Messages

any advice on how to best seal the centreboard bolt below the waterline would be appreciated.
Matt
N3486

It might be instructive to see where the developments are focussed recently in unrestricted classes. Off the top of my head - an almost certainly not an exhaustive list

• Waterline beam - lower wave making whilst retaining the beam. Restricted by the rise of floor measurment give or take a bump, and the no hollows rule.
• Sail plan - restricted by the complex sail measurements, and yes that does have an impact on top end speed - evidence the cherubs who carry more righting power on twin trapezes and do go faster than pre 2005 rules with smaller sailplans.
• Daggerboard fitted with hydrofoils. Clearly the twelve won't fly but there is no room to experiment with foils to reduce the speed at which the boat planes. Restricted by the anti daggerboard rules.
• Capitalise on new materials and reduce the 'size' of the boat to reducing weight to promote upwind planing or flight. Restricted by the weight rules.
• Rudder fitted with T-foil. An area where 12's are experimenting.

So as far as I can see the rules do prevent N12's adopting or developing all but one of the recent innovations in other classes. I'd say then that its entirely fair to blame the rules for a lack of change in the class. Yes, it's probably right to say that there is potential for speed improvements within the rules but its asking a lot of the class to innovate in isolation. That is the main reason why no-one has created a ground breaking innovation within the rules for a long time despite some major innovations in other development classes.
I'd even go a bit further and say that 'most' of the recent (last 20 yrs) N12 rule  changes were formulated initially to stiffle a development - evidence? daggerboards is definatly a case, ..... mast weight  preventing the full development of carbon as a spar material ..... weight restrictions as new materials become available .....
Seems to me that it is unreasonable to expect the class to create major improvements in speed and efficiency within the rules simply because the class wants to restrict anything that changes the boat. Presumably there are somethings about the class that is held dear and is too sacred to interfere with. This gives the designer a unique set of restrictions ... and frankly there are easier classes to apply their imagination to. I guess we ought to be clear and open about what is sacred in the 12 and have a discussion about whether those sacred ideas are out of step with the modern world.
3 for starters.

• The shape. we are round and we will always be round.
• The sail plan. we will never have a spinaker even if we'd be fast and be able to carry heavier crews.
• The centreboard. We will never use daggerboards even when other classes are growing and regenerating by attaching foils to them (moths and RS600FF's)

I'm sure we can add others.
 
Matt
N3486

yipes - I hope you don't beat me over the water.
Matt
N3486

Thanks john,
I don't have the book so please could someone send me Jon Browns, and Gavin Wilkins numbers. Much appreciated
Matt
N3486

The measurement guide state "The overall length includes the stem band (if fitted) but excludes normal rudder fittings within 60mm of the centreline"
What constitutes "normal" in these circumstances?
I am planning a rocking plate system to change the angle the rudder makes with the waterline between -2 and +7 degrees. I do not expect the plate to extend more than a couple of inches beyond the transom and the whole mechanism will be contained within 60mm of the centreline. However the rudder fittings will not be off-the-shelf pintle or gudgeons.
Please could someone from the technical committee respond as to whether the system is likely to pass measurement?
Cheers
Matt
N3486

with regard to the objections regarding my fixed rudder choice I'd just say that I only need the rudder the the nationals. Thats the only time I sail at sea. I could I suppose make a rudder that fits the existing stock but I can't help thinking that the transom could be quite a bit lighter. As the rudder will only see sea use I'm hoping that the encounter with immovables will be relatively rare. More of a worry is an encounter with other docking boats.
I have actually tried to build a stock before and its a damned sight harder than building the rudder as it has to be significantly reinforced to take point loads. Do that on the rudder itself is trivial in comparison. Building the stock too seems disproportionate in terms of effort and materials for a rudder that won't see a lot of use. I guess the over-ridding reason for choosing a fixie is that I havn't got a lot of time. One thing less to break too.
Cheers
Matt

DavidG,
yes you are probably right. I'm more than happy with the AA's performance in light airs and on flat water but I guess because of my poor sailing skills I've found the rudder insufficiently reactive in waves. Think I'll build on aobut 20-25% larger in area. Fixed rudder this time to save weight and make docking more errr ... interesting.
thanks for all your ideas everyone.
Matt

accepted but what is length is good. I can presumably have a high aspect ratio rudder of 50cm length but that won't let me turn effectively in waves.
As for spinnaker I can't d/t child care responsibilities.
Matt

I sailed gregory's girl in the nationals a few years ago. lovely boat as you describe. We had a good few comments on its 'bus' like dimensions but that was before the Wilkin's boat 'revealed' the ergonomic advantages of high freeboard. Actually Phil Diamond and Ian Gregory had that issue completely sorted in 1981.
Its good to see the rig updated but I wonder whether you'll get much advantage by replacing the gorgeous hog's and woodwork with carbon space frames. The Rig will have already gifted you a big advantage already and replacing the hull structure puts the whole hull at risk. I spoke to Ian at the time and he was very cautious about removing the Hogs' because the cold moulded hull isn't really suited to life without integral structure. Just a thought - its just great to see this boat modernised and racing again.
 
Matt N3486

does anyone have a feel for what's the right rudder length and chord for sea sailing. my Annies Apple rudder is too small - I know that much!.
Matt
N3486

I've currently got the spreaders fixed and the mast does pre-bend as necessary. If I take out the restraining bolt the the spreader 'opens' and the mast looses prebend - though I'm not sure if this happens under sail. I think I'll give that a try next time I go out sailing.
ta
Matt

think I wouldn't like gybing with a sloppy rig. sounds dangerous to me. Also the crew has a lot to do already at make roundings.

swinging spreaders:
Is there a full-proof way to set up swinging spreaders? I tried it on 3486 a couple of years ago but found that when the shrouds were on tight the spreader would swing forward an inch or so rather than lock back and push the mast forward.
As I understand it the spreader when locked on is supposed to push the mast forward and outwards (ie. away from the locked shroud) so it seems to me that the pressure held in the mast is released by unlocking the speader and dropping back to its neutral bend. (clear? - probably not). Thats what seems to be happening on 3486.
I've designed a nifty mechanical thing to swing the speader forward against the pull of a bit of elastic (which helps it swing back into lock) but I bet its not needed if the spreaders are set up properly. So any help you can give will save me ages in fiddling.
Cheers
Matt
 
 
 

going back to your original point Tim I have a feeling that you have missinterpreted the importance of the quality of the events on the nationals turnout. If you did this analysis for the national 12's over the last 10 years I think you might find that the step decline in the turnout for nationals correlates (inversely) closely with the turnout for gill series events. The interpretation being that what people want is big fleet racing (where big these days is 20 boats). In the past this was provided by the nationals and norfolk week. Now however the class has a thriving alternative by way of the gill series so competative sailors do not have to go to the trouble, expense and pure physical effort of a week sailing long races out at sea.  
If you look at it that way you'd conclude quite the opposite - cull the gill series if you want a healthy nationals turnout. Further the smaller and one day events are entirely irrelevant to gill and nationals turnout as they cater for a completely different sort of National12 sailor. i.e  the type who don't have a competative boat and don't sail to win - rather the enjoyment of fleet sailing and a good position against their neighbours. There are a vast number of that type of sailor in the N12 fleet and to deprive them of local open meetings will only disengage those sailors.
I'm not suggesting that either course of action is right. Rather be a bit more positive about the health of the class. A high number of events is a sign of a thriving class, a core of well attended competative events provides a focus for the elite and a large number of locally fed smaller events proves that the 'rump' of the class is catered for and is engaged.
Matt
N3486
 

Ted,
That sounds good. I'll give you a ring later.
cheers
Matt