Question
Member Arne asked:
When I tuned the rig on my OVNI, it started vibrating/resonating in the wind when on anchor. It starts at fairly low wind speeds, and I can’t tell exactly where in the rig it is. I can sometimes feel some vibrations in the shrouds. It sounds like a motorboat approaching a couple hundred meters away, so not super loud, but pretty annoying still. Is this a problem you have experienced or have any tips on a remedy?
Answer
Rigging vibration is both common and hard to diagnose, and even harder to stop completely. A few things based on my own experience over the years that may help:
- Although it does happen, vibration and hum are rarely caused by wire standing rigging. The wire may vibrate, but that’s unlikely to be the source.
- Rope rigging is likely to be the original source. Places to look include:
- Topping lift, probably the most common source.
- Rope running backstays. We loved the change to HM rope on our McCurdy and Rhodes 56, but there are always tradeoffs. The wire never hummed and the rope often did.
- Rope halyards that are not in use and set up hard can often be the source.
There are probably more proposed solutions to the rigging vibration problem than there are sailors, and few, if any, work every time. Here are a few that have helped us, but none are a panacea:
- Change the tension on the offending halyard or stay.
- If it’s the topping lift, get rid of the damned thing.
- If you must keep the topping lift, attach a piece of shock cord. Might not fix it, but it’s a good hack.
- If it is the wire rigging, install a backstay adjuster so you can slack the rig off at anchor. It’s a great upgrade for a whole bunch of reasons.
- Stringing a piece of shock cord from a tight and humming runner to a shroud and then varying the tension and position until it stops.
Comments
That’s all I got. Anyone else have any bright ideas on how to stop rigging hum?
Note, we have already covered rig pumping, which is a different problem.
I used to own a 36ft Beneteau and when the the breeze caused a harmonic frequency vibration in the rig when moored, I would ease the tension on the mainsheet and that nearly always fixed it.
I replaced the backstays on my Abbott 36 with Amsteel which would vibrate in the breeze – I used a trick from my Dad’s violin, and put a mute on the string – meaning I tied a line around the bottom of the backstay that absorbed the vibration before it got going, and stopped it entirely.
I’ve had humming or vibrations like that many times, never while sailing. Most times it’s been the topping lift. Let go a bit on the sheet to reduce tension and it’s gone. Some times it’s been the head stay. That has a furler alu extrusion on it. It can occasionally move quite violently. Rotate it a bit and vibration is gone, until the wind direction changes… Putting an unused halyard in spirals around much of it will help more permanently.
We experience a very loud noise which started as a low hum then built up to a sound like a ships fog-horn, which vibrated through the whole boat (also an Ovni). Anchored off a deserted island, with an abandoned lighthouse, made the ghostly sound even more unsettling. I had tried everything suggested by others above before it suddenly dawned on me. The Spinnaker Pole was still attached vertically on the mast instead of being returned to it’s normal home, flat on-deck, in the chocks. The space between the pole and the mast made a very effective, loud, low frequency whistle. Presumably wind and tides had conspired to move the boat in and out of whistle mode. Quickly solved.