Looks more to me like the pin came out of the bottom gudgeon? Otherwise I
have
a hard time seeing how it would bend at the location on the picture.
Christian
On 9/10/07, Dave Lindsey <lindsey@xxxxxxxxxxx> wrote:
>
> **Just a little info I thought I would pass onto other builders.**
>
> My rudder pulled off my boat today. Mike offered to sail the Red Violin as
> a
> sort of sea trial. It was a beautiful day with winds at about 12-15 kts.
>
> Mike pushed off with no problem. I watched him as he sailed her close
> hauled
> west of the pier. Later I watched as he very skilfully doused the main and
> struggled to come in on the jib alone. Eventually it became obvious he
> required some assistance.
>
> The rudder had completely ripped off the boat. See the attached pictures.
>
> I think it is fairly obvious what happened. A strong bending moment bent
> the
> pin which lead to the upper gudgeon block pulling away from the bar. I
> think
> this lead to the lower end of the pin bending and the whole works falling
> off.
>
> If my assumption is correct, the lesson is that we need to eliminate all
> bending moments on the pin. Do not use a spacer as I did. Keep the rudder
> box attachment point as close to the gudgeons as possible. Shear is
> acceptable, but try to eliminate any and all bending moments.
>
> Now I have to figure out how to fix this mess. Any suggestions. No smart
> ass
> remarks please?
>
> Oh, one final point; I used screw (4) to attach the gudgeon to the bar.
> I'm
> glad I did. I very purposely wanted this to be a failure point vs.
> breaking
> the bar. Now I question if the rudder box should be designed to pivot
> with
> a shear pin. Comments?
>
> David Lindsey
> CAN 046
>
>
> This is the Swift Solo mailing list. For unsubscribe instructions,
> visit here: http://catzooks.com/swift-solo/
>
>
|