Mast is buzzing

[Driftwoods]

I recently got new running rigging and had the mast and standing rigging "tuned" (a little inversion and the boat gad sat for several years before I got it). Everything works so much better now, the main sail rolls up in the boom smooth as butter. I'd be happy but now there is a vibrating, buzzing like sound every time the wind gets above more than a couple of knots. Something's gotta be moving and bouncing in there now and it's really annoying, especially in the middle if the night.

Any ideas what it could be and the fix?

[jeremiason]

My topping lift signs when the wind gets up around 15kts when I have it really tight.

Check you other running rigging and ease it a bit. See if that helps

[S/V Antares]

When it happens can you isolate the sound to the main sail? Is it in mast furling? You should be able to "Feel" the vibrations on the specific rigging.

Hood seafurls used to howl in the wind. The solution was to hoist a tape ou the mainsail slot.

My headsail roller furling starts to vibrate in high wind if the sheets are loose.

[htraudes]

Usually standing rigging vibrating in wind. Not running rigging. You mention your standing rigging had been tuned. Means tightened? High up means hard to diagnose. Does it sound like clear harmonic? Wind along free wire. Sounds more like high pitch fast drumming? Steel cable rubbing on mast. Already discussed with shop that did the tuning?

[Driftwoods]

Thanks guys....

It is a in boom furling system (profurl) and whatever it is sounds like it runs nearly the length of the mast. The standing rigging was tightened but not more than a couple of turns on a turnbuckle or two - didn't seem like a lot to me anyway.

It's not high pitch, sounds more like a buzzing insect than anything else and just a couple knots of wind will fire it right up. I tried to "feel" where it could be coming from but it really feels like it's inside the mast itself; weird right? Rain has stopped, next time it happens I'll go from steel cable to cable and see if there's anything to notice there.

Calling the rigger is probably the best solution but it'll probably be 2 weekes before he can get to me.

[Vasco]

I've heard that the slot the sail fits into (it's offset from the mast) on a Profurl can cause noise.

[scuba0_1]

go into the boat and put your ear on the mast. is it humming. if so loosen your main see if it is still doing it. loosen your boom Vang or your toping lift a little. if its still doing it loosen your main a little. you have something to tight making a vibration. Mine was doing that with just the main out haul to tight. when you loosen your lines the lifting arm on the cleat should not be extremely hard to lift and pop when you do.

[scuba0_1]

when your sailing do you see some slack in the shrouds the sail is on?

[hellosailor]

Do call the rigger. Even if he can't come back, he can tell you to back off a turnbuckle, say, mark it and back it off two turns. That way it is easy to keep track of what you've done, to undo it, or to try the other way. Something has just hit a sweet spot for resonance, and the odds are if you patiently check each fitting, something just has to be tweaked a bit.

Or, you try to get your boat a spot on late night tv and ask folks to sing along.

[Driftwoods]

The winds have died, as soon as it starts back up, I'll be listening. I do see some slack in the shrouds on the side the sail is on - about as much as I was expecting.

It could be too tight after the adjustment. Call going into the rigger ASAP. Thanks guys!

[Kenomac]

Ours hums all the time when the wind picks up. It's been tuned twice by two experts... no change. Now we are just used to it... the boat must be happy, she's singing.

[Zanshin]

I have in-mast furling, and if I have the vang tight and the boom midships in winds I get a really loud humming that is surprisingly loud and uncomfortable. I find that the sound disappears when I tie the boom off to the side I built a snap-shackled line to tie the boom to a stay when at anchor and the whole system is quite quiet now.

[xeon_tsd]

+1 to Tom My boom sings because of the topping lift. Hopefully my new hard vang will solve that problem.

[Ukeluthier]

Any stretched wire has a natural resonant frequency that is dependent on the length, tension and mass of the wire (think musical instrument strings). The same is true of a beam like a mast.

If that resonance is "excited" (that's a physics term... nothing naughty about it ) by wind of a particular direction and/or strength, the wire will vibrate strongly at the resonant frequency. If the wire and/or mast are coupled to the deck, the deck may well act as a soundboard and reinforce the volume of the hum.

Altering the length, tension or mass of the wire will change the pitch (frequency) of the resonance, but it likely will still occur under the right conditions.

Just think of your boat as a big aeolian harp and be happy!