A Critical Sheave Replacement

On the last sail of 2014, the jib halyard sheave broke, and I finally had time to replace it today to get ready for spring racing at the Austin Yacht Club. Either the sheave broke because of age (33 years), but more likely because I tighten the halyard to tightly! The sheave was so old, that Harken does not make it any more. In fact, I learned through the process of finding a new sheave that rope / wire halyards are out of style given the lighter synthetic lines now available. The West Marine representative I spoke to about the part suggested I try EBay. I did, and I found a brand new replacement for Harken part number RF455 via Sailing Services out of Miami, FL!

 Front side of old sheave on left and new sheave on right.

  Back side of old sheave on left and new sheave on right. The failure was that the sheave axle pulled through the fitting wall on the left above. 

 The original sheave was only installed with rivets in the four corners. This may have contributed to the failure - not sure. So, I remounted the new sheave with six rivets. Because the mast and the rivets are aluminum and the sheave is stainless, I put silicone on the back side of the sheave assembly, and I put small nylon washers from Lowes between the rivet head and the sheave assembly to prevent electrolysis as much as possible.

The finished repair!