#1388 - 08/05/01 11:55 PM
capsizing and pitchpoling on a 16 foot craft
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Carpal Tunnel
Registered: 06/16/01
Posts: 9582
Loc: North-West Europe
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Phill was right to some extend
a wider than Taipan 4.9 platform could achive more power without danger of picthpoling both in 1-up and 2-up.
go to :
http://www.geocities.com/kustzeilen/heeling_pitchpole.html
and se ethe graphs. A 5 mtr. by 2,5 mtr F16HP would be pitchpole limited in all conditions except 45 degree and faster than 0,35 speed of wind. going lower or slower would put you in pichpole area again. Going higher will just keep you out of danger. Going wider and you're in trouble.
draw your conclusions and make comments when you feel the need to. Do we need to change the max width from the tempory 2.5 mtr. max ?/
Wouter
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Wouter Hijink Formula 16 NED 243 (one-off; homebuild) The Netherlands
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#1389 - 08/08/01 12:07 AM
Re: capsizing and pitchpoling on a 16 foot craft
[Re: Wouter]
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enthusiast
Registered: 07/13/01
Posts: 344
Loc: Arkansas, USA
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Wouter-
I don't think we need to go wider than 2.5 mtr (in fact I'm sort of for 2.4 mtr since it seems to accomodate all the current boats?) for the HULLS, but I wouldn't mind a "Maximum overall width of racks/ladders/etc." set. I'm not sure what I would set this at but I would probably be liberal.
Correct me if I'm wrong but increasing width of the hulls has one effect on pitchpoling while increasing the counterbalancing weight (ie. racks and trapezing crew) has another.
By the way- What do you think of the 11' wide 18 squares? Seems they ought to be pitchpoling a lot??
Kirt
Kirt Simmons
Taipan #159, "A" cat US 48
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Kirt Simmons
Taipan #159, "A" cat US 48
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#1390 - 08/08/01 09:17 AM
Re: capsizing and pitchpoling on a 16 foot craft
[Re: Kirt]
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Carpal Tunnel
Registered: 06/16/01
Posts: 9582
Loc: North-West Europe
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I 'm thinking about ruling a maximum rack width relative to crew weaight but I'm a litle dawnted by enforcing this.
It seems that 2,5 mtr. is a very good maximum width, It seems to be trailorable everyware and provide a repectable heavy air performance.
I'm a little lost with what you mean by :"increasing width of the hulls has one effect on pitchpoling while increasing the counterbalancing weight (ie. racks and trapezing crew) has another"
Can you explain ?
About 18 squares. Thank you, I've found an error in the accompanying text. The numbers in the graphs are correct but the claim that it is solely dependable on the distances isn't.
ratio F16HP = (150 * (2,5+1) + 2,5/2 * 100) / (150 * 1/2 * 5) = 650 / 375 = 1,73
ratio 18 sq. = (75 * (3,35 +1) + 3,35/2 * 160) / 75 * 1/2 * 5,49) =
594 / 205 = 2,90
This would indicate that 18 sq. are rather picth happy even on close reaches. You have an 18 sq right Kirt, what are your experiences ?
And Ohh, yeah before I forget; The wind must be strong enough before picthpole can happen.
Hobie 16 has a ratio of 1,86
Wouter
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Wouter Hijink Formula 16 NED 243 (one-off; homebuild) The Netherlands
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#1393 - 08/11/01 07:47 PM
I would very much like to hear John P.'s comments
[Re: phill]
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Carpal Tunnel
Registered: 06/16/01
Posts: 9582
Loc: North-West Europe
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Width to crewweight might work. I'll wait for the others to respond first before I do.
Wouter
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#1394 - 08/12/01 01:29 AM
Re: I would very much like to hear John P.'s comments
[Re: Wouter]
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old hand
Registered: 07/15/01
Posts: 953
Loc: Western Australia
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perhaps we could just rule that there is a max width from the centre line.. Rather than a "hull" width.. Allows for wide boats and boats with racks..
I personally distrust the weight for width ideas.. Its used on the 49ers and the doping with diauretics and laxatives to reduce a few kgs before weigh in is a huge concern..
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#1395 - 08/14/01 12:36 PM
Re: I would very much like to hear John P.'s comments
[Re: Stewart]
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enthusiast
Registered: 07/13/01
Posts: 344
Loc: Arkansas, USA
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Well, I'm for a max. "hull" width, kept within easily trailerable/storable dimensions and including the most common current boats (we could always "grandfather" in some current slightly wider boats), I believe 2.4 meter will do this. I'm ALSO for the provision of "racks" to potentially extend the width out to some other maximum. I would set an "overall" max. to start with and see what happens.
I think we NEED to remember this is NOT going to be an "all out" speed/performance class! My idea of this class is along the lines of a "pocket rocket", relatively small, light, but quick too. If we let the boats get too wide, too complex, too expensive, or too "fragile" (don't really want to get into that one again!) everybody will just get BIGGER boats!
I agree with Phill that we need to accomodate the current boats or this will NEVER get off the ground except as a "manufactured" class run by companies trying to sell only NEW boats- And they will have an interest in making the rules such that only new boats essentially meet the rule.
Let's make the rules around the existing classes that "fit" and THEN if any manufacturers want to come up with "new" boats they WILL design them within OUR rule specs (ala the F18's).
Just my opinion of course-
Kirt
Kirt Simmons
Taipan #159, "A" cat US 48
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Kirt Simmons
Taipan #159, "A" cat US 48
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#1396 - 08/15/01 03:06 PM
I would than suggest the following setup + POLL
[Re: Kirt]
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Carpal Tunnel
Registered: 06/16/01
Posts: 9582
Loc: North-West Europe
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Use Texel as default to calculate F18 equality on handicap. This will always imply that the F16HP's have a ISAF rating that is equal or slower than the F18's.
Getting the max out of the Texel rating of rounded of 103 which is no less than 102,51 means
Rated Mainsail =< 13.00 sq.mtr.
Rated Jib =< 3,1 sq.mtr.
Genaker =< 21 sq.mtr. but is restructed to 17,5 for other reasons
weight min sloop without genakergear = 95 kg's
THis will be the F16HP sold
In the rules however will be declared later after the class is well established that
over crewweight ###1 (Undetermined yet)
Max rated jib will be something like 3,1 sq.mtr.
Genaker size 21,0 sq.mtr. Hoist max 8,00 mtr
or
Max rated jib will be something like 4,1 sq.mtr.
Genaker size 17,5 sq.mtr. Hoist max 7,55 mtr
Chosen by the crew.
over crewweight ###2 (Undetermined yet)
Max rated jib will be something like 4,0 sq.mtr.
Genaker size 21,0 sq.mtr. hoist max 8,0 mtr.
In total three groups of different sail sizes.
This will than function as a A LA F18 weight equalisation system without carrying weights.
F16HP equal to F18 will require all teams to sail in the light crew configuration or take 1 or 2 % handicap hit.
Official F16HP races will use the equalisation principle as described.
Solo races will always use the small genaker size.
The start will be a pure F18 style F16HP to keep things simple, later on when needed will the equalisation system be implemented.
Agreed ?
Wouter
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#1397 - 08/15/01 03:54 PM
Re: I would than suggest the following setup + POLL
[Re: Wouter]
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old hand
Registered: 07/15/01
Posts: 953
Loc: Western Australia
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still unclear why we cant have main only with a genacker... guess Im just thick..
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