Lee helm

[simdim]

Folks,
I am very new to sailing, so guestion might sound stupid ...
We were out on our e29 with couple of friends who had sailed for a long time (they had catalinas and sabers) and they talked us into trying to sail under jib only. Wind was about 12-15 knots with very calm water, however the boat was totally unresponsive - extremely sensitive to the wheel and would not tack. My understanding that with this configuration center of effort is too much forward and you would have lee helm, our friends were very surprised by that behavior and we tryed it on their saber 28 later that day and sailed no problem under jib only. Any commens would be welocme.

Cheers,

Simon

 

[treilley]

Not sure about the 29 but my 35 will sail just fine with headsail alone. In fact I will get weather helm if overpowered.

Try opening up the top of the sail a little. Also try this with less sail and see of that helps.

 

[Morgan Stinemetz]

Simon,

It strikes me that you probably were sailing rather close to the wind with just the jib up and probably not going very fast. You need some way on to be able to tack. If you delay the release of the jib sheet just a bit, the wind will catch the jib and blow the bow around. But getting the boat moving is the important factor.

Morgan Stinemetz

 

[CaptDan]

Folks,
I am very new to sailing, so guestion might sound stupid ...
We were out on our e29 with couple of friends who had sailed for a long time (they had catalinas and sabers) and they talked us into trying to sail under jib only. Wind was about 12-15 knots with very calm water, however the boat was totally unresponsive - extremely sensitive to the wheel and would not tack. My understanding that with this configuration center of effort is too much forward and you would have lee helm, our friends were very surprised by that behavior and we tryed it on their saber 28 later that day and sailed no problem under jib only. Any commens would be welocme.

Cheers,

Simon

Morgan's right - you were probably trying to point too high for the jib to provide ample drive and helm response. Windward ability is aided by the mains'l; even if it's reefed, balance would be better than trying to sail closehauled without it. Or - ease out the jib and sail lower if not setting the main.

Also, the type and cut of headsail affects balance. Perhaps your friend's Saber28 had a flatter cut jib than your boat has. Or, maybe your jib is either too full or blown out to perform well on the wind without benefit of the main assisting in achieving lift and balanced helm response.

Plenty of variables - hull design/dimensions, waterline length, sea state, trim, helmsmanship, and condition/type of sail.

YMMV.

Capt Dan G>E35II "Kunu"

 

[tenders]

My 32 also sails very nicely under genoa alone--with a bit of lee helm with lighter winds, but not much. It sails very poorly under main alone -- it gives symptoms like you've described.

It's also possible that your standing rigging is not well-adjusted. If the backstay is too loose you can get a lot of lee helm.

 

[simdim]

Folks,
Thank you for the help. Here are more details that I forgot to mention before - the jib we were using is 150 Genoa on the roller furling and our forestay was a bit loose. We had put more tension on the forestay and will try it again next weekend if weather cooperates (we are already on borrowed time here in Michigan). It sounds like we need to reduce the jib first and see how that alters things and then start practicing reefing on the main.

Cheers,

Simon

 

[treilley]

Odd. A 150, I would think with it's overlap, should produce less lee helm than a 100.

 

[SASSY]

Lee helm is often caused by too much sag in the fore stay, either because the mast is leaning too far forward, or the fore stay is too loose. On my 87 E-34 the mast head is supposed to be 5" behind the mast base at the deck. In order to find out if your mast is in column take your main haliard and add weight to the shackle and allow it to hang just off the deck, it should fall behind the mast, how far would be specific to your boat. Also check and see that it is not leaning to one side or the other. Your best bet is to loosen all your rigging and re-tune it to specs. Over tightening the Rig only puts more stress on the mast base. If you have any more questions please let me know.
Andy

 

[CaptDan]

Odd. A 150, I would think with it's overlap, should produce less lee helm than a 100.

Yes - but would it point above a low close reach?

My boat will sail nicely with the 135 rolled all the way out in <>10-14kts apparent, but its fuller cut is more effective on a reach without the main set.
In heavier winds, I can sail a bit higher with the jib rolled down to about 100%, and the jib leads moved a few feet forward.

The other thing worth mentioning is, a headstay shouldn't be too taught with a roller furler. Small gains in pointing ability might be mitigated by stress and potential fouling of the furler.

Again - YMMV.

Capt Dan G>E35II "Kunu"

 

[treilley]

My 150 all the way out will point almost as high as with the main. It has more of a racing cut to it. Not a sweeper but close. The mast on my boat is fairly far aft. The J measuremnt is nearly 16ft.

 

[Dave Hussey]

My 27 on 150 genny alone will do a broad reach, but not much closer to windward. Under main alone, it is almost unsailable, with lee helm. It is beautifull balanced with both sails set, and the gap tight.

 

[simdim]

Since e27 and e29 are sisters - it sounds like I should stay away from single sail configurations...

 

[simdim]

Possible answer

Folks,
We had discovered last night that our mast is raked about 10" forward - this might explain the lee helm. We will try to readjust it this week to the proper 9" aft and see if this makes a difference.

Cheers,

 

[Seth]

Rake

For sure you need to get that mast straight in the boat or slightly raked (as opposed to bent) aft.

A note of clarification on some earlier comments:

"Lee helm is often caused by too much sag in the fore stay, either because the mast is leaning too far forward, or the fore stay is too loose. On my 87 E-34 the mast head is supposed to be 5" behind the mast base at the deck. In order to find out if your mast is in column take your main haliard and add weight to the shackle and allow it to hang just off the deck, it should fall behind the mast, how far would be specific to your boat. Also check and see that it is not leaning to one side or the other. Your best bet is to loosen all your rigging and re-tune it to specs. Over tightening the Rig only puts more stress on the mast base. If you have any more questions please let me know."

Actually this is not the case, for several reasons:

Lee helm is almost entirely caused by having the CE of the sailplan fwd of the CG of the boat.. This can be caused by 2 primary things: Amount and direction of mast rake, and having on one sail (headsail in this case) flying-but as was said before there are many variables....

If the mast is not raked fwd, and you have a 150 up, there is still a fair amount of sail AFT of the CG, but if the rig is way fwd, this may not be the case, and you could have lee helm. With the mast in the right spot, and only a 100% or less headsail flying, you will certainly have some lee helm.

BUT-consider the things which can counteract lee helm: Heel-the more heel you have, the more weather helm you have. This is why the boat may have lee helm with just a small jib up in light air and flat water, but add 15 knots or more of breeze and some heel, and you may find the boat very well balanced.
Having weight forward of the keel will create some weather helm, and weight aft will do the opposite....

But I digress.

In light air, when a boat is starved for power and is not up to speed, we ADD sag to the headstay for several purposes: Easing the headstay, especially with a mainsail up, allows the rig to rake AFT, which will add a little weather helm (or at least counteract lee helm) and help the boat point higher. Also, a looser headstay adds power to the headsail (rounder entry), which in low speed conditions helps with speed AND pointing. A tight headstay (in light air) starves the headsail for power and REDUCES pointing and weather helm.


So, get the rig straight in the boat (or slightly aft), and try this again (but make sure the genoa cars are in the right spot-if they are too far fwd. the leech will be closed down, and air cannot "depart" the trailing edge of the sail, meaning it is not creating lift). My guess is that in under 5 knots of air you will have slight lee helm, but if you allow the speed to build up to 2 knots or so, you should have no trouble tacking. As the breeze comes up the boat will become more and more balanced.

Finally to put a point on this, consider when we were learning to sail, and the exercise was the steer without the rudder..With main and jib set you can adjust course with the sails. Ease the main and trim the jib harder and you will bear away, ease the jib and trim the main and you will head up..What you are doing is moving the CE of the sailplan fwd and aft of the CG in the keel (a pivot point)...

Nuff said?
S

 

[simdim]

Seth,
I had started to save your posts in a separate document - they are full blown tutorials - can not thank you enough!
I went out last night to see if I can adjust that rake but aborted that mission since main halyard is not running directly on the mast - it's sheave is offset aft and this will alter the measurement (since i do not know what is the value of the offset up top) My next plan of the attack is to insert something in the main sail grove attach a line to it and hoist it up - this will give me measurement from the trailing edge. Am I off base here?

Cheers,

 

[sleather]

My next plan of the attack is to insert something in the main sail grove attach a line to it and hoist it up - this will give me measurement from the trailing edge. Am I off base here?

Should work fine! Pick up a sail slug and some 1/8" cord and attach the halyard w/ a couple of zip-ties you should be able to get it "almost" to the top of the mast.

 

[Seth]

K.i.s.s.

In fact, the small offset to the side won't make much difference.

To keep it simple, just attach something heavy like a wrench to the main halyard shackle, and as long as there is no wind (or very little) and the water is flat, set the halyard so the bottom of the heavy item is just touching the deck. The distance from this point to the center of the mast (in the fore and aft plane) at deck level is the amount of aft rake-which is different from bend.

To check bend or prebend, while you have the halyard out like this, cleat the halyard off and grab the halyard and bring it forward so it touches the aft face of the mast at the gooseneck level. The max distance between the halyard and the back side of the mast as you look up the rig (think archery bow) will be the amount of bend (or prebend if you have no adjuster being used) existing in the current state of rig tune. For your boat I would not expect much bend-anything from under an inch to maybe 1-2" is conceivable, and not really important unless you are having trouble with your mainsail being too flat or too full. If you feel it is too full, and observe the bend as nill, try inducing some bend by easing the aft lowers and taking up on the fwd lowers. If you feel the sail is too flat, and see you now have an inch or whatever of bend, try to remove the bend in the opposite fashion..

But getting back to the RAKE....
I would be Ok with anything from 1-6". If the boat sails well, leave it alone.

If you have no rake or less than a couple of inches, go ahead and ease the headstay an inch and take up the same amount on the backstay, and go sailing. In no case do you want fwd rake (or bend for that matter).

You can tell things are good when sailing upwind in about 8-10 knots of breeze (if you have a genoa of 130% or bigger), maybe 10-14 knots if you only have a working jib, and with both sails correctly trimmed, let go of the wheel/tiller. You should have been able to steer with one hand and not much deflection of the wheel/tiller. As you let go of the wheel/tiller the boat should slowly round up into the wind and eventually tack. If the boat goes straight or bears away, add some more rake. If it snaps head to wind right away, you have too much aft rake and should remove a little.

Of course, this assumes you have the sails correctly trimmed, and have the weight on the boat in normal positions.

If you have excessive weight in the bow, you will see more weather helm, and the reverse if you have a ton of junk in the cockpit lockers.

Have a ball!

S

 

[Randy Rutledge]

A 1.75 of Jose works fine for the weight, the handle and all. I sailed my 29T at Mobile Bay in 20 knots of wind and the 110 only and she handled great and hit over 7 knots in three foot chop. Great sailing.
Lee helm is not a characteristic of the 29 the change to the tall was to move the center of force forward and reduce weather helm. The boom was shortened 2 feet and the mast is 1’ 8” taller. There is still the tendency to have weather helm at around 14 knots of wind.

I just added rake to my rig to try to get her pointing higher. Will a vang help make her point higher? I haven’t installed the vang since I came back form Mobile due to the interference with opening the hatch behind the mast.

 

[Seth]

Rake

Adding some more rake should help you point a bit in light air, but this is because aft rake increases weather helm (the 2 are tied together)-so the "right" amount of rake allows the boat to point well without excessive helm when it is breezy (and you have the right sail combo up)..

A vang will not directly help you point higher-other than by providing more control over the overall angle of entry of the mainsail-if the boom cannot be controlled (as with a vang) it will rise up as you ease the sheet, which has the effect of allowing the top half of the mainsail to be relatively more eased than the bottom half-meaning the bottom may be trimmed correctly and the top could be luffing-which in turn can hurt your pointing.
Conversely, too much vang will "overtrim" the top of the mainsail, increasing weather helm excessively, and while the boat will seem to want to point higher, you will be dragging too much rudder and heeling too much, so the result is a net loss.

So, the vang is not really a tool to help with pointing per se, but a tool to help control the shape of the sail-specifically the angle of attack.


S

 

[Randy Rutledge]

Thanks Seth. I get in a pointing contest with a Catalina 25 every race and he has edged me out this season where at times I have out pointed him. I know 4400 pounds to my 8500 pounds and light air make a difference. I hope the added rake will help with this battle.

Thanks again.