted them in after John's erudite and reasoned submission.  Having finally upgraded to carbon last year (in a 20 year old boat) and, despite the resultant hole in my savings, I have to say that it was the right way to go. So John, what's your opinion on winged rudders?

Posted: 10/06/2009 23:36:21
By: Fat Pig
The Merlin Rocket is after all a development why not let this line of development progress a little further before banning it outright? There could be many benefits from it on many different planes, for example it could help ease the Winder domination and get other builders into the market?

Posted: 11/06/2009 17:00:21
By: Hugh Fletcher
Hugh, i think that you (perhaps inadvertently) might have hit the nail on the head. 

Is the Merlin really a development class or is it a restricted class? The N12, Cherub, I14 and Moth are clearly in the development camp, but my view has always been that the Merlin is a restricted class and happy to stay that way. This distinction might sounds like pedantic semantics (if you can put those two words together like that) but is very important to the decision that you Merlin sailors need to make before the AGM. If you like the class the way it is, as a virtual one-design with freedom of kit then you do not want adjustable wings on the back.... if you would like some hull development and new things to be going on in the class then wings are the future.....

My opinions as a 12 sailor and friend/observer of the Merlin class


Posted: 11/06/2009 18:39:52
By: Antony
Yep, the MR is a restricted class, that means that there are some things that you can and cannot do. The Rules (as they are at the moment) do not mention lifting surfaces at all. There are Rules about double luffed mainsails, mains that pass around the mast, etc. but nothing about rudders except that double rudders are not allowed. Everything that is not specifically mentioned is OK and up for grabs.

I note that no one has their knickers in a twist about putting a small set of winglets on the bottom of the centreboard which is also allowed, as long as you can get them inside a 50mm slot in the keel. I guess that you could have some form of hinged mechanism to retract the fins when the board comes up ..... (and no I do not want to see this)

The class has moved on significantly from 1946 and I am sure that the foundling fathers would have approved. I do not think that they had a quasi-one design in mind when they framed the Rules in the way they did. No one has produced something that has significantly stolen a march on the fleet and instantly made everything before it obsolete, so I think that augers well. Most developments have been backwards compatible, so older boats can be brought along for the ride. We are having a blast with our 1986 boat, carbon rig, plastic sails, long poles, etc. and giving much more modern boats a view of our transom - admittedly not for long, but for long enough if you get what I mean.

A T foil rudder might change the hull forms, but not overnight. This might mean that Winder's hull mould might need tweaking. Someone might actually develop a hull specifically for a T foil rudder (which would be the way it would have to work). There is a lot of mights in that and trying to "ban" everything that some lateral thinker might come up with is not what this class is about.

If we did then we would not have carbon rudders (1992 AGM tried to ban that one if I recall), no carbon rigs, no plastic sails as we'd still be with dacron, short spinnaker poles, need I go on?

It is still a bit of a mute point though as the best sailors will still be at the front, those who have the best crew work, get the best start, go the right way.

I'll get off my high horse now and await the next MR magazine with interest to see the reasons for the proposal at the AGM.

Posted: 11/06/2009 19:46:08
By: Andy Hay - Enchantment 3386
A few years ago I spent a few hours at the Dinghy Show talking with everyone I could find from the RYA to try to get an official definition of the difference between a "development" class and a "restricted" class. It was a frustrating and ultimately futile exercise. Nobody from the RYA could give me a definitive official answer. I got a great deal of personal opinion but it seems there is no technical difference. It would appear to be simply a subjective judgement about the level of restriction within the rules. Perhaps we should stop claiming that we are fundamentally different from other classes which can "develop within the rules".

This brings me on to the winged rudder debate. Andy has a very valid point. Over the years there have often been calls to alter the rules to allow development (bigger sails, lighter boats, etc. etc.). The argument generally used against these suggested rule changes is that we should continue to make performance improvements WITHIN the existing rules. Winged rudders ARE within the existing rules. Are we not in danger here of banning developments that are allowed under the current rules and therefore of preventing precisely the kind of developments which have made the Merlin Rocket into "The ultimate hiking dinghy for two people – refined over 60 years of development"

I too await the next magazine to read the arguments, but in the meantime we should all be grateful that we can explore such issues in reasoned debate on this forum!

Posted: 11/06/2009 22:30:40
By: Richard S
Some of us with shallower pockets will welcome the rules committee keeping a check on the cost of our racing, whilst still allowing development in many other areas.

Posted: 12/06/2009 11:01:20
By: Mags
I agree totally, you should not have to spend thousands of pounds on a competitive boat. I know many people with 12's who use them at club level, who would love to do the open circuit, but simply can't afford a new carbon boat. Yes-Merlins should be developed, but surely a different way of development can be used.

Posted: 12/06/2009 11:39:59
By: Mr Average
I know I need to develop my tacking and gybing, more than anything.

Posted: 12/06/2009 11:58:12
By: Mags
I'm not surprised Richard couldn't find anyone from the RYA to define a development class from a restricted class. The RYA are only interested in one-designs and those that are raced at the Olympics at that. When have you ever heard the RYA endorsing the Merlin Rocket or any of the national classes come to that??

Posted: 12/06/2009 12:13:19
By: Dave
There are lots of "average" boats out there in inumerable classes the competative modern Merlin Rocket is a very special boat and as such attracts a premium and few can afford it even fewer can sail it.

Posted: 12/06/2009 14:59:27
By: ..
Well I feel sorry for you, the class will simply die out if people have that sort of attitude (In my view). The class should do all they can to encourage people to join, especially in this finiancial climate.

Posted: 12/06/2009 16:05:17
By: Mr Average
Sorry to say it, but a Merlin Rocket is not average: the best for the best

Posted: 12/06/2009 16:20:18
By: Dont mess with the best
Going off track here a bit people. 

I don't think anyone would disagree that the Merlin Rocket isn't at the premium product, we know that the cost of a new boat is prohibitive to many but fortunately we have a healthy second hand market with high quality competitive boats thanks to Mr Winder, Jenkins and Driver.

Turnouts for the Championships and Silver Tillers are still relatively strong compared to the majority other classes and the competition is seriously tough. New people entering the class all the time and very much a case of more the merrier!

So,...backed to winged rudders or indeed rigs as per the original topic of this thread.

Posted: 12/06/2009 16:34:09
By: Alex
This is quite interesting although in some ways uninformed.  I have a Paradigm 2 National 12 with a winged rudder

Jo does not have a National 14 and nor do I. What the wing does on both of our boats is interact with the wave leaving the transom of the boat. We both articulate the angle of the T-foil as you can imagine the shape of this wave leaving the boat changes dependent upon the speed of the boat.

The observations are as follows:

Your boat can have more rocker and thus tacks more easily and carries more weight. 22 stone is competitive in a 12, so what would a Merlin carry?

The speed benefit is most noticeable in marginal planing conditions.

You sit further back in the boat all of the time.

Launching can be an issue. Both Jo and I have lifting rudders so have solved this problem. Other people do not and this makes it harder, however there is clearly a choice.

You can collect weed on the wings. We have trouble with this. Jo however has swept his wings back and does not have a problem.

The biggest issue is transport. We carry ours in the boat out of preference, tied in, like we do with the boom. It is no big shakes. The old rudder had been in the boat ever since we had kids anyway.

It is interesting and it is changing the playing field in the Class. A winged rudder costs about £200 more than a normal rudder which is about the same as a jib, a few weekends away or a Championship entry fee. It does seem to last a bit longer too.

Probably the most exciting thing about Jo's boat is he did about 5 things different from the consensus. The cat is among the pigeons, and it could in fact not be the T-foil at all. Jo has a trim tab on his centreboard and had devastating upwind speed on the windy final day. Maybe this is the secret weapon or maybe it is indeed the whole package. Getting back to the rig, this was marginally further aft but with a typical ratio. The idea is that with all the lift from the rudder why have the centre of effort of the rig causing you to nosedive. Another nice idea.

Enjoy your AGM.

Posted: 12/06/2009 20:54:43
By: John Meadowcroft
If a "development class" allowed free development then Merlins would become say, 49ers. Merlins are a "limited development class" where restrictions apply. The art is to work out the restrictions.

Posted: 12/06/2009 21:37:51
By: John Saunders
Well said, John, John & Alex.

I also note that rudder gantries are not excluded either ....

You cannot make or change the Rules to keep old boats competitive. Period. You can upgrade old boats to hang on to a point - and believe me we have tried with the one-string, rig, sails, etc. - but at some point the new boats will steal a march (although this is probably as they are better sailors, but this is not part of the discussion). After all if the new boats were not faster, why has Alex, Matt, Richard, et al upgraded their slightly less new Winders for new ones?

This is a sign of a healthy class and feeds those newer boats down the chain for others to upgrade.

I think that the definitions previously asked for are:

"Restricted" - evolution derived design improvements within reasonably open Rules, with the boundaries continually pushed, resulting in boats having a long competitive lifetime
"Development" - periodic rewriting of Rules to make massive leaps in performance immediately making all previous boats redundant

Anyway as Alex says, back to rigs. Anyone for a self tacking jib?

Posted: 12/06/2009 22:19:01
By: Andy Hay - Enchantment 3386
Self tacking jib on a merlin already tried many years ago. Ask Ian Holt.

Posted: 13/06/2009 16:54:29
By: ..
Can't use a puller with a self-tacking jib track, surely?

Posted: 14/06/2009 21:50:00
By: Mags
12's have done lots of things that make them better boats on open water on the back of "development" (development class only got written into their rules in the seventies), but in the process have made them less practical boats on restricted waters or with novice crews.  

IMO wing rudders are in the same direction, and if sailing at venues like Salcombe and river clubs, or reservoirs with weed are important then you may end up with a two tier class with different rudders and possibly designs for different venues. Strikes me that the strength of the Merlin is the adaptability of different designs brought about by the variety of the Silver Tiller venues and Salcombe.

Posted: 15/06/2009 10:59:07
By: David
Seems to me that restricting a modification or design evolution because of weed would be problematic for the class. We already have the situation where members of the class have "river" boats and "open water" boats. Personally, river sailing is a once a year headache to get my restricted event in for the Silver Tiller (this year we have twice the pleasure!). I wonder how many of the top guns - Alex, Matt, Glen, etc. - were playing with their one string controls at Cookham?

The puller question, earlier, is perhaps symptomatic of the class as it is at the moment, viz:

A Merlin sailor has a problem with his mast inverting, because he wants to use a light weight, probably overly flexible mast: so they add a bit more string, which costs a few quid more and gives the crew another job to do at every hoist and drop. This is where we are now.

Another Merlin sailor has the same problem, but analyses it and contends that a stiffer lower mast or even struts in place of lowers might resolve it. Both would allow a self-tacking jib, save a few quid on blocks, give one less job for the crew and is one less thing to forget, etc. A few grams more carbon on the bottom metre of the mast might solve it.

Of course, I am surprised that no one has yet cried for centreboard tabs to be banned. These are allowed under our Rules at the moment, as long as the board goes through a 50mm wide slot in the keel.

Posted: 15/06/2009 13:55:41
By: Andy Hay - Enchantment 3386
I was always surprised that you boys never put a minimum weight on your masts.  In my opinion it’s one of the things we did get right in the 12s (5.5kg).

It keeps the weight sensible i.e. no point building a very very light rig. No point adding the expense of carbon spreaders and things like that. Typically a ‘standard’ SS or proctor rig will come in on weight with tin spreaders and ‘standard’ wire rigging. A more expensive, but not full on Gucci, Chipstow will require a bit of lead, I think that’s a heavier section than you guys use as well. It does help avoid the old law of diminishing returns, helps keep the price down and avoid overly fragile rigs.

Posted: 15/06/2009 14:14:27
By: 12
I have to disagree to that, if a mast is built correctly and is light, then is should not be handicapped by adding lead to it.

Posted: 15/06/2009 15:57:24
By: :)
cheque book sailing surely the best way to destroy a class

Posted: 15/06/2009 17:21:42
By: .
Not sure if there is a class in existance that does not involve some element of flexing the plastic - even the ubiquitous Laser requires a carbon tiller and new sails every time you go out.

Point of fact though, the Merlin has often had a reputation for cheque book sailing and I think that we are still going, even after the worst of the excesses ....

Posted: 15/06/2009 20:21:11
By: Andy Hay - Enchantment 3386
Plenty to discuss at the AGM then!

Posted: 16/06/2009 09:35:08
By: ..


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