Originally Posted by Undecided
Quote
The collapse process is reasonably clear – the bottom casting broke at the lower attachment point


If the F20C rudders are attached in a similar fashion to the old N20, then another possibility is that the castings had vertical play/slop in them. When this happens its possible for the top eyebolt to come off the gudgeon and then torque the bottom casting on the pin. The new pins are double welded and pretty robust so it wouldn't surprise me that it could break the casting instead of the gudgeon like they used to.


Mmm, I don't think this is possible unless the F20c castings are significantly lighter than the N20 castings (possible). We had the incident Undecided describes happen to my weather rudder on the N20 during the 2010 Tybee 500, the top of the casting popped off the upper gudgeoan and bent my lower double welded gudgeon. The weld doesn't break, the gudgeon post just bends instead. Since I don't have a F20c to evaluate the loads myself, I can't say the same thing would happen on that boat.

Glad to hear you made it back to shore in one piece!

Last edited by samc99us; 10/04/11 09:35 PM.

Scorpion F18