Boat Design Forums  |  Boat Design Directory  |  Boat Design Gallery  |  Boat Design Wiki (beta)  |  Boat Design Book Store  |  Thanks to Our Site Sponsors  |  Sitemap

Go Back   Boat Design Forums > Design > Sailboats
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 03-09-2009, 01:00 PM
Flumixt Flumixt is offline
Junior Member
 
Join Date: Oct 2006
Rep: 10 Posts: 38
Location: California
Swap Sail Rig

Would this work aytall?????

I'm thinking of swapping my Y-Flyer sail rig onto a Johnson Class C Scow.

The Y-Flyer [wood] is 18 long, 5.5 wide with design main and jib 176 sq ft.

The C-Scow [glass] is 20 long, 8 wide with a Cat rig (main only) 225 sq ft.

I often rig the Flyer with a bigger jib which gives me 195 sq ft.

Naturally I'd step the Flyer mast further aft than the C mast.

Seems to me I'd get about the same power with more sail flexability since I carry 3 size jibs and 2 size mains to handle all the pickles I get into. Plus the extra beam would give me a bit more stability for single handing.

Waddayathink?

Then I could burn my Y-Flyer which is rotting faster than I can pour epoxy and chopped glass into it. Assuming it would dry out enough to burn.
Reply With Quote
  #2  
Old 03-09-2009, 03:44 PM
bistros's Avatar
bistros bistros is offline
Senior Member
 
Join Date: Jan 2007
Rep: 146 Posts: 368
Location: Ottawa, Canada
Why not? Sounds like you've got nothing to lose and only fun sailing to gain. I'd be careful about making permanent changes to the hull that would make the hull illegal for class racing - resale value always depends more on being class compliant. If resale isn't an issue, then do whatever you like.

It may be worthwhile to consult one of the naval architects here, to help determine the optimal place for the rig. It also may work out better to leave the mast step where it is and reduce the board size for the new "Y-Flyer" rig.

Rig location is balanced between the center of lateral resistance and center of effort - it also is a balancing act between sail area and lateral plain of the board & rudder. Using the twin scow boards with the Y-Flyer rig may not work as you hope - and single handling may not be comfortable.

Too much lateral resistance will cause the boat to heel a lot and reduce the effect of hiking. Remember the technique of pulling up the board a bit in heavy wind? What you are doing is effectively the opposite.

Best of luck,

--
Bill


Update: Noticed you said Johnson C-Scow - this may be different from the Melges I'm familiar with but the comments still apply.

--
Bill

Last edited by bistros : 03-09-2009 at 06:10 PM. Reason: Noticed a detail in your post ....
Reply With Quote
  #3  
Old 03-10-2009, 09:52 AM
Flumixt Flumixt is offline
Junior Member
 
Join Date: Oct 2006
Rep: 10 Posts: 38
Location: California
>>Using the twin scow boards with the Y-Flyer rig may not work as you hope - and single handling may not be comfortable.<<

Hi - Could you expand on this?

I also have a V-21 rig that could be used instead tho that mast doesn't rotate.
Reply With Quote
  #4  
Old 03-10-2009, 10:31 AM
bistros's Avatar
bistros bistros is offline
Senior Member
 
Join Date: Jan 2007
Rep: 146 Posts: 368
Location: Ottawa, Canada
Quote:
Originally Posted by Flumixt View Post
>>Using the twin scow boards with the Y-Flyer rig may not work as you hope - and single handling may not be comfortable.<<

Hi - Could you expand on this?

I also have a V-21 rig that could be used instead tho that mast doesn't rotate.
I did already I thought:

"Too much lateral resistance will cause the boat to heel a lot and reduce the effect of hiking. Remember the technique of pulling up the board a bit in heavy wind? What you are doing is effectively the opposite."


Boats are designed with the lateral resistance in proportion to the sail area - change the proportions of either one and the balance and righting characteristics change as well.

--
Bill
Reply With Quote
  #5  
Old 03-10-2009, 02:50 PM
Flumixt Flumixt is offline
Junior Member
 
Join Date: Oct 2006
Rep: 10 Posts: 38
Location: California
OK. Looks to me like the C board is about the same size as the Y-Flyer board so I don't see a big problem. As you say the board can come up a bit. I grew up on scows so heeling is just a day at the office. At this preliminary point I don't see a problem with the boards except finding a good mast position (there may not be one, of course). I can nearly match the C sail area by setting a bigger jib. Oh Boy! Can't wait to try it. :-)
Reply With Quote
  #6  
Old 03-12-2009, 01:48 AM
tspeer tspeer is offline
Senior Member
 
Join Date: Feb 2002
Rep: 404 Posts: 1,246
Location: Des Moines, Washington, USA
I sounds like you are trying to revive the D scow!

I'm skeptical that the smaller rig will improve the performance of the C. If I were looking to improve the performance of the C, I'd look at a taller, higher aspect ratio rig. Perhaps raked so the center of effort was in the same place from the existing mast step.

The mast step problem shouldn't be underestimated. The bottom of the C's cockpit is not reinforced to take the vertical compression of the mast You may need to install some kind of truss to stiffen it up. You may not be able to go any further back than the front of the cockpit. But a post there to take the compression ought to work.

When the MC came out, I was once interested in putting a more forward mast step on my wooden Melges M-16 so I could sail it as an MC as well as an M-16. I asked Melges about it, and they (of course) said don't do it. Of course, the MC is one-design, and although the hull shapes are the same, the M-16 hull & twin rudders wouldn't have been legal.
__________________
Tom Speer
Reply With Quote
Reply



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Sail Loading on Rig, Rig Loading on Vessel brian eiland Sailboats 91 05-29-2009 09:58 PM
wingspar sail rig alan white Boat Design 26 02-20-2008 06:38 PM
Sail rig for Ellen flydog Sailboats 4 04-19-2007 07:15 AM
New Balance Rig sail? Wellydeckhand Sailboats 3 04-29-2006 01:44 AM
Sail rig hardware? Kris Boatbuilding 3 04-13-2004 08:10 PM


All times are GMT -5. The time now is 08:14 AM.


Powered by: vBulletin 3 Copyright ©2000 - 2009, Jelsoft Enterprises Ltd.
Web Site Design and Content Copyright ©1999 - 2009 Boat Design Net