Get me the rating points and I'll calculate an approximate rating

Hi Simon

I've extracted these numbers from the Taipan 4.9 rules and the AHPC site. They're probably about as accurate as the Mozzie figures I gave you!
Of course the Taipans have now changed their mainsail and I'm pretty sure these areas came from the old rules but lets not confuse things.

1, No of crew cat 1, sloop 2
2, No of crew on Trap cat 1, sloop 2
3, Min Weight of the boat incl sails etc in KG - cat 97kg, sloop 102kg
4, Overall length - 4.95m
5, Max Beam - 2.34m
6, Max mainsail and mast area combined - 1.28sqm + 13.7sqm
7, Vertical luff length of sail (luff len will do) - 8.05m
8, Jib Area - 4.2sqm
9, Vertical luff of the jib (Luff will do) - 5.04m
10, max allowed Spi area - 17.5sqm
11, Max authorised board area - 0.215sqm
12, Max allowed depth below the hull - 0.65m

OK< I'll try and do this tonight (just off out to The City).

Or you can do it yourself by downloading the clac routing from the ratings page on the SCHRS website www.schrs.com

Corrections Taipan specs :



Is wrong the real area is 1.40 sq. for mast and 14.58 combined mainsail+mast. At least that is what Texel has measured in the past.




Since many years the Taipan are using smaller boards then allowed in the class rules. The AHPC boards area protruding 0.55 mtr below the keel line and have a width of 0.290 mtr. Their area per board is therefor 0.1595 sq. mtr.

As you can see (Buccaneer) the current Taipan boards are significantly smaller then the very original ones late 80's. Of course the new F16 boards (not used by taipans yet) are another extention of this trend.

Wouter

So there is no room for disagreement without insults? <img src="http://www.catsailor.com/forums/images/graemlins/confused.gif" alt="" /> Is that your rule? <img src="http://www.catsailor.com/forums/images/graemlins/blush.gif" alt="" />
For you my friend the doctor recommends more time on the water and less time getting red faced at computer. <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />

Happy sailing, <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

I dont know how old you are or how much computer experience you have, but.. In the early days (80s) the professional workstation displays could in some cases have strong enough emission as to make you red faced if you sat in front of it long enough <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

I thought the narrow board trend came out of the America's Cup. Please correct me if I am wrong, but at the A worlds in NZ which was soon after the 2003 Americas Cup one of the Team NZ designers put the A through the program and found that the boards at that time on the Flyer were too wide. By moving to the high aspect board currently seen on the A and keeping everything else equal, the boat would be 6 boat lengths quicker to the top mark on a 1nm beat. Don't know what wind strength they were using and the other assumptions, but this started the trend to these boards in Aus starting in late'03/04. One of the A sailors brought these back to Oz for the Flyers with converter kits.

Don't know how the high aspect boards would work on a Taipan as there are different fundamental aspects to the rocker compared to a Flyer (or the F16 case the Blade).

I know that when I first sailed the Blade with their slightly longer retro-fitted Taipan boards, I felt that this one of the boat's weaknesses. It just didn't feel right with the board lift etc. I had just spent a week sailing a Capricorn so knew what to expect but the stubby fat Blade boards just didn't compare.

I know that the AC has changed foil design in race yachts with most new designs having thin narrow sections with large T-bulb. Interesting to see how this has crossed over to cats.

Cheers

Bob, I like you (we go way back in the way of communication, 2000 I think) and I would gladly go for a beer with you and have a laugh. It is just that you are so far off track with your board comments, and repeately so, that it has to stop. Come back and give us your opinion when you have spend the effort to form a COHERENT opinion. Right now you have only written down certifiable nonsense that often contradicts itself.

No ill feelings outside of this particular disagreement from my side.

Wouter

Long daggerboards (high aspect) were already persent on the Nacra Inter-18 = F18 (nacra inter 20) as early as 1995. The trend already started here with respect to high aspect daggerboards. The A's were a little late with regard to this development but have since then moved to the forefront of it.

Interestingly enough the Blade with the old boards would point a little higher to the Taipan in the 1-on-1 testing. But I do think the new design is better, although not by a huge amount.

I feel the Taipan gets a significant portion of the pointing from the hulls itself and so it could well favour the board design it has now.

It is certainly true that you don't want to lift the board to early on the Blade. But then again I only lift them on my taipan when it is howling.

Wouter

given people are dis-agreeing on plate sizes I put in a size that made them rate the fastest

one up 0.983
two up 1.006

erm that wasn't emissions. It had more to do with frustration getting the thing to work properly. Still happens a fair bit.

Tiger Mike

F16 cat 0.994
F16 sloop 1.020
Taipan cat 0.983
Taipan sloop 1.006
F18 1.005

So the Taipan is rated faster than the F16, and the cat is faster than an F18!
And that's before we add the new main - maybe my numbers are not right. Doesn't make much sense otherwise.

You bring a tear to my glass eye Wouter ,for someone so pedantic you should consider what you type before you send it .

Frigging :

frig

• verb (frigged, frigging) vulgar slang 1 have sexual intercourse with. 2 masturbate.

— ORIGIN originally in sense move restlessly, later rub, chafe: of unknown origin.


Perform another search of the Compact Oxford English Dictionary

Is this your intention ? <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />

In this part of the world "feking" is becoming a more accepted word for the one you so unskillfully avoid

Keep it up , someone has too <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

I used wouters mainsail + mast measurement



Lighter boat, similar size sails. IMO should be faster.

Or, put another way - shorter, narrower, smaller sails, 20 yo design and only 7kg lighter - how could it possibly be as fast?

As for a cat rigged Taipan being rated faster than an F18 - I know which one I'd choose in a boat for boat race. It makes me think the SCHRS is weighted very favourably for the bigger cats.

Or is it just heavier cats?
In the Mozzies we have a "heavyweight" division for older boats, where the minimum weight is an extra 10kg. How do the Mosquito numbers come out with 10kg of extra weight added? I'd be interested to see the difference.

Tim,

we don't have much data coming from Aus, if you have results in a sailwave format, please send them to me and I'll store them up for later test fleet races. I also need as much info about the course as possible, tide state and direction, if it turned during the race and at what time (if available), wind speed, sea state and some idea of the level of skill across the fleet. This may sound like a lot of info, but it's usefull as we can then try and iron out any strange results (consider a w/l race, one lap light wind with strong tide). We would expect an A class to do well in this race as they do have very good performance upwind and in this race the boats would spend a longer time sailing upwind on the race.

As for numbers, download the utility from here and have a play with it yourself !

I just did! 10kg didn't make as much difference as I expected. I'll just have to sail faster I guess, if weighing the boat down won't do it.

I think Simon has made a few typo's in the calculations and that is the cause of the weird rating numbers.

If I punch in the specs of the Taipan 4.9 (NO SPI !) into the schrs calculator (off the www.schrs.com website) then I find :

Taipan 4.9 sloop no spi = 1.055
Taipan 4.9 cat no spi = 1.058

With spinnakers we get

Taipan 4.9 sloop + spi = 1.025
Taipan 4.9 cat + spi = 1.008

As you see these numbers are very close to the ones for the F16's

F16 2-up = 1.020
F16 1-up = 0.994

(Texel has F16 2-up = 102, F16 1-up = 101)


Specs used for the Taipan (real measurements) :

mainsail + mast : 14.58
mainsail luff : 8.03 mtr
jib 4.08 sq. mtr.
jib luff : 4.85 mtr.
weight ready to sail : 102 kg
length : 4.95 mtr.
width : 2.34 mtr.
board area : 0.160
board depth : 0.550

Wouter

Wouter, what do you get with aspect ratio 4.5 on the plates. (IIRC i ised area .223 and depth 1m (just to get 4.5 aspect ratio)) If you re-read my post I said I used max plate ratio as people were arguing about actual plate sizes.

Yes, but since then people have intepreted your rating numbers as being for the standard Taipan 4.9; of which they have a feel for actually performance. Either way, a larger misunderstanding is perpetuated.


Also



Is a rediculous set of specs for Taipan or F16 boards. It will make the boat bad behaved and mostly likely significantly slower in all conditions as the board will not be operating at the optimal angle of attack. (best lift to drag ratio).

from very earlier onwards (I think a year after the design waslaunched) the Taipan boards were made narrower and maybe also shorter. Since then the board area (per board) = 0.290 * 0.55 = 0.1595 and the wetted depth is 0.550 mtr. This has not changed since then. The max specs given in the Taipan class rules are useless as no-one is even getting close to those. If more then 10 boats out of 325 build still sail with the old original daggerboards then I would be surprised.

Also 1 mtr long boards (as in wetted length) are unrealistic For Taipan's and F16's. For reasons of optimal lift to drag ratios you'll need a minimal angle of attack and this requirement limits the boards area for these boats to 0.185 sq. mtr. or less (preferably slightly less). In order for such a board to be 1 mtr long it needs to be 185 mm wide or less. This is too little to make the board both strong and stiff enough. So this board can not be build in an economic viable way. Of course, a custom board can but you'll be pouring that full of carbon cloth to get at the required specs.

Commercial builders however won't take these risks for their production boats, especially not when such boards are not really attractive because of the ease of stalling them or "tripping" over them. Both well proven disadvantages of very long/high aspect boards.

So up till now all builders are converging on F16 boards that are around 0.75 mtr long and on average just under 0.200 mtr wide. Resulting in rougly 0.150 sq.mtr. area and averaged aspect ratio's of 4.

I think your own boards, Simon, are the only exception to this rule at this time.

Wouter