Blog 30th+

October 30th

Six and a half metres under ground, we wake at 5am to Rick Astley singing "Never Gonna Give You Up".  A student stumbles out of bed and fumbles in his bag, and Rick Astley stops again.

At a slightly more civilised hour we get up.  We charge.

I solder the telemetry receiver antenna back together, which involves near endless walks between the follow car to find gear, the lead car to find other gear, and the TV room where I've plugged my soldering iron into power.

We set off.  It's a complicated shuffle this morning: we put a towing rope on the solar car and tow it the couple of hundred metres uphill to the (now closed) control point which was our nominal stopping point.  Then John jumps out of the follow car's driver seat, we detach the tow rope, Leonie leaps in, a couple of students leap in to passenger vehicles, we set up to roll out, and then we get word over the radio that the support bus back at camp has a flat battery.

But it's too late: we're already rolling out of Coober Pedy and onto the highway.

We solar on.  The car misbehaves and loses power: we're not sure if it's because the motor has overheated or because the motor controller has become confused.  It doesn't help that telemetry is very hit-and-miss today: it seems my repair of the antenna is imperfect.  We continue.

The school bus catches up: with the help of a large number of students pushing, they've managed to roll-start it.  We pause for lunch and charge, and continue.  The school bus goes on ahead.

A little further on, we run out of time: we must put the solar car in the trailer and go forward in order to reach Adelaide in time tomorrow.  We've solared 143 km for the day, bringing us to a total of 950 km for the event.

We meet the bus (and the parents of two of the students) at the Port Augusta control point.  We don't bother to serve our full 30 minutes: since the Challenge rules forbid us from doing any more solaring, there's no point.  We continue to Port Pirie, and check into a caravan park.  The caravan park is free for school groups, which is nice, but it features the port Pirie Jumping Prickle, which is not so nice.  These prickles somehow leap off the ground onto your sock, and then burrow in until they can stab you.


October 31st

In the morning we get up early to trailer in.  Several other teams are trailering on the same part of the highway, all attempting to hit the same deadline as us.

We arrive at Torrens parade ground, and get in line: there's a queue of solar cars waiting to do the 2 km run up the the official finish line at Victoria Square.  After an hour or so it's our turn.  We put the solar car on King William Road, and then the bus that will carry us to the finish line arrives.  We're required to leave our own support vehicles behind.  The bus supplied by the Challenge travels in front of the solar car, and has no rear window, so we can't see what's happening.

At the line, the bus pulls in so we can get out, while the solar car waits just short of the line.  Then we walk across the line with it.

Challenge officials check that our battery seals are still in place, and we walk the car to its spot in a marquee tent, in the shade.  We wander around for a bit looking at other cars, including the wreck of Umicore.

Lunch is a find-it-yourself affair, and then we go to the closing ceremony.  The Istanbul team are very very happy to have won the "best newcomer" award.

Usually the closing ceremony features a bit where all the team managers go up on stage and receive a participation award.  This time that time is filled by a large number of Eco-Challenge awards: best small diesel, best large diesel, best small petrol, best large petrol, etc, etc; and there's simply an announcement at the end that team managers can come and pick their awards up from a corner of the room.

There's a chin-wag and shirt-trade: I get an official observer shirt.

There's an after-party at The Woolshed, but our under-age students are not invited.  So we go for Subway.  It's Halloween, and there are a variety of undead, monsters, angels and demons wandering past.

Then to bed.


November 1st

Three of our drivers are old enough to drink, and they come in from the after-party at about 1am.  Then the Germans in the next room stagger in at 3am.  Then at 5am it's Rick Astley again.

Most of the team goes down to clean support vehicles and sort equipment for shipping back.  The bus begins its trip back to Perth, with the solar car trailer behind; driven by the same teacher who drove it up to Darwin.

Students play pool at the pool table on the balcony of the backpackers'.  Pool is much better for money when the players are no good at it: they can play much longer for their $2.  The table's habit of occasionally neglecting to return the cue ball when it is pocketed merely adds to the fun.

Dinner is at the Chinese restaurant we usually go to when we visit Adelaide.

Tomorrow we'll fly back to Perth.

--  Doug Burbidge   http://dougburbidge.com/

Blog 28th and 29th: Alice to Coober Pedy

October 28th

We stay overnight at our usual Alice Springs accommodation, the Macdonnell Ranges caravan park.

In the morning, I try to re-solder a bypass diode on the rear array.  My gas iron won't light -- I suspect that the fitting on the refill can is wrong and I'm just not getting any gas into it.  I try my 240V iron, running off an inverter plugged into a cigarette lighter.  It doesn't get hot enough -- I think it doesn't like the inverter's output, which is not true sine wave.  On my third attempt, I get an iron that works.

We spend several hours charging.  I try to get some telemetry numbers, but I am unable to even flip the coin: the Bluetooth receiver dongle for the laptop has gotten crushed, and is broken: Windows doesn't even notice when I plug it in.  I try to repair it, and succeed to the extent that when I plug it in, Windows now recognises it as an invalid device.

We go in to town to buy a replacement.  On the way, we notice that one of the back streets that the route notes instruct solar teams to use to get to the control point is closed by the council: they're resurfacing it.  Solar teams trying to find it will have to detour, in a strange town, with no map, and no signage.

Sure enough in town we see a solar car, lost.

We buy a Bluetooth dongle at Jaycar and return to the control point to serve the remaining 12 minutes.  Then we trailer 60km out of town to the next long downhill run, and begin solaring.  Telemetry works, albeit with reduced range.

We solar most of the day, with a break for lunch and charging, and end 12km short of the next control point, Kulgera.  Into the trailer and trailer forward the remaining 12 km, and we get in at 11 minutes to 5.  This is only a 10 minute stop, so at 4:59pm we're free to go.  We elect not to solar onwards for the remaining one minute of the day, so we charge and camp.  We've solared 187 km for the day.


October 29th

I repair the bluetooth dongle with a single strand of wire taken from a larger piece of multi-stranded wire, soldered onto a quarter-millimetre wide solder pad scraped carefully clean of its protective coating with a craft knife.

We charge, and I get in the solar car to drive it out of Kulgera.  I turn the "go" knob.  Nothing happens.

I turn it again, just in case.  Still nothing.

I turn the motor controller off and on again, and try again.  Not a sausage.

We pull the lid off and ponder the wires.  Trent notices that the brake lights are on: the motor controller refuses to allow you throttle up while your foot is on the brake.  But the brake lights are on even when my foot is off the brake pedal.  The switch that is supposed to tell when the driver's foot is on the brake has come loose, and is confused.  John wraps it in tape, thus persuading it that my foot is not on the pedal, and we begin solaring.

Again we solar steadily then pause for lunch and charge.

As we take the rear array off to charge, the telemetry antenna breaks off.  I swap in the antenna from the follow vehicle, and in the follow vehicle I switch back to using the antenna-less, reduced-range Bluetooth dongle.

We solar some more.  The tape we wrapped the brake switch in lets go and the car rolls to a halt.  So we cut the wires to the switch.

A little short of Cadney homestead, we put the car in the trailer and trailer forward to the Coober Pedy control point.  We have solared 213 km for the day.

Our stay in Coober Pedy is much like our last two challenges: accommodation at the underground backpackers', dinner at the pizza shop, concluding with making sculptures with the detritus of the meal.

--  Doug Burbidge   http://dougburbidge.com/

Blog 25th to 27th: Darwin to Alice

October 25th

Before dawn, the solar car gets trailered to the supreme court car park. Later, I and the other drivers join it. We're in a regular car parking bay, with Willetton on the side closer to the start line, and Cambridge on the other side.

The telemetry (heads!) works. I zero out the telemetry numbers.

Everybody stands around for a while. Members of the public mill around too. Peter Schloite comes through and shepherds everyone off.

I go to the follow car where I plug the telemetry laptop in to power. The power is a home-made 3-way cigarette lighter splitter. Unbeknown to us, the plug on it that plugs into the car socket has a 3 Amp fuse. John turns the key. The laptop beeps: it has power. The laptop beeps again: it has lost power. The fuse has blown.

Last year, cars left the start line at one minute intervals. This year, we've been hearing rumours of two minute intervals. In fact it turns out to be about 30 second intervals. Solar cars are coming off the line and being joined by their lead and follow vehicles, causing a non-trivial quantity of traffic. We wind up waiting several cycles of the lights to turn right onto Daly Street. Daly Street becomes Stuart Highway, and we're away.

Several hours out, the motor suddenly stops pushing the car. We don't know why. We pull up on the side of the highway and give it a look. I put the pyrometer on the motor to measure its temperature: it's at 146 degrees. That's at least 20 degrees hotter than we've ever had it.

There's a certain temperature above which the magnets in the motor stop being magnets, and the motor therefore stops being a motor.

I spray water on it.

We mark our point on the road, put the solar car on a tow rope, and tow forward to a side road.

A Kormilda car shows up. We send them shopping for the fuse we need.

I spray more water on it.

It turns out that our motor has a thermal cut-out. This is designed to prevent the motor from getting hot enough to demagnetise. We didn't know this motor had one. Eventually it trips back in, and the motor runs again.

But the motor has a large thermal mass and is surrounded by an insulating epoxy, so it only cools very slowly; and it is all too willing to heat up again. It cuts out twice more during the day. We become adept at pulling over before it cuts out, and spraying water on it.

We trailer forward to the control stop at Katherine, and end the day there. We have solared 181 km for the day.


October 26th

Dawn patrol take the car back to the control stop to charge. We join it before 8am, and solar out of Katherine.

One of the many oddities of our telemetry (heads!) is that the motor controller's opinion of the bus voltage as displayed in the car is correct, but as displayed on the telemetry PC in the follow car it's wrong. As we solar, I install Visual Basic so that I can edit the telemetry software.

Just short of Mataranka, the car runs slower and slower: the battery pack is flat. We pull over to charge.

As the battery pack rises back towards its nominal flat voltage, I can compare the voltage displayed in the car with the telemetry number. It turns out that it's too big by a factor of exactly 3.6.

After a couple of hours of charge, we solar on. After 163 km solared for the day, it's time to trailer forward to Dunmurra, to get there before control stop closes. Every other tail end team is there, too. The Challenge is now much shorter than it used to be, and control stops close correspondingly earlier. So the entire trailer pack (all those cars that have been forced to trailer to make a control stop) are very bunched up.

At the control stop we talk to a northbound trucker, who tells us of a large dust storm to the south. We trailer forward to Renner Springs. Again, every other team has the same plan, so six solar cars camp together. The setting sun is dimmer than a full moon would be under a clear sky.

The dust clears a little during the first half of the night, but then the wind picks up, the tents blow around, and a slow rain of grass and leaf shards fall in through the vent at the top of my tent.


October 27th

We charge under a dusty sky, trailer forward to the Tennant Creek control stop, serve our half hour, then trailer forward to just short of Alice Springs. Australia (or at least Australia as cross-sectioned along the Stuart Highway) is shaped approximately like a peaked roof: uphill the first half, downhill the second half. Just short of Alice Springs is where it turns the corner.

We set down 65 km from Alice, solar past the Tropic of Capricorn, past a marker declaring this to be the highest point on the Stuart highway, and on downhill.

The car pulls more amps than we'd like. The battery, therefore, runs flat faster than we'd like.

The Alice Springs control point has moved (again). This time it's in a hotel well off the highway. There are directions in the route notes, but they are not entirely obsessively complete, and so following them while our battery dips lower and lower is rather stressful.

Nevertheless, we find the control stop and check in, at 18 minutes to 5. That means we'll have to serve another 12 minutes tomorrow. At dusk we put the car in the trailer and go to the MacDonnell Ranges caravan park for the evening.

-- Doug Burbidge http://dougburbidge.com/

Blog 24th October: qualifying

The day starts at the track.

Today is track testing: each car must run a timed lap; then pass a steering test and a braking test, both at 35 km/h.

Peter Schloite runs a meeting for captains and drivers in which he explains how the whole day will work: cars will go out in pairs onto the track: either a pair of fast cars, or a pair of slow cars. Then we adjourn back to our respective pits.

I fire up the telemetry system. It (flip a coin...) works.

John lets Peter know that our car is ready to go. Since Peter can't find any other cars that are ready to go, he sends our car out first, by itself. We do our timed lap, and post 3'14". Then our car pulls into the drag strip to do the steering and braking tests. The only thing we do wrong is that we do them at faster than the mandated 35 km/h. But it's still a pass.

We are qualified. No other cars are yet qualified.

For a few minutes, we are winning the World Solar Challenge.

Then Nuna and Aurora go out on the track, and also qualify, beating our lap time by a large margin. Aurora post 1'53", with Nuna about a second behind them. (For comparison, V8 supercars do this track in about 1'09".)

Willetton's Sungroper qualifies 0.68 seconds faster than us.

I download 200 megabytes of stuff that John Treen has suggested will help with the telemetry. I also field some phone calls from my boss, who is a few hundred kilometres away in the Timor Sea, setting up some equipment on a floating oil production and storage facility.

We go to the briefing meeting at the showgrounds, where we meet our observer for tomorrow morning. Then we return to the pits, clean the array, pack the contents of the pit (including the car) into trailers and vehicles, and retire to the accommodation.

Tomorrow we begin the World Solar Challenge.

-- Doug Burbidge http://dougburbidge.com/

Doug's blog 23rd October: breakers and string

Yesterday was scrutineering.

We failed.

We rocked up somewhat before our appointed time at the Darwin showgrounds, some of us coming straight from our accommodation; some of us detouring to Hidden Valley to pick up the solar car. We all register, our drivers weigh in, and we are given ballast bags.

Meanwhile, Hammerhead has been moving around the scrutineering station. We pass the first two stations with flying colours. Since the first two stations are stickering (where they put a World Solar Challenge sticker on the car) and measurement (where they weight the car), it's hard to fail these.

The third station is driver seat angle and ingress/egress. The seat angle is close to passing, but not quite. Which is odd, because the same seat passed last year, and the rule hasn't changed. They let us through anyway.

They check the eye height. The rules require that the driver's eyes be at least 700mm above the road, and the way they check this is they put a driver in the car wearing black goggles, and shine a laser in. If the laser is below the mark on the goggles, it's a pass.

The laser hits out car below the bottom of the windscreen. So that's all good.

The ingress/egress rules require each driver to get in to the car in 15 seconds, and to get out of the car in 15 seconds. Some other teams are having trouble with this; we do it in half the time available.

Next is NT Roads, who check the car mechanically. They ask us to wrap some brake lines to protect them from abrasion. No worries.

Then it's electrical. There's a new electrical rule this year which requires battery isolation to be built integral to the battery box. Said isolation is to be operable by both the driver and the emergency pull on the side of the vehicle. Our car has isolation in both of these places, but it's not integral to the battery, so it leaves a metre or two of wire live, which is a no-no.

(Rumour later is that about half the teams have failed on this same rule.)

So we must re-work our isolation. John Storey, the electrical scrutineer, explains a way to do it with a 12V supply and some additional batteries to drive that supply.

We return to the track. Steve Morgan, on hearing about the problem says, "Just use some string!".

John and I pick up the relay from our old battery management system, and head out. We go to MM, who send us to Delta, who send us to ISAS, who haven't got a relay that big. We go back to the showgrounds and show our relay to John Storey, who says it's unsuitable: it's a solid state relay. The rule specifies that the isolator must be a mechanical device, and ours isn't. He tells us about a device called a "contactor", which is basically like a relay only bigger and uglier.

So we go back to ISAS, who send us back to Delta. We have a lengthy chat to Dennis at Delta, and John realises that we don't need the complicated deal with the 12V supply and the auxiliary battery pack if we have two separate breakers: one for the driver, and one for the side of the car. Both must still be contained within the battery pack, so to get the pull to those two locations, we'll just use some string!

Dennis sends us to MC, who sell us two breakers and some DIN rail. Back to the pits, to find the box we already have is just too small, so off to Bunnings and Jaycar to buy a bigger box and some conduit to run the string through.

Back at the pits we do enough work to prove to ourselves that this solution will work, then end for the day. Dinner is whatever we want at Mindil Beach markets.

The following morning it's a 7:30 departure for the pits to finish our new battery breaker system and some attendant rearranging of wires.

Then we want to get some track testing. I fire up the telemetry system and today it (flip a coin...) doesn't work.

We go without telemetry, and the car gets as far as the first corner, where it conks out. The people in the follow car leap out and have a look, but can't see what's gone wrong. They leave the solar car where it is and return to the pits to check with Challenge personnel as to how to retrieve it. They instruct us to bring it back up the drag strip. Peter S, the Challenge safety officer, meets us out there and guides us through the tyre debris all over the strip as we tow Hammerhead back to the pit. We troubleshoot, and track down the fault to a connector that I had assembled with insufficient force. We replace the connector, and the car goes again.

We do several laps, returning to the pits after each lap or two to change drivers. The car performs fine, except for the telemetry. Most people return to the accomodation while John goes to Jaycar for a null modem cable to help me debug it. We use the cable to grab a boot log from the car, and return to accommodation. This evening, most of the students will go to an official do at Parliament.

-- Doug Burbidge http://dougburbidge.com/

21 October - Bluetooth and Blunt Objects

21 October

Yesterday I focused on the telemetry. There's a Bluetooth dongle connected to an embedded computer in the car, which turns the car effectively into a Bluetooth device, visible to other computers. So we fire up a laptop, and tell it to search for Bluetooth devices, and the car pops up on the screen.

The first problem is that Windows wants to know the PIN for this new device. We guess a few at pseudorandom (0000, 1234, etc.), but have no success. We phone John in Perth who wrote the software, and he tells us that it's 7260, which is the model number of the embedded computer board.

Obvious, really. Why didn't we think of that?

(The reason that I am documenting this PIN here is that in two years I will have forgotten it, and will then search my own blog in order to find out what it is.)

We muck around with the boards to general success, and then move the embedded computer to a new location in the car, one that will be less vulnerable to getting hideously crushed whenever we lift the batteries in and out of the car.

After lunch we return, and test the car computer in its new location.

It doesn't work.

Damn.

Windows is showing it as a Bluetooth device, but not as a Bluetooth _network_ device, which is a necessary thing for it all to actually work. I rearrange things, reboot things, spin thrice widdershins, call John in Perth, etc., all to no avail. Some of my testing is done in the front seat of our follow car as Tom does test laps.

We wrap for the day without me solving the problem.

We get partway back to our accomodation before I realise that I've forgotten to turn off the car. "We've forgotten something, go back!" is becoming something of a catch-cry for the team.

Today it was down to the pits again for a little more testing before our next thing. We get there, and discover that we've left the Bluetooth dongle back at the accomodation. "We've forgotten something, go back!" And John does.

The rest of us stay at the pit and clean the sides of the trailer, because our next thing is a visit to St John's school.

John returns with the dongle, and I continue to attempt to narrow down the problem. It starts working again. I don't know why.

We pack the car into the trailer to transport to St. John's school. I am reminded of Hofstader's Law: "Everything takes longer than you expect, even when you take Hofstader's Law into account."

We visit the school. We're visiting this particular school because the principal is married to the principal of Leeming. The visit goes well, and most of the team return to the accomodation for lunch, while I and a few others go take the car back to the pit for more troubleshooting.

The Bluetooth stops working again. I don't know why.

There's a Tesla Roadster in the car park in front of the pits, charging. The charge cable is connected to the car at the point you'd expect the fuel cap to be, and the cable is as thick as the hose on a petrol bowser. The other end of the cable connects to a generator on the back of a truck. The generator is bigger than the car.

The Bluetooth starts working again. I don't know why.

I am becoming gradually more of the opinion that it is not Windows' fault, but is a race condition on the car computer.

Steve Morgan and crew work on the brakes. There are two sounds of Hidden Valley for me: one is the sound of a solar car zooming down the straight. This always causes me to glance up, too late: the solar car is no longer visible through the narrow end of our pit, and the only thing I see is the solar car's follow wehicle. The other sound is Steve Morgan calling, "Press... release... press... release...", as they bleed air out of the brake lines.

We end the day with the Bluetooth still working, and with us (reasonably) ready for tomorrow morning's event: scrutineering.

-- Doug Burbidge http://dougburbidge.com/

Monday 19th October

Yesterday we set wing for sunny Darwin, where the x are hot, and the y are hotter.

(You can substitute your own values for x and y. If you're stumped for a good value for y, I can tell you that it's pretty damn warm inside a solar car.)

This is my fourth World Solar Challenge, and my third with Leeming High School. As usual, we rocked up at the airport, and team leader John Beattie distributed a variety of odd-shaped packages to students to hand carry onto the plane, including two-way radios, cameras, embedded computers, and a spare solar car battery, for which he has had to phone Sydney and get a dangerous goods form.

We fly: thirteen students, one ex-student, three teachers, a principal and me. The captain comes back to chat to us during the flight, to find out what it's all about.

We arrive, and meet another teacher in the gate lounge. He's driven a school bus towing the solar car trailer, complete with solar car, four thousand odd kilometres from Leeming to Darwin. He hands over the keys, and gets on to the plane we've just got off. He'll do the reverse in Adelaide: fly in, meet us, take the keys, and drive back to Perth.

We make a mountain of our luggage, sign rental car forms, transfer the mountain to the bus, commute to our hotel in Darwin, and unload.

Nuna, the team who have won the last three challenges, are already there. We chat. They've been in Darwin five weeks, and have already pranged their car. (It's all better now, though.)

The rest of the day is quiet.

In the morning, John Beattie rises ridiculously early, as is his custom, and goes to get the logistics trailer which contains a wide variety of our supplies and which had been shipped separately.

The rest of us take the school bus to pit 19 at Hidden Valley racetrack. We meet and greet a variety of other teams, and borrow a spanner from Bochum to remove the wheel chocks from our trailer.

We fit the computer and the driver control board and displays into the car, and they all work.

Last time, I fitted the wrong thermistor to the motor. This time, I've made sure that I have the one the manual specifies: a 10k thermistor, negative temperature coefficient. I grovel around exensively under the car, taking the old one off the motor, verifying that the new one really really is negative slope by dipping it into a cold can of soft drink and watching the resistance decrease, soldering the new one on, turning on the motor controller, and discovering that it's still wrong.

It turns out that I did fit the one that the manual specified last time, but the manual is wrong, at least with respect to our particular controller. Our motor controller is one we picked up cheap because it was the manufacturer's prototype. A quick call to the manufacturer elicits a promise to have a look around and see if they can figure out what the right thing is, but given that it's a prototype of a now-obsolete model, I don't hold much hope. So tomorrow we'll probably figure out how to attach a different type of temperature sensor.

To finish the day, we take the car out for a couple of laps, with me in the driver's seat. All works well, except that when I pull back into the pit, I realise that I've left the handbrake on the whole time.

Spot the braincell.

-- Doug Burbidge http://dougburbidge.com/