30T Rudder design flaw

[Steve Parfet]

My 1980 30T rudder was made with dissimilar metals which almost caused a catastrophic breakdown. While cleaning the bottom for a race last summer, I noticed the rudder stock was moving inside the rudder, only a half inch. I dropped the rudder while at the buoy and clamshelled it open at a friends shop. I was surprised to find that the bar stock coming off the stainless rudder stock was aluminum. Two of the three bars had completely corroded away near the rudder post and the last one was close. If it had broken like the other two, there would have been a complete loss of steering. The rudder stock would have just turned inside the rudder. If I had been alongside another boat at a start, it would have been very exciting. This should be another line on your prelaunch checklist.

 

[Surveyor]

Steve

I will grant that it was not the best practice in hind site, but it lasted 30 years! We never thought the 304 stainless schedule 80 pipe would last that long. Rudder shafts and bearings were a weakness on Seidelmann Yachts. Because the shafts were unmachined SS pipe which has large tolerances in diameter, roundness and wall thickness, slop in the bearings was also common.

My 1980 30T rudder was made with dissimilar metals which almost caused a catastrophic breakdown. While cleaning the bottom for a race last summer, I noticed the rudder stock was moving inside the rudder, only a half inch. I dropped the rudder while at the buoy and clamshelled it open at a friends shop. I was surprised to find that the bar stock coming off the stainless rudder stock was aluminum. Two of the three bars had completely corroded away near the rudder post and the last one was close. If it had broken like the other two, there would have been a complete loss of steering. The rudder stock would have just turned inside the rudder. If I had been alongside another boat at a start, it would have been very exciting. This should be another line on your prelaunch checklist.