onesea
Well-Known Member
There's no fracking going on in the area is there? :ambivalence:
"Noisy" topping lift
- Thread starter DannyB
- Start date
europe172
Well-Known Member
A cylindrical object is libel to turbulence shedding, a wind passing over a line will at all times shed turbulence, this is caused by flow attaching then separating on the line, when the frequency of this attachment hits the resonance frequency of the line the amplitude of the vibration will increase, at some point these forces balance and a steady note is produced (IMHO)
PetiteFleur
Well-Known Member
Get rid of the topping lift and fit a Barton Boom Strut. They are not noisy!
alan_d
Well-Known Member
As others have already pointed out, the OP was asking what caused the vibration - he already knew how to stop it (without spending money).
michael_w
Well-Known Member
nimbusgb
Well-Known Member
Takes very little energy to get resonance going and even if it is dead calm at deck level there could well be movement at mast head height. Wind gradient in the boundary layer is most pronounced at very low windspeeds.
DJE
Well-Known Member
jbweston
Well-Known Member
Yeah it's an irritation. I like utter silence from banging, humming and jangling. I find the problem is that I can stop it by tightening or slackening the topping lift or mainsheet but it starts again if the wind increases or decreases or the boast swings at anchor.
One solution is to put something on the topping lift that damps vibration. A clothes peg sometimes does it.