Re: [Amel Yacht Owners] Re: Slowing down in increasing winds
Bill,toggle quoted messageShow quoted text
Your comment about a real preventer needing to run to the end of a boom raises some interesting questions. Namely what are some factors that determine the shock loading that the boom and the rig receives in an uncontrolled gybe? Here a a few things that I believe are significant:
1. The elasticity of the mainsheet. A modern super low stretch fiber as opposed to using conventional Dacron for instance will greatly increase the shock load.
2. Because our mainsheet attaches to the bottom of the boom and the mass of the boom is I assume above the centreline of the boom with the sail attached, the ability of the boom to rotate longitudinally should absorb some of the shock since that rotation would occur in opposition to the membrane of the sail. A fixed/ non rotating gooseneck on the other hand would receive a large torsional load by comparison. I would very much be interested in your input on the rotating gooseneck design of our boats because I had not thought much about it until this discussion came up, but I am starting to like it.
I would like to add that compared to what I am used to on other boats, the weldements on the boom for the attachment of the mainsheet seem to be incredibly strong. The boom itself also seems to be a heavier extrusion than what I would expect for a boat the size of mine. Being a Ketch of course shortens both the main and the mizzen booms and thereby reduces the risks of a jibe causing damage. While all measures to prevent an accidental jibe are important, it seems to me that Amel may have done a lot to help reduce the risk of damage to the rig due to an uncontrolled gybe.
Does anyone know of an instance where the main or mizzen boom or rig of a SM, SN or Maramu was damaged in an uncontrolled gybe? That could be an interesting data point given the Ocean miles that some of these boats have accumulated over the years.