Wet Sand Driving

[Andy]

Gents,

Can I have some advice on techniques and avoidances for driving on wet sand. As you are aware there was a rollover in Liwa at the weekend, thankfully there were no injuries, in the same weekend ME4x4 had a rollover in Liwa with an Xterra and I have also found out that a Wrangler (not with any club) rolled as well. I dont believe either our guy or the ME4x4 guy was doing anything stupid, and both are experienced in the sand in normal conditions. So I guess that there is something different about the sand at the moment which has caused these accidents.

Can I get some advice please from our seasoned members, this may also be of interest to other Newbies?

Thanks...Andy

[TINTIN]

I've been told that when the sand is wet a kind of crust forms on the top that is pretty sturdy, but if you are side sloping for instance, and the crust cracks the weight will be thrown to the lower wheels causing the center of gravity to shift rapidly thus causing the car to roll over. Also when stopping on a descent rapidly this can cause the same effect with the added stress of the front/rear wheels digging into the sand, these are also factors to beware of even in the dry, soft snad but more so after rain. So beware when sidesloping, or just avoid it alltogethert if possibe.

I hope this is correct and informative andy.

[Viking]

I did some sidesloping this weekend and it is OK to do if you keep the speed up. The problem occur when you starting to loose your speed and still pushing to stay up there. The risk is then that the car will start slide and the lower wheels will start dig. Suddenly you leave the soft muddy sand in the tracks or crack the upper layer and your wheels hit the firm layer beneath.
To go up and then steer down before you loose the speed is still OK based on my experience.
In the soft all through dry sand you can slide downwards but now you risk hitting the hard layer underneath and that might be enough to tip the whole car over.
Be careful!!!! I think we had more than enough of these already.

[mike0967]

Advise ? OK let me try some words here. Due to the firm and wet sand you can go virtually places at the moment you can only dream of during summer. The sand is hard as Tarmac and allows a lot more to do than usual. This is very, very tempting, but it has also downsides.

Hard like Tarmac means it is really hard. When you go straight line against the dunes, you can hit real hard on the other side or even on top of the crest and this may cause damage to the car. When you follow in a sideslope and you get into the deep tracks of the car in front of you, the hard sand may not allow you to steer, you drive like on a rail track, trying to escape left or right may cause your tyres to pop out as the hard sand gives so much resistance. With the dunes on steep downhills it may happen that the firm crust may be loosened by your car weight and floats down like an avalange on the soft layer under it, you cannot steer or do anything against it, it just takes you down.

The accidents that happen during this time of the year are not really attributable to the sand conditions, they are more attributable to the temptation the hard sand goes along with, e.g. that you can drive things that are impossible in summer where a winter Newbie track can go to an extreme fun.

Basic guideline is to avoid extreme sidesloping, especially if you are one of the cars that follow 2-3 others that left deep tracks already and to avoid steep and fast uphills against the dunes as you can take really hard hits when you come down on the other side. Also avoid heavy angles sidecresting as the hards sand may just float down with your car on the soft layer underneath.

Mike

[Xof]

:iagree:

long story short : dry sand = slidding VS wet sand = digging

Something else i have seen in a recent trip, newbie looking at more experienced driver get the feeling it is easy to side slope, dune climb, etc... With over confidence, you put yourself in some dramatic situation.

So only one advise (always the same): come play in sand, learn everytime, stay humble... then, you will find the answer to your questions by yourself.

[G-man]

Driving on wet season is fine but please slow down before you turn. really slow down. Do not accelerate hard out of a turn either which is no different than drifting. To me Drifting or side sloping on unpredictable terrain is a big NO NO.

On tarmac, its more predictable... But on the sand, wet or dry season, Any sudden deceleration in the lateral movement of the car could cause a roll over. Even in the most dry/powdery evil sand, if your wheels touches a bundle of roots while side sloping or drifting, that sudden deceleration of any of the "inside of the turn" wheels as opposed to the rest of the car...possible rollover.

Just physics mate... things want to keep going in the original direction and speed they were at before something slowed or stopped the bottom of the car, while the top of the car wants to carry on.

It could be anything, a bush, a hidden root, a fox hole.

Even the best of us with the most experience doing such maneuvers, always involves a bit of luck which no one can guarantee.

Just don't "side slope" or "Drift" Period. In any condition.

Its just not worth it in my opinion, to flip a coin every time to side slope.

If you want to feel Lateral G forces, go to Disney Land or join the Armed Forces.

Furthermore, we (the more experienced offroaders) should not encourage or endorse such driving at all.

Drive smartly and stay safe!

[vikid]

GMan: Very well said!

keep your motor always in your front.

[Abo Omar]

Very important advice , Perfectly said .... Thanks GMan

[Andy]

Thank you guys, excellent advice....

[Bulldozer]

Above all that keep inmind that U cannot fight against Gravity when u loose it (speed, momentum) steer dwn the hill or it will Roll u dwn.

[kghaleb]

very true and I think all the excellent tips mentioned here we all have experienced in different ways and levels ( G Man you are right - with a bit of luck sometimes)

Keep safe is the word...you won't get a medal

[Desert_Dragon]

easy advice...dont by FJ

[humaid_uae]

Driving on wet season is fine but please slow down before you turn. really slow down. Do not accelerate hard out of a turn either which is no different than drifting. To me Drifting or side sloping on unpredictable terrain is a big NO NO.

On tarmac, its more predictable... But on the sand, wet or dry season, Any sudden deceleration in the lateral movement of the car could cause a roll over. Even in the most dry/powdery evil sand, if your wheels touches a bundle of roots while side sloping or drifting, that sudden deceleration of any of the "inside of the turn" wheels as opposed to the rest of the car...possible rollover.

Just physics mate... things want to keep going in the original direction and speed they were at before something slowed or stopped the bottom of the car, while the top of the car wants to carry on.

It could be anything, a bush, a hidden root, a fox hole.

Even the best of us with the most experience doing such maneuvers, always involves a bit of luck which no one can guarantee.

Just don't "side slope" or "Drift" Period. In any condition.

Its just not worth it in my opinion, to flip a coin every time to side slope.

If you want to feel Lateral G forces, go to Disney Land or join the Armed Forces.

Furthermore, we (the more experienced offroaders) should not encourage or endorse such driving at all.
Drive smartly and stay safe!

I agree with you 100% as once one guy has rolled his car because of this..he was going up hill and then he decided to turn back...so he hit the accelerator so hard that one tire start digging and his car rolled over !!!

[Tom]

Sliding and sidesloping have been very well covered. I will talk about some other isues related to driving on wet sand. First, I like to run my tyres at much higher pressure when the sand is wet. The same terrain that needs 14 psi when dry can be done easily at 16 to 18 psi when wet. The wetter sand means there is a greater chance of your tyre sidewall being deformed when turning, starting up or reaching the bottom of a dune. This means you are more likely to pop a tyre off the rim. Running a higher pressure means the tyre resists the deformation and is much less likely to pop off the rim.

Second, damp sand holds it shape much more strongly than dry sand. This means that steep approach and departure angles that you can do easily when the sand is dry, because the sand will be swept away by your bumper, will now hold like concrete. You are much more likely to run you bumper into the ground when coming down a steep dune, or into the dune when starting up a steep one. The answer to this is to go more slowly, and to avoid angles where you bumper will contact before your wheels.

Cresting on wet sand is fun. It is great to see even short wheelbase Jeeps getting high centered at the top of sharp dunes. Once again, sand that would break away when dry will hold like cement giving you a nice picture of your car with all four wheels in the air. To overcome this you need to approach the crest just fast enough to get over without going airborne. Landing on hard sand gives much more of a jolt than landing on soft sand. The cost of going too slow is getting stuck. The cost of going too fast is damaging your car. Keep practicing with small increases in speed until you can judge them properly. Always err on the slow side to avoid problems.

Descending steep dunes in wet sand is much more dangerous than in dry sand. Your car will tend to pick up much more speed on wet sand tempting you to use the brakes. Using the brakes often causes the back end to swing around leading to a potential roll-over. The only way out of this is to accelerate just enough to get going straight again, only now you have the problem of even more speed. Going down steep wet dunes requires you be stopped at the top before going down to minimise your starting speed. Shift into low gear 1'st or 2'nd depending on which works better in your car. Let engine compression do your braking while going down to avoid sliding sideways. Only accelerate to keep the car straight. Avoid using the brakes. Hopefully you are still going slowly enough when you reach the bottom that your front bumper does not dig in.

My short wheelbase Defender 90 always tries to slip the back end around when I am the first one going down a wet dune. My long wheelbase Series III 109 does not have this problem. My advice is if you are driving a short wheelbase let someone who knows what they are doing go down first. You can follow in their tracks exactly and avoid having your back end swing around.

Going up steep dunes is also different. You get much more traction on the way up than you do with dry dunes. If you don't make it up the first time stop, switch quickly into reverse and let engine braking take you down backwards in your own tracks slowly. Try again a little faster next time or find another way around. If you approach a steep dune too fast you will bury your bumper into the face of the dune. Approach as fast as you can without this happening and accellerate hard once your front wheels have started up the dune face. It is better to have smoothly applied power without wheelspin than having your wheels spinning and sand flying. It takes time and practice to be able to feel when this is happening.

Once you reach the top of the steep dune you do not want to go airborne. Look at the paragraph on cresting above.

Little gullies and very small bowls, usually less distance across than the length of your car can be much worse wet than dry. Your front bumper tends to dig in and stay on the side you want to exit from. The only thing you can do is avoid them, or have someone pull you out backwards when you drive into one.

From my experience this advice will give a newcomer the safest experience in wet sand. It would be nice to hear what others think.

[9ball]

Love it when you give your input Tom, always learn something. Thanks!