Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 28-11-2011, 23:02   #1
Eternal Member
 
monte's Avatar

Cruisers Forum Supporter

Join Date: Jul 2011
Location: Australia
Boat: Lagoon 400
Posts: 3,650
Images: 1
Square Top Mains for Cruising ?

I'm just wondering whether to get a square top main for a new Lagoon 380.
Any pros, cons etc. sail shape ok when its reefed , easy to handle and reef?
I will be primarily short handed cruising tradewinds.
__________________

__________________
monte is offline   Reply With Quote
Old 28-11-2011, 23:47   #2
Registered User
 
Kiwikat's Avatar

Join Date: Jun 2007
Location: New Zealand
Boat: Fountaine Pajot Bahia 46 Maestro
Posts: 287
Re: Square top mains for cruising ?

About 3 hours ago I observed a Lagoon 380 sailing down the coast here at the Gold Coast. She had a square top main and it looked sweet. A relative of mine with a square top main on his tri says it is a bit of a pain in the bum for cruising cos you have to loosen of the top batten when you drop it down, to stack it away properly but I heard somewhere that lagoon? or someone has solved that issue. Very keen to hear others' opinions.

Cheers
__________________

__________________
Kiwikat is offline   Reply With Quote
Old 29-11-2011, 00:27   #3
Registered User
 
careka's Avatar

Join Date: Apr 2009
Location: Egersund,Norway
Boat: Lagoon380 Comfort#637
Posts: 704
Images: 2
Send a message via Skype™ to careka
Re: Square top mains for cruising ?

Yes its no work at all.
i have it to. works very well. lower down close the zipp-pack and open a cold one. thats all.
here are some pictures.
Lagoon380 Careka: Erfaringer
__________________
careka is offline   Reply With Quote
Old 29-11-2011, 02:55   #4
Eternal Member
 
monte's Avatar

Cruisers Forum Supporter

Join Date: Jul 2011
Location: Australia
Boat: Lagoon 400
Posts: 3,650
Images: 1
Re: Square Top Mains for Cruising ?

thanks...
how about sailing with a reef or two in? does the head still pull in hard to the mast and the sail shape still ok?

btw I found this interesting A square deal! | Lagoon Inside
__________________
monte is offline   Reply With Quote
Old 29-11-2011, 06:49   #5
Senior Cruiser
 
colemj's Avatar

Cruisers Forum Supporter

Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,049
Images: 12
Re: Square Top Mains for Cruising ?

When we had a new mainsail made, we got rid of our square top. The thing was always a pain trying to raise and store it in the bag. Sailmakers can mitigate the loss of the extra small amount of the square top through proper design of a non-square top. In other words, we didn't loose any significant sail area and now have parallel battens that raise and store easily. We have noticed no difference in performance (well, our new sail performs much better than the old blown out one, but I still remember how the old one used to perform when new). Personally, I think they are one of those things sifted down from racing that just look cool and make you a cooler person for having one, but doesn't improve anything on most cruising boats.

Mark
__________________
www.svreach.com

You do not need a parachute to skydive. You only need a parachute to skydive twice.
colemj is offline   Reply With Quote
Old 29-11-2011, 07:39   #6
Registered User
 
ozskipper's Avatar

Join Date: Aug 2010
Location: NSW Australia
Boat: Traditional 30
Posts: 1,981
Re: Square Top Mains for Cruising ?

In MHO aside from aesthetics, the extra power gained may be limited. As square tops are usually on racers, who have plenty of body mass on the rail to provide stability. The COE will move up the sail somewhat, I would assume. Meaning you either need more bums on the rail or an earlier reef. I am still yet to figure out how there isnt just one massive tip vortex at the top of a square top. Someone smarter than me will know of course.
__________________
Cheers
Oz
...............
ozskipper is offline   Reply With Quote
Old 29-11-2011, 10:28   #7
Senior Cruiser
 
senormechanico's Avatar

Cruisers Forum Supporter

Join Date: Aug 2003
Boat: Dragonfly 1000 trimaran
Posts: 5,826
Re: Square Top Mains for Cruising ?

Careka,
Very slick solution !
__________________
Memento,homo, quia pulvis es, et in pulverem reverteris.
senormechanico is offline   Reply With Quote
Old 29-11-2011, 10:48   #8
Sponsoring Vendor
 
boatsmith's Avatar

Join Date: Oct 2008
Location: Jupiter Fl USA
Boat: Wharram Tiki 30 Abaco
Posts: 286
Re: Square Top Mains for Cruising ?

My understanding is that it provides better airflow. It would also seem to me that for a given sail area the overall mast height would be lower. And by gawd I do so want to be cool
__________________
David Halladay | BoatSmith Inc.
561.632.2628 | www.BoatSmithFL.com
www.youtube.com/boatsmthfl

[SIGPIC][/SIGPIC]
boatsmith is offline   Reply With Quote
Old 29-11-2011, 15:16   #9
Registered User
 
Hydra's Avatar

Join Date: May 2009
Location: Lorient, Brittany, France
Boat: Gib'Sea 302, 30' - Hydra
Posts: 1,229
Re: Square Top Mains for Cruising ?

If I understand correctly, the purpose of these sails is adapting automatically (through good choice of batten stiffness) to changes in wind speed and direction, when close-hauled or close reaching.

I am not sure that it is relevant for what monte has in mind.

Alain
__________________
Hydra is offline   Reply With Quote
Old 29-11-2011, 16:05   #10
Registered User
 
threadkiller's Avatar

Join Date: Aug 2007
Boat: Corsair 31-1D
Posts: 32
Re: Square Top Mains for Cruising ?

Well, from what I understand, they do a number of things.
1) Extra sail area aloft, where there is more wind away from the boundry layer/shear caused by drag. Up to 20% more.
2) They twist off in stronger puffs, depowering naturally. In the light they stay firm to give the extra power.
3) The flat edge give an "end plate" effect, the reason racing yachts have deck sweeping headsails, and airliners have canards on the wing tips. It REDUCES tip vortex/drag.

2 cents.
I want one.
__________________
threadkiller is offline   Reply With Quote
Old 30-11-2011, 07:31   #11
cruiser

Join Date: Aug 2005
Location: No longer post here
Boat: Catalac Catamaran
Posts: 2,462
Re: Square Top Mains for Cruising ?

They just look so cool .... I want one too
__________________
Tropic Cat is offline   Reply With Quote
Old 30-11-2011, 08:56   #12
CF Adviser
 
Bash's Avatar

Cruisers Forum Supporter

Join Date: Dec 2008
Location: sausalito
Boat: 14 meter sloop
Posts: 7,260
Re: Square Top Mains for Cruising ?

Quote:
Originally Posted by boatsmith View Post
My understanding is that it provides better airflow.
They also improve light-air performance, because when it's light you'll tend to find better breeze farther from the water's surface.
__________________
cruising is entirely about showing up--in boat shoes.
Bash is offline   Reply With Quote
Old 30-11-2011, 11:01   #13
Senior Cruiser
 
senormechanico's Avatar

Cruisers Forum Supporter

Join Date: Aug 2003
Boat: Dragonfly 1000 trimaran
Posts: 5,826
Re: Square Top Mains for Cruising ?

Quote:
Originally Posted by Bash View Post
They also improve light-air performance, because when it's light you'll tend to find better breeze farther from the water's surface.

Boy do we know that around here!
In summertime, I've often seen a 30 degree difference in apparent wind direction from masthead to deck.

__________________
Memento,homo, quia pulvis es, et in pulverem reverteris.
senormechanico is offline   Reply With Quote
Old 30-11-2011, 13:53   #14
Registered User
 
Hydra's Avatar

Join Date: May 2009
Location: Lorient, Brittany, France
Boat: Gib'Sea 302, 30' - Hydra
Posts: 1,229
Re: Square Top Mains for Cruising ?

Quote:
Originally Posted by threadkiller View Post
3) The flat edge give an "end plate" effect, the reason racing yachts have deck sweeping headsails, and airliners have canards on the wing tips. It REDUCES tip vortex/drag.
Unfortunately, this is not true. To be sure to reduce the tip vortex and the associated drag, you need either a winglet at the tip or a rounded (neither square nor pointed) tip, such as on Spitfire aircraft of WW II vintage.

On modern planes with square wingtips, the end vortex is controlled by carefully designing the twist in the wing. This is made possible because planes fly only within a narrow range of incidence.

Alain
__________________
Hydra is offline   Reply With Quote
Old 08-12-2011, 17:21   #15
Registered User
 
ozskipper's Avatar

Join Date: Aug 2010
Location: NSW Australia
Boat: Traditional 30
Posts: 1,981
Re: Square Top Mains for Cruising ?

Quote:
Originally Posted by threadkiller View Post
SNip

3) The flat edge give an "end plate" effect, the reason racing yachts have deck sweeping headsails, and airliners have canards on the wing tips. It REDUCES tip vortex/drag.

2 cents.
I want one.
Actually, I have always wondered why a smarter person than me hasn't put a little wing (canard) at the mast tip to try and remove some tip vortex. Especially on boats with Tri colors, aerials and other disturbances up the top.
__________________

__________________
Cheers
Oz
...............
ozskipper is offline   Reply With Quote
Reply

Tags
cruising

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not 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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
450: Purchasing and Commissioning roetter Lagoon Catamarans 232 14-04-2014 15:37
For Sale: Parasailor: 125 Square Meters (1345 Square Feet) Steve Rakoczy Classifieds Archive 5 03-02-2012 17:51
440: Square-Top Mainsail Mikromidas Lagoon Catamarans 9 19-08-2011 08:29
Top Square Sail Schooner toosail General Sailing Forum 25 23-07-2011 07:36
Battery Terminal Cover or Cover Entire Battery Top ? sdowney717 Electrical: Batteries, Generators & Solar 5 14-07-2011 05:14



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 02:55.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.