Weather Helm on IOR Ranger 37 - Rudder Modifications?

I am cruising on a stock Ranger 37, it is solid and crossed the Atlantic happily, however, no matter what I try I cannot get it to sail without two hands on the tiller. Almost all points of sail, with the mainsail down, under large genoa alone, it exhibits weather helm that can wear out a wind vane, autopilot, or a strong helmsman. I am stumped. With all the effort forward from the genoa why is it still heading up? I am aware of the IOR squirelliness and just want some ideas(weight balance, keep the boat flatter, less sail, rake the mast forward etc..) or do I need to modify the rudder to be more balanced? Thanks in advance for any and all ideas and questions to clarify...

Michael

 

Welcome to the Forum Michael.

Here is some more info on the Ranger 37 for reference - the GA drawing below is taken from this link.
SailboatData.com - RANGER 37 Sailboat https://sailboatdata.com/sailboat/ranger-37



Can you get her to sail herself close hauled when the helm is locked or lashed, or would she then still want to round up?
That is quite baffling re how you have so much weather helm, and especially with just the genoa driving the boat.
I would have thought that with a hull form like this, and fairly well balanced waterlines, she should be easy to steer.

I am sure that other folk much more knowledgeable than I will be along soon to offer some useful opinion re your weather helm problems.

Edit - your Ranger is very similar in many ways to the She 36 designed by S & S -
SailboatData.com - SHE 36 Sailboat https://sailboatdata.com/sailboat/she-36
Your displacement ratios are higher - the Sail area / Displacement ratio for the Ranger is 16.46, and for the She it is 12.89.

 

The first generation (mk1) of the Corbin 39 suffered of the same problem, I think it was due to an important forefoot in the water combined with a slightly too backward position of the mast / keel wing. This was solved with both a mast moved forward by 32'' and a forestay on a bowsprit 36'' , leading to the mk2 version :
https://corbin39.org/wp-content/uploads/2020/02/Corbin-39-weather-helm-summary-DS-20-02-20a.pdf

You may joined the Corbin 39 owners association for more feedback in this issue :
(7) Corbin 39 Owners Group | Facebook






Envoyé de mon iPad

 

The ones I'm familiar with in SF bay sailed best with weight out of the stern and up on the rail. Like most typical racers, they didn't let gear accumulate either.

 

Post #4 is quite correct,you need a few hefty bodies on the rail or you need to reef in good time.IOR hulls sailed most effectively if they weren't allowed to heel more than about 20 degrees.The skeg hung rudder doesn't allow for any area ahead of the pivot axis so the only way to reduce tiller loads with the current rig configuration would be a longer tiller.A much more complicated solution would be a conversion to wheel steering.

 

Use a pole to pole the genoa out any time it isn't wrapped hard around the spreader. I run a 160% on my Catalina 38 and that helps. She has a mast height of nearly twice the waterline, so she does want to round up when healed. Rig tension is another consideration. I run about 3000# on the backstay at the dock. Make sure you can unload and luff the top of the genoa when you want to. When sailing with the genoa, very little mast bend is wanted so the fore stay has maximum tension (something I don't have to worry about on my Catalina - no inner stays)

 

Modify the rudder or move the foresails forward by using a bowsprit. You would not be the only one to change the rudder, even the designer had one or two revisions drawn.
My advice, remove the skeg and fit a much bigger balanced rudder.

 

My observation as well, although it looks like a moderate modification of the skeg, and a modified rudder to put some area forward of the axis would go a long way to lessen steering forces.

 

I agree too but would put less emphasis on cutting away skeg and put more emphasis on a new deeper rudder that shortens the cord and extends forward of the pivot axis below the skeg. If there isn't any weather helm on an unbalanced rudder, the rudder is not resisting leeway and you are at risk of weather helm when the boat rocks upright. Balance the rudder first before you alter the boat. Most likely, only the rudder needed to change.

 

Changing from a skeg mounted rudder with the rudder supported at the bottom of the skeg to a rudder mounted on a rudder post cantilevered from the hull is not a minor modification. The bending moment on the rudder post and the load on the bearing/bushing at the hull will increase significantly. Careful engineering would be in order.

 

If you are seriously considering something as involved as a keel/rudder mod, why not convert her to a shallow full keel with a centerboard. That would move your CLR aft, improve the overall natural tracking, give you more sailing options in areas like the Florida Keys and Gulf Coast, and allow for adjustible balance for deep heeling at sea.

'Full keel' may not be exactly the right term. Maybe a 3/4 or 2/3rd keel.

 

Changing the genoa for a small headsail will improve weather helm by shifting the center of effort forward. Reefing the main will also help.

 

Speaking as a guy who just installed a hydraulic steering system, that seems doable.

 

I suggest you have a bit of thought about that.In most of the world weather helm is regarded as the boat having the CE too far aft which leads to a tendency to round up.

 

Exactly. So a smaller headsail will have the center of effort farther forward. Also, those designs tend to round up when heeled too much. Give it a try.