Beach Sand PSI

Hi

Yes - soup is a good description of the sand+water mix sometimes encountered. Driving on dry (or partly wet) sand relies on the friction between sand grains to provide traction – letting your tyres down lengthens the footprint and results in an increase in the area of sand where friction between sand grains is being applied (in the direction of drive force – that’s why “fat” tyres are not necessarily better in sand).

In your circumstance the sand grains were more or less floating in water so the benefit of reducing tyre pressures didn’t exist to the same degree and possibly (depending on nature of sand/water mix and underlying lithology) it would not have been a solution at all as there may have been no significant friction between sand grains that could be harnessed for traction.

Best method I can think of is prevention (i.e. exercise extreme caution on beaches you are unfamiliar with) …especially when by yourself.

Cheers
Greg

Hi Ash,

At first I thought it was an early Friday Funny ……. Had me trying to work out which coast Kalgoorlie was actually on …. Lol ….. anyways ………….

I agree with The Explorer ………… prevention is far and away better than cure ……. although in the general scheme of things, the “do I have to go there??” is usually over-ridden by the “sure I do!!”

Driving on sand is a very neat …. and sometimes not so ……… balancing act between momentum and flotation …………. and it can take a few misadventures before getting it correct.

"Dropping the pressure more may have helped" ..... very possible.

How low can you go (with air pressure) before running the tyre off the rim is an issue?

Tyre manufacturers will tell you to go no lower than 20lbs pressure per square inch … or psi

Others may tell you to go no lower than 15 psi …… as the air pressure holds the tyre to the rim ………….. me, if I was REALLY stuck ……………. I would go to ZERO ……….. just to get me out of trouble and then re-inflate back to my optimum sand driving pressure.

There have been times when we have been driving in soft sand, where the tyre pressure is at 10 psi, other times it has been as low as 4 psi.

It depends on the vehicle type and conditions.

Cheers for now.
Wayne & Sally.

id say your issue was hitting the beach with road pressures in your tyres

20 psi gives little if any advantage i go to 12 psi straight away and dont have an issue

i often seed eastern states advice to start at 20 so i can only imagine how hard packed the beaches are over there

also dont be afraid to drop the pressures alot more in the situation you speak of i wouldnt hesitate to go to 5 psi to get out

also i very much suspect your tyre gauge could be not the best and you were running pressures higher than you thought

another thing to look out for is shell beds patches of cockle shells which swallow anything

Hi,

I have a 2006 Rodeo Diesel with BF AT's, we go onto Stockton beach near Newcastle all the time, often will a full load of scouts and their gear in the back, I find that 15psi works fine on even the softest sand when going over the soft dunes etc. I have heard of people going down as low as 12 psi on Stockton but much lower than that I feel at any sort of speed and you run the risk of rolling the tyre off the rim in a corner. (seen a couple of cars up there with tyres off rim, it's not a pretty sight).

Lachy

The tyre pressure required depends a lot on your tyres and the vehicle. My 3T cruiser needs around 20psi to make my LT BFG TA's suitable for easy sand. But I have been down as low as 10psi and driving very carefully to get thru in some cases. My previous (many years ago) Diahatsu on LT's neede 12psi just to get them to bag, it was a light vehicle with stiff sidewall tyres. And it has been as low as 5psi to get out of a soft patch.

Cheers

Captain

I have had a similar experience in Tassie where I thought having had plenty of occassions on sand in Qld, I'd be fine. My downfall was what I believe to be a variety of quick sand. As you were, I wasn't close enough to the ocean to be lapped by waves, but I sunk in a wetish mixture all the same. I'd say it was half water, half sand mix that looked relatively dry on top. It happened quick and there was no driving out. Luckily though we sunk to the rails and just stopped well away from wave or sinking danger. We had two vehicles so we got out fine. The scary part was 10 minutes after we had got out, there was almost no evidence of the car ever being stuck.

It does sounds a bit odd that another vehicle was driving on the sand well enough to tow you around. Did you ask what pressures he was running?

As for lowest pressure, I'd say single digits are out of bounds unless an emergency or you enjoy trying to refit sandy tyres back onto rims. (Or you're secretly running bead locks :D)

Hi Ash

I have been on beaches on the south coast from Esperance to Albany and some just have sand that has been fluffed up by storm or incoming weather. And you can get a beach around the corner facing a different direction that is so hard a push bike could ride on it.

When the beach has been all fluffed up as others have described there is just nothing that gets over it. It is much like a snow drift that is fluffed up. Only thing that might work is those track things you lay on the ground to drive over. Or some drift word or foliage.

I did get stuck on such a beach once with some friends. I was prepared to go down to single digit numbers and managed to tow the friends out but in the process of turning around rolled a rear tyre off the rim. Bit annoying but fixable.

So I believe there is times when some beaches just get too soft to drive on.

Cheers

Serendipity

Definitely grain size has a lot to do with it. As pointed out, the more famous east coast beaches (Stockton, Fraser etc) have a fine sand that compacts when wet and is about as easy as it gets to drive on.
Other places with brown sand beaches (N.T. has some crackers) are a bit more coarse and emulsify when wet.
The reef areas and torres straits have what looks like sand but is generally just decomposed coral which can be driven on one day and swallow a larc v the next.