A good definition of weather helm please....

[Francois Machabee]

Hello all!I have been trying to tune my rig for a little while now on my O'Day 37 CC with little success.I am trying to reduce what I think is weather helm. Now the question is...what really is weather helm and what is not...let me explain...I have been out sailing in different conditions, trying to get acquainted with the behaviour of my boat in different wind conditions.In lite air 10-15 knots (less than this and its not worth talking about), the boat seems to need about 10% turn of the wheel to starboard to keep her heading (from the point of view of the dead center of the rudder when the wheel is a position 0% on my turk's head).If a large gust comes (20-25 knots), I need to increase this temporarily to 45% (or 1/4 turn if you want) to keep my heading.In fun winds, (25-30 knots), with the boat heeled to 25-30% and the rail almost in the water, I need to have the wheel at almost 180% (1/2 turn or more ) to keep her heading. Yes...I know, reduce sails, take a reef and live longer.....In all cases, the boat wants to go into irons. Now, I have sailed on few sailboats before, and they all did this. In fact, I was told once that this is the sign of a good ship.Do I have weather helm?If so, I know that I need to retune the mast forward to reduce it or let out my main sail a bit and use the vang to keep the sail shape so as not to loose any power. My problem is that I have tried to slacken the backstay but the headstay is somewhat fixed via the furler attachment. Also the fact that the O'day 37CC has a bolt going through the mast right under the mast wedge to stop the mast from pumping in a seaway stops it from being tuned at all (.Totally confused? I am....FrancoisS/V Starshine III

 

[Don Evans]

Sounds Like You Have a Good Grasp

Francois, you seem to have a good handle on your boats capabilities. It does sound like you may have a bit too much weatherhelm. Too much just creates underwater turbulence and will slow the boat down. A bit is good though because rounding up is an important safety feature if you become seperated from the boat (God forbid). I'm recommending Steve Colgates interpretation of boat and sail balance and his wisdom to correct this (I'm a big fan of his sailing wisdom). He speaks of obtaining proper balance between the the Centre of Effort of the sails and the Centre of Lateral Resistance, which is underwater. Personally, I would start with a properly tuned rig, then play with the mainsheet traveller, the vang tension and the reduction of the sail as the wind speed warrantes. I also have some weatherhelm and I have tried to reduce this without loosing the feel of the helm. Hope the reference helps.

 

[Francois Machabee]

Thanks!

I will look into this wisdom myself!

 

[Olivier Ruhlmann]

Me too!

Hi Francois!I have the same "problem" with my boat. Since I sail in the San Francisco Bay and that the wind is almost always strong and gusty, it gets to be a pain. I have just installed a boom vang to help a little. Also my main sail is very old. Peter pointed out that a new main sail makes all the difference. I have also read it. How old is your main sail? An old stretched mainsail will baloon too much aft and move the center of force too much aft, hence creating weatherhelm. Just in case a new main does not do it for me, I am adding an inner stay to my boat (you can see a photo of the chainplate on the last photo of the photo forum I created). Adding a small sail forward will do the following (I hope!):-Add sail area in front of the center of rotation of the underwater body, creating a bit more of lee helm-I will be able to reef the mainsail and leave more sail area exposed, and I hope to have a better control over the weather helm-I will have more sail area when needed-I will have an independant storm sail that is also independant of the roller furler-The additional (removable) inner stay and back stay will brace the mast and prevent pumping of the mast.I personnally would like to avoid bending the mast or moving it forward so much that it will look odd. Also, my mast is not currently connected to the deck like yours (May be it was an impovement that was added later on)Olivier