The plot thickens

For those who might be reading this blog hoping for engaging stories of unusual places and interesting people, sorry, today is about motors.

I’ve now figured out how to add more trials to the plot and show the three separate days on which tests were done with the Torqeedo.  It definitely more colourful – But whether its useful remains to be seen:

The red series is the first day we tested the Torqeedo and there were 8 people on board, and the motor was jury rigged in position in the well. That might explain why both the other test days, (yellow and blue) show higher top speeds.  But its odd that low speed the red line is the best – that is, not drawing much power to maintain the speed.

And I had hoped that the streamlining of the flaps would have helped make her faster at all speeds.  But doesn’t seem so.

But I think this exponential regression plotting thingo is influenced by the number of observations.  And so if going one way I was engaged in conversation and didn’t take many readings, and then coming back I was focussed and took many readings, well maybe that skews the graph towards the side where many readings are taken.

Its sure to get better as I collect more information and learn more about how to interpret it properly.

Speed trials

Here’s some results from the Torqeedo speed tests done just before hauling her out.  These results are wind and tide effected but include readings taken in both directions and I’m hoping they would balance.  The curve fitting is done by the charting software and I’ve chosen the exponential regression option because I think it should be an exponential shape.  That is, as speed increases the power required increases by an exponential amount.  It looks about right to me.

Power vs Speed

Photo on day of Torqeedo test

with Isabella and waiting for slipping
photo by Erik Gastellars

Here’s a photo taken by Erik as we were waiting for the slipway to be ready to haul us out about a month ago. On board are Phil from Dragon Song and Claude the Torqeedo man for those tests.

In the foreground is Erik’s beautiful junk rigged dory, Isabella. Check out the sleek timber foremast – unstayed to suit the junk rig. Erik took her out just a few days ago for her first sail and she enjoyed frolicking in Deception Bay.

She’s the same design as Badger that featured in Annie Hill’s Voyaging on a Small Income.