Stavanger, Friday
Different boats, different needs
One of the main messages in Bill Belcher’s book about windvanes (see Newsletter 51, p20) is that one should assess the boat’s handling carefully before deciding on type of self-steering gear. The idea was to get away with as simple gear as the boat type would allow. The two main factors discussed were the power needed to steer the boat and the feedback needed to avoid that the selfsteering gear should over-correct, resulting in a constant zigzagging course.
A well balanced boat with good yaw-damping and a good balanced rudder can be handled by a gear working directly on the tiller (see NL 51 p16 about "Reggy the Regulator") while other boats, which are more demanding to steer in general, may need the powerful, but also more complicated servo pendulum gear.
On boats with an outboard rudder Belcher often recommended using a trim tab, driven by the smaller version of his horizontal shaft vane. This vane is plenty powerful enough to overcome friction.
I sailed for two summers with this windvane ("Otto" a smaller version of "Reggy") on my 23’ Malena. It steered Malena surprisingly well and was easy to rig and alter the course with. I used it on a trip across the North Sea, but also regularly for day-sailing. One of the assets with the direct drive was shown each time I came back from a sail and was to lower the (Bm) sails. I then sheeted both sails in for close-hauled sailing and then had Otto pinch a little closer, but without backing the genoa. Then I could go forward and when dropping the genoa it would fall perfectly inside the rail. After securing it temporarily I lowered the mainsail. The boat would now, if un-tended, turn for a downwind course, but Otto pushed the tiller to the lee so Malena was parked beam-on. This gave me all the time I needed to sort out the mainsail and start the engine.
When Malena got the JR, Otto was soon made a pensioner, and that for two reasons:
When sailing on a reach and when close-hauled the boat would steer well enough with a locked tiller, and furling the sail was, as you all know, so quick that no help was needed.
On the downwind leg Otto was not able to stand up to the yawing forces produced by the new, big, single sail. I guess Otto could have controlled Johanna better, since her balanced rudder makes the tiller forces so light, but I still think that the bigger "Reggy" version would have been better. Have a look at the photo of Otto. The vane was very easy to fit and take down, thanks to the long, needle-type, horizontal shaft and the hook-on steering lines. Also, a steering wheel can be spotted which made course setting very easy. Finally, note how the counter-weight can be shifted up or down. The rule is; bottom-heavy vane for upwind work and top-heavy vane for downwind work.
Arne
PS, the day after: Inspired by Annies's letter below, I attach a photo of Badger's windvane which I took during a rally in 2006. Obviously, something must be right with that thing since it has been in use for so long and over so many miles. When was it built and who designed it? Here is another of Badger. Next to dead calm, but still enough to (just) inflate the panels.