Problem with lee helm

What exactly makes this a perfectly good thread?

An owner has a BCC, a very well known boat. These boats are infamous for their weather helm issues. His boat had the normal helm of the other BCCs. He has replaced a headsail and now his boat suddenly has extreme lee helm.

He has received “solutions” from members of this board that include:

o Ease the main to balance the helm. This is exactly the opposite of what should be done.
o Ease the jib. What???
o Rig the headstay off the Sampson post. What???
o Rake the mast. Well, the boat was fine before the jib swap, so this should not be the solution to the problem. Since BCCs have weather helm issues this would be a bad idea considering other potential sail combinations.
o Cut down the brand new sail. Why? It is no bigger than the old sail that worked well.
o Cut down the bowsprit. You have to be kidding!
o Add a big roach main. We’re back to the issue of the BCC being a weather helm monster, especially considering the potential sail combinations.

None of those suggestions are based in reality. Many are simply disinformation, some are downright silliness. Of course there are the various discussions about CoA, CoE, CLR, and dragging the boat by the fairlead. All are a big waste of time and bandwidth. Such suggestions do not a “perfectly good thread” make.


Now, at least three people have mentioned the new lead looks too far forward. This is unacceptable to the owner, who positioned the lead himself (using an incorrect methodology, see attachment). He could not be mistaken! In fact he says some crazy thing about the lead angle being so steep that moving it would render the sail useless. What???


Let’s look at the facts.

The boat has been sailing as a normal BCC with no issues before the sail change.

The helm returns to normal when reaching off. Funny how that coincides with the fact that you need to move the headsail lead forward for correct trim while reaching?

The new sail would not have changed the overall Center of Lift of the combined sailplan more than a couple of inches. This would not account for the change in helm.

Even the drawing that the owner has provided shows that he has incorrectly positioned the new lead. If you check every other headsail on that drawing you will find none of them have a lead-clew line that would intersect 50% up the luff. If you look at the drawings from any able designer you will find the same. The lead-clew always lines up with the headstay at about 40% of the way up. This is elementary design, not rocket science. I’m attaching a copy of the relevant page from Skene’s as reference.

The owner will consider all sorts of loopy things (raking the rig, re-cutting the new sail) but will not consider the one simple thing that is right in front of his face. He is infallible. Ego? Sounds like it.

The funny thing is, when he rakes the mast he is going to inadvertently rock the clew down and he will find that the jib will be sheeting better to his current, incorrect lead.


So…

This “perfectly good thread” has a majority of the posts that are basically useless gibberish in context, and the few posts that identify a real problem are ignored by the person asking the question. This sounds less than perfect to me.

Anyone who knows how to sail “as well as most anybody” could step aboard this boat and find the problem in the first couple of minutes. The solution could be mocked up while underway. Solving this problem should not take months of sailing with the wrong configuration, followed by all sorts of hand wringing on the internet.

 

That's the important part.. Got to say you know the sails but perhaps miss something in social skills ¨

to OP
Anyway too much camber now. Put another sheat where the yankee sheat was and try how's the behaviour changes easing tightening btw sheets. Might be something wrong with the sail cut too..

 

"I never did give anybody hell. I just told the truth and they thought it was hell."

Harry S. Truman

 

Paul B,
Yes, this was and is a perfectly good thread, even with your pontification. You seem to have a good grasp on the situation with the BCC. But your dogmatic tirades make your comments unwelcome.

1) For example, the comments re: sampson posts and cutting down the bowsprit. Yes, it was not relevant, but it did get me to thinking. Because of the way my jib is set up I have an almost infinite ability to change the position of the tack. Next time I take Shanti out sailing I will experiment with this as it can move my CoE aft rather easily, and correspondingly move my fairlead aft.

2) So you can see it was not a “waste” of bandwidth.

3) The comment regarding moving the fairlead aft was in relation to locating it back where the yankee sheeted. The difference in position would have been so extreme it would have made the sail useless. The entire upper 2/3 or more of the sail would have been luffing at that position. How is wanting my sails to be trimmed correctly crazy?

Your “facts”:
1) Correct. No issues before sail change.

2) Of course I moved the fairlead forward while reaching off, from it’s position while beating. No idea why that is “funny”.

3) I would not have thought the new sails small change in CoE would have accounted for the change in helm. That is why I started this thread …hello!

4) I stated in the thread that the drawing was not entirely accurate. That it was positioned aft of the lower instead of forward. This positioned was arrived at by trimming to the tell tales. Not using the trim stripe. The trim stripe I mentioned as only a confirmation. Twice I stated that I used tell tales to trim the sail. This has always been the way I trim. In fact I have NEVER used a trim stripe for the fairlead before. And I did not use it this time. I just happened to go up and deck the other day while sailing and lay on my back, sighting up that trim strip to see how it was working relative to my trimming by telltales. Bingo, it lined up very accurately. So that was the reason I put it in as an additional confirmation as to trim on the jib. I did not want this thread to be a discussion on sail trim.

5) Not only did Doyle tell me they used the 50% method, but I also check with North Sails. I talked to one of their designers Grant Spanhake. You can check out his resume here http://www.gsyachting.com/ . He confirmed the 50% method used by North Also. Then there is also this video on sail trim http://www.youtube.com/watch?v=bNT64BmMezc&NR=1 . But this is ALL beside the point as I trimmed my sails by the tell tales.

6) I am not going to rake the mast. I have never considered that option. I only commented that I liked the look. I may have the sail recutt, but that depends on my final comparison sailing with the previous sail and discussions and conclusions.

7) I haven’t ignored relevant posts. How do you know what I have put weight in and what I have ignored?

8) You have no idea about my sailing ability. You don’t even know me. So how can you make such assumptions? This is what puts your credibility in question. There have been no months of sailing with the wrong configuration. Where do you get this??? Starting a discussion on lee helm and corresponding CoE etc is hand wringing? … JEEZ give me a break. Now that is silliness!

9) “Anyone who knows how to sail “as well as most anybody” could step aboard this boat and find the problem in the first couple of minutes” is another baseless assumption on your part. You have no idea what the forces are at work on my boat. If it was so easy, why didn’t you offer up some suggestions instead of your dogmatic insistence that I don’t know how to sail?

Anyone who caricaturizes a sincere contribution to a discussion as “useless gibberish” has no idea what a “discussion” is all about.

 

People in denial are often angered by others who dare to tell the truth.

This should not be neccessary. Moving the tack back on the sprit is the wrong thing to do on a BCC.

I didn't make that comment, and you didn't read what the writer said. Go back and try again. Maybe this time you will comprehend.

What you don't seem to be getting is if the lead is too far forward and the sail is trimmed to that lead and it looks correct, guess what point of sail you are on? Now when you are on that point of sail with the sail trimmed correctly will the sail break evenly? Will your "trim stripe" line up?

What you keep saying is the guy who designed your boat didn't know what the hell he was doing. Ditto others who do things the same way he did, like some guy named Herreshoff (see pic), another named Stephens (see pic), and many others like Uffa Fox, William Fife, Doug Peterson, etc., etc.

Seems unneccessary.

Yes I do. I have read what you have written.

Re-read what you have posted.

I know exactly what's up with BCCs. Yours is not magically different.

If I was still in the boat biz I would take your challenge and fly down there and fix your problem in one day. Of course we would have to have a nice wager about it first to make it worth my time. If you have an interest in getting the thing on track correctly I have a couple of names I could give you who could fly out within the next week or so.

 

It seems to me that the sail swap has resulted in the upper portion of the rig being depowered. This is a combination of trim, CoE, cut, and perhaps the issue of the new higher aspect/ shorter lead sail being much fussier to manage than the old yankee. If this is so, when the boat heels, the center of driving effort will not move outboard as much as before, and there will be a smaller moment rounding the bow into wind. I'm not very optimistic that the sheet lead can be adjusted to put the lost power back in the top of the rig, though. That depends on the cut and construction of the sail (I'm making the assumption that the sailmaker knew what he was doing and that the sail was in fact designed for the sheeting angle shown).

I don't recall you mentioning why you made the change. If you were trying to improve the windward pointing, you may have succeded in getting a sail that will set closer haulled, but that doesn't necessarily mean the hull will point better. Have you taken your sail maker sailing?

 

Phil's comments strike me as constructive & quite possibly correct.

In response to Paul B: my remarks were consistent with my experience successfully addressing weather/lee helm problems (from a designer's, not a sailmaker's, point of view). They do not reflect familiarity with the particular boat. If you are familiar with the class that puts you in a better position to analyze. If addressing sail shape issues is an easier and better fix than raking the mast, than by all means go that route. By the same token, if mast rake can be easily adjusted...

 

Sails trimmed, yes. Boat out of trim, yes.

Sorry to but in, and yes I is new to the forum, but I remember once reading or being shown a fair lead on a traveler that allowed this fair lead to be lead for and aft.

The explanation was that a jib with the fair lead forward would be more efficient at low speeds. The larger camber allowed would equal more lift(heeling force, being a pilot I think lift) at lower speeds than the aft sheeted flatter sail. As the air speed over the sail increases it continues to produce more lift, and a lot more drag and turbulence at the leach.

As the traveler is pulled more aft the camber is reduced, the increased speed delivers the lift the flatter sail reduces the drag and improves the slot effect. So off we go, now pulled still further aft as the boat becomes a rocket(sort of).

I also remember something about air shooting down off the foot and the lifting of the bow(???), which is supposed to improve low speed acceleration. If all this is accurate I bet this is a racing kind of thingy.

So if I have been lucky with my surmise your trouble could be that your new sail is maybe producing enough lift to pull your beauty around by her nose while spoiling the air moving over the mainsail’s luff. My notion here is supported by her weather helm returning off the wind. Off the wind the sails are less like airfoils and more like a oldie style parachutes.

I wish to retire to the USVI, so I wish I could help in person.

And let me shout out a hello to the forum, with a thanks for the many hours of entertainment and great information this forum provides to me.

Thank you all.

Robert