Last year I replaced all the rigging on my '79 Westerly Berwick ketch
, including a roller furler system that works with hank-on sails. It basically is a pair of barrel swivels with a drum which is attached as part of the forestay, so that the entire forestay rotates when furling the sail.
The main mast rigging, which is an exact copy of the original rigging, aside from the furler, has a breaking load of 3500kg but the furler has a breaking load of only 2700kg. The manufacturer assures me that it is more than strong enough for the boat, but I can't stop worrying anytime the wind picks up whether I'm going to lose my forestay.
Am I worrying needlessly? What is a minimum reasonable breaking load for a forestay for this size of ketch?