Tuesday, October 9, 2012

Dual purpose tell tales

Jeff on s/v Ces't la Vie solves a common problem with roller furling headsails - it's a simple and ingenious answer...

Seeking a break from the work in the engine compartment, I looked to the sails for a diversion.  We added a roller furling 130% genoa last fall and are very pleased with the increased performance and ease of use.

After using the sail for one winter, I realized two shortcomings.  First the only tell tales on the sail were aligned vertically with along the luff.  Unless the sail was fully extended no tell tales were visible.  When sailing to windward I rely heavily upon the forward sails tell tales to trim.  Secondly, with our roller furling sail there was no way to quickly judge the percentage of sail aloft.  "Did we unfurl a 80% jib or a %110 genny?"

With the sail off the foil for storm season the time is right to remedy the issues.  By strategically adding tell tales I hope to kill two birds with one stone.  C'est la Vie's "J" (the distance from her mast to forestay along the deck) is 184".  Thus the foot of a 100 percent sail on C'est la Vie would measure 184".  Each time we roll out or roll in 18.4" along the foot of our sail we are altering the sail area by 10%.  Ok this is Jeff logic so someone out there is welcome to correct me if my logic is flawed.

To provide an indication of the amount of sail out I placed new tell tales at 37" increments (18.4" x 2 = 36.8" rounded up) back from the original tell tales along the luff of the sail.  This will allow us to estimate sail area via the tell tales placed at 20 percent intervals.

Fully unfurled equals 130%.  Roll in to the next tell tale equals 110%. Roll in halfway to the next tell tale and we have 100% aloft.  Or perhaps more importantly if we roll out to the first tell tale we have a 70% head sail aloft.  You get the idea?  I placed three new tell tales along the lowest level and two at the second tier.

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