Friday, December 21, 2012

One Sail Tied Behind My Back

August 24, 2012

It was another gorgeous day at Lake Hinuma with winds of around 10 knots. We launched without our jib.   We had never sailed Bluesette with just the main, and I wanted to see how she handled.   Would it be easier to sail solo with just the main?  The reason for the question was in an hypothetical instance when K didn't want to go sailing and I decided to take the train up to the lake and go out alone. (Doesn't really sound like much fun, actually, when I think about it.)

If there are any other pilots (aviators) out there, you will appreciate that a jib acts much like the leading edge slats which are deployed on airliners during the approach to landing phase.  (Some light planes have a similar feature built into the wing in the form of a slot).  Like the slats, the jib's purpose is to increase the amount of sail(wing) area,  but importantly slats and jib also direct and smooth the flow of air over the wing/mainsail's leading edge, increasing that wing/sail's "lift".   In the case of the airliner, it allows the plane to fly slower.   For a sailboat, it allows the boat go faster than if one had just increased the size of the main by the area of the jib.

  

Here's a diagram of jib and mainsail sailing into the wind:




Thanks to Sanscaper for this link to an exhaustive discussion of the physics of sails:

 http://syr.stanford.edu/SAILFLOW.HTM

Of course, the aerodynamics of wings and sails is much more complex than I have space to discuss here - or the expertise to do the topic justice. 
 

As expected, the asymmetry of the setup made the tiller pull hard as the boat tried to turn to windward.    It wasn't too difficult to overcome, but the added drag of the rudder being used to correct the weather helm slowed us down a bit.   Where the lack of a jib really proved to be a liability though was while coming about.   Without the jib to pull the bow around, she turned like an overloaded barge.   She'd come up initially all right, but then slow way down the middle of a turn.    In sum, my question about single handing the boat without the jib was answered: no, it would not be easier than single handing with both sails unless perhaps the wind was really howling, in which case I shouldn't be going out alone anyway.

Haul on the tiller, we sang that melody,
Like all tough sailors do, when they're far away at sea.
(apologies to Bob Dylan)


Uh, oh.  Without the jib, K has little to do except perhaps serve beverages on the down wind legs.  She's smiling now, but how long will that last?






The problem I had not foreseen, was boredom for the crew.    Without her jib duties, K became restless.  There were rumblings of mutiny on the forecastle.    ("rumble rumble rumble, mutiny, mutiny, mutiny").   I tried to keep her occupied taking pictures of the scenery, while keeping an eye out for signs of trouble.



This fishing boat, which ran aground during the tsunami surge of March 11, 2011, still sits on the rocks; its twin outboards mounted on the transom.  I'm surprised they haven't been pinched, though I guess it would be hard to do without the culprit being obvious.


Mt. Tsukuba was visible to our west - our miniature Fuji-san.

I thought about putting K to work swabbing the deck, like they always do in those old seafaring movies, but I thought I'd be pushing my luck.  Besides, there isn't much deck to swab on a Lido 14 and what there is is covered in gel-coat so very easy to clean.

Finally, I relented to the crew's demands and we ended the single sail experiment and went for lunch at Mama's Kitchen.  Any chance of mutiny was nipped in the bud and peace and order returned to Bluesette.


Until next, sweet sailing.

9 comments:

Sandscraper said...

Pandabonium, maybe you could find a smaller used jib, or have one made, to act as a storm jib. You would then reduce the sail area but still have the slot effect. Just a thought, I used a storm jib many times when I sailed my Tartan in some very stiff breezes, with favorable results.

Pandabonium said...

Sandscraper,

Thank you. That is an excellent suggestion. You know, in thinking about this post, I remembered that the jib on the first Lido I sailed - #443 which was built in the 1950s - was smaller than the one on Bluesette.

Along those lines, I've also thought of having a smaller mainsail made to have a set of sails suitable for high winds. But as (at this point anyway) I'm just sailing for fun, the cost of doing something like that seems high.

Thanks for the suggestion though. Food for thought.

Sandscraper said...

What the Hey, give it go and enjoy!

George A said...

Pandabonium: Does the Lido 14 have a dagger board or a pivoting center board? If your boat has a pivoting center board you can experiment with pivoting the board up just a tad. This moves the tip of the blade (and the center of lateral resistance) aft, which in turn compensates for the shifted center of effort of the sail plan when the jib is not used. Once "balance" between the CoE and CoLR has been restored your boat should not be so hard mouthed without her jib. Just a thought.

Smooth sailing,'
George A.

Sandscraper said...

Pandabonium, I see that your mainsail is not loose footed, you could have 1 reef point put in just above your window, that might be a less costly solution. I have a window in the sail of my Puffin, two sets of reef points, one below the window and one above, that combination allows me to sail in some very substantial winds.

Sandscraper said...

Pandabonium, my last comment, I promise. Some day when your are bored with nothing to do, checkout this website.

http://syr.stanford.edu/SAILFLOW.HTM

Pandabonium said...

George A. - pivoting centerboard it is. Good suggestion. Thanks.

Sanscaper - the sails I use these days are very stiff and reefing them would damage the fabric. (We even have to be very careful in the way we stow them.)

Thanks for the link. I've updated the post with it and show a drawing from that website. Cool.

O Docker said...

I used to single-hand our old dinghy quite a bit. It was a 15' Mutineer, with more sail than a Lido. I almost never used the jib when I was alone, and the boat handled very well without it.

After one terrifying day in 20 knots, I had a single, substantial reef put in and it was a good solution for heavier air. You may want to discuss this with a sailmaker. Properly installed, it should work even with a new, stiff sail.

Our boat's helm was sensitive to heel, though. It really wanted to be sailed flat, which is where the reef helped a lot.

Pandabonium said...

O Docker - thanks. Your comment tips the scales for reefing and I'll look into it further. (I tried a reefer in college, but didn't inhale.)