Into the Desert - The QAA Line
Friday, 5 November 2021
The Simpson Desert is a vast area covering central Australia. It is made up of a series of high sand dunes hundreds of kilometres long. During winter it is a adventure to drive a number of sandy tracks across this vast area. From 1st December to the 15th March the area is closed because of the extreme heat.
These desert tracks include the QAA line from Birdsville to Poeppel’s Corner, The Hay River Track north to Madigan’s Tree. The Madigan’s Line east back towards Birdsville.
Each track means driving over hundreds of sand dunes some 20-30m high.
The most famous is Rig Red.
To drive such dunes is a art, and that art is very much vehicle related. The normal ( and I add incorrect ) process for a Landcruiser etc is to hit the dune at high speed allowing the momentum to carry you up and over.
In a 6 tonne truck, speed is just not possible. Hence it comes down to driving style, tyre pressures and choosing the correct gearing. In this new Gaz that process took about an hour to experiment with different techniques to finally get it down to perfection.
The process started with the first accent in low range and tyres still at gravel road pressures ( Front 45 + Rear 55 ). We know it was not correct but one has to start at the beginning. Without speed and simply because there was no flotation and the Gaz stopped 3/4 the way to the top of Rig Red.
Now it is a matter of finding the balance between how far down one can take the tyres for improved flotation and on the other side the reliability if keeping the tyres on the rims knowing there is some rough country ahead. Keep also in mind, at this late time in the season nobody else is out here, we are extremely remote and any repairs have to be attended to ourselves.
Gaz recommends as low as 0.9Bar ( 13PSI) with a maximum speed of 15KPH, I know that is too low for inter-dune travel, with the potential of sharp ruts.
Slowly we experiment with decreasing pressures and at the same time experimenting using the 1, 2, and 3 gears manually, automatic drive, and High and Low range.
Big Red is driven in low range auto with the Front 2.1 Bar and Rear 2.5Bar, it works well but we think there is still a better option.
The tyres are now at Front 1.4Bar ( 20Psi) and Rear 1.7Bar ( 25Psi), in high range it is much improved. The best unstressed drive was using the 1, 2 and 3rd gears manually as the auto seems to change down too late when needed for the accent.
This Gaz is fitted with the optional after-market Allison Auto 6 speed box. It is a brilliant transformation, but what we have discovered is that it ‘learns’ and is adaptive to the driving style.
Hence after a few attempts the auto now responds spectacularly .
Truly after this ‘learning’ its brilliant.
Approaching a sand dune in high 4x4 Drive, speed is at a comfortable and controllable 20KPH, the Gaz walks up at this speed, as the steepness increases the auto changes down with ease, then approaching the crest where there is a more vertical sand blow, we apply slightly more power and the gears change down again. Surprise, that kick down actually increases speed and you can feel the power as the Gaz impressively climbs the final ridge.
For a 6+ ton truck to drive such dunes is a pleasure.
Some words on the Gaz 4x4 system:
Engaging 4x4 automatically disconnects the ABS system ( very sensible) it also disengages the exhaust brakes. Also sensible because when descending a slippery hill the last thing you want is a sudden application of breaking causing a slide.
Turning the 4x4 knob from 4x2 to 4x4 can be bone on the fly and a light is shown on the dash. There are no free wheeling hubs.
From 4x4 High to 4x4 Low the vehicle must be stopped and a further dashboard light is shown
Todays run is on the QAA line and it’s 148Kms to the salt lakes on the Nth Territory /Queensland Border.
We are late in the season so the sand is dry and soft.
Our process of dune driving is perfected and there is not one dune that caused issues.
Tonight’s camp is just off the main track and about 15kms short of the salt lake on the Nth Territory border.
We have our 4x4 GX Fuso Canter based motorhome and John and Bill are swagging it.
Here we are:
North west of Poepple’s Corner
