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post #4 of Old 01-26-2010
JohnRPollard's Avatar
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I agree, SD covered most of the pros and cons succinctly. And as josrulz added, much depends on how you weight those individual factors. After a decade of owning boats with near maintenance-free outboard chainplates, and constantly reading about headaches associated with the higher stress and leak-prone inboard chainplates, it would be tough to go back. Your mileage may vary.

However, I did want to elaborate a bit on the question of sheeting angles. Because some less obvious variables are in play, there is a tendency to make generalizations that overstate the correlation between inboard and outboard chainplates, sheeting angles, and pointing ability.

Sheeting angles do have an affect on pointing ability. Many boats with outboard chainplates sheet their genoas outboard of the shrouds to a track on the caprail. Intuitively, this would seem to lead to a wide sheeting angle. But not necessarily.

The actual sheeting angle is determined more by the geometry of the foretriangle, than the placement inboard or outboard of the chainplates. To envision this, consider two boats: A traditional narrow-beamed cutter, and a more modern, relatively beamy, fractionally rigged sloop. With its mast stepped farther aft, and possibly a short sprit, the cutter has a long foretriangle. The fractional sloop, with its mast stepped much farther forward, and the tack at the stem head, has a short foretriangle.

Next draw a centerline along the decks of these boats, extending it forward to the tack of the headsail. Now measure the respective sheeting angles, from that centerline to their lead tracks.

You might be surprised that, due to its large foretriangle and narrow beam, the cutter with the outboard chainplates and tracks has tighter sheeting angles than the frac sloop, with its short foretriangle, greater beam, and with tracks outboard of the inboard chainplates.

I am not trying to open a debate about whether the cutter rig is more weatherly than a modern fractional sloop -- I only use these two examples to point out the danger of over generalizing.

Another factor that SD mentioned and worth elaborating on, is the placement of inboard vs outboard jib/genoa tracks. Some boats with outboard chainplates, have both inboard and outboard jib/genoa tracks. Some have ONLY outboard or ONLY inboard jib/genoa tracks. An example of the latter is in some modern fractional boats that compensate for the short foretriangle (and associated wider sheeting angles) by putting the chainplates completely outboard and sheeting the headsails inside of them (best of both worlds?)

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Pacific Seacraft Crealock 31 #62

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