Mainsail Furling

[Tom Wood]

What are the disadvantages of  mainsail furling systems?

Tom Wood responds:

I always feel awkward just giving one side of a story, and in the case of mainsail furling systems there are many advantages that outweigh the drawbacks.  But since you want just the disadvantages, here are my thoughts:

1. Cost.  Whether behind the mast, add on to the mast, in-mast, or in-boom, mainsail roller-reefing/furling systems are expensive.  Almost all need professional installation and a new mainsail, which adds mightily to the final price tag.

2. Weight and windage. Except for the newer in-boom systems, mainsail roller units place a good deal of weight and windage up high—right where you don’t want it.  This adversely affects performance, stability, and the vessels motion.

3. Performance loss. Most systems cannot use battens, so the mainsail roach is sacrificed. In addition, the sail must be cut somewhat flatter than is normally desirable. When partially rolled in heavy air, the sail shape can be less than optimal. All of these things are not in the best interests of good performance. The loss of the roach occasionally affects the boat’s balance, so much that the headsail area also has to be reduced in order to maintain some weather helm.

4. Safety and maintenance. Mechanical roller systems, especially those where the sail is sheathed in a housing or inside the spar, can and do fail. Mainsails sometimes jam, usually due to overload, which means at the worst possible moment. Keeping breakage and jamming to a minimum requires a rigorous maintenance schedule for all halyards, outhauls, swivels, tracks,furling lines, and blocks.  Incidentally, in-boom furlers must have a fixed,rigid boom vang keeping the boom at one precise angle or they will jam every time they are rolled up.

Now, all I can hope is that someone writes in and asks for the many advantages.