Anchoring Flexing Noises in Windy Conditions

[Pgtjs]

Hi there fellow C350 Owners,

I have a problem when I am anchored in windy weather - during the night I sometimes hear a loud "thud/bang" in the front cabin which sounds like the mast is flexing or something else is perhaps causing the hull to flex. I let off the tension on the halyards and the jib sheets and that seems to mitigate the frequency of the bangs which are exacerbated by the drum effect of being in the contained cabin. From outside on the foredeck, the sound is hardly noticeable. A couple of weeks ago I was anchored when a big weather shift came through after midnight. Winds were up to 25 knots. It seems to flex about every 30-60 minutes mostly when gusting. When it is calm there is no such banging noise. So far as I can tell it is not the roller furling in the mast but perhaps could be the headstay roller furling. I had a rigger up the mast and he told me the rig tensions are all ok. The noise does not come from the anchor chain - I had about 150-160' out in 40' depth of water on this occasion but that does not seem to be a factor as the problem has occurred ever since the boat was new and I have anchored in all kinds of depths and currents and scopes depending upon the winds..

By the way, one possibility is that my windlass is flexing on it's base. I have a heavy snubber rope line attached by a loop to the windlass and a hook attached to the chain about a foot above the water. The rope takes up the stress and the chain is loose and not transmitting any stress to the gypsy.

Does any one have any ideas as to how to stop the flexing or whatever is causing the bangs? Or what else could be the source of the problem?



Cheers, Geoff C350 #392, Blaine, WA.

[johnjab]

I was getting a thud and found it was the anchor roller sliding 1/4 of an inch on a windy night. I now put a wooden wedge in that space and it stopped the noise. I also use a snubber line, but I attach it to the cleat in the anchor locker since this takes the strain off the windlass.

John Jablonski
C350 #156

[R.B.]

I found the loud clunking to be the groove in the anchor roller. As the wind pushed the boat to one side the rode would pull out of the roller groove and up to the edge of the roller. Then when the boat swung the other way it would clunk back into the groove. It would be very loud if the weather was especially windy. I added some heavy chaffing protection to the rode by the roller (old hose from a fire department). This cushioned the clunking.

[jbd3]

Anchor line for me as well. I place a chafing guard over the nylon part of the rode to keep it from abrading on the bolt heads right at the end of the anchor support and to keep it from popping into or out of the groove

[jking]

Hi,
If its not the anchor, I bet its the roller furling. I had this happen and tightening the main halyard stops it.
Jan

[John Z]

It took me a few trips to the deck in the early morning hours to determine the anchor roller, with its 1/4 inch space on either side of its axle was banging into the sides as the boat swung from sdie to side. I wrapped a piece of line on the axle of the anchor roller and the roller had no where to go. The banging stopped.

John Z
"Outstanding"
# 472
Portsmouth RI