Beneteau 361 (and other models) Mast Howling in the Wind — Problem discovered and need help solving...

[Harry Mathias]

Like many people owning Beneteau's when the wind blows hard my in-mast-furling main howls with a rhythmic cadence. I've tried to solve this before and I've read the public apology of the Beneteau mast sub-contractor saying something about "the slot in the main causes whistling", but prior to this I have never found the real cause of that howling.

On a very windy day at my slip I happened to be talking to someone with my hand on the boom and discovered that the boom was vibrating. Further examination indicated that it was the boom lift line that was twanging like a bass fiddle and vibrating the boom. If I stopped the boom lift line from vibrating in the wind then the boom was silent and this was repeatable any number of times.

The problem is Beneteau provided, as a boom lift line, a quarter inch in diameter non-stretch Hi tech line which is as tight as a guitar string and vibrates in the wind. I would much rather have that lift line be a heavier gauge so it could be used as an emergency halyard or a Lifeline block and tackle to winch someone back aboard if they fell overboard. And I don't really need a boom lift since I have a boom Vang that already supports the boom.

Ok, now here is my problem: I want to use the existing boom lift line as a messenger to pull a heavier gauge line, (say 11mm) through the mast sheave, but the line is totally stuck! It appears to be jammed in the sheave at the top of the mast and it won't move one way or the other. Is there anyone out there who has had any success replacing this line? I can't even tell where it's attached except it goes to the top of the mast. I really don't want to climb my mast now because I have to replace my halliards first. I don't trust them in their current age and condition.

Thanks for reading all this!
Harry

 

[cymeyer]

Like many people owning Beneteau's when the wind blows hard my in-mast-furling main howls with a rhythmic cadence. I've tried to solve this before and I've read the public apology of the Beneteau mast sub-contractor saying something about "the slot in the main causes whistling", but prior to this I have never found the real cause of that howling.

On a very windy day at my slip I happened to be talking to someone with my hand on the boom and discovered that the boom was vibrating. Further examination indicated that it was the boom lift line that was twanging like a bass fiddle and vibrating the boom. If I stopped the boom lift line from vibrating in the wind then the boom was silent and this was repeatable any number of times.

The problem is Beneteau provided, as a boom lift line, a quarter inch in diameter non-stretch Hi tech line which is as tight as a guitar string and vibrates in the wind. I would much rather have that lift line be a heavier gauge so it could be used as an emergency halyard or a Lifeline block and tackle to winch someone back aboard if they fell overboard. And I don't really need a boom lift since I have a boom Vang that already supports the boom.

Ok, now here is my problem: I want to use the existing boom lift line as a messenger to pull a heavier gauge line, (say 11mm) through the mast sheave, but the line is totally stuck! It appears to be jammed in the sheave at the top of the mast and it won't move one way or the other. Is there anyone out there who has had any success replacing this line? I can't even tell where it's attached except it goes to the top of the mast. I really don't want to climb my mast now because I have to replace my halliards first. I don't trust them in their current age and condition.

Thanks for reading all this!
Harry

Hi Harry,

we had the same issue with our Beneteau 321 after 15 years. We decided to step the mast and replace the lights etc at the same time. With ours, the steave at the top of the mast was worn flat and would not turn. The line was wedged in there pretty good. I suspect you can go up the mast, but this was the first time we had ever taken the mast down so it was a good time to look at its condition.

We too had a solid vang but used the topping lift to get the right boom angle for our in mast furler.

Good luck!

Chris

 

[Harry Mathias]

Hi Chris,

Thanks for your answers! I have 3 questions: 1. Did you install a larger size line on your topping lift? Did that help with my howl? 2. Was your vang spring strong enough to lift your boom alone when slacked? 3. Is the factory-installed topping lift threaded through a mast main sheave then led internally down to the cleat? Or, is it threaded through an external pulley like the spinnaker halyard is?

 

[Mechone]

Your spring may have lost some of its lift, as is available from US spars P/N 1800(medium vang) I believe, it gives you the measurement or 1781 (large vang) , with that said I machined a delrin spacer about 2 inches put it in then the spring lifting the boom . I don't really use the topping lift which is loose and no noise

 

[Harry Mathias]

Hi Mechone,

Thank you for that valuable information. Absolutely, it's true that mechanical springs continually lose strength with use. I could machine a spacer also. You mentioned 2" as the length, do you happen to recall what the diameter of the spacer was?

 

[cymeyer]

Hi Chris,

Thanks for your answers! I have 3 questions: 1. Did you install a larger size line on your topping lift? Did that help with my howl? 2. Was your vang spring strong enough to lift your boom alone when slacked? 3. Is the factory-installed topping lift threaded through a mast main sheave then led internally down to the cleat? Or, is it threaded through an external pulley like the spinnaker halyard is?

Hi Harry,

1. I followed the manual and installed the line specified. Seemed to be slightly larger than what was installed. Yes, it helped with the vibration we had along with the howling sound.
2. Vang is strong enough to support the boom but i like the boom higher when sailing to make the main furling easier.
3. On our 321, the topping lift sheave was at the top of the mast. It is a dual track sheave and the pin that holds it just pushed into place. I think the sun had an impact on that sheave since I seem to recall it was exposed. Ours was not threaded thru a sheave on the side of the mast. On the top. It was a 2000 model 321.

You should check the manual and see if you can order the sheave before you go up the mast.

Chris

 

[Harry Mathias]

Thank you Chris Excellent and very useful information.
I really appreciate this.

Harry

 

[Jentine]

The harmonic vibration you describe is caused by a tight topping lift. Either loosen the topping lift or loosen the traveler. Both will have the same effect of upsetting the harmonic.

 

[cymeyer]

The harmonic vibration you describe is caused by a tight topping lift. Either loosen the topping lift or loosen the traveler. Both will have the same effect of upsetting the harmonic.

Jentine, you are right but Harry has an issue that the topping lift line is stuck. My guess is it is either wedged between the sheave and the mast or the sheave is worn off (like ours was) and it was otherwise jammed. Needs to have someone go up the mast or take the mast down.

 

[Harry Mathias]

Exactly (thank you both for the wise advice). I was on the boat today trying to relieve the topping lift pressure with the boom vang. I discovered that the boom vang has a total adjustment range of about 4 inches, tight to slack. The spring must be metal-fatigued and so have a limited adjustment range left. Don't know how long the previous owner kept it compressed, but the adjusting line is chafed in one spot, so I would say always. So off to the US Spars website to order a new replacement spring. The issue is that the dimensions on my vang do not match either of their 3 sizes, and my serial number is "0". I probably have a prototype vang.

Thanks for listening...
Harry

 

[cymeyer]

Exactly (thank you both for the wise advice). I was on the boat today trying to relieve the topping lift pressure with the boom vang. I discovered that the boom vang has a total adjustment range of about 4 inches, tight to slack. The spring must be metal-fatigued and so have a limited adjustment range left. Don't know how long the previous owner kept it compressed, but the adjusting line is chafed in one spot, so I would say always. So off to the US Spars website to order a new replacement spring. The issue is that the dimensions on my vang do not match either of their 3 sizes, and my serial number is "0". I probably have a prototype vang.

Thanks for listening...
Harry

Excellent, Harry!
Hope you can replace the topping lift line and sheave at the top of the mast next time your mast comes down.
Chris

 

[Harry Mathias]

Thanks, Chris I am hoping to do it without taking down the mast. Being in CA we keep the boat in the water year round.