Quite slowly, as the independent military windscreen wipers brushed back and forth across the windscreen, the back of our vehicle began to overtake the front. The trouble was that our vehicle wasn't a Volkswagen, it was a 4 tonne Volvo Military 4WD.

The sky was grey, even though the day had started with a rich yellow sunrise and a horizon-to-horizon double rainbow. As we continued south away from Balladonia, a steady drizzle sprinkled down.

In a very smooth and untroubled motion, with hardly any fuss at all, the back of the truck caught up with the front. So now we were travelling along the road sideways, at 90 degrees to our original (and highly desired) direction. I couldn't work out why we should be going sideways - after all, the road was perfectly straight, even if it was a bit muddy. I really didn't want to tip over. I knew with my inner soul that vehicles that travelled sideways sometimes tipped over onto their sides.

Volkswagens were always prone to a case of the tips. The Volvo did begin with a "V", and it was a whopping 2.4 metres from the ground to the top of the solar cells.

I remembered the last time, about 5 years ago, that I had gone sideways along the road out of control. I had nearly hit the side of the road, thanks to an unmarked 90 degree turn in the road, about 1 metre past the top of the hill, on a road that had been straight for 20 kms, and no reflective Scotchlight signpost!

The reduction hubs on each wheel did give me a beautiful rock-eating 40 cm ground clearance under the lowest part of the vehicle - the diff centres. But as I slid sideways down the road, I would rather have preferred the 20 cm ground clearance of a conventional 4WD.

But then I relaxed after a quick glance at the crew. Both Mary and baby Godzilla had their seat belts on, and I remembered that I had sensibly siphoned down the 80 litres of fuel off the roof when one of the two 140 litre tanks had emptied on our trip across the Nullabor. So if we tipped, we probably wouldn't get hurt or burnt, and I did carry a 3 tonne lever chain block, and nylon and steel ropes. There were enough trees around for anchors to pull us upright again onto our skinny 14 ply 8.25x16 inch Super Grippers.

I touched the brakes lightly, and then took my foot off the pedal. Touching the brakes did not give me back any control of the steering wheel, but at least it didn't make things any worse. But the truck was still spinning slowly, and we were still travelling down the road backwards. It couldn't hurt to be travelling slower, so I touched the brakes, and we gradually slowed down.

Anti-lock braking systems are a great idea if you're driving on a sealed road, but they're not so great on dirt roads. The Volvo had a simple but effective compromise. Whenever you worked the brakes, 4WD would automatically engage. This meant that the front and rear propeller shafts were turning at the same speed. I also had engaged the rear diff lock soon after passing the sign "Road Impassable When Wet".

Mary and I had figured that the road wasn't really impassable, because it wasn't really wet. We had come to WA from Sydney the long way, taking about 6 weeks to get to the Nullabor. And we had seen only 2 patches of rain in the whole 6 weeks, and certainly no rain for the last 2 weeks. So with this drizzle that had magically sprung up over the last 30 minutes, the road wasn't wet, it was just damp.

And when the drizzle turned into a light rain, we agreed that the dirt road would be still soaking up the water. We found out later that it had been raining on this road for the last 3 weeks.

And when the back of the truck began to snake from side to side, so that we were pointing up to 15 degrees away from our direction of travel, I'd done the right thing. I'd assumed that we were driving on very slippery mud. So I had engaged 4WD and the rear diff lock, kept our speed down to about 30 kms, and like magic, we straightened up.

We finally came to a halt, and I gave up on logic, and heaved a great sigh of relief. The right front wheel was touching the left dirt gutter, and we were facing 150 degrees back down the road.

We spent a few moments to savour the stillness, and to appreciate that we wouldn't have to spend half the day righting the vehicle. The problem was that I didn't have enough positive grip. I engaged the front diff lock, and got moving down the road again. The steering wheel kept on dragging to the left. Suddenly I realised that the left front tyre was flat. The reason that we had done that 150 degree spin was the drag on that flat tyre. I jumped out to change the tyre, and nearly fell over. The clay was so slippery, that just to get around without falling over, I had to walk like a long-term alcoholic, with my legs far apart.

The light rain turned into a steady rain, and I could hear the loud plops as the mud slurped off the truck onto the road. I quickly made the right decision - I took off my clothes. After half an hour nude wrestling with two 14 ply tyres, I was covered with mud. But I just turned on the engine to run hot water into the heat exchanger, plugged the shower hose into the bayonet fitting, switched on the electric pump and I was clean again.