During the summer of 2021 we noticed that our halyard had a small section where the sheath was gradually being picked apart, and by the end of the season the core was almost completely exposed for 2 inches. When the mast came down in the fall we thought we had addressed the problem but wanted to be sure before purchasing a new line so we turned the halyard around and went another season. Sure enough, the same problem became apparent this year. After some investigation we determined that the sheath failure was happening inside the mast at around the middle mast bolt (holding the two sections together). When we pulled out this bolt we found that the aluminum shank was worn flat and the exposed threads worn almost to the root (see photo). The halyard was found looped over the bolt so that the line was deflecting around the bolt when the halyard was pulled tight. Our assumption is that with the halyard deflecting around the bolt and pulled tight, the movement of the mast causes the line to rub back and forth against the bolt wearing the sheath and the bolt.
Our questions:
- Does our hypothesis seem reasonable?
- is there a world in which the halyard should be routed over this bolt to keep it off away from the mast wall?
- Should we simply allow the halyard to travel up the mast as close as possible to the sail track? (our assumption).
This is our second full season owning this boat. A significant amount of work was done a year before we purchased her. The halyard was brand new at that time.
Note on the photo that the light section of the thread is normally in the bolt. The darker section is exposed inside the mast. Also note the flat area on the unthreaded shank.
Thanks
Bill Kroes
“Canatara” NS36 Sail No 24
Sarnia Yacht Club (Southern Lake Huron)