Tackling the Desert by Bill Collyer

Tackling the Desert by Bill Collyer

Tackling our Deserts

 

Australia is over 90% desert so not surprisingly almost all 4WD drivers will at some time be on a desert adventure. Most will already have had 4WD driving experience so the following is more about the things you need or will encounter that are not written in all those “expert” articles. You may well disagree with some of what is written below and that is good since it means personal experience has given you a different approach and hopefully it is experience that is disagreeing rather than ” Someone told me that …………”.

 

First let’s talk about fuel. How much will you need? Not that long ago our sandy deserts were the province of petrol engines since diesels simply did not have the power to climb the sandhills, that has completely changed and now the serious desert traveller will be diesel powered. Yes you can take your petrol Freelander and it will perform well but remember that if the going gets really tough your fuel consumption will skyrocket. As a guide if you are getting around 10 litres/100 on the bitumum – petrol or diesel – then for tough open country desert (no track) your consumption can be as high as 30 to 40 litres per 100 for the diesel AND up to 40 to 80 litres per 100 for the petrol. No you read that correctly, the petrol vehicles can get consumption up close to a litre per kilometer when pushed. On a recent trip over the Madigan the two petrol vehicles used 310 and 330 litres ( a Prado and a Patrol ) and the two diesels 190 and 200 litres ( a Discovery and a td5 Defender ). Our pre trip calculations had indicated 300+ for the petrols and 220 for the diesels. Although the petrol guys were sceptical they did carry their 300 litres – and spent the second half of the trip worrying about fuel !

 

To do your trip fuel calcs divide the trip into segments of similar characteristics (of fuel consumption), multiply each segment by its likely consumption and add together to get the total fuel required. For an example we will use the trip from Birdsville across the Simpson via the QAA line and the French track to Dalhousie. (You cannot get fuel at Dalhousie but it will do for an simple example.) The section out to Big Red, about 60 km, is excellent gravel and you will sit on around 80 km/hr, that will give you consumption about as good as you will ever get, better than round town on the bitumum. So, say we are in a Discovery diesel, we will get about 10 l. per 100 km. The section from Big Red to Poeppel corner is big sand hills and wide interdunal flats, hard on the hills but a good run between dunes, mostly 2nd or 3rd high and 1st on the dunes, say about 25 l. per 100 km. – from memory a distance of about 120 km. From the Corner we take the French line, the sandhills are smaller but the track is more convoluted and rough making it difficult to run in the higher gears and also the lack of run up makes the dunes much more difficult. We will probably use about 30 l. per 100, for this section from the Corner to the Colsen track turnoff – about 130 kms. From here to Dalhousie the road is fair with sections of very good gravel so about 18 l. per hundred for this section of about 150 kms.

 

Add all the above together and we get 102 litres which will be very close to the mark. Yes you would use less if you are lightly loaded and gentle with your right foot ! But if Eyre Creek is flooded and you need to take the detour – an additional 80 km of rough travel – you will certainly use more. If you travel in the cool of the morning or evening you will use less or if you get stuck a few times you will use more. So on top of your estimated consumption you will need to add a

safety margin so you can relax and not pay too much attention to fuel consumption. The approach above is conservative so an additional 10% should be enough, that is 112l. should do the trick.

 

Now let’s talk about your load. There is a very simple guiding principle here, the lighter you are the easier it will be. Write down a list of your essential items for your trip – then cut it in half. The order of importance in your vehicle’s load is fuel, water, communication, first aid and spares. You may have noted by now that food did not appear on the list, and for a very good reason – you can survive for a very long time without food but only a few days without water. Of course you will take food but actually it is not essential. You will take other non essential items too: camera, wine, chairs and so on, but always bear in mind that these items are NON essentials. However having said that we are making our trip for pleasure and some non-essential items give us great pleasure (rum?) so we take them. Try very hard to keep your GVM below 2800 kgm, for smaller vehicles this should be less, for larger more, this is for a Discovery. For say a Defender this is about 3050 kgm. That gives you around 800 kgm for “stuff” which is actually not a lot. You should try to keep your camping gear ( tents, bedding, fridge, chairs, stove, utensils etc etc ) to under 200 kgm. You will not get close but keep trying ! Look critically at every item and ask yourself – it is essential ? – if it is ask if you can find a lighter substitute.

 

This leaves you 600 kgm for the rest, should be plenty, right. Wrong. First we have the extra fuel, let’s say 80 litres (56 kgms), then the water. In winter 1 litre per day per person is enough, so 2 adults, 2 kids for 10 days is 40 litres. Add to that our washing water and safety margin and we are at 60 or 80 litres, at least 60 for some comfort, but let’s settle for 80 (80 kgms). Your communication gear will not weigh much unless you are carrying HF radio when you should allow 20 kgms. A sat phone and charging gear is only about 700 gms. Similarly your first aid will only be about 8 kgms.

 

We are up to 144 of our 600 kgms already but I must digress on to the First Aid kit. For

serious remote work you should carry an extensive First Aid kit. As a guide to what that will include you can have a look at the AMSA (Australian Marine Safety Authority) web site for Class 2C vessels (trawlers and similar small vessels). It is only necessary that one vehicle in the convoy carry such a kit, all the rest can carry smaller versions. I actually carry my 2C kit stowed away and a much smaller one in the console for the minor wounds and scrapes – it includes things like band aids, panadol, cortisone cream etc etc, stuff you use often and need handy. The 2C kit does include things like antibiotics, silver burn cream, stitching and splinting equipment and so on, some of these items you can only get with a prescription, so look to your friendly GP.

 

Back to our load with now some 450 kgms remaining. The last item on our essential list is spares and if we are not careful this will take up all the remaining 450 kgms leaving no room for food and other luxurys.

 

First item on our spares list is the second spare tyre, this maybe a complete wheel or just a carcass if you are confident you can fit it. A carcass is to be preferred since the weight is a lot less and also it is light enough to be carried on the roof. Your rubber is very important and we should try for six new tyres, or at least four. We already have our own opinions about what is the best rubber and I

am not going to get into that argument. Suffice to say we should choose the rubber to suit the trip, tyres suited to sand for the desert, tyres suited for mud for Cape York. Together with two spares we will need tyre repair gear; compressor, plugs, tyre patches, tyre levers and perhaps a tube. While you can get punctures anywhere, the desert is the biggest culprit. On a trip from Tennant Creek to Lajamanu on the Wiso Track I managed 38 punctures in the 300 odd kms of the Track, we rated each puncture by the number of plugs needed – a ‘one plugger’, a ‘two plugger’ etc up to a ‘five plugger’. The two (new!) Front tyres were history and were replaced at Kununurra, the rears made it back to Brisbane before being retired after just 6000 km – but that was twice the 3000 km from the front. The rest of the convoy managed ten punctures between them but they were very careful to drive precisely in my wheel tracks ! So two spares and all the necessary gear to keep all your rims off the ground at least while you are moving.

 

So what other spares do we need ? Well all the ‘usual’, belts and hoses, oils (5 litres engine, 1 litre PS fluid, 1 litre gearbox oil, 1 litre 90/140, 500 ml brake fluid) and grease, fuses, etc etc. You may consider more exotic items, if you have a Nanocom or similar you will consider carrying some of the more common (and troublesome ) sensors, your local dealer may well give you an emergency pack which you can return on your return. One thing you really must carry is a wide selection of glues and adhesives, araldite, supaglue, silicone, contact cement, rubber cement and Tarzan’s grip. Your weightier spares will include a front and rear shock plus perhaps a coil spring if you are tackling some serious stuff.( On the Rovers you will find a nice spot near the gearbox to bolt the coil to the chassis rail. ) What weight are we up to ? The little lot above comes in at about 90 kgms which leaves us with 360 kgms for us, our food and all other luxury items such as beer and wine – good luck if you can manage it !! ( PS don’t forget some tools ).

 

We need a footnote about the distribution of our load. The big problem is how to get weight forward, in sand we want the weight on each wheel to be equal, or better still somewhat more weight on the front axle. The reason is simple, we will not get stuck going down the sand hills only going up and it will be the rear wheels that dig in – so get the weight forward. For serious stuff we carry 40 litres of our water on the bull bar together with the spare shockers and the tool box, about 75 kgms well in front of the front axle and this helps considerably. But we still try and get the heavier stuff as far forward as possible inside the car, the fridge just behind the front seats and so on.

 

There you have it. Keep your car light and well balanced and you have the battle half won. Once again I must stress just how important it is to be as light as possible.

 

Bon voyage,

Bill Collyer

One comment to Tackling the Desert by Bill Collyer

  • Geoff Taylor
    Geoff Taylor

    Spot on advice! Used the factors on the trip in 2016 with the club. All worked well, no breakdowns and all participants went up (shot up) Big Red from the desert with no changes and surprised the watchers . Thanks to Bill for the advice.

    Reply

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