Thursday, December 15, 2016

Tanzer 16--Stern up improves upwind peformance

Tanzer 16--Stern up improves upwind performance  --  December 15, 2016  For a couple of years the two best racers in our little fleet said that we needed to put more weight forward when we were going upwind.  Actually Kevin--the more colorful of the two--said, "Get the ass up in the air."

The fall regatta was a unique opportunity.  Winds were light and variable, we had too much crew, and the committee boat was willing to take lots pictures.  It was helpful that we race against two Harpoons that have approximately the same rating as our Tanzer.  We had some great starts--different post--but obviously we weren't going to win any races--time to experiment.

If you were going for comfort and ease of moving about the cockpit, the boat would trim out like this. The stern is in the water, and it is, of course, aggravated by hanging an outboard on the back.

At this particular moment we were headed down wind, but this weight dis-
tribution gives an even worse case of stern down when you are headed
upwind.



















We intentionally tried different trims by putting my weight and Susan--not so much weight--as far forward as we could get.  Tony pulled out the extension and scooted forward too.  The boat trimmed out like this.

In this picture Tony is still farther back.  Susan and I are are up on the deck
and the transom is all the way out of the water.


















In this photo we had Tony move forward while we sat on the deck.  The stern
is way out of the water, and the bow is probably down a little too much.
















What we learned from these experiments:


  • Weight forward definitely improves tacking.  With the weight forward, even when we were over-trimmed, the boat tacked as fast as the competition.  It also was far less likely to get locked in irons even in light winds.  In addition, it took a lot less rudder to turn through the eye of the wind.  We assume that moving the weight forward, and thus altering the trim, moved the pivot point of the boat forward.
  • Weight forward reduces wetted surface.  This made the boat a little faster in the 3 - 5 knot winds.  In general we were almost as fast as the Harpoons even with the extra weight.  (Almost is not fast enough when you owe them a few seconds every 15 minutes.)
  • Weight forward improved pointing--a little.  We usually point almost as high as the competition, but with the weight forward it was improved slightly--they did not outpoint us. When we added a little makeshift barber hauler (not legal in class rules by the way) we pointed even a little higher.  We could also get another degree by holding the boom up to weather.  I have no doubt that the bridge style traveler is a better racing configuration than the standard traveler. But I doubt that I am a serious enough racer to make that change.  For now we will just hold the boom when we are not sure we will make the weather mark.
  • Weight forward is kind of a pain in the butt.  For starters we should leave the outboard at home.  The engine plus the bracket puts a lot of weight at the far end of the lever that is the boat sitting in the water.  It takes a lot of weight to compensate for that 2 hp Honda which was pretty much the lightest four-stroke I could find.  But it can be a long paddle back to the marina so the engine probably stays.  Sitting forward of the centerboard trunk requires a lot of mobility for the crew.  Since our youngest guy is 63 and I am 69, that is not a small issue.
So racing summary for the year.  We continue to improve.  We are not beating ourselves with bad maneuvers  We did manage to beat a few boats now and ten.  Kevin, did honor us with a hard luff at the starting line so that we had to do a 720 turn.*  If we get the spinnaker thing working and keep our weight forward.  We might just win some races.

*This will be a later post.  In retrospect, I think maybe it wasn't a legal luff and I should have protested him.  Maybe we were just giddy to start first a couple of times.