Tiller Tremble

[Candover]

I am about to purchase my first yacht and had a trial sail recently. I was a bit concerned by the fact that the tiller trembled noticeably while running. It didn't happen while reaching or beating. It also trembled quite a bit under motor. Does anyone have any thoughts on what may cause this?

The yacht is modern design sloop with Fin keel and semi balanced rudder. It was built in 1999 and has been lightly sailed by families.

Thanks

 

[Steve_N]

Disturbed water flow over the propellor whilst sailing, probably. Reaching or beating it would be lessened by the leeway being made. And then prop-wash from the propellor whilst motoring.

Normal in my experience with this keel/rudder combination.

 

[philip_stevens]

Bushes/bearings for the rudder stock may be worn.

 

[Guest]

0 - 4 knots my race boat is quiet on tiller .... 4 - 6 knots a tremor starts and its continuous ... over this and the tiller increases till it vibrates significantly .... but not uncomfortable.

Why - rudder has dynamic shape and flow from keel aft hits the shape at slight angle causes the rudder to react by trying to turn in unison with flow ... helm keeping rudder at slight angle to maintain course of course prevents this ... so vibration sets up. Mine is worse on pointing, running is significantly less near zero.

 

[Sans Bateau]

Agree with you steve, had EXACTLY the same effect on our last ETAP, certainly under power, we had a folding prop so no effect whilst sailing.

 

[joss]

We had this on a used Beneteau First 31.7 that we bought. Under sail the rudder is very light, but under power it was very wobbly, or trembling. We noticed that it became much worse after a cross-channel trip when we motored all the way back. Lifted the boat and found bottom bearing had lots of play. Dropped rudder and reseated the bearing and the problem was much reduced. Figure that it must be combination of finely balanced rudder and prop turbulence. Hope this helps.

 

[danera]

I would also check the rudder is smoothly faired and the trailing edge comes to a sharpish ridge as any unevenness causes turbulence leading to vibrations.

Ivan

 

[seaesta]

My Westerly 25 has done this for years especially at higher speeds.There is some wear on the rudder bearings but I would not do anything especially to stop the vibration. I always think that she comes alive when the tiller is trembling!!
Martin

 

[Mirelle]

Our ten ton displacement gaff cutter with wooden rudder stock with straps and check pieces, i.e. as old fashioned as you will get - the sort of rudder you will find on the Cutty Sark or the Victory - and it will tremble when running fast. I think it is a sign of excitement. Going to the other extreme, our 12ft Firefly dinghy does just the same thing.

 

[Colvic Watson]

There may also be an anode on one side of the rudder blade. Our Macwester has one and it induces some turbulance.

 

[alahol2]

Had this on our Stag, replaced prop with a folder and the sailing tremble went away but the motoring tremble stayed. Have now replaced engine and had to replace folding prop with another fixed prop, result, sailing tremble is back...