Topping lift "hum"

[mikeandrebecca]

Hi all

Has anyone else experienced a hum (vibration) created by the topping lift at anchor or at the dock? I thought it might have been created by the shackle which attached the topping lift to the boom so today I removed the shackle and reattached the line with a bowline. Shortly after that the hum returned. It is intermittent and can be partially eliminated by easing the topping lift. I would like to know if this is just us or if anyone else has experienced this.

Mike

[SecondWind]

All halyards hum if drawn tight.

[mikeandrebecca]

OK, please forgive me as I am new to the whole boating thing, but the topping lift is kept tight when not sailing, right (unless we have cool boom gallows like in the other thread). Is there a solution? It is QUITE pronounced and annoying. Do you experience this too?

[SecondWind]

There is no solution unless you build a boom gallows and relieve the tension on the line, or use a solid boom-vang to hold the boom up. Think "violin string". Any vertical line drawn tight will hum (Halyards, lady jacks, etc.) and any too loose will clank against the mast. It is the music of a sailing vessel.

[thinwater]

I always disagree Seriously, this has a free fix.

I have never had a hum problem, but I think that is because I always create a triangle for the boom and don't keep the TL that tight.

I have a ~ 5-foot length of 1/4 line clipped to the end of the boom. When sailing, both ends are clipped to the boom, out of the way. When I want to secure the boom I loop one end around a deck cleat the PO placed aft and inboard of the secondary winch ( but a line to a stanchion or the end of the traveler track would do fine). With only the slack out of the main sheet, I then pull the traveler to the center until it is tight enough, which isn't all that tight. The boom ends up a few feet to one side, which is best on the 32 because of the steps.

The boom doesn't wiggle, the TL is not under great tension, and there is no hum. I did the same thing on my Stiletto for many years.

[mikeandrebecca]

I will try that Drew. Thanks.

[Page 83]

Halyards that have stretched out can have an oval cross section that is more conducive to singing in a breeze. they are also easier to mute by twisting a dozen turns on them so that the don't look like a continuous airfoil to the breeze. Different sections will fly in different directions and cancel the harmonic. OR they will sing in three part harmony.

what gets really wierd is when the various openings in the mast want to act like a flute. A contra bass flute. With nasal drip.

[thinwater]

I posted a few pictures that show the brace line that secures my boom.

http://sail-delmarva.blogspot.com/2010/05/scraps.html

[Katlin]

Try running the topping lift line through the middle of a tennis ball (you select the color). Acts as a damper.

John Sawyer
Katlin MV34 (but a former sailor)

[mikeandrebecca]

Thanks John. I will try that.