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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 any momentum,
as you may not be able to regain it.
Tire Pressures
The first thing to do before driving on
sand is to lower your tire pressures. This is done to provide better flotation
by increasing the size of your "footprint" and thus dramatically
improving your traction. It also reduces the amount of strain on your vehicle
and minimizes wear and tear on the tracks.
The optimum tire pressure depends on your
vehicle, the type of tires fitted and the terrain. The following technique
provides a good starting point to find the optimum pressure and is best
performed before leaving the bitumen.
Park your loaded vehicle on a level
surface and place a brick 1 cm away from the sidewall of your rear tire. Deflate
that tire until the sidewall just touches the brick and then measure the tire
pressure. Use this pressure as your starting point when initially lowering your
tire pressure for sand driving. As you become more familiar with sand driving,
you con alter this pressure as the terrain dictates.
If you haven't performed the above
technique before you reach the sand, don't fret. A good rule of thumb is to use
a pressure of 15 psi.
Remember though, if you are going to lower
your tire pressures, ensure you have a pressure gauge and some means of
pumping your tires back up.
As you lower tire pressure, the tire
becomes more vulnerable to damage by stoking the sidewall or rolling the tire
off the rim. The lower the pressure, the higher the risk. However the gain in
traction can be remarkable and may make the difference between becoming
hopelessly bogged or simply driving away. The "correct" tire pressure
becomes a decision between better traction versus increased risk of tire damage.
In severe cases of bogging, tire
pressure can be lowered to a minimum of 40 kPa (6psi), as most tires require at
least 6psi to remain seated on the rim while stationary. In almost all
situations 10psi should be used as the minimum pressure as 6psi is likely to
result in tire damage ie. tires rolled off rims or punctured sidewalls. Speeds
should be severely restricted at these low pressures. To minimize tire
damage, it is important that these low pressures are only used on sand and tire
pressures should be increased if limestone or rocky outcrops are encountered, or
when the terrain becomes more firm. Failure to do so will almost certainly
result in tire or rim damage.
Sand Driving
Techniques
When traveling on sand, you should
endeavor to follow in the tire tracks of the vehicle in front as they have
already compressed the sand to form a firmer surface than un-traversed ground.
Never drive on vegetation as this will destroy it and lead to erosion and
environmental damage.
You should avoid rapid changes in speed
when accelerating or braking. Braking on sand will cause a mound to build up in
front of all wheels and possibly prevent your vehicle from taking off. Rapid
acceleration simply digs the wheels in and can actually lead to slower take-off
speeds.
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 amount of engine torque
available and will provide that extra gear if you encounter a particularly soft
patch of sand. Check that your tires 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 minimize 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 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 can be traversed only straight
up or down. If you drive even on a slight angle, the weight transfer is to the
downhill side wheels. If the vehicle starts to slip, the downhill wheels tend to
dig in and make the angle of the dune even worse, leading to a potential
rollover.
If you are traveling straight down a steep
dune and the back end starts to slip sideways, it is best to accelerate slightly
to try and straighten the vehicle. Never use the brake, as this will cause
weight transfer to the front wheels and can increase the back end movement.
If traveling up a dune and you do not get
to the top, reverse down the dune in gear, NEVER coast down the dune and NEVER
attempt a U turn.
When you return home after a beach trip,
it is important to hose down your vehicle to remove all traces of sand and salt.
Pay special attention to areas like the mudguards where sand is sprayed around
and tends to get trapped. Thoroughly hose underneath your vehicle as well, as
there are many nooks and crannies where sand con also get trapped.
Vehicle
Recovery in Sand
As soon as you become bogged, avoid the
temptation to simply floor the accelerator as this will just make vehicle
recovery more difficult. 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. Hopefully 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 tires 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 tires. See if any part of the underside is touching. 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 tire
pressures to 10 psi. Also, never underestimate the assistance of your passengers
giving a push. As mentioned earlier, tires can be lowered to 6psi in extreme
cases, but this should be avoided if other means of vehicle recovery are
available.
If you are still stuck and your tires 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.
Summary-Sand
Driving
- lower tire pressures to greatly improve traction and
reduce track erosion
- drive smoothly with gear changes at high revs
- ensure wheels are pointing straight ahead when taking off
- avoid the 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 tire 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
- thoroughly hose down your vehicle after a
beach trip
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