Facebook

Login

Support Sailonline

If you haven't already - join the SAILONLINE YACHT CLUB!

Please also consider making a donation - all amounts are greatly appreciated!

Board » General Discussion » Boat planning.

Page: Previous 1 2

Posted by
Rod


Users avatar

Posts
392
Registered at
2010-06-24 22:30:48
2014-04-07 17:30:41 - Re: Boat planning.
I'm in general agreement with your statements about Footy design. The British trend is towards very high bows to counteract Nose-dancing.
I have been following a different approach involving a narrow bow at the waterline, swelling to a much greater volume as the bow is pressed down.
If it breaks, it's not strong enough--if it doesn't, it's too heavy.
Attachments
Posted by
JB


Users avatar

Posts
305
Registered at
2013-03-07 08:54:34
2014-04-08 09:22:59 - Re: Boat planning.
Wow Rod, very nice boat (“Glass Petrel II”).
And above all, very different from the Harpy design, from which I’ve made my overall thoughts about the Footy design, more precisely, the Harpy model.

Looking to your boat pictures two aspects immediately caught my attention:

1 - the high aspect keel with a bulb end, very refined indeed, and;
2 - the enormous rudder, “door” shape alike and, to my mind, totally out of scale.

In theory a rudder with such a large cross section induces more drag than a rudder using a higher aspect ratio, with/without a NACA cross section profile.
Higher drag on the rudder translates to superior forces induced to the helm, obviously influencing the boat behavior.
I wonder if part of the boat’s “nose dancing” instability doesn’t come precisely from having that huge rudder cross section.
If you’re already using a sophisticated keel why don’t you try to some change on the rudder?

At we were talking about the VOR70 I can’t resist to bring up this links:

- stockmaritime.com VO70
- youtube: RC VO65 with genaker (stockmaritime)

And also some planing on the waves:

- youtube: RC VO65 surfing waves (stockmaritime)


___
Edited links to fit column width

--- Last Edited by prokkyer at 2014-04-08 10:32:39 ---
Sail Fair.
Posted by
Rod


Users avatar

Posts
392
Registered at
2010-06-24 22:30:48
2014-04-08 20:56:07 - Re: Boat planning.
Agree that the rudder is too large, but the model has proved difficult to tack. It is also restricted by the Box Rule for the Footy class, where the rudder must fit through a slot of limited depth.
I will try this summer to reduce the rudder size, while still needing to tack smartly. With such a small light hull, the momentum is small, and stalling during a tack is a continuing problem.
The info on the tilting keel models was interesting--unfortunately, class racing allows only two controlled channels. It may be possible to "automate" a swinging keel and a reefable gennacker, which would be interesting, but I doubt if a strict interpretation of class rules would allow them.
Some early radio-controlled sailboats had just a single channel for steering, with the sails controlled automatically by a wind vane at the masthead. This would leave a control channel available for the furlable gennacker, or for the swinging keel
I have contemplated the possibility of a mast-keel-fin unit pivotting in a boat hull which would remain level. Suitable gearing might allow the keel fin to move through a much greater angle than the heel of the mast.....?

--- Last Edited by Rod at 2014-04-08 20:58:12 ---
If it breaks, it's not strong enough--if it doesn't, it's too heavy.
Posted by
JB


Users avatar

Posts
305
Registered at
2013-03-07 08:54:34
2014-04-09 19:08:26 - Re: Boat planning.
Viva Rod.

Talking about the Footy rudder I was thinking in something more like the one seen in the attached picture, positioned before reaching the stern or after it as you have in “Glass Petrel II”.
Anyhow, the idea was a rudder with a higher aspect ratio and, obviously, less drag effects.

Other aspect that intrigues me Rod, is why the front and, I suppose, also the aft sections, aren't more “vertical”, in order to increase the water line length?
Sail Fair.
Attachments
Posted by
JB


Users avatar

Posts
305
Registered at
2013-03-07 08:54:34
2014-04-10 13:29:42 - Re: Boat planning.
By the way,

Sometime ago I tried to track a boat I’ve sailed for years owned by a great friend of mine.
She was the J8 “Finola”, a 1930 William Fiffe design and built by William Fife & Son, Fairlie (fintra.de Yachten von William Fife).

Part of her story goes here: britishyachtingarchive.org.uk Finola

During that search I’ve found a scale model of her. Rod, what a beauty! (rcsailing.net Finola 8 metre of Fife).

__
edited links



--- Last Edited by prokkyer at 2014-04-10 14:48:38 ---
Sail Fair.
Attachments

Page: Previous 1 2

Please login to post a reply.

Races

Next Race: 00d 00h 00m

Current Races:

The British Isles Circumnavigation 2026


The British Isles Circumnavigation is here! Inviting skippers to take on an epic 1,720nm clockwise voyage around Britain and Ireland! Starting and finishing in Cowes, the course passes some of the most iconic landmarks in offshore sailing, including Fastnet Rock, Tearaght Lighthouse, Black Rock, St. Kilda and Muckle Flugga before the long run home. Racing in our fast and versatile TP52, this Super-Buddy Championship race will reward smart routing, changing weather strategy and sustained concentration over every mile. Good luck!
Race #2052
INFO by brainaid.de
TP-52 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SUPBUD - SYC
Race starts: Aug 09th 10:00 Registration Open!
▶ Flash
GO TO RACE

SSANZ Triple Series 2026 - Race 2

Welcome back to race two of the SSANZ Triple Series—it's time for the Lewmar 100! Our dynamic fleet of Young 88s returns for another exhilarating 65 nautical mile battle across the stunning waters off Auckland, New Zealand. Once again, our skilled Sailonline racers will test their strategic minds and endurance. With intense competition, shifting conditions, and plenty of tactical decision-making, this race promises high-energy sailing and edge-of-your-seat excitement from start to finish!
Race #2047
INFO by brainaid.de
Young 88 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SSANZ - SUPBUD - SYC
RACE CLOSE: Friday,
August 14 at 2300 UTC.
Race starts: Aug 08th 21:15 Registration Open!
▶ Flash
GO TO RACE

Lake Vättern PYOC 2026


Back in 2013, longstanding SOLer Musigny and his friend xthyra invited us for a three race tour of beautiful Lake Vättern in the heart of southern Sweden. After many years, we return there for a quick sprint from a start in front of the village of Brandstorp, either way around Visingso island in the middle of the lake, but PORT HAND ROUND a buoy off the Granna piers on the eastern shore and back, once again avoiding Visingso as best you can. At least 20nm in trusty Scandinavian 11m One Designs; good luck!
Race #2046
INFO by brainaid.de
11m OD PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SPQ3 - SPCH - SYC
RACE CLOSE: Wednesday,
August 12 at 2300 UTC.
Race starts: Aug 08th 21:00 Registration Open!
▶ Flash
GO TO RACE

Easter Island to Tristan da Cunha 2026

Welcome to the second leg of our RNW series, rounding Cape Horn. This middle-most leg Round the New World, from Easter Island to Tristan da Cunha, is also part of our Ocean Championship, and as such the second race of OCQ3 2026. This race, like the previous race in the RNW series, will be sailed in our revised 'version 2' Imoca 60 Foil. Race #2050
INFO by brainaid.de
Imoca 60 Foil v2 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: OCQ3 - RNW - OCCH - SYC
Race starts: Aug 03rd 11:00 Registration Open!
▶ Flash
GO TO RACE

Go to race archive

SYC Ranking

  1. Sailonline Yacht Club Member KaSToR
  2. Sailonline Yacht Club Member CriticalHippo
  3. Sailonline Yacht Club Member WRmirekd
  4. Sailonline Yacht Club Member Panpyc
  5. Sailonline Yacht Club Member rafa
  6. Sailonline Yacht Club Member cdhinman
  7. Sailonline Yacht Club Member rthinman
  8. Sailonline Yacht Club Member ms0689
  9. Sailonline Yacht Club Member BRENTGRAY
  10. Sailonline Yacht Club Member Sax747

View full list

Series

Mobile Client

SYC members have the benefit of access to our mobile/lightweight web client!

The mobile client