14th March: Anemometer cups, Air draft, and Outboard tests
Replacing the anemometer was a fiddle since it meant fitting some small washers and a very small nyloc nut to the instrument shaft while standing on the jetty with the lowered mast top moving up and down with the boat in response to the wash from the rowers’ ribs. The old anemometer looked a bit crazed but not exceptionally so. However when I gently waggled one of the two remaining cups it came away, suggesting that the sensor has been degraded, presumably by UV damage.
I also took the opportunity to measure the air draft with the mast lowered. At present it is about 3m with the anemometer being the highest point. If I did not have the instruments on the hatch top the mast would drop further. At present, where the mast rests on the instrument panel it is about 20cm higher than it could actually drop. That is at a position 3.37m from the hinge and the mast is about 7.3m high, so the mast could drop about another 43cm making the air draft about 2.6m.
Having got the mast back up I measured the outboard sound levels. However those I will report in the next entry which describes fitting the Vibra-stop pads.