TAKING ON DUNES: Andre Botha shares his advivce on taking on sand driving. Image: Shutterstock/ Philip Lange
Taking on sand dunes presents all sorts of problems for even experienced drivers – unpredictable terrain, inclines and drops and the inevitable bogging down in the sand.
From driving techniques to vehicle recovery the African Off-Road Academy's Andre Botha shares advice on tackling driving in sand.
Botha said: "The fundamental theme with sand driving is to conserve your momentum. Since traction is at a premium any increase in speed can be difficult, if not impossible, and you do not want to lose momentum as you may not be able to regain it."
Before attempting sand-driving, make sure you lower your tyre pressures as it will provide better flotation by increasing the size of your "footprint", improving traction. Ensure you have a pressure gauge and the means to re-inflate your tyres.
Botha said: "Park your loaded vehicle on a level surface and place a brick or rock a centrimetre from the sidewall of a rear tyre. Deflate the tyre until the sidewall just touches the brick and then measure the tyre pressure. Use this pressure as your starting point when initially lowering your tyre pressure for sand driving.
As you become more familiar with sand driving, you can alter this pressure as the terrain dictates."
"As you lower tyre pressures so the tyre becomes more vulnerable to damage or rolling the wheel rim. The lower the pressure, the higher the risk.
"Speed should be severely restricted at low pressures. To minimise tyre damage, it is important that these low pressures are only used on sand and tyre pressures should be increased if limestone or rocky outcrops are encountered, or when the terrain becomes more firm. Not doing so will almost certainly result in tyre or rim damage."
Try to follow the tracks of the vehicle ahead as they have already compressed the sand to form a firm surface. Botha adds that you should never drive over vegetation "as this will destroy it and lead to erosion and environmental damage".
Botha said: "Avoid rapid changes in speed when accelerating or braking. Braking on sand will cause a mound to build up in front of all four wheels and possibly prevent your vehicle from moving off again. Rapid acceleration simply digs in the wheels and can lead to slower take-off speeds.
Andre Botha, member of the African Off-Road Academy, courtesy of Arrive Alive.
"Take-off should be performed as smoothly as possible with gear changes done at fairly high revs. Sand driving requires plenty of engine power to get your vehicle "planing" on the sand. It is advisable to use low range as this multiplies the engine torque available and will provide that extra gear if you encounter a particularly soft patch of sand.
"Check that your tyres are pointing straight ahead when taking off to reduce the takeoff effort required. When stopping on sand, depress the clutch and allow the vehicle to coast to a stop. This will minimise any sand build-up in front of the wheels. If the terrain permits, coast to a stop, rather than braking, with the vehicle pointing downhill as this will aid take-off."
Avoid the soft sand at the base of most dunes and in gullies when stopping. When turning, make the turn as wide as possible to reduce the chance of bogging. Your front wheels act more like a rudder in sand and turning too sharp has a similar effect to applying the brakes. Steep sand dunes must be traversed only straight up or down.”
Bothas adds that you should never use the brake, "as this will cause weight transfer to the front wheels and can increase back end movement".
Despite your best attempts, getting bogged down is a regular occurrence. As soon as you become stuck, avoid the temptation to floor the accelerator.
Botha said: "Put the vehicle in reverse and gently try to back along your tracks as they provide a compacted path. When you have reversed a sufficient distance, try going forward again while being careful not dig yourself in. Hope you will travel further each time you repeat this technique and eventually be able to slowly pass through a particularly soft section.
"If you cannot reverse out of trouble get out of the vehicle and let your tyres down further. A rule of thumb is to drop them by a further 12 psi. Before trying to reverse out, remove the build-up of sand from behind the tyres. See if any part of the underside is touching the ground. If it is, clear the sand away to allow the vehicle to reverse out.
"You may need to try this several times. If necessary, continue to drop the tyre pressures to 10 psi.
"If you are still stuck and your tyres are down to the minimum pressure, you will have to resort to a snatch strap, winching or jacking to extricate yourself. The easiest method is usually by snatch strap, but this relies on another vehicle being present. If you are by yourself you will have to resort to winching (if you have one!) or jacking."
SAND DRIVING SUMMARY
• Lower tyre pressures to improve traction
• Drive smoothly with gear changes at high revs
• Ensure wheels are pointing straight ahead when taking off
• Avoid soft sand at the base of dunes and gullies
• Make turns as wide as possible
• ONLY travel straight up or down dunes
• Follow in others tyre tracks to drive on compressed ground
• Avoid braking by coasting to a stop
• Do not floor the accelerator if you are bogging down
• When bogged, try to reverse on your own tracks
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