Boom Reef blocks and winches installation design As you remember I made 4 reefs on my new main sail, and 4-th i would likely never use ;) I tried to calculate what could be loads in reef lines on my boat and get really surprised numbers. My sail: Configuration Luff remaining Estimated area Full-sail area Full sail 11.14 m 25.60 m² 100% Reef 1 9.45 m 19.2 m² 75% Reef 2 7.80 m 13.6 m² 53% Reef 3 6.13 m 8.8 m² 34% Reef 4 4.46 m 4.9 m² 19% At fourth reef set, about 4.9 m² of mainsail remains exposed to the wind.  At a worst-case wind speed of 60 knots, that sail area produces approximately 3.7 kN force.  If about 40% reaches the reef clew, the clew must take 1.5 kN. Because the two reef-line legs pull at a shallow angle of about 10°, each leg carries approximately (1.5 ÷ [2 × \sin(10°)] = 4.3) kN. Allowing a 50% increase for gusts, flogging and shock x1.5 =  6.4 kN. so, a reef block i need for about 8 kN working load. The same logic calculation gives us about the same loads o...

Sails New Mainsail outhull  setup. Original boom end is a total disaster. Clue end of the boom has just hook on the end to lead outhull from clue to hook, then to block turn line back to horn cleat on the end of the boom ?!?!?! How I suppose to adjust it under way??? Original end on the boom lines arrangement.   Boom end outhull hook   Topping lift line. Very strange setup. No way to put any reasonable tension on the outhull a specially for windy conditions, near impossible to adjust tension under way.  With new sail I want  to be able to do mainsail foot adjustments underway.  I  built 4:1 purchase system for outhull line.   It is temporary solution and I am looking completely rearrange my boom to accommodate 4 reefs (instead of one I have now), outhull and topping lift. add V-cleats and horn cleats  to hold reefs locked.  Future plan. Internal lines  mount block inside the boom at the end for outhull and put second purchase  ...