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zexwax

IRC sail plan nonoverlapping headsails.

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hi im new to the sailing anarchy forum. just looking for some advise.

 

i sail on a formula 28 modified half tonner.

our current irc is 0.914 we have got the hull remeasured she came in lighter but with a sorter water line and on the trial cert she has dropped 2 points already. the owners are considering getting a non overlapping battened jib as aposed to an overlapping and putting a 50 square meter kite on i think the curent kite is only 42 square meters. our sail maker reckons this new configuration will give us a further 5 point drop witch is 7 points off for next season happy days.

 

but im just wondering has anybody had any experience converting to a non overlapping headsail for irc racing?

what are the pro's and cons ??

 

thanks, Johnny from Ireland.

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What is the average wind conditions where you race?

Does the boat suffer in light airs already?

What is the Area drop?

Does your Spreader angle and chainplate position allow the correct Aspect ratio headsail with the correct sheeting angles?

Will the foils tolerate this CE change?

Will this position you in bad air against your competition?

 

It is a given less area will give you a lower rating. But whether or not the boat is bettering it's Speed/Rating ratio is another thing.

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Dear Johnny from Ireland....it's advice you seek and much will be forthcoming once you have posted pics of Dick Dastardly's "girlfriends" tits and been told to Fuck Off!

 

While you may have been advised by MSA....he is from Western Australia and not to be trusted.

 

Hope this helps

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Dear Johnny from Ireland....it's advice you seek and much will be forthcoming once you have posted pics of Dick Dastardly's "girlfriends" tits and been told to Fuck Off!

 

While you may have been advised by MSA....he is from Western Australia and not to be trusted.

 

Hope this helps

 

Thanks for the kind note Evo...... Not sure what my geographical location at this point in time has to do with trust.. Does it change when I am in Sydney??

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The kevlar hulled Formula 28 in its original config was probably overpowered upwind and a little under juiced downwind for the company it would be in at the weather mark.(I have heard bar stories of one beating Moonduster to the weather mark on a light day.)

Can't help with the specifics but thought a bit of background might help others chime in.

 

IMHO the reason for dropping the points by the owner is to make the class cut off for the ICRAs - avoid the tricked out half tonners and Corby 25's.

For what its worth it seems a sensible plan to me.

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The kevlar hulled Formula 28 in its original config was probably overpowered upwind and a little under juiced downwind for the company it would be in at the weather mark.(I have heard bar stories of one beating Moonduster to the weather mark on a light day.)

Can't help with the specifics but thought a bit of background might help others chime in.

 

IMHO the reason for dropping the points by the owner is to make the class cut off for the ICRAs - avoid the tricked out half tonners and Corby 25's.

For what its worth it seems a sensible plan to me.

 

thanks for this info yeh thats the plan anyway to get her down a class for icra's and some other regattas.

she is a weapon upwind in the light stuff a little slugish downwind tho. we sail with 4 onboard and spent most of the season full hike on the rial so i think given the boats performance in the light stuff we can afford to take a hit on headsial power and could really do with 5-7 points off the rating with more downwind speed.

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A 'fat head' non overlapping jib may be worth investigating -its not 'free area' as such but may be worth the performance

- should give you a little more bite upwind

...thats my 2 cents - best of luck !

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Theres a formula 28 with non overlapping jib in howth rating .907. Not sure what work was done exactly to modify the boat but would be worth getting in touch with them or the previous owners who are from howth aswell. They go well in medium to heavy airs but arent to bad in the light stuff either. Your probably a bit undercrewed at 4 aswell

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Theres a formula 28 with non overlapping jib in howth rating .907. Not sure what work was done exactly to modify the boat but would be worth getting in touch with them or the previous owners who are from howth aswell. They go well in medium to heavy airs but arent to bad in the light stuff either. Your probably a bit undercrewed at 4 aswell

 

yeh we went up to see her yesterday took measurements of where her jib cars were moved to and were getting the same sails made up off mcwilliams. she seems to be doing well enough. our formula is lighter and doesn't have an inboard engine witch i think will prove an advantage when we race her. im not sure if formula 28s have ever been a class winning boat not much info on them.

 

i think 4 crew works great when everybody knows what there at.

thanks for the feedback everybody keep it coming. l

 

ooking to hear success or failure stories with regards changing your sail plan.

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How will Non-Overlapping headsails sheet? I presume the Chainplates are inboard?

 

were going put a new jib track in board of the chainplates and also a barbourhauler on the jib sheets for getting the right slot angel.

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Have you thought of trying a larger main and the non over lap? Take the area of the over lap from the current set up and stick it in the main.

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Most of the Formula 28 I have raced against have rated 0.912 and sre very quick in light breeze, less than 10 knots. Once it goes above 10 they begin to struggle unless the rail is well loaded. A crew of four has no chance in these conditions, it might be easier and cheaper to recruit a few heavyweights for windy days before spending any money on changing your sail plan.

As far as I know the rating band break at ICRA is usually 0.920 so you wont have to worry about the Corbys etc. A Sigma 33 or J24 might cause you much bigger problems depending on the weather.

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Johnny, I'd get a trial certificate in before ordering those sails, your sailmaker might be talking out of his transom if the spinnaker size that you quote is accurate -you may get penalised if it's too big..........!. Yes you will lose handicap points with a non overlapping jib but the boat will lack power below around 10 knots of wind, given the wind range in Dublin you'll be looking for more horsepower from somewhere upwind and unless it's really blowing your boat won't plane downwind even with the bigger kite though it will be faster than it's present form.

Have a look at Harmony and Checkmate to see how it's done on an older half tonner -.New Keel, Rudder, Rig and sail plan to get the best out of this type of conversion. Spending that amount of money on an old boat makes a modern competitive boat an attractive proposition!

 

Pot hunting can be very expensive.

 

Good Luck.

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You have to remember that these boats were designed to be raced with at least 5 people on the rail with a weight of about 14 stone each, apart from one crew that needed to be about 11 to 12 stone who could go on the foredeck without sinking it and coming off the rail to adjust things and change sails etc. On windward lewards you might get away with the 50sqm kite, but if you have to reach you are going to need a lot of weight. Generally I think you will be able to take a 10% penalty pole and then 180% of that penalty pole length, but things have moved on a lot since I last looked at these things, so could be talking out my arse. My gut feeling is that the successful conversions appear to have lengthened the J and raised the I, so that the sail area of the headsail is still quite large even though it is non overlapping. Also the rigs have been changed to swept back spreaders to again maximise the foresail area and loose the runners and checkstays to bring the rating down.

I can still remember racing against the Formula 28 "Flash" at Cork week in the late 90 when on Demolition and they were very quick and well stacked up on the rail. (we did beat them though, remember ugly is fast with IOR)

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Any general formulas we can apply?

A pupose built non-overlapper will have mast (and keel) furter aft to increase HSA relative to main. But 'retro' changes to nonoverlapping has worked in eg J109 very sucessfully for IRC racing where it is worth 10 to 12 points on handicap.

So can we compare ratio of J to E to predict if it will be sucessful on a Formula 28? Or maybe ratio of foretriangle area (or foretriangle plus main sail area) to displacement?

 

J109 J=4.05 E=4.72

F28 J=2.83 E=3.81

 

... Your J looks relatively small ! Plus you are about 3/4 fractional compared to the J109 10/11ths.

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The kevlar hulled Formula 28 in its original config was probably overpowered upwind and a little under juiced downwind for the company it would be in at the weather mark.(I have heard bar stories of one beating Moonduster to the weather mark on a light day.)

 

 

I have no stories of a Formula 28 beating Moonduster to the windward mark, however, as a nipper, I was sailing on a very similar boat to Moonduster, a boat from Bangor called Born Free (Holland design, instead of a Frers design, but a masthead, cold moulded IOR 50 none the less) that was beaten to the windward mark on a light day by Skboo, a locally built half tonner, built for the 1984 worlds in Troon, and fabulously well sailed. She did it to Born Free (aka Born to Bark, she was never anywhere near as competitive as Moonduster) once that weekend, and always lead all of the scottish 3/4 tonners round the course...

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