TECHNICAL FORUM

Annie Hill wrote:I think that what Kurt is saying is 'if it ain't broke, don't fix it.'  Pete - an inveterate (and maddening!) tinkerer once took scissors and sewing machine to our gorgeous green sails and inserted shape a la Arne.  It didn't seem to make much difference.  We took out the battens, just to see what happened.  It didn't seem to make much difference.  We had sailed tens of thousands of miles in the boat by then  and quite a lot either without engine, or choosing not to use it (average use 25 hrs per 10 000 miles).  We took out the shape and carried on as before.

'Fantail' has a slippery hull and is fairly light displacement.  In a flat sea she will sail herself close-hauled, but if I go down to the galley to make some coffee, I have to move slowly and carefully so that she doesn't shy from the sudden adjustment in trim.  'Badger' used to sail herself to windward regardless of how many were on board and what they were up to.  From this I infer that a sensitive hull will respond more noticeably to tweaking.

Kurt is not only content but actively happy and appreciative of his simple rig.  What more could anyone wish for?

Alan "Maddog!" MacBride wrote:

Kurt Jon Ulmer wrote:Great comments, everybody. Thanks.

Now, how can I convince the world that buttons are better than Velcro (TM)?

(only kidding...)

KJU

They make less noise at the movies?

Paul Thompson wrote: ..
The extra line that some are making a fuss about is what is called in the west a Hong Kong parrel. Hasler mentions them in PJR (page 47 in the second Ed.) but he did not know what they were for. An understandable mistake since he also thought that junk sails are flat and since he used modern sail cloth which has tremendous diagonal stiffness he would never have see any reason for them.

Hong Kong parrels are used when the cloth does not have enough diagonal stiffness to keep intact the parallelogram that makes up the shape of each panel. When the cloth lacks diagonal stiffness, you get diagonal creases in each panel that is complaining. The Hong Kong parrel is then rigged diagonally from the top batten to the lower one. The angle should be 45 deg or more, generally the more acute the angle (within reason) the better as less acute angles have more of a tendency to pull the battens together. The parrel is normally rigged in the luff area but I can see no reason why they could not be rigged in the leach area where they would have less effect on the shape of the sail.

..

So lemme get this straight.

Hong Kong parrels were only used around Hong Kong,  now you've got me diving into my copy of "The Junks and Sampans of the Yangtze". There is no mention of HK parrels there (Hasler notes he didnt see any other reference to them either) Looks like junks everywhere else had quilted sails - that is reels of diagonal lines from yard to boom so they didn't need HK parrels.  

I have a suspicion Hong Kong junkmen, after observing foreign sailing ships and their ballooning sails, reduced the number of battens, got rid of the quilts and liked the results. They had to invent HK parrels  to fix a problem which popped up when all those diagonal ropes were removed. So maybe ballooning sails, or cambered as we say, was not an accident.