Boat Design Forums  |  Boat Design Directory  |  Boat Design Gallery  |  Boat Design Book Store  |  Thanks to Our Site Sponsors

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 03-26-2004, 03:11 AM
Mariachi Mariachi is offline
Junior Member
 
Join Date: Mar 2004
Rep: 10 Posts: 2
Location: New Zealand
Our trailer-sailer won't point!

We recently bought a 20' "Dancer" trailer sailer with a swing keel. We have sailed it twice now in 10-15 knots. On our first outing the mast was raked back excessively so that the boom hit everyone. By the second outing we had rectified the rake and brought the mast back to vertical. However on both days the boat would not point in to the wind. The lee helm was extraordinary and when boat speed dropped there wasn't much we could do till the boat was reaching.
We think it might have something to do with the swing keel. I dived down at the end of our second sail and saw that the keel was about 2/3 down (60 degrees from horizontal). We couldn't persuade the keel to drop any further but we are suspicious as the mechanism is v stiff and rusty.
What are the effects of the keel not being vertical (all the way down) on a boats ability to sail into the wind?
What factors usually impact a boat's ability to point?
I have found a few diagrams on the web of swing keels and some of them don't swing fully down to vertical, Is this common?
Reply With Quote
  #2  
Old 03-26-2004, 02:56 PM
dna dna is offline
Junior Member
 
Join Date: Mar 2004
Rep: 10 Posts: 3
Location: Melbourne
if the keel is meant to be more vertical the effect of it being only partially down will be to move the CLR (centre of lateral resistance) further aft. This means that your bow will continually get blown downwind and you will not be able to point all that well. When the mast was racked back that probably helped because you moved the centre of force on the sail back as well and it was more in ballance. with the CLR too far aft you should have experienced lee helm, needing to constantly push the tiller away from you to keep tracking straight. Try to get a line drawing of your boat to see if the keel should be down further. Old worn sails will also prevent you pointing well as would pinching, or trying to sail to high without first building a bit of boatspeed.

cheers,
dna
Reply With Quote
  #3  
Old 03-27-2004, 02:29 AM
Mariachi Mariachi is offline
Junior Member
 
Join Date: Mar 2004
Rep: 10 Posts: 2
Location: New Zealand
DNA
thanks for your help. You confirmed our thoughts, we're just going to have to get that keel down properly. Tomorrow is another testing day!
Nat
Reply With Quote
  #4  
Old 03-27-2004, 03:50 AM
tspeer tspeer is offline
Senior Member
 
Join Date: Feb 2002
Rep: 1329 Posts: 1,523
Location: Des Moines, Washington, USA
And a 60 degrees from the horizontal, the drag due to lift of the keel is 1/3 greater and the leeway will be greater. That doesn't help the pointing any, either!
__________________
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
25' trailer sailer LP Sailboats 44 09-02-2005 09:24 PM
25 foot trailer sailer restoration. DennisRB Wooden Boat Building and Restoration 3 08-02-2005 02:47 AM
Designing a trailer sail boat Bioptica Sailboats 10 11-23-2004 05:05 PM
Building A Trailer Sailer Frogman111 Boatbuilding 2 04-26-2004 05:43 AM
australian trailer sailer swap for 30ft plus inwater or on hard ron213 Sailboats 0 02-24-2004 10:30 AM


All times are GMT -5. The time now is 07:08 PM.


Powered by: vBulletin Copyright ©2000 - 2012, Jelsoft Enterprises Ltd.
Web Site Design and Content Copyright ©1999 - 2012 Boat Design Net