Windward performance - Page 3 - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > General Interest > General Discussion (sailing related)
 Not a Member? 


Like Tree2Likes
Reply
 
LinkBack Thread Tools
  #21  
Old 04-01-2012
Low Salt Diet Sufferer
 
Join Date: Feb 2010
Location: San Francisco Bay Area
Posts: 64
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 5
kulokoo is on a distinguished road
Re: Windward performance

Quote:
Originally Posted by AdamLein View Post
Are you wondering about hydrodynamic effects on the leeward side, or aerodynamic effects on the weather side?

In the first case, if you're heeled over that far you have other problems. In the latter, I can't imagine it would have much affect on windage.
I am wondering about the hydrodynamic effects. For instance, does pronounced tumblehome produce a lift to leeward? Or maybe it helps the leeward hull side "stick" in the water and reduces leeway?

The boat with pronounced tumblehome I have sailed on is a Catalina 38 which points and goes to windward very well, and buries the rail (and of course the tumblehome) when there is sufficient wind. It seems to like that.

The tumblehome was part of an S&S race design as I understand it, so I am assuming it was done very purposefully. But why?
Reply With Quote Share with Facebook
  #22  
Old 04-01-2012
MedSailor's Avatar
Closet Powerboater
 
Join Date: Mar 2008
Location: Anacortes PNW
Posts: 2,371
Thanks: 57
Thanked 49 Times in 41 Posts
Rep Power: 7
MedSailor is on a distinguished road
Re: Windward performance

Quote:
Originally Posted by kulokoo View Post
I am wondering about the hydrodynamic effects. For instance, does pronounced tumblehome produce a lift to leeward? Or maybe it helps the leeward hull side "stick" in the water and reduces leeway?

The boat with pronounced tumblehome I have sailed on is a Catalina 38 which points and goes to windward very well, and buries the rail (and of course the tumblehome) when there is sufficient wind. It seems to like that.

The tumblehome was part of an S&S race design as I understand it, so I am assuming it was done very purposefully. But why?
It may have been for looks, reminiscent of when tumblehome kept the weight of the cannons closer to the center-line and helped deflect cannon-balls. Not all design features are for performance. These links might help:
Tumblehome, stability, and performance

Boat Design Forums

From the link above:
"There are several advantages to tumblehome: as already mentioned, it reduces inverse stability; it allows outboard shrouds to be moved in relative to overall beam and thereby reduces sheeting angles; since a curved panel is stronger than a flat one for a given scantling, one can achieve greater strength with less displacement. The disadvantages are reduction in side deck area and a slight increase in tooling costs. Since offshore racing boats do not utilize outboard shrouds, one can only assume that the reduction in side deck area was a safety factor considered more important by the developers of a rule intended for crewed vessels. Brad"
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


I have a sauna on my boat, therefore I win.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
What would you buy for $100,000? swo104 Boat Review and Purchase Forum 130 08-30-2013 11:51 AM
low-budget performance passage-maker catamount Boat Review and Purchase Forum 16 07-12-2005 06:12 PM
Performance 420 Stepford Boat Review and Purchase Forum 2 09-27-2004 04:56 PM
Gibsea Quality / Sail Performance corvette4_5_4 Boat Review and Purchase Forum 8 03-21-2002 10:58 PM
best "performance" cruiser ~100K wardtj Boat Review and Purchase Forum 4 01-13-2002 07:08 PM


All times are GMT -4. The time now is 08:36 PM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012