singing rigging - SailNet Community
Reply
 
LinkBack Thread Tools
post #1 of 11 Old 01-14-2012 Thread Starter
dbb
Junior Member
 
Join Date: Jan 2012
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
singing rigging

I just bought a 20' Goman Express that is named the "Bailero". which is the name of a French folk song. There is a passage in the song done by a single flute which sounds almost like the whistling that my boat produces when enough wind is blowing across the mast and rigging. Multiable notes
at the same time fluctuating with wind velocity.

I paid for a years moorage at a local campground/rv/marina resort and moved the boat in last Wednesday, this morning the manager phoned and complained that my boat made a bunch of noise that she described as haunting. She said when the wind got up it was very loud and could be heard from all over the resort.

I have no idea what is making the noise but it sounds like I'm going to have to do something about it or find a new place to keep her.

Anyone ran into this problem before? Any suggestions?
dbb is offline  
Sponsored Links
Advertisement
 
post #2 of 11 Old 01-14-2012
Senior Member
 
Siamese's Avatar
 
Join Date: May 2007
Posts: 1,036
Thanks: 3
Thanked 28 Times in 27 Posts
Rep Power: 13
 
It's haunted.

Heck, I don't know. There's a 56 foot ketch on my dock that sings with every moderate breeze. I wish he'd tow it away and scuttle it.
Siamese is offline  
post #3 of 11 Old 01-14-2012
Member
 
VK540's Avatar
 
Join Date: May 2011
Location: Blind River Ontario, Canada
Posts: 57
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
 
If your rigging is tuned properly and it still persists than perhaps this website can help?

The Stay Quiet - Vibration Dampening

"BLISS II"
1977 38 foot C&C Mark 1
Hull #92
Sailing the Exuma Islands, Bahamas
VK540 is offline  
 
post #4 of 11 Old 01-15-2012
Bristol 45.5 - AiniA
 
Join Date: May 2006
Posts: 4,526
Thanks: 5
Thanked 124 Times in 112 Posts
Rep Power: 14
 
Does your mast have a slot that the mainsail slides up? If so, the sound could be coming when the wind flows across the slot. Happens with my Bristol at times (wind from quarter). The boat actually came with a 'flute-stopper', the sailmaker's name for it, not mine. It is strip of stiff sailcloth about 6" wide with a large plastic 'button' pop-riveted on about 3 feet. You hoist it up the mast with the main halyard with the cloth inside the mast and the buttons riding up the outside. If your mast slot is the problem you could make a smaller version that would fit your mast.

After the refit we have decided to sell Ainia. We want something smaller that would be could for the light summer winds of Lake Ontario, although we plan to spend at least a couple of winters in the Caribbean before heading north.
killarney_sailor is offline  
post #5 of 11 Old 01-15-2012
Senior Member
 
Faster's Avatar
 
Join Date: Sep 2005
Location: New Westminster, BC
Posts: 19,488
Thanks: 160
Thanked 587 Times in 558 Posts
Rep Power: 16
     
We have a Dyneema backstay that thrums loudly when fully tensioned in a breeze. Easing tension quietens it. Perhaps you might check rig tension.... if you have an adjustable backstay ensure it's slackened at the dock. Your boat will thank you for it.

Ron

1984 Fast/Nicholson 345 "FastForward"

".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
Faster is offline  
post #6 of 11 Old 01-15-2012 Thread Starter
dbb
Junior Member
 
Join Date: Jan 2012
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
thanks for the tips guys,

I know the previous owner raced her and the shrouds feel singing tight
(he, he)
so until I can get a loo guage to set them I'll try just loosening them a few turns. Evenly of course.
dbb is offline  
post #7 of 11 Old 01-16-2012
Senior Member
 
Liquorice's Avatar
 
Join Date: Nov 2007
Location: Alberta, Canada
Posts: 170
Thanks: 0
Thanked 3 Times in 3 Posts
Rep Power: 12
 
Try turning the boat around - see if that makes any difference!

sam :-)
Just because you're paranoid ...doesn't mean they're not after you!
Liquorice is offline  
post #8 of 11 Old 01-16-2012
Senior Member
 
Join Date: Feb 2010
Location: Narragansett Bay
Posts: 19,466
Thanks: 82
Thanked 548 Times in 525 Posts
Rep Power: 11
   
Oddly enough, my rig resonates loudly at anchor (bow into wind) if the boom is cranked down too hard. I take a bit of tension off the mainsheet and it stops completely.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Jeanneau 54DS

In the harsh marine environment, something is always in need of repair. Margaritas fix everything.
Minnewaska is offline  
post #9 of 11 Old 01-16-2012
Senior Member
 
RichH's Avatar
 
Join Date: Jul 2000
Location: Pennsylvania
Posts: 5,021
Thanks: 54
Thanked 326 Times in 310 Posts
Rep Power: 21
   
What is going on is whats known as an 'induced harmonic vibration response' in the rigging or mast system. This is what makes a violin or cello, etc. string vibrate. The Rigging or a mast (or combo of both) is being 'excited' by wind conditions flowing over or around the rigging/mast ... and is producing a sound that is 'harmonic' to the 'energy, etc. conditions' of the wind.

Such vibrations are dependent on two things: rig tension and the mass of the wire/rigging. If you change the tension or the mass (by simply 'hanging' some weight in the rigging) you will either change the 'note being played' or will arrive at a vibratory condition where there is no harmonic response; Rx: change the tension or hang a weight onto the 'wire thats vibrating'.
For a mast that is 'pumping' or radically vibrating, add the proper 'prebend' to the mast by correct rig tension - typically 3/4" forward bow to a single spreader rig or 3/4" forward bow per each spreader set on a multi spreader rig --- the mast manufacturers all have specific 'pre-bend' specifications on each mast section offered. Using a mast without 'prebend' is an open invitation to 'mast pumping' / radical induced harmonic vibrations (and your mainsail was cut to match that expected 'pre-bend'; without that pre-bend the mainsail will always be slightly 'powered-up'). Adding 'pre-bend' changes the 'apparent stiffness' of the mast and changes the 'natural frequency' at which the mast vibrates.

To find the part of the rig that is the 'culprit', when the 'note is being played' simple go to each component and with your hand & 'feel' the part that is 'buzzing' and affect the correction (tension or weight change). If you cant 'feel' the errant vibration, borrow a vibratory tuning gage from a stringed instrument musician and when the gage shows a B#, etc. ... thats the wire that needs 're-tuning' --- just re-tension up or down until the harmonic ceases (but may issue another 'note' when the conditions are correct for that new tension).
In cases of severe 'harmonic response' (mast pumping) where the mast is actively and noticeably 'rocking back and forth' (can be 'violent' rocking/bowing), especially in high wind conditions ... this must be quickly corrected as such high energy harmonic vibrations can soon cause mast / rigging FAILURE (the classic example of destruction due to 'harmonics' is the failure of the Tacoma Narrows bridge in the late 1930s). The quickest emergency remedy is to pull the wire or mast with a rope attached or tied to it and pulled at a perpendicular angle and led to a winch, etc.

However if you have an in-mast furler (acting like a 'flute' with air flowing across the slot and producing the 'note') then the only way to solve this is cover the 'slot' by any means possible - raising a 'twisted or 3 stand 'rope' in very close proximity to the 'throat of the slot', etc. ... anything to disturb the air flow 'across' the open slot, or closing the slot.

:-)

Last edited by RichH; 01-16-2012 at 03:31 PM.
RichH is offline  
post #10 of 11 Old 01-19-2012
Semper Fidelis
 
Join Date: Apr 2009
Location: Pensacola, FL
Posts: 26
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
I second RichH's post. Hoist a piece of line up the inside of the boltrope track roughly the same diameter as the boltrope on your mains'l to silence the "flute-ness" of your mast. If that doesn't work, try tieing a small piece of line to the different wires of your standing rigging. When the boat sings, pull the lines until you find the culprit. Tugging on the line will tention the wire and dampen the resonance.

-Matt

-S/V Far Niente


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
mxracer19 is offline  
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Singing backstay n0w0rries Gear & Maintenance 2 05-17-2011 10:19 AM
Rigging gerryB37 Gear & Maintenance 8 11-16-2010 08:04 PM
Junk/Sampan rigging vs. Cat rigging ClaireFAISE General Discussion (sailing related) 10 09-21-2010 08:59 PM
Caffari singing in the rain after historic voyage (Times Online) NewsReader News Feeds 0 05-21-2006 07:15 PM
How to stop a singing mast? e31 Gear & Maintenance 10 09-20-2004 04:52 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome