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Having thought about it further, I think having a one piece L shape boom that could all pass through the 102mm circle would put so much stress at the angle joint it would be tricky to get right, As STU W suggest a Lever arm that is sleeved over the boom and then pinned or bolted in place is the way to go. I guees the problem then lies with the Fixed fittings rule. My boom wouldn't pass through the circle with the main sheet blocks attached, I would have to get a pair of plyers to remove them. I'm my opinion bolts, pins and screws would be removable but rivits and glue not.
Kevin, you would need a boom designed for the extra load, the load on the mast however would be more or less the same as a standard kicker.
Peter

A Temple Vang is an alternative kicker arrangement, a lever is attached to the boom at the gooseneck end at 90ish degrees and is pulled towards the mast under the boom, see attached pictures.
This has the advantage of freeing up space for the crew and reducing kicker loading.
However i'm not sure if it would be legal under the rules. 
As far as I can tell there a two rules that concern booms :

• 9.3 Booms including fixed fittings, shall be capable of passing through a circle of 102mm diameter.
  
• 9.5 Prohibitions: Jumper struts, permanently bent masts and booms, rotating masts and other similar contrivances.
  

As I see it making a L shape boom (like the first picture) that could all pass through a 102mm diameter ring would be prohibited as a  "permantly bent boom".
However a revovable leaver arm could be used as in the second picture, or would this be prohibited as a "Jumper Strut"?
A few 12's have gnavs i can't see how they can be allowed and temple vangs not, just want to make sure before I breack out the epoxy  
 
Peter

As a Engineer (well in training anyway), I have reverted to type and looked at some data and done some maths

specifically a NHS study summarised on this site:
https://suite.io/catherine-whitlock/2s0z24x
and NHANES study from 2006 for Americans through Wolframalpha

Assuming a N12 is sailed by Mr and Mrs Average, the crew weight from 1993 is 145.5kg and 154.1kg in 2008 this is a increase of 8.6kg over 15years or 0.57Kg a year, My boat was built in 1980, so in 2008 it would have been 28 years old, Assuming a linier average weight gain of the crew of 0.57kg, the crew weight will have increased by 15.96kg. so Mr and Mrs average from 2008 - 15.96Kg gives a average crew weight of 138.14kg in 1980. this is 21 stone 10 pounds. As you would expect  this falls within the 16-23 stone recommended weight.  

Assuming our N12 helm and crew are of equal weight and wanted to fall within weight range they would have to weigh 11.5 stone each, nowadays (well the data's from 2006) only 38% of adults fall below this value, so already we are excluding 62% of people from being competitive, I suspect in 1980 the percentages would have been the other way round.

taking me as a example, I weight about 85Kg so if I wanted to match Mr and Mrs average from 1980 I would need a crew who weights 53kg this limits me to 5% of the adult population or if I want to be within the competitive range 17%

I would be interested to know how many N12 owners bought their boat with a crew already in mind and how many, like me see who's about on the day/organise the week before
 
Peter

My reading of the rules is that a L shape boom would be prohibited as a perminant bend of mast or boom (9.5)
not realy sure though
Peter

an idea to encorage home building,
i'd like to think of myself as compitant with the expox and carbon/fiberglass, the odd repear here and there or the extra bracket. for me by far the most daunting part of home building would be geting the design right. you could spend mounths in the shed only to find your new boat is slow. there are plenty of guides and tutorials on how to build in wood or carbon on this sight, the cherub page has lots of usefull info too. but there is no info on what to build. i segest a "open sorce" rule where the plans or nowadays the CAD files of any new boat should be published under a none comertial licence. this would allow a home builder to go straigt from the shed to the front of the fleet.
a few other clases also have a set of class moulds that can be borrowed/hired

Having just bought my first 12 (N3124) and coming from a low-rider international moth,

I think we need to make the boat more comfortable to crew, and generally update the rules, but I also think it is important not to ban anything currently allowed

1. allow dagger boards, having no centre board case would make more room in the boat so should be easier to crew although downwind with the dagger board most of the way up it might be a bit tricky, but if you allow them and their rubbish you've not lost anything as no one will use them
2. more sail area, I would reduce the rules to a max luff length(set this so current masts can be used) and max area(say 12 or 13m^2), at the moment we have the width of a RS400 with the less sail area than a RS200, allowing fully battened mains and jibs with a square top mains would modernise the look of the boat and make a big speed difference to us river sailors and also get both crew sat on the side sooner which is much more comfortable
3. allow none standard kickers, as far as I can tell gnavs are allowed although I'm not sure if anyone has one, but temple vangs are banned by the boom dimension rules, they would give the crew much more room to work
4. mast CG correctors seems a bit pointless when carbon masts are not much more expensive than alloy ones, keep the same overall sailing weight but losing the mast correctors would reduce the height of the GC of the boat and I think would make a noticeable difference to the stability and ease of righting from a capsize
5. winged rudders, I think with extra sail area winged rudders would make a larger difference than they do now, they could make the boats much easier to handle downwind especially in big chop, I would allow a gantry system similar to I14's as I think this would make them easier to fit to older boats 
 
Peter