Rig is throbbing after recent tune

[teneicm]

We recently had the mast down on our cat and the riggers tuned the rigging after it was re-stepped. Now in any wind over 15 knots the rig vibrates and throbs with such a noise that I thought at first that a motor was running somewhere on the boat. Is this indicative of the rig being too tight or too loose or something else? Need it to stop as it's getting hard to sleep with the noise!!

Cheers- Matt

[44'cruisingcat]

I don't suppose it could simply be your topping lift? Maybe a new one was fitted?

If I have our mainsheet a little tight against the topping lift, it throbs just as you describe.

[teneicm]

I get the topping lift throb too- but this is a diffrerent one. Even loosening the topping lift all the way doesn't remove the throb.

[Watercolor]

Not seeing the boat and sailing her I'd suggest looking on the web for some tuning videos. It's also possible they mounted something wrong. Might be worth a trip up the mast.

[islandplanet]

Not only will it interrupt your sleep but the vibrations will shorten the life of your rig. Find a rigger who knows how to tune a cruising cat rig.

[jeremiason]

The is a common occurance with sailboats....

My guess is this is only happening at the dock. It is a result of the wind coming from the stern or quarter of the boat and pumping the mast, which normally doesn't occur at anchor. The pumping usually starts when winds climb over 15 kts.

Ask your rigger about it.

[Hermanns]

Very common in our marina too - mainly from a beam wind.

One thing that causes 'pumping' on our mast is of the halyards are hitting/rubbing on the mast. Our head sail / genoa halyard is wire cable and it can make quite a racket (and vibration) if banging against the mast.

I pull mine away with a sailtie while in the slip.

Hope that helps

[GordMay]

See ➥ http://www.cruisersforum.com/forums/...mal-27923.html

[sushirama]

Mine would mast pump like crazy too. take your main line and wrap it around the mast to break up the air around the mast . basically creating a vortex shredder