Join Date: Feb 2000
Location: Annapolis, Md
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I tend to be something of a lone voice on this so maybe this is just me, but in-mast furling seems like one those many trends that come along for one half-baked reason or another, and in my opinion should quickly go away. Like roller reefing booms of the 1960’s, I see these as another half-baked idea being foisted on a sailing public that hopefully will become as archaic as cotton sails, baby stays, and roller reefing booms.
I suppose in-mast furling is an acceptable system for coastal cruising for those to last to haul up a halyard, as long as nothing goes seriously wrong, but from conversations with experienced delivery skippers and owners who have experienced heavy-weather HIHO jambs it is not a great system for offshore work of sailing in high wind venues. I base my comments on a series of nightmare stories from sailmakers, delivery skippers and owners, many who have successfully used these systems until something has gone seriously wrong.
To begin with, the sailmakers tell me that if the sail is left reefed for a period of time or in high winds, the leech of the sail at the head slowly creeps towards the foot as the furled layers of sail slide over each other. (We have all seen this phenomenon in the fat center of a reefed headsail, even one with the luff altered with rope or foam.) As the leech slides down the furl, it does it a series of things. The sailmakers tell me this creates high concentrated loads on non-reinforced areas of the leech, stretching the leech and shortening the life of the sail (the in-mast furling wild leech flap is one symptom of this problem). They tell me in-mast furler sails have a greatly shortened life over similarly constructed conventional sails.
As the leech slides down the sail, the sail bunches up inside the mast. Multiple delivery skippers and owners have told me stories of spending periods of time in heavy weather where they could neither pull the sail in nor let it out. In the worst case, they actually sent someone up the mast to cut the mainsail off the mast rather than risk losing the boat in a worsening offshore storm.
Beyond the safety issues and shortened sail life, I have serious concerns about the performance loss, especially when off of the wind. To make an in-mast furler work well, the leech of the sail is generally cut hollow. (Yes, there are in mast furling battens, either parallel to the mast or furling battens, which allow a straight leech or slight roach, but most in-mast furling mains have hollow cut leeches.) Masts are considerably heavier reducing stability and hurting angular motion comfort. Depending on the region, PHRF allows 9 to 21 seconds a mile for in-mast furled mainsails. That is a huge penalty for a small amount of added convenience.
I know there are lots of these systems out there that have never experienced a jamb, but for me the risk of a jamb is way too great, especially when you think of how reliable and quick two line slab reefing really is. I personally would consider in-mast furling a deal killer based on the loss of safety, the shortened sail life and loss of performance.
But then again, maybe this is just me….but then again, thankfully, I see that the bigger manufacturers are stepping back from offering in-mast furlers on many of their smaller models, offering slab reefing, and lazy jack, sail cover hybrids instead.