Topping Lift and Sail Shape - SailNet Community
Reply
 
LinkBack Thread Tools
post #1 of 14 Old 06-27-2009 Thread Starter
Senior Member
 
Join Date: Dec 2008
Location: North Carolina
Posts: 614
Thanks: 0
Thanked 11 Times in 7 Posts
Rep Power: 7
 
Topping Lift and Sail Shape

Today I went sailing and observed a Hunter 260 with his topping lift very tight so that it lifted the boom to the point that his mainsail never was anything but a flapping piece of fabric on any point of sail. I wanted to pull along side and to suggest to him to slack off so that the sail could take a proper shape, but he was with his girl/wife, so I was afraid that I would embarrass him. Later he put up his bimini and it became obvious that he had shortened the topping lift so that the boom would clear the bimini (but he was attempting to sail this way even before the bimini was raised). With the rig that he had, he will never get satisfactory sailing performance. And, probably in time, he will abandon sailing as being frustrating and unfulfilling.

If you happen to have a similar situation on your boat, take the sail to a sailmaker and get it recut so that the boom will clear your bimini without using the topping lift to hold the boom clear of the bimini. If you sometimes sail without the bimini and want the full size of the sail, then have the sailmaker to put in a flatting reef cringle/reef points on the sail....this is a relatively shallow cringle at the boom/leech end of the sail used normally to flatten the sail, but if done properly for this application, it will lift the boom also.

I'm sure that someone will disagree, but don't sail with your topping lift tight...if you do, you distort the shape of the main sail. Slack the topping lift off so that it does not distort the sail shape....the boat will sail better. Also, never sail with with boom attached to the pig tail wire on the back stay if you have one...the pig tail is to support the boom when sails are down. And if you don't have a topping lift, put one on your boat, but don't sail with it tightened....use it to keep the boom from dropping down into the cockpit when putting up sails.
NCC320 is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 14 Old 06-27-2009
Senior Member
 
Join Date: Feb 2002
Posts: 221
Thanks: 3
Thanked 3 Times in 3 Posts
Rep Power: 14
 
Ditto. The topping lift is there to hold the boom when the sail is NOT raised. Of course, if you are sailing with the bimini up you probably don't have any idea what your sail shape is anyway, so....
jgeissinger is offline  
Quote Quick Reply Share with Facebook
post #3 of 14 Old 06-28-2009
Telstar 28
 
sailingdog's Avatar
 
Join Date: Mar 2006
Location: New England
Posts: 43,290
Thanks: 0
Thanked 14 Times in 12 Posts
Rep Power: 14
         
The only time you might want to sail with the topping lift tight is if you're in very, very light winds... and that only in very rare circumstances. Other than that, it should really be slackened enough to allow the boom's weight to load the leech properly....

Sailingdog

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

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
sailingdog is offline  
Quote Quick Reply Share with Facebook
post #4 of 14 Old 02-22-2011
Junior Member
 
Skipper995's Avatar
 
Join Date: Feb 2001
Posts: 23
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
NCC320, you are SO right on. I removed the topping lift from my boat as soon as I bought it. It's just another line to get in the way. It's not a sail control and if you have a solid vang (which I highly recommend) there is just no need for the topping lift.

I have to disagree with sailingdog on one issue however. In very very light conditions the main needs to be made as flat as possible to try and squeeze as much power out of the breeze as possible. In these conditions air flow has a very hard time staying attached to the sail. Detached air flow means loss of efficiency and power. A flat sail allows the breeze to maintain nearly complete flow attachment for best sailing performance.
Skipper995 is offline  
Quote Quick Reply Share with Facebook
post #5 of 14 Old 02-23-2011
Just another Moderator
 
Faster's Avatar
 
Join Date: Sep 2005
Location: New Westminster, BC
Posts: 16,518
Thanks: 104
Thanked 309 Times in 299 Posts
Rep Power: 10
     
Quote:
Originally Posted by Skipper995 View Post

I have to disagree with sailingdog on one issue however. In very very light conditions the main needs to be made as flat as possible to try and squeeze as much power out of the breeze as possible. In these conditions air flow has a very hard time staying attached to the sail. Detached air flow means loss of efficiency and power. A flat sail allows the breeze to maintain nearly complete flow attachment for best sailing performance.
... the problem is, though, that the weight of the boom will close the leech of the sail off and you'll lose that attached flow because, essentially 'the flaps are on'. The topping lift's support will allow the leech to maintain its proper shape without the force of a reasonable breeze.

Today's rigid vangs can often provide the same function.

Ron

1984 Fast/Nicholson 345 "FastForward"

".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
Faster is offline  
Quote Quick Reply Share with Facebook
post #6 of 14 Old 02-23-2011
Junior Member
 
Skipper995's Avatar
 
Join Date: Feb 2001
Posts: 23
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Faster, I hear you and have a suggestion. Next time you're out in ultra light conditions try flattening the sail and give the boat time to establish a steady speed. Then without changing anything else apply your topping lift as you suggest and watch the boat speed. I guarantee it will drop as the boom lifts.
Skipper995 is offline  
Quote Quick Reply Share with Facebook
post #7 of 14 Old 02-23-2011
Telstar 28
 
sailingdog's Avatar
 
Join Date: Mar 2006
Location: New England
Posts: 43,290
Thanks: 0
Thanked 14 Times in 12 Posts
Rep Power: 14
         
In very light conditions, a flat main won't generate any lift...and you won't move... also, not supporting the boom will close the leech of the sail, as Faster pointed out, which was my reasoning for supporting the boom with the topping lift...to allow the sail to have a fuller shape to help generate lift and to keep the leech open. Yes, flat sails help with attached flow, but you have to balance keeping the flow attached with sail shape to maximize lift. A flat sail generates almost no lift.

Quote:
Originally Posted by Skipper995 View Post
I have to disagree with sailingdog on one issue however. In very very light conditions the main needs to be made as flat as possible to try and squeeze as much power out of the breeze as possible. In these conditions air flow has a very hard time staying attached to the sail. Detached air flow means loss of efficiency and power. A flat sail allows the breeze to maintain nearly complete flow attachment for best sailing performance.

Sailingdog

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

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
sailingdog is offline  
Quote Quick Reply Share with Facebook
post #8 of 14 Old 02-23-2011
Senior Member
 
jackdale's Avatar
 
Join Date: Dec 2008
Location: Calgary, AB, Canada
Posts: 9,028
Thanks: 27
Thanked 59 Times in 56 Posts
Rep Power: 7
 
Full sail for light air.

Flatter sail for heavier air. I will flatten a sail prior to reefing.

Compare that to airplane wings. Short Take Off and Landing planes have deeper camber, while high speed fighters have much thinner wings.


__________________
ISPA Yachtmaster Offshore Instructor Evaluator
Sail Canada Advanced Cruising Instructor
IYT Yachtmaster Coastal Instructor
ASA 201, 203, 204, 205, 206, 214
As I sail, I praise God, and care not. (Luke Foxe)

Last edited by jackdale; 02-23-2011 at 11:44 PM.
jackdale is offline  
Quote Quick Reply Share with Facebook
post #9 of 14 Old 02-23-2011
Senior Member
 
Liquorice's Avatar
 
Join Date: Nov 2007
Location: Alberta, Canada
Posts: 170
Thanks: 0
Thanked 3 Times in 3 Posts
Rep Power: 8
 
I agree with Skipper995!
Below 2 or 3 knots wind the sail needs to be flattened or you can't keep the flow attached.

sam :-)
Just because you're paranoid ...doesn't mean they're not after you!
Liquorice is offline  
Quote Quick Reply Share with Facebook
post #10 of 14 Old 02-23-2011
Just another Moderator
 
Faster's Avatar
 
Join Date: Sep 2005
Location: New Westminster, BC
Posts: 16,518
Thanks: 104
Thanked 309 Times in 299 Posts
Rep Power: 10
     
Quote:
Originally Posted by Liquorice View Post
I agree with Skipper995!
Below 2 or 3 knots wind the sail needs to be flattened or you can't keep the flow attached.
I'm not arguing flat vs full...what I'm trying to say is that in real light air, the full weight of the boom alone will physically pull the clew down (gravity sucks...) and this will cause the leech to turn hard to 'windward', closing off the leech. This creates a very non uniform camber that cannot promote good attached flow - it is, as I said, like having full flaps on an airplane wing.

Whether you're of the 'flat' or 'full' mindset - you want a smooth uniform curve and a clean exit...

In light air do you crank on the leech line on the genny to induce a 'hook' in the leech??? Same thing.

Ron

1984 Fast/Nicholson 345 "FastForward"

".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
Faster is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Heavy weather sailing sailorfrank Learning to Sail 26 09-10-2013 06:32 PM
Windward performance deseely General Discussion (sailing related) 21 04-01-2012 02:42 PM
Traveler question sohi07 Learning to Sail 11 10-21-2006 11:47 AM
Sail Repairs at Sea Brian Hancock Gear and Maintenance Articles 0 09-22-2003 08:00 PM
Choosing the Right Headsail Dobbs Davis Racing Articles 0 01-29-2003 07:00 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome