Other things we need to consider with the square top sail before we go to much further.... and this seriously needs to be part of our discussions....
(remembering all I have is a roughed out hand drawn modification on the jib to work from at the moment)



Will we need to re-cut the jib design for the sloop rigged catamarans running the square top sails ?

Who can re-design the jib to suit a square top and who pays ??

Do we alter the jib into a more squarer topped sail aswell ???






just being fair here.... mk1 AND mk2 mozzies should BOTH benefit from a change and those changes should work as best as possible be it by one sail or by 2

square top jibs ?????

on an A-class

I like the the idea of the big advertisement too. How much does it cost to be included on the sail?

There does not need to be any modifications to the jib to work with a square top. Square top jibs are new and still in development besides they need major modifications to the rig to work.

If people want to play with square top jibs that is what development classes like f16 are for.

As for the the sail on 1781 and few others they are totally within the current class rules.

I do think the advertising on the sails can be beneficial to the class and should certainly be encouraged.

Personally I don't think anyone here wants to go F16, for me its more of an upgrade to a design that keeps the boat both modern in its appearance with a slight performance gain thrown in, we after all are playing with the very future of the class so extreme care is well warranted as it's equally as important as the change to non timber hulls and the addition of the spinnaker. It worries me to think that if we cant make a few well planned and thought out changes through the decades that people will infact go F16 or other classes to stay in a modernish boat & that cant be good for the class in the long run
The fact that we have changed from home built timber hulls and the addition of the spinnaker suggests we have already taken tiny steps down the development road









From what I have read on the subject your quite right, but the question had to be asked, just to make everyone aware that one change to the mainsail could have a flow-on effect from those running a jib further down the road....




never doubted it for an instant.... but its already 'trending' to a squarer sail shape in my opinion .....




..... without question in my opinion aswell

Can anyone give us a what it cost breakdown please

the wording on my and my bro sails costs from Irwin about $140

Could the change just make the gap between fastest and slowest even bigger?
Change sail shape, make boats faster, handicap changes again.
Blokes with older boats (me included haha) are then at a disadvantage.
No more going to regattas sailing your old clinker well and collecting a trophy or two.
I'm not saying I'm completely against the idea, Infact anything that does make the class stronger I'm completely in support of, but I could see it turning people without the $$ to adjust to the changes away from the great mozzi class or even discouraging new comers because of the extra coin they have to lay out to be competitive. Just another opinion to consider.
Al scorpion 1101

I agree with Kingy.

I think it is poor that people are recommending going to another class just because we are asking a question! We are investigating an option to get more people into the class, not repel existing members.

Square tops are a subject that has been considered in the past, they are a development that other similar classes to ours have gone with and certainly something we should at least rationally talk about. My understanding is that Mozzies are scaled down Tornados, and square tops are something they adopted many years ago.

As our state and National results illustrate, the better sailor will always beat the better boat within our class. Most competitive sailors update their sails every 5 years or so, and the sail should cost the same but be a different cut. The only changes the Arrows made to their rig was a shorter boom and lower or adjustable gooseneck. If the existing boom was modified then the costs would be minimal, as are the increases in performance, however the modernised look would make a big difference to updating our class.

Perhaps before this becomes too much of a hot topic, we should get some details from the South African mozzie with a square top about what is required to reduce the conjecture and allow us to make an informed decision.

Luke

Hi All,

I thought I would put my 1 or 2 cents worth in as I was commenting about this on Saturday while looking over the Arrow fleet at Portarlington.

The Arrows have gone to a newer section mast to support their square head sails and kept the same jib. I should say going to, as there was a mix of old and new sections with guys having plans to upgrade first sail then mast. I understood that the fittings were simply taken from one and put on the other, making the cost more about the section and time than a complete rig. The winningest (!) Arrow had a square main, new mast and more than probably a sailor onboard that may have been able to win using bedsheets and a broomstick.

I have spoken to a couple of the Mossie sailors over the last year or so about the square top main idea. As I understand it, one of our top sailors had one made a couple of years ago and tested it out. It was shelved as the consensus was that while it showed an improvement in upwind speed, it was not as fast downwind. total achieved gain for the change was zero.

Now with the advent of spinnaker boats, we have that missing speed downwind - Should the newly (about to be) adopted Mk3 boats be granted a square top main to go with the spinnaker?

The Mk3 already has a different handicap, why limit it to a single change?

Those sailing with it have shown that cost comes in third place to enjoyment and speed, so adoption within the natural turnover of sails could run at about 3 -5 years for most.

Some downsides would be 2 separate sections to be held by the association, and 2 complete rigs to be carried with the spinnaker boats. I am sure there are many others, none insurmountable.

Cheers

Trevor

Hi All,
As discussed on the weekend a fellow sailor says our mast is too "soft". we need a mast section that is heavy and stiff. by saying that alot of weight is on the mast on a light boat. The boat would be heavier and the righting moments woundn't be correct unless we widen the platform or heavier platform. There has been talk about carbon rigs too. They would be ideal and would work BUT......$$$$$$. could pay $2k and beyond for one mast section.

yep it was very obvious he'd sorted out the change to square top

and yet the other square top wasn't anywhere near as competitive in comparision, it really only ran slightly better than the others with the traditional sail




and yet at their Aust Championships @ Loch Sport (29th December 2012 to the 4th January 2013) the story was different.....






different version again....



more pics here.

Those of us that are mentioning F16's and such arent recommending going to another class in fact I am always pushing our class to people, we are simply mentioning if you want to experiment and such there are classes to do that. I think one of the strengths is that the class is affordable for a range of people. Im not saying we dont develop the class but we also dont want to push people out of the class because they cant affort to get a new rig and get left behind on the water. We need to look at this carefully so we dont see a repeat of the class implosion from years ago.

As for the Tornado. A- they are a scalled up mossie we arent the scaled down version, we are older. B- When they updated their main to a square top and added the kite they also upgraded their mast section to a wing mast ie wider section to get a stiffer mast section with less mast bend which is what you need with a square top.

Our current section is flexy and will bend, therefore in a gust the mast bends which will open the leech and depower the main. With a square top you are relying on the main to do its own depowering by the head falling to leeward and opening the leech therefore depowering they dont need the mast section to depower. You cant sucsussfully combined the flexy mast and the square top.
Just my point of view having spent quite some time working with bigger cats and Skiff sails with square heads.

Just thought I would mention again, just in case it was forgotten .There is a mast section available that is the same profile as the current mast section but has internal stiffening ribs as a part of the extrusion.

this is a possible way of addressing the soft mast argument.Also the weight increase would be minimal.
Dave 1724

I have heard back from the South African chapter and they are forwarding my questions to the owner of the square top who apparently has a lot of information about it.

Again, lets not start speculating until we get some actual information.

Luke

Well there's a lot of posts since the last time I had a look at the forum been busy, going sailing does that .



Dave can you tell us where you can get this section that fits Mossie rules, the person that orders masts from Capral for the VMCA has never heard of it and as the South African Mossies and Cobras buy at least some of their sections from the VMCA, if something better was out there I think they would be using it. Also one member has spent years chasing a stiffer mast for his own project of a taller rig but has not been able to come up with a different mast that didn't incur too great a weight penalty.

It must be remembered that the reason why a Mossie performs so well with a small rig, is it's power to weight ratio, you put the weight of a Taipan mast for instance up on a Mossie and the hobby horsing would be horrific and when you're rocking back and forth you're not going forward. Believe me States reminded me of how bad hobby horsing can be in the Bay chop .

Mossie sailmakers I have spoken to, don't seem to think it's practical from a performance point of view to go square top, asthetics is something else, but not worth chasing in my opinion.

Arrows in Vic have not been saved by the square top (as yet anyway) and as mentioned need a stiffer mast, so more cost.

Until somebody can come up with a reasonably priced light weight mast alternative, I can't see how the Mossie can go square top.

May be time for an explanation of my situation which in turn would help explain as to why I'm watching this thread so closely....


Jurassic Karp 1740 (rebuild nearly done) will need a new mast and main-sail after the broken mast damaged my best sail

Twice Shy 1182 definitely needs the ~30 year-old "main-sail" replaced as well


I don't want to have to do it twice as the expense will mean one will simply be parked, I can afford to replace the sails and mast now but to find out in a couple or even a few months time that square top rigs are now 'ok' would mean I'm one that will be left behind purely on the affordability side


I'd even go as far as to offer the two boats as testing platforms ......

a reasonably "on weight" and fairly current Mosquito that has the ability to be sailed as cat or sloop & spinnaker for either setup
an older cat that's in the +65 league that's sailed sloop and cat rigged.... I could hook the spi up too I guess
& I sail both on lakes & the sea, and the windier the better (drifters were for people that wanted a Chrysler Panel-Van or sidways action in the car )


so should I put my hand up to test out a square top on both boats if one was available ...[img]http://www.outerlimits4x4.com/images/smilies/icon_ruff.gif[/img][img]http://www.outerlimits4x4.com/images/smilies/icon_ruff.gif[/img][img]http://www.outerlimits4x4.com/images/smilies/icon_ruff.gif[/img][img]http://www.outerlimits4x4.com/images/smilies/icon_ruff.gif[/img][img]http://www.outerlimits4x4.com/images/smilies/icon_ruff.gif[/img]





do I want to buy a new main and mast for Karp and a new main for Shy only to find out their redundant before they are broken in.....

I recall reading on another classes forum........

90% was asthetics.... 5% performance & safety..... so I bought one simply because it looks so damn good

Ladies and Gents,

As promised here is the response from Kevin- the owner of the Square top in South Africa. Makes for an interesting read and he certainly is facing some of the challenges discussed.

Regards,
Luke

Hi Luke

I must start by saying that it is still early days, and I have a lot of
experimenting to do before I can say that this is the way to go.
A bit of history - I have a few other yachts - Hobie Tiger, Dragonfly D800
tri, and a Farrier F9R Tri, all with BIG square top mains - and they work
very well! So for me it was a natural upgrade for the Mosquito to change
from pinhead to square top - something I have been toying with for a number
of years.

One of the big problems is to get everyone to agree - so what I did was to
build a new main, but with exactly the same sail area as the old main - I
shortened the luff to 6600cm, the foot to 2350cm and added that to the top,
which ended up at 830cm. This way I could convince the negative guys that I
gained no advantage from additional sail area, and then set about proving
that the square top is faster because of design and better sail control. The
mast remains the same length, the boom can be shortened or replaced. The
only cost is a new sail - same price as the old cut.

The positive things:
The boom is higher for the crew to get under
The boom is now parallel with the deck (looks much better)
The main sheet attaches to the clew - this means we can use a very
light boom (28mm aluminium pipe)
The boat looks updated and fast (I feel important for attracting
young sailors to the class)
The price is the same as the old main

Sailing with the square top:
I have had a mixed bag of results - but mostly good. In very light
conditions I found a definite advantage - I was able to point higher than
anyone upwind and go slightly faster - downwind little or no advantage at
this stage. I managed to win our provincial championships fairly easily in
light winds.
On the other end of the scale I find a big advantage upwind and downwind in
strong conditions. The sail is easy to flatten with the Cunningham - as you
tighten it, the leech opens at the top and the sail flattens - every puff I
accelerated away from the rest and managed to extend my lead through the
race.
At first I battled downwind with the spinnaker - The boat kept nose diving
and bus stopping as the puffs hit - so I decided to sail it more like a
Tiger - sheeted in the main and travelled in on the traveller - thereby
reducing the exposed sail area at the top and the tendency to nose dive - I
found I was the same speed in puffs, but faster in the lulls - no more bus
stops - very happy with those results.

Sailing in medium winds was a problem (8 - 12knts). I found I had no
advantage and at times felt to be at a disadvantage in these conditions.
However, I expected this due to the mast problem!

From the outset I felt that the mast would be too soft and bendy to carry a
square top. After the first sail I knew I would need to address this. I have
fitted a forward facing diamond (parrot perch) between the foot and the
hound. This has worked well, but poses a few problems:

The diamond does interfere with jib when tacking - not badly, but
crew needs to help sheets through.
The mast is stiff enough between foot and hound, but bends a lot
above the hound.

In medium wind, I can't get enough leech tension - I sheet in harder to
close the leech, the mast bends, sail flattens and leech opens again.
Creases start forming - use a bit of Cunningham - mast bends and leech
opens.............
So I found myself soundly beaten into second place at our national champs
over December.

Unfortunately I have not had another opportunity to sail my Mosquito again,
but I will be making a few changes to stiffen the mast and overcome the
problem.

On the whole I am very happy with the square top, and can positively say
that once I have sorted out the mast stiffness, it will be a big improvement
on performance and aesthetics!!

I will also be experimenting with a carbon mast - while I know this will
work and will be the best solution, I have to think of the cost to the fleet
- this is however another fight for another day!!

One last comment - The Mosquito is still my favourite and preferred cat to
sail ............... I'll keep you updated of any progress.

Cheers
Kevin

Kevin's Sail Does look good! Interesting comments from him also.

Ross
No Turbulence
1774

Sorry for the late reply to your question Gary. I went and found out some more information on mast sections from the catamaran expert up here in Brisbane.

The mast section with the internal ribs was made specifically for the Mari-cat class. The length of the mast for these boats would be to short for the Mossie and there are only a few left. But wait there's more. One longer section is still left that is long enough for a Mossie mast.

The supplier of this mast section owns the die to make these. A deal could be made to run more of this section if the association spoke with the supplier.

The supplier strongly suggested going with a larger section mast the same as the Nacra four five. more readily available and a more reasonably priced.

So in summary as it stands realistically the original Mossie section is out of date for a square top sail.
Dave 1724