Stuck - again.
Axle deep in sand in the interests of science.
Getting dramatically stuck in the Sahara is not to be recommended, but earlier this year I was helping a Canadian scientist, Jan Franke, gather some data about depths of sand in the dunes of the Ubari Sand Sea, Libya. Breaking all the rules in our Health and Safety document, we took only one truck, my Carawagon, into the desert, but our research area was only about 20 km’s into the sand, we had a Satellite Phone, and there was a lot of oil exploration going on in the same area. We would never be stranded for long, should the inevitable happen.
Jan has developed an extremely powerful form of ground penetrating radar. What looks like a length or rope with two small aluminium cans distributed along its length, is dragged across the sand behind the Land Rover. A radar signal is sent out from the first one, down to a depth of about 50 metres, and received by the other one. This data is then transmitted, via Bluetooth, to Jan’s laptop, on his lap, in my passenger seat! A super accurate GPS system monitors where we are to within a 5 cm’s and the whole system builds up a pretty clear picture of what lurks below the surface. My role was to maintain a steady 20 kph and try and keep the Land Rover in a straight line, whatever the terrain.
I knew we would get stuck somewhere on this escapade and driving up a dune, in the hope of easing the Land Rover over the top and down the other side, I was unable to go fast enough, and came to a gentle stop with all four wheels off the surface and the centre cross member bottomed out on the crest of the dune. The radar ‘tail’ remained in a perfect straight line back down the dune elevation. This was not a huge problem and the two of us dug away at the warm, dry, sand under the Carawagon, then used the High Lift Jack to raise the weight as much as possible, so we could slide sand ladders under the rear wheels. This done, I had a ‘do, or die’ go at launching the Land Rover over the top, the rear wheels gripping the sand ladders, and the centre cross member now clear of sand. It worked and we sailed majestically onwards.
Jan was pleased with the data collected over a 30 km transect, but had ambitions to make history. He wanted to be the first person ever to build up a 3D image of a sand dune, down to a depth of 50 metres. Cynical readers may question the logic of this, as surely, it is just more sand, but this is not strictly true. Ground penetrating radar could show up unusual features long hidden beneath the sands - domestic structures, metal objects, or deposits that could be water, or oil. The latter having a great value.
The following day we found a low dune that would be easy to drive over and marked out an area 300 x 200 metres, using bright yellow buckets filled with sand - there was plenty about! Starting at one corner we drove slowly along the edge, did a big ‘U’ turn and drove back, the left hand wheels following their own line back again. Having completed that traverse, we did another ‘U’ turn and returned, the right wheels now in their track. After the first hour we stopped and assessed how far we had come. Disappointingly, only about 10% of the total distance. This was going to be a long day!
I kept the Land Rover in third and fourth gear, low ratio and the speed steady at 20 kph. Any faster could spoil the data. Any slower and we would not be able to finish the job and it would be difficult to restart another day.
Jan was able to collect 2.5 million data points, by the time we finished and checking it all later that evening we found we had driven a total of 120 kms. All within an area of two football pitches! And at no more than 20 kph! It had taken a whole day, but the data revealed there were actually two layers of sand - one blown in from the north, probably about 2000 years ago and another, more recent one, blown in from the South. Whilst there was no evidence of human occupation, there were some interesting areas of ‘weird data’, that may well have been the edges of small oil outcrops. It was these that clinched a meeting with a big oil company the following week and an opportunity for Jan to sell his process to the oil industry Geologists. With luck he will land a contract and I will hold an unofficial record for driving the most miles within a 200x300 metre rectangle of sand within a day!
Copyright Toby Savage.