Andrew is leaving us today, returning to Darwin. That means he also gets to do dawn array patrol. We're allowed to start charging at dawn, so Andrew and some others drive 4km or so from the caravan park to the checkpoint, roll the solar car out of its trailer, and put the array on its mounts on the side of trailer, facing the rising sun.
I rise a little later, and we travel out to join the car.
Strategy: we can't start solaring before 8am, so our only choice 'til then is to charge. But from 8am onwards, we have options. We've got enough in the battery pack from this morning's and yesterday evening's charge to solar for maybe 4 hours at maybe 35 km/h, we have 7 hours to get to Dunmurra checkpoint, and it's 358 km away. Clearly, we have to spend some of this distance trailering at 110 km/h. So of our 7 hours, which 4 should we spend solaring? The correct answer, for those of you who are following along at home, is approximately the middle 4 hours of the day, when the sun is most directly overhead, and we will get maximum possible output from our array.
So at 8am, we set out trailering.
Or not. We don't have our act together, so we actually start trailering at 8:35. We go forward 140km to a bay marked on the official route notes, set down, and solar at about 36 km/h.
We driver-change a couple of times, then trailer forward to Dunmurra. At the checkpoint, there's a board showing who went through this checkpoint when: Nuna was in the lead, with Michigan hot behind. We also get a new observer: Wendy. We hold for our compulsory half hour, then trailer onwards. We set down and solar some more, but the battery goes flat before we reach the pull-over that we were aiming for. We spend some frustrating time crawling along, ever slower, then give up, pull off the side of the road, and load. We trailer forward to Elliott, which is our camp site. We get there at 5:18pm, which puts us into penalty time: for every minute from 5:00pm to 5:10pm, we must start one minute later tomorrow; for every minute beyond 5:10pm, we must start two minutes later tomorrow. So our 5:18pm finish translates into 8:00 + 0:10 + 0:08 x 2 = 8:26am.
We're camping in the Elliott caravan park. When I get there after our dusk charge, camp is already set up. We eat, barbecued marinated beef and chicken with mashed potato, peas and corn, in a big circle of camp chairs under a ghost gum. I mention to the circle at large that some of the chirping sounds we can hear are sonar pings, as bats whirl and swoop to the campground's lights, snapping bugs out of the air. One student immediately retreats to her tent.
We discuss strategy for the following day, and sleep.
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Footnote for WAians: John is talking to Eoin Cameron each day before 8am NT time, so that's before 6:30am Perth.
-- Doug Burbidge
