Towing in sand

Ok Steve,

If you are driving on sand you will have increased fuel use. If you are towing as well then it will increase again.

I drop my trailer tyre pressures to match the towing vehicle because the increased floatation it affords makes life easier for me and for the car.

I don't knwo if you have ever tried to push a wheelbarrow full of bricks along a sand covered path. If the tyre pressure is too high the barrow sinks in and becomes very difficult to push, if the pressures are too low then the tyre squirms about and it is hard to push. The right pressure is a compromise between these two, and is based on how soft the sand is and how much load is in the barrow. Same when you are driving in the sand. It applies equally to the trailer.

Is that clear, I have done a fair bit of this sort of driving and what I have explained above is the theory as explained to me. It is also what I have found to be hte case from experience.

Duncs

Don't worry about a decrease in econony, just that its a lot easier on the vehicles drive-train, and you may still get bogged, but its unlikely.

What you are doing by dropping tyre pressures, is increasing the "foot-print" of the tyre, ie its length, and it is that that gives you the grip. ( hope I put that right ? ).
The sidewalls will balloon out a little, but trust me that is secondary.

Puts me in mind about those 2 dudes at Big Red, near Birdsville, they had a 200 kw chipped up "wizz bang" Cruiser ute, with difflocks front and rear,, and they had about a dozen goes to get up that sand dune,, failed every time.

Finally they listened to me and dropped their pressure to 15 psi, turned off the diff locks, and guess what ??? ,,,,,, they actually got up there.

At a pinch I am prepared to go down to 8-10 psi, but only in a straight line.

As far as your trailer goes, then its still better to drop tyre pressures to give you the same "foot-print" as the tow vehicle, then all things are equal, and you then can enjoy the experience.
You can actually do this at home before you leave, on hard ground, by placing a bit of dowell, or twig, at the front and the back of each tyre, and measure the distance between them. Let the air out to get the same distance on all 4 tyres on your tow vehicle. Repeat the proceedure for the camper, loaded up. You may find pressures on the CT may be different, but the foot-print will be the same on everything. So when you hit the sand all you really have to do is to drop pressures to those predetermined at home ...

Hope I haven't confused you too much ?

All the best

Cheers
Bucky

It's not the 'broader footprint', but the longer footprint gained from dropping tyre pressures.

Some folk dispute this, advocating width as the definitive factor. Width will play a part but only in combination with length. I've seen garbage trucks etc drive onto beaches across the soft access tracks and get off again without lowering pressures. The length of the footprint is maybe twice that of a standard 4wd but no wider. But I can't see that if I had 13" wheels and was using wide rubber I would have superior traction to my 16" wheels with a much larger rolling diameter.

I think weight plays an important part in regards to the above; a very light-weight vehicle like a quad-bike WILL get enough flotation with small wheels but wide rubber, but the heavier the vehicle the more important the LENGTH of the contact is.

We could try an experiment; soft sand and two tyres. The aim is to push by hand each tyre through the soft sand. One tyre is 5 feet high and 3 inches wide, the other is 3 inches high and 5 feet wide. Now add 2.5 tonnes of weight or more on to 4 of each tyre and think about which one will be easier for your vehicle to drive/push/pull around.

A longer footprint on your trailer's tyres will reduce the stress on your vehicle and reduce the chance of becoming bogged. I would be thinking that a fuuly loaded trailer with High pressures being DRAGGED through the sand would increase fuel consumption.

Skis (long) are better on soft snow OR sand then ordinary shoes (short).

And thats the long and short of it.

Traction AND support to prevent sinking. As already said above, it's a compromise between pushing a bow wave of sand (drag) and more support.

So larger Diameter AND wider tyres on lower pressure and everybody should be happy.

Slightly OT but have a look here:tyre pressure changing on the move they've got a movie worth seeing.

I think this bloke Site Link has a pretty good handle on sand driving (and with trailers)....

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Thank you one and all. I only posted this yesterday. 442 views and seven replies and a few bites. Amazing.
I like the tip about testing the footprint while at home to determine the correct pressures for the towing vehicle and the trailer... I'll do it.
I expect that we will have plenty of time to experiment with this ourselves on the Googs track. We're coming down from Nth to South and we're in no hurry.
Thanks again everyone who posted a response. This is a fabulous resource.
Steve L.