DRAGONFLY Trimarans User Forum

I was sailing along with the boom vang/preventer on last weekend. All of a sudden, the Ronstan block failed. There were no unusual circumstances and winds were relatively light. No harm was done, but just wondering whether others have suffered this experience. If so, have you replaced like-with-like or did you upgrade? I'd guess the block was original from this 2007 boat.

how did it fail? which part broke?

I had a few (5 or more) Fredricksen blocks fail. all in the same way: the plastic around the shackle pin disintegrated. I had some replaced under warranty. The rest I've been replacing with similar or higher spec aftermarket blocks. Personally, I prefer lewmar. They are cheap, widely available and seem to be reliable.

My warranty replacements were all ronstan, and they held up very well.

BTW, I noticed that all blocks at the outboard end of the amas tend to bang against each other and slowly break or chip the cheeks of the blocks.

Sudden failure. The plastic either side of the smaller sheave broke off. I'm told by Q they use Selden now.