New Posts New Posts RSS Feed: Another question, spinnakers , alt/assym/sym
  FAQ FAQ  Forum Search   Register Register  Login Login

Another question, spinnakers , alt/assym/sym

 Post Reply Post Reply Page  <1 78910>
Author
Sam.Spoons View Drop Down
Really should get out more
Really should get out more


Joined: 07 Mar 12
Location: Manchester UK
Online Status: Offline
Posts: 1392
Post Options Post Options   Quote Sam.Spoons Quote  Post ReplyReply Direct Link To This Post Posted: 17 Feb 18 at 1:56pm
Originally posted by iGRF

That is of course after the learning how to trapeze phase has passed, but single hand trapezing? How difficult could it be?

I do it quite often in the Spice but, obviously only in the lighter stuff (I can get wiring in 5 or 6 knots with 16 M2 up the stick, add a 22 metre kite and I can stay wiring downwind in similar). TBF the Spice is pretty docile sub F4 so gives a pretty stable platform. Coming from windsurfing you'd think it would be second nature but without the boom in your hands it's a bit like tightrope walking without a pole. It's not that hard though and while the Farr will be a bit more lively I'm sure you'll manage (and it's damn good fun).  Big smile


Edited by Sam.Spoons - 17 Feb 18 at 1:57pm
Spice 346 "Flat Broke"
Blaze 671 "supersonic soap dish"
Supernova 395 "dolly the sheep" (now sold but considering a second (mk3) Blaze as her replacement)
Back to Top
turnturtle View Drop Down
Really should get out more
Really should get out more


Joined: 05 Dec 14
Online Status: Offline
Posts: 1913
Post Options Post Options   Quote turnturtle Quote  Post ReplyReply Direct Link To This Post Posted: 18 Feb 18 at 1:20pm
Originally posted by iGRF

Originally posted by Rupert



As for the Farr, an extra sail may well make it more fun and maybe even first back to the beach on open water. But I'd say it is unlikely to make it a regular winner on handicap, assuming it gets an EN, and doesn't keep the non spinnaker number.


That about sums it up, I'm told it's already a fun boat to sail so it may not be necessary, but the fun bit needs wind and if we get a long summer of doldrums, open sea sailing on big courses can be tedious in extreme if you've nothing much else to do but sit there. So mucking about with a kite, maybe even goose winging it could make for more to do and a little less boredom, the trouble is in reality it then becomes a different boat so I could see me starting the series in the Farr37 then getting another set of results in the Farr37S that's likely how they'd handle it and most definitely it would be very unlikely to win on handicap, as I said elsewhere on my measurement based spread sheet calculator is comes up 1062 but the class advisory is 1039. Adding an 12 mtr kite brings it down to 1058 on my sheet and recalculated with 1039 it comes down to 1035 and given our courses you rarely get to use a kite on more than two legs so I don't see it being a particular bandit and racing it for fun will be the key factor, which suits me and if I get lucky now and again it'll be a bonus..

That is of course after the learning how to trapeze phase has passed, but single hand trapezing? How difficult could it be?


Back to Top
Rupert View Drop Down
Really should get out more
Really should get out more


Joined: 11 Aug 04
Location: Whitefriars sc
Online Status: Offline
Posts: 7880
Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Posted: 18 Feb 18 at 4:37pm
Are you sure adding 12sq m of sail really only once 3 or 4 points off the handicap? That would suggest that either they are almost useless or that your prediction programme has a glitch. I'll go with the latter.
Firefly 2324, Lightning 130, Puffin 229, Topper 44496, Minisail 3131, Minisail 3446
Back to Top
JimC View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 17 May 04
Location: United Kingdom
Online Status: Offline
Posts: 5631
Post Options Post Options   Quote JimC Quote  Post ReplyReply Direct Link To This Post Posted: 18 Feb 18 at 5:14pm
Spinnakers do make surprisingly little difference. But then when you analyse it in detail...
Supposing on a notional course you spend 100 minutes of your time beating, 30 mins reaching and 20mins running. (I'm making all these numbers up BTW)
The extra windage, weight in the ends and up the mast etc make the boat 1% slower upwind, so you now spend 101 minutes beating.
A run is a run, and it doesn't make that much difference how much rag you put up because each increment in speed is less apparent, so lets say 5% faster, thats now 19mins running. Finally we go 50% faster on the reach, which would be pretty impressive, so what, 20mins reaching. Total time round the course 140mins instead of 150 mins. What's that, under 10% faster round the track for 50% increase in reaching speed...
Back to Top
Sam.Spoons View Drop Down
Really should get out more
Really should get out more


Joined: 07 Mar 12
Location: Manchester UK
Online Status: Offline
Posts: 1392
Post Options Post Options   Quote Sam.Spoons Quote  Post ReplyReply Direct Link To This Post Posted: 18 Feb 18 at 5:24pm
That sounds about right. FWIW I did some sums using the Int Canoe and Assymetric Canoe as examples as the old IC's had the same hull as the AC does now. The 2017 PN's are 893 for the IC and 866 for the Assymetric Canoe. Bearing in mind the IC has been a development class (with the all up min weight reduced from 87kg to 50kg) since 2009 after many years having a one-design hull while the AC has retained the one-design hull. The CA are suggesting pre 2009 ICs (with the same hull as the AC) have a PN of 920. That suggests that the difference the kite makes to the IC is nearly 6% (or roughly 10 mins in a 150 min race). The IC has a standard rig of 10 M2 and the kite is only limited by the mast and pole lengths, apparently most are around 23 square metres. That's still 54 points though not 3 or 4.......

Edited by Sam.Spoons - 18 Feb 18 at 5:28pm
Spice 346 "Flat Broke"
Blaze 671 "supersonic soap dish"
Supernova 395 "dolly the sheep" (now sold but considering a second (mk3) Blaze as her replacement)
Back to Top
Rupert View Drop Down
Really should get out more
Really should get out more


Joined: 11 Aug 04
Location: Whitefriars sc
Online Status: Offline
Posts: 7880
Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Posted: 18 Feb 18 at 9:23pm
Under 10% I can well believe, and less for a boat like a Feva, which would struggle with the 50% reaching figure. Less than 1% would suggest a totally unsuitable hull form, maybe a displacement class where adding more sail simply puts pressure on everything. The Farr 3.7 certainly isn't that, even if it lacks the length and righting moment of the IC.
Firefly 2324, Lightning 130, Puffin 229, Topper 44496, Minisail 3131, Minisail 3446
Back to Top
Sam.Spoons View Drop Down
Really should get out more
Really should get out more


Joined: 07 Mar 12
Location: Manchester UK
Online Status: Offline
Posts: 1392
Post Options Post Options   Quote Sam.Spoons Quote  Post ReplyReply Direct Link To This Post Posted: 19 Feb 18 at 9:26am
Yup, maybe more on long open courses and less on a river.

Any way you look at it on a planing hull adding 150% extra sail area is going to go more than 0.4% faster.
Spice 346 "Flat Broke"
Blaze 671 "supersonic soap dish"
Supernova 395 "dolly the sheep" (now sold but considering a second (mk3) Blaze as her replacement)
Back to Top
JimC View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 17 May 04
Location: United Kingdom
Online Status: Offline
Posts: 5631
Post Options Post Options   Quote JimC Quote  Post ReplyReply Direct Link To This Post Posted: 19 Feb 18 at 10:16am
Originally posted by Rupert

less for a boat like a Feva, which would struggle with the 50% reaching figure.

That was meant to be an extreme value. I very much doubt there are many classes that go 50% faster with the kite up.
Back to Top
Dougaldog View Drop Down
Far too distracted from work
Far too distracted from work


Joined: 05 Nov 10
Location: hamble
Online Status: Offline
Posts: 265
Post Options Post Options   Quote Dougaldog Quote  Post ReplyReply Direct Link To This Post Posted: 19 Feb 18 at 11:07am
Jim C - I know that the IC scene is not my 'specialist subject' so the view I expressed in the reports were really just what I was  seeing for myself, first hand. But after spending  10 days + out on a RiB in Tremadog Bay reporting on the IC pre-worlds/Worlds, I was more impressed by the performance of the new design ICs than I was by the ACs. With the exception of one day which was very light, most of the racing was conducted in what could best be described as a 'good breeze' and whilst the ACs were undoubtedly quick in a straight line downwind,  the gains they made seemed to be wiped out heading back upwind. There were also big losses in time when hoisting and recovering, as many of these were accompanied by a swim or two......
I couldn't make a direct one on one comparison as the ACs did w/l whilst the ICs did triangle sausage and I stress again - I was looking at this as an 'outside reporter' but the performance of the Maas boats, Dragonfly and the Morrisons was - eye catching!

Dougal H
Back to Top
JimC View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 17 May 04
Location: United Kingdom
Online Status: Offline
Posts: 5631
Post Options Post Options   Quote JimC Quote  Post ReplyReply Direct Link To This Post Posted: 19 Feb 18 at 11:15am
The new ICs and the ACs seem to be reasonably level round the racecourse. But a typical fleet of anything seems to be around 20% front to back, so its very hard to make comparisons.

Edited by JimC - 19 Feb 18 at 11:18am
Back to Top
 Post Reply Post Reply Page  <1 78910>

Forum Jump Forum Permissions View Drop Down

Bulletin Board Software by Web Wiz Forums® version 9.665y
Copyright ©2001-2010 Web Wiz
Change your personal settings, or read our privacy policy