There are many different types of terrain when you go off the road. Mud, rocks, gravel, uneven ground, steep climbs – you name it. But the most popular surface of all for off-roaders, says Francois Rossouw, is sand and dunes.
The advantage of sand is the fact that it does not damage a vehicle like the hard stuff. The vehicle can lie on its belly on a dune and be towed out without damage.
However, driving in dry sand is quite difficult, especially the sand in dunes, which get very loose.
When the sand is wet after rain, it is much easier to drive in. You get up the dunes much more easily and don’t need to deflate the tyres as much. But sand that has had just a little rain a short while before you tackle it may still be loose, although it is wet. This is when sand driving gets a bit trickier.
On the flat, it is easy to drive through wet sand, but getting up a dune becomes a problem. If you’ve got enough momentum the vehicle gets up easily, but if you accelerate as you would for normal loose sand, it is easy to overdo things.
It rained on our last Kalahari trip – just a few millimetres before we got there – and the top 30cm of sand was wet, with a dry section below it. It was in these conditions that Festus Balt floored his Land Cruiser to get up a difficult dune. He is used to soft, dry sand and accelerated hard in order to get as much momentum as possible, to ensure that he did not have to try a second time. After all, his ego was at stake!
The harder sand on top caused the 4×4 to go up the dune much more easily than usual, and before he knew it the Land Cruiser was airborne. All four wheels lifted off the ground, or shall I say the sand, and he started flying.
Festus was lucky that the dune was round at the top, so the landing wasn’t as hard as it might have been. However, while he was in the air, the brakes obviously couldn’t work, so when he finally landed, he ended up on a grass knoll and had to use all his experience to keep the Cruiser under control.
Everybody in the group saw what had happened and was very wary of the harder sand. Drivers exercised such caution that in the process they over-compensated, causing quite a few vehicles to get stuck on the dune.
Because the sand was slightly wet and loose, it could be dug out by the wheels very easily. As soon as a wheel started spinning, it dug in so quickly that by the time the driver realised the wheels were digging in, he was already solidly grounded, and had to be pulled out.
The wet layer of sand that had caked together was quickly kicked out from underneath the wheel and a hole developed, while the other wheels were still on the wet, harder sand.
When you eventually reach the dry sand below the wet layer, the driving gets tougher and you are more likely to get stuck. So keep in mind that a little rain does not spoil the driving fun in the sand; it just makes it a bit more technical.
On the other hand, a lot of rain makes the sand so hard that it is much easier to get through the dunes. In such circumstances we normally choose steeper dunes and shorter approaches, so that the challenge is still worthwhile.