After having the TI steering trouble since day 1, and seeing the post on describing how the rudder does not seat in the groove properly, I checked mine on land and it appeared to be trouble free. However, my rudder always seemed to work except when at higher speeds. I surmised that no matter how tightly the rudder line was pulled, the rudder is still able to pop out of the groove when the water pressure builds, causing the lack of steering (maybe you saw my video on a previous post).
My new theory (after 4 days of sailing this past week) is that the rudder just isn't big enough to turn the boat. This past week I was sailing in 15-20 mph winds in 3-4 foot chop. Every time I had the boat slightly into the wind so that I was running at a good speed, the boat refused to turn away from the wind. This would happen when I was sailing with the wind coming towards either side of the boat. However, if I trimmed the sail out, effectively slowing the boat, the boat would then begin to turn away from the wind. This would happen when turning either to starboard or port, so I assume it's not the rudder popping out of the groove issue. If any of you master sailors have any other input on the physics of why this would happen I'd love to hear it. That withstanding, I believe when the boat is moving at a fast pace the rudder does not have enough surface area to turn the boat from running slightly into the wind through perpendicular, and ultimately away from the wind.
Now, onto the very frightening good stuff...the evidence. I have spend a lot of time holding the rudder to one side or the other while sailing with no direction change in the boat. This week the rudder completely failed. I tried to use a paddle to steer myself back while sailing. This is when I realized the tremendous amount of pressure that is exerted on the rudder. After feeling this force for way too long I began to wonder how the rudder is able to handle this force when it is turned flat against the oncoming water, especially when it is turned flat against the water and the boat continues to go in a straight line for lengthy periods of time. You would think the rudder would just rip away from the boat. Well this is exactly what happened. I'll spare you the frustrations, the danger of my situation, and my fear to now take this boat out on any expedition trip. When the rudder first went limp I assumed I had a broken rudder pin. But when I finally made it back to shore I noticed that was not the case. The rudder had actually been pulled away from the boat.
I could not believe my own eyes, but the lower screw had completely been ripped apart!
Here's another view:
and the top screw was obviously bent:
After feeling the force the water exerted on the paddle, and knowing how long I've spent holding the rudder to one side or the other with nothing happening other than the boat continuing to move briskly in a straight line, I can begin to understand how this single screw could fail. Nonetheless, it was very shocking that this could happen to a stainless steel screw and nothing else breaks in the assembly. I believe the rudder would have to be turned sideways and locked in the down position for some time, while the boat continues to move forward in a straight line, for this screw to fatigue and fail like this. This is why I have deduced that the rudder just isn't big enough to turn the boat when moving on the course I described at speed.
I have replaced the screws and the only ill effects left are very sloppy rudder handles. There's probably 3 inches of play in the handles now before the rudder moves. I have not spent much time trying to determine a fix for this, but if anyone has had this problem and knows how to tighten this movement, I'd appreciate the input. I'm thinking that maybe some of the knots slipped in the steering lines and need tightening, but this does not seem likely. Of course, a stainless steel screw being snapped without any plastic hardware failing first also seems unlikely.