Overwhelming weather helm when close hauled in strong winds

Zen Zero

Zen Zero

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We had a lovely 5 day cruise in the Southern Tyrrhenian / Gulf of Naples and encountered some strong winds (F4 to 6) for the first time since a re-rig. Now I've noticed a weather helm with the old rig but nothing like this. Close hauled in 20+kt of wind with a reef in the main and the genoa about half furled as soon as the boat gets moving, she heads upwind, and slows; no amount of fighting with the helm can stop this. As soon as she's slowed a little the rudder starts to work again and she's off, getting up to about 6.5 kt then heading upwind again. The whole process can take about 5 mins.

30 nm and 9 hours of this is very tiring!

We weren't heeled all that much, which made me think I didn't have too much sail up, and the sheets were not completely tight since we had more than enough wind. We could have got a better heading with tighter sheets but with an inexperienced young crew I didn't want to take things to extremes.

Is this called broaching? Any ideas how to fix it?

Thanks
 
The mast may be leaning to far back after the re-rig which I understand will cause her to luff up. With the head sail area small (1/2 reefed genoa) compared to the single reef main this would have added to the imbalance as the main will naturally want to drive the boat to windward.

It reads as if the mast is not set up correctly and mainsail was accentuating the boats balance to turn into the wind.

What to do about it? Obviously have the rigging checked for correct tuning of the mast first. If sailing like this as others have said, another reef in the main and more headsail area should counter the weather helm tendency.
 
Sounds like too much main. You may have felt that easing the main should have reduced the weather helm but, in fact, you needed to flatten the main and kill some of its drive.
Many people oversheet their main in the belief that as they haul it to windward or crank in the mainsheet they are increasing their pointing ability but are actually reducing its effectiveness. You may have been inadvertantly increasing the drive from your main by slacking sheets or letting the boom down the track. This would actually lead to weather helm if at the same time you had too little headsail drive.
 
If it's a big genoa you can sometimes kill a bit of the weather helm and avoid reefing by sheeting the genoa in hard and easing the main. The genoa will backwind the main reduce the power from the mainsail. If you were racing and on a short beat this iused to be quite common with the big genoas of the 70's era boats. The best way varies from boat to boat, never mind model to model though.
 
The variable is the re-rigging of the boat, so I'd look to that first.

Is the mast rake correct? Is the pre-bend correct? Is the middle of the mast falling off to leeward? These will all have a bearing on balance.

The other often overlooked cause of weather helm is a closed leech on the main. Close hauled in heavy airs, just opening the leech a touch can eliminate even quite severe weather helm. Again, the shape of the leech could have been altered by differences in mast bend when the rig was re-tensioned.
 
Zen Zero said:
We had a lovely 5 day cruise in the Southern Tyrrhenian / Gulf of Naples and encountered some strong winds (F4 to 6) for the first time since a re-rig. Now I've noticed a weather helm with the old rig but nothing like this. Close hauled in 20+kt of wind with a reef in the main and the genoa about half furled as soon as the boat gets moving, she heads upwind, and slows; no amount of fighting with the helm can stop this. As soon as she's slowed a little the rudder starts to work again and she's off, getting up to about 6.5 kt then heading upwind again. The whole process can take about 5 mins.

30 nm and 9 hours of this is very tiring!

We weren't heeled all that much, which made me think I didn't have too much sail up, and the sheets were not completely tight since we had more than enough wind. We could have got a better heading with tighter sheets but with an inexperienced young crew I didn't want to take things to extremes.

Is this called broaching? Any ideas how to fix it?

Thanks
Click to expand...

How much 4 and how much 6?

If all the latter I can understand it more easily.
Just over 3Kts average with F4-6??

If you only have on the heavy side of 20 (not near 30) I'd have allowed a little more fore-sail, to counter-act the effect. the other alternative - with appropriate sea room is to sail more freely - and use the higher speed to offset more distance? It certainly feels better than super close hauled fighting sails , boat & wind. How much kicker, out haul , cunningham were you using? Do you have a flattening reef near the outhaul??
That kind of hard work sounds worth avoiding, but you will need to find some similar weather to try different things out...
 
Yes, as others have said, too much main / unbalanced rig.

A deep / full length skeg in front of the rudder can cause the rudder to stall; the answer is to keep water flowing over the rudder if possible, but this can be difficult !

I had a Carter 30 with a full length skeg which stalled and broached like a ***** no matter what we - experienced racing boat types - tried !

I hate to say it, but if anticipating this snag an engine fired up giving propwash over the rudder is a great help.
 
Flatten the main as much as you can. Halyard tight so the max draught is further forward (I think LONG_KEELER has alluding to that already). Outhaul on hard.

Excessive rake is maybe it, but you should find that would let the top of the leech twist off more, which would reduce heel and should mitigate the weather helm.

Puzzled by what you were saying about it increasing with boat speed. Obviously boat speed increases the apparent wind, but perhaps there is something in the hull shape that caused it as the bow & stern waves build up, but if you've had the boat for a while and not seen it before then I'm puzzled.
 
Thanks everyone! Interesting ideas! I need to spend more time sailing!

There's no skeg, it's a spade rudder.

The genoa is huge (and yet the boat was built in the 90s)! which is why I tend to furl it in strong winds. Two summers ago I brought her back from Corsica to Rome with just the genoa because the main halyard had jammed at the masthead and she handled beautifully, though the winds then were not strong. The main, by comparison is a bikini! We got 2kt out of the main before we unfurled the genoa and got 6kt.

Outhaul and reefing lines are as yet without mechanical assistance (though this is due to change with a new coachroof winch waiting to be installed) so flattening the main is a bit of an approximate affair.

Next time I'll try with more headsail.

The reason I think speed has something to do with it is the underwater profile and in particular the bulb which is a rather un-aquadynamic block of lead slabs. Heeled and at speed, I'm sure this presents a significant eccentric drag on the boat.

Another thought I had is that upwind, you're sucked rather than blown along so having too much headsail might suck you round to weather ... (this is probably ****). There's also the fact that, tightly sheeted, almost half of the genoa is aft of the mast.

I left the boat in Salerno, but I'll have a chance to test these ideas on Saturday.

Thanks
 
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