Anyone had their rudder pintles fail with a sheer fracture ? My lower one sheered off on Sunday.. rapidly followed by the top one when it reached a 90 degree bend.. I was left with two stumps of pintles stuck in the gudgeons.. and a rudder hanging on by a thread!! Shame 'cos were were on the last lap and miles in front! Incidentally, this was a new rudder.. only been used half a dozen times.
Ah yes. the bend pintle saga.. I had that happen a while back. Horizontal retaining clip causes that one.. This is a stress fracture rather than a bend... According to one of our new members, who is a Project Manager in a Stainless Steel Fabrication company.. (handy guy to have around!) it looks like a vibration fracture, so is most likely to be a substandard fitting. There are various grades of stainless steel, trading hardness against corrodability.. I handed broken remains to Sandy from Laser....
So that nice humming noise that the Stratos makes is actually vibrating it to bits! Maybe you managed to sail at the exact speed to hit the resonant frequency of the pintle.
The humming noise comes from cavitation on the aft edge of the rudder. If you look closely you will see that it is actually square. Take a piece of fine sand paper, gently round off the edges and the humming noise will be considerably reduce or may even disappear.
I think I had the first occurence of this problem about 3 years ago. Flat out planing at Lake Bala when the rudder "fell off". Investigated after it happened a second time. The lower pintle (the shorter one) can ride up out the gudgeon at speed, the retaining clip (if horizontal) and "circlip" thingy don't resolve the problem. I replaced the short pintle with a long one (ie. now two long pintles), changed the horizontal clip to vertical (which I think is now standard anyway) and have never had the problem again.
Fractured rudder pintles
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Posted - 08 Jun 2004 : 11:15:40
