DIVISION OF NATIONAL MAPPING

 

GREAT SANDY DESERT AND CANNING BASIN W.A.

 

GOING AND GENERAL INFORMATION SUPPLIED TO WAPET

 

22ND APRIL, 1963.

 

 

Editor’s Note: In 1952, under the banner of WAPET (West Australian Petroleum Pty Ltd)

Chevron and Texaco joined AMPOL to explore leases covering most of the

sedimentary basins of Western Australia for hydrocarbon deposits. In February

2000 the WAPET banner ceased to exist, operational activities now being

conducted by Chevron Australia Pty Ltd.

 

 

1.      Vehicles

 

We have had sterling service from all our Landrovers over many years. These are 109" long wheel base and fitted with 7.50 x 16 by 8 ply normal rood tread tyres - no queer bars or lugs are used which act as bucket scoops in the sand and dig down, as well as guiding in punctures, which would otherwise often glance off normal road tread tyres. It was with regret that 3 years ago we began to change over to bigger 1 ton vehicles (International) since the Landrover could not carry sufficient fuel and water plus technical and camping gear to penetrate such areas as the Canning Basin.

 

We cannot speak too highly of the performance of the 1 ton International AB120 trucks, 126" wheel base, which now comprise our entire cross-country fleet. Those are fitted with 8.25 x 16 by 10 ply normal roadtread tyres, and have two 14½ gallon petrol tanks on left and right sides with switch tap, plus a 60 gallon petrol tank built in the back, also a 50 gallon water tank. The radiator has been modified by International Harvester Company to take, a crank handle, and heavy bumper bar, stake screen and bough rods arc fitted, plus stronger air cleaner support and three steps to climb on the roof.

 

At 45 mph, (which should not be exceeded with these oversize tyres) on a good road, these 1 ton Internationals give 11-12 MPG. In normal flattish sandy cross country going they give about 6-7 MPG and in the very worst sections of sandridge areas encountered between Wells 35 and 45 the vehicle used gave 5 MPG.

 

This same vehicle had two 44 gallons drums of petrol battened immediately behind the 60 gallon petrol and 50 gallon water tanks. With the 4 gallon jerrycan, making over 180 gallons of fuel, this vehicle had a range of 900 miles in the worst of any going encountered.

 

In the trip of over 8000 miles from Melbourne to Callawa, Callawa to Well 35, thence along the Canning Stock Route to Billiluna, Halls Creek, Christmas Creek, Balgo Mission, The Granites, Alice Springs, Kingoonya, Ceduna, 150 miles North of Cook and back to Melbourne, the only troubles encountered were:

 

a) 4 punctures

 

b) slight carburettor trouble on one occasion and only through temporary inexperience of this type of carburettor

 

c) the nylon washers on the body holding down bolts wore out from the terrific pounding and could not be tightened, eventually tearing out several of the bolts. This was rectified at Alice Springs by welding plate tacks to the bolt head to prevent turning, replacing nylon washers by heavy rubber belting washers, and two lock nuts

 

d) 2 broken front springs, one 400 miles and the other 150 miles from Alice Springs, after negotiating over

 

e) 1000 sandridges and extremely, rough sand-filled spinifex bushes, even in the flats in many places. From experience on our other International 1 ton trucks, these front springs seemed rather light and are being strengthened. No rear springs on any of our Internationals have broken.

 

The axles were removed and examined at Alice Springs, were apparently perfect and were replaced.

 

The AB120 has a very powerful and efficient motor, with 4 forward gears, and high and low ratio in its 4 wheel drive. Most sandridges were crossed in 2nd gear low ratio - the easier ones in 2nd gear high ratio. 2nd gear is a very smooth, flexible gear, with a big ratio difference between 2nd and 3rd gears. On occasions, it was possible, in not very rough flats, to roll along easily, breaking a new track in flattish sand, in 2nd gear 2 wheel drive - 2 wheel drive gives a less rigid ride wherever it can be used, but engine revolutions must be kept up in heavy going.

 

1st gear low ratio was never used in heavy sand; or for crossing a sandridge. It is very comforting to have, however, when a slow crawl, or great power on firm going is needed.

 

Our supply trucks are 3 ton Bedfords. It was not necessary to take a Bedford right to Well 35, but it is thought a good driver could take one to Well 35 along the track from Callawa, even in its present state, and certainly if two sandridge crossings were packed with spinifex bushes.

 

2.      Tyres and Tubes

 

As mentioned, only normal roadtread tyres are ever used on our vehicles. Various members have various opinions of the best make and Olympic, Hardie, Goodyear, Dunlop tyres have all given good service. The surveyor who did the initial reconnaissance of the Warburton to Carnegie and Callawa to Well 35 to Halls Creek traverses on both occasions was fitted with Dunlop tyres, and has specially studied various performances under low pressures - he believes Dunlop are the best tyres he has used under such brutal treatment as we must perforce give them – being convinced that tyres are cheaper than transmission failures in remote area.

 

On reaching the sandridge area, pressures are dropped from 40-45lb on our International truck tyres (8.25x 16 by 10 ply) to 13-15lbs in the rear, and 11-14lbs in the front. These are cold pressures in the morning, and each side is carefully checked against the other. Valves must be watched in bad sand for turning and tearing out. With sensible driving this is a reasonably slow process and once it is seen to be angling the valve stem, the two back wheels should be changed left to right, and they will then work back the opposite way. On the Canning trip it was necessary to remove the rims and go all over the tyre-adhering part of the rims with a heavy cold chisel and hammer. This was quite effective. The front valves never moved.

 

Michelin tyres were tried last year unsuccessfully. Once under-inflated; the walls, which of course start to bear and spread the weight, were too vulnerable to the many sticks encountered. Special Sand Tyres, 9.00 x 13 have previously been tried on our Landrovers. They give good traction but are far too vulnerable to the bushes and stakes, which cover those so-called deserts.

 

We have used a product called Safety Seal in our tubes on four occasions. It is a mixture of hair and liquid rubber, which will seal a hole made by say a 4" nail, once the object is removed, and lets even a big staked tyre down slowly, so that it is not ruined, as can happen with a half turn of a flat tyre, at times - £60 lost on a Bedford.

 

If a vehicle is driven at high speeds on good roads, the heat will cook this Safety Seal, but with correct inflation and careful driving of not over 45 mph on good roads and since in the sand it is rarely possible to do over 20 mph, it will last a full season, which time the tyres will be finished most likely, anyway. It costs about £3 per tub, and quickly pays for itself in tyres and time saved from puncture-mending.

 

3.    Sandridge Driving

 

Speed, abuse of vehicles and rough handling, are the main causes of breakages and breakdowns. In sandridge country or rocky going vehicles must be nursed. Every sandridge should be inspected on foot before it is attempted. Even if the approaching side seems smooth, the top is often badly windscoured, or has rough solid sand-filled bushes, or the opposite side is so steep it is impossible to return in one's tracks should one wish to do so.

 

It is understood Wapet reconnaissance party trill have aerial photographs, plus the previously mentioned recent 1:90,000 compilation sheets. This is important since the sandridges are so thick in places that they often show as a white blaze on the 4 mile photo-maps.

 

If it is possible, it is strongly advised to select your proposed routes, using compilation sheets, and photographs and stereoscopes in the office, before leaving for the field. This will greatly help petrol conservation, and allow you to form your best positioned tracks for detailed ground investigation.

 

There generally is no difficulty in your Permit Area to travel along the flats between the sandridges, even for your trailers, and especially from West to East, since the prongs of the forked sandridges point that way.

 

Where sandridges have to be crossed, they should be examined firstly by fieldglasses for obvious low crossings, but if this gives no definite indication, it usually pays to head for the highest top, which will often be at a fork, or at one end of a saucer. The vehicle should stop about 100 yards from the ridge, and the best approach then selected on foot - this will save much turning and petrol. At the foot, look along both ways for the boot grade over the ridge - this changes frequently along a ridge.

 

Often the biggest, that is widest and highest, sandridges are easy to cross and far easier than low,

badly scoured ones with loose drift walls.

 

Any drifts, even with only a foot high face, are usually soft and hopeless. If no good crossing is obvious, walk along the ridge for a low part - sometimes the wind will scour right through, to give an easy low, smooth crossing. Also look for a sloping terrace - sometimes these can only be seen looking up or down them in one direction, so one should look back frequently, in case one has been passed.

 

A shovel should be carried on this walk and a few minutes spent in removing a sand–filled spinifex bush on the top, or on the approaching side to give a good run, may well save a gallon of petrol, or a broken spring or axle. The shovel can also be dragged to mark the exact route of the wheels, which can be vitally important, to miss an obstacle.

 

Physical energy and patience are essential where sandridges are being crossed, if transmission and spring breakages are to be avoided. In heavy going one can walk quicker than the vehicle, which can be waved on, as soon as a crossing is found, if it is standing 100 yards out from the ridge, much more easily than being turned if right under the sandridge.

 

4        Salt Lake Travelling

 

Lakes Percival and Tobin were found in the main to be sandy soil-covered dry marshes growing samphire and herbage - the soil being about 12 inches over mixed soil and gypsum crystals.

 

Although the International tyres sank about 4 inches into this softish soil, it was immediately compacted and gave an easy running track for further vehicles. In some parts sandridges were encroaching across the lakes, from 8 ft high ridges down to 6 inch high embryonic features, but rough and wind-scoured, and growing various bushes.

 

It is thought, with care, you could well use the chain of lakes, stretching from East of Lake Tobin, thence Westwards through the Percival Lakes, Southwards through Lake Wooloomber and Lake Auld, Southwesterly through Lake Auld and George, thence Northwest through Lakes Blanche and Dora to make a good supply route and then selecting your routes out generally along adjoining flats between ridges, which you wished to investigate.

 

Where those lakes are traversed, the greatest care must be used in selecting the initial route to avoid serious trouble.

 

The following points are made:

 

a) White surface salt is usually a danger sign and that the area is damp, and slippery at the least,

 

b) Be very careful and test with a spade or sharp stake the immediate 10 or 20 yards of any sandy edge of a lake, before driving over it, especially if the lake is damp on or near the top, even if hard crystals are 6" or 9" below this damp top. Seepage from the higher ground or flats often turns this sand (which is dry for the top, 6"-12") into a bottomless quicksand. This applies to many dry looking creek beds, which are fed by salty springs, especially soon after big rains which have made these rivers run, and whilst this sub-surface sand is still wet and oozy, even though the top 6-12inches seems quite dry,

 

c) The smoothest, hardest and safest surface is usually on the lake proper, 10-30 feet from the edge of the sand,

 

d) Test with great care any arms of the lake running inshore, before short-cutting across them. The only reliable way is to dig holes with a shovel to establish without doubt, hard bottom, and which is not too far down. Sometimes there is only an inch or so of dampish mud, which a vehicle at some speed negotiates easily, but this mud gets deeper as the sloping hard floor, probably of crystals, gets out from the shore, until the vehicle looses its speed and cannot be turned back before it is seriously bogged, up to the axles and deeper, far from the shore with no wood or bushes to pack and lift the wheels; which turn freely in this ooze, even over gypsum crystals.

 

It is easy to drive across fairly dry looking mud or crystals and break through into bottomless muck.

 

If the vehicle should be bogged in ooze over hard bottom, the tracks should be opened up to dry cut, especially over night, and at daylight next morning, with the tyres about 11 lb pressure (they should be well down for lake work, anyway, just as for sandy going) it will have its best chance of getting out before the capillary action from the Sun softens the mud. If a Lake surface of dampish slippery mud over hard crystals must be crossed, early morning, and the colder it is, is best for the attempt. For this matter, sandridges are always easier in early morning, and in Winter, and of course very easy after rain.

 

Unless the lake is tested and thoroughly known, it is very unwise to go far out. Getting bogged even 100 yards from bushes is hard work - several miles out could take days to get out.

 

e) There is no substitute for someone's walking ahead with a shovel to test by actual and frequent digging the slightest doubtful area; or where the surface changes colour or appearance; or where bushes or herbage finish, especially. Whoever is in charge of the party is the best person to do this.

 

5.    Water

 

A dyeline of Surveyor A.W. Canning's plan of the Stock route should be obtained from the Survey Department in Perth. This gives full descriptions of each well, depth, quality, quantity, its situation and surrounding country, etc., which are very helpful in locating these wells, some of which in sandridge areas are hidden in bushes and teatree, and not so easy to find now that no mobs have traversed the stockroute for 4 years, and all signs are fast disappearing.

 

Unless recent heavy rain has fallen, no rockholes, such as Water 38, Godfrey Tank, etc should be relied on. They were bone dry in September - October 1962.

 

Well 48 has completely caved in and Well 45 was dangerous in 1962, but all other Wells visited in 1962, and from Wiluna to No. 14 in 1959 were in good repair, and are likely to be so, still.

 

At Well 45(?) early 1960s

 

Dead birds formed a scum over the surface of all the Wells last September and October, with every day over 100°F, and this was brushed aside with the bucket before pulling the water.

 

There must be a foot or more of this sort of decomposition at the bottom of every Well, but only at Well 45, where there was apparently something very much more powerful, was the water boiled before pouring into the main tank.

 

Water purifying tablets would be well worth carrying.

 

Bucket and rope, are essential, and if much water is required for a big party then some pump, with its own small power unit, or fitted to a drive from a vehicle, and with a hose to be dropped down the Well, would be worthwhile.

 

There are no doubt many native Wells all through the area, but with the almost complete absence of aboriginals to point them out or to use them they are likely to be found only be accident.

 

However, wherever the broad-leaved teatree is found in the flats and near the lakes, and especially if associated with outcropping limestone, water is generally assured - also usually at depths from several feet as in the dry marshy lake at Well 42 (Guli Tank) to about 30 ft - but as a rule about 15 ft.

 

Near the water table, there seems to be a type of sandy limestone, fairly hard when it is wet in the hole, but softer and crumbly after exposure to the air and drying.

 

The Well dug near traverse station NMF177 was 12' deep and put down by shovel and bar, but a small boring plant, when any main work commences, would almost certainly, obtain water without difficulty at any teatree indications and doubtless at others more scientifically selected. Anywhere in the vicinity of the lakes seems very promising.

 

6.      Tracks

 

It is understood you may be taking boring plants and heavy vehicles into the Canning Basin though where, and to what extent doubtless depending on your preliminary geological investigations.

 

What type of prime mover is used to drag the heavy trailers is not known, but probably only caterpillar tracked types would negotiate any of the sandridges with trailers in tow unless great distances were added in “running out the ridges” to easy crossings.

 

Even the lightest 2 wheel trailers were found impossible anchors to Landrovers on bad sandridges, and hastened the change-over to long wheel base International 1 ton vehicles.

 

The following already graded or proposed tracks have been mentioned to Mr. Koop and marked on the maps handed to him:

 

a) Warburton Mission to Carnegie - Graded in late 1958. It was deeply cut in making, and was heavily scoured and washed in the first rains before any use was made of it at all. Last report in early 1962 was that it was badly scoured in places - it is doubtless filling up with light wind blown sand.

 

b) Giles to Warburton Mission - Heavy trailers, or even 4 wheel drive heavy trucks will find this very difficult and likely to cause transmission failure. The track traverses 70 miles of bad sandridges, which section even if there is a fair amount of traffic on it, can deeply drift over with one day's wind.

 

If it were necessary to take much heavy traffic between Warburton and Giles, a rough scraper dragged along the more South Easterly route which is approximately shown between Giles and Scamp Hill and near Bedford Range on the Petermann Ranges 1 million map would more than pay.

 

A few vehicles have been along this route, including a 2 wheel drive. It is not necessary to cross a sandridge along this route.

 

c) Callawa to Well 35 - At the moment this is only well-used wheel tracks. A scraper was dragged from about NMF167 to NMF176, over 100 miles, until vehicle breakdowns and supplies necessitated the return to Port Hedland of our Bedford truck which was doing the pulling of this light scraper, and by the time it returned, the survey was too far ahead, and time running out in October, to complete it.

 

However, by July or August, it is thought this whole route from Callawa to Well 35 and then Eastwards about another 120 miles to Jupiter Wall (marked on the plans given to Mr Koop) will be lightly graded by a Department of Supply grading party.

 

In this meantime your Landrovers will have no trouble in negotiating the National Mapping route from Callawa to Jupiter Well, and, as mentioned, even in the routes present state your Bedford should be able to reach Well 35 if properly driven, and some packing is put on several ridge crossings. There are two steep crossings some miles West of Jupiter Well which would probably stop a Bedford especially if travelling West to East but if needed before this track is graded about August, it should be possible to select a better route round these two places, and take a Bedford from Port Hedland to Alice Springs - Landrovers and Internationals have no difficulty on this present track.

 

Special care was taken in traversing the route from Callawa to Well 35. All vehicles kept meticulously in the main track; where necessary, sign posts were erected to show the main route; there were no odd wheel tracks going off to cause confusion to others, who might come along later, and who might well find themselves in serious trouble, if they took the wrong route; on the few occasions that investigating tracks did break off from the main route, boughs were placed across the side tracks in the normal bush sign to warn any potential user. The erection of appropriate signs for any turn-offs, especially well-beaten turn-offs, by any of your parties would greatly assist and avoid dangerous confusion to subsequent users.

 

d) Young Range Northwards to Well 35 - Work should commence in 2 or 3 weeks by the Depart­ment of Supply track grading party, in making a lightly graded track Northwards from Young Range to Well 35.

 

This is good going, with no sandridges involved, and it is expected this track will be rapidly completed.

 

This grading party will then lightly grade from Well 35 to Jupiter Well and from Well 35 to Callawa. After this it will probably return from Well 35 along the new track towards Young Range and at about Latitude 23° 20' grade a track generally West and W.N.W. to Wells 23 and 24 and the Mackay Range.

 

This spur may be done on the way North from Young Range, however.

 

Both approximate positions have been shown in Mr. Koop's maps.

 

Travelling in the same wheeltracks along the scraped track

 

e) Well 35 to Well 45 - Either late this year, or next year, a light cut will be made near the reconnaissance tracks from NMF162 to Well 45. No attempt will be made to make a track for heavy vehicles. It will be a light strike across the flats and square across the sandridges at the best crossings readily available, so that, a good smooth run can be made at each sandridge, instead of the rough, wind-scoured approaches and tops now prevailing. This would then make a comparatively easy route for International 1 ton and Landrovers.

 

f)  Well 45 to Billiluna - In April 1964, just prior to our survey traverse along the already reconnoitred stations, between We11 35 and Halls Creek, it is expected that a lightly graded track will be made from the general vicinity of Balgo Mission Westerly along the Stock Route past Well 51 to Crown Point and thence to Well 45.

 

A good supply base for petrol etc could be established for any future work in this general area, to work out in any direction from Well 45.

 

7.    Track Making

 

It is thought that a simple scraper dragged behind a small tractor, or tracked vehicle, such as a Bombardier (this has been explained to Mr. Koop), would more than pay on your operations, in smoother and much faster travelling and less mechanical breakdowns.

 

The more conventional this tractor is, the more chance it has of not failing at a critical time, or of not requiring some specialized part, hard to get, or impossible to improvise in the bush.

 

If a wheel-typed tractor is decided on, then advice on Safety Seal to fill the tubes, instead of water, as is sometimes used; seems well worth while, and also the obtaining of the smoothest tyres available, instead of the great ribs usually supplied on tractor and grader tyres, which break up the soft soil, as well as guiding in stakes.

 

Natmap’s tractor in action in 1967 in the Great Sandy Desert

 

Map of main locations

 

It seems impossible to get across to track makers, who rarely return to see the results of their ignorance and damage, how tracks should be made in those remote and light sandy soils, when such tracks will have infrequent use and probably little or no maintenance.

 

Unless there are stony outcrops or dense and heavy scrub, bull­dozers are unnecessary and can be destroyers of a new track.

 

It seems there is an irresistible compulsion on the part of most bulldozer drivers to turn on the great power available to them at the touch of a finger in pushing out trees (which might often be readily avoided by a slight deviation) and thus leaving great soft holes which immediately subside with the first vehicle and occasionally the first heavy rain, or in ripping down 12"-18" into the light soil, which had taken centuries to firm to its previous state, then pushing, the soil back and smoothing it over.

 

There is usually a 12" high bank of spoil (soil, branches and bushes) left on each side of the track, and often a foot deep channel cut on each side - inside the banks, supposedly to run off the water. The levelled off soft sand is usually full of broken stakes, puncture producing.

Two things should be appreciated about remote, arid, light, soil areas:

 

a) Rain is infrequent, but almost invariably, when it does rain, it deluges down, after a drought, probably inches in an hour, with no herbage to steady its rush on any slope. This water gets channelled in deep cut tracks, tearing ruts and washouts feet deep; and the track becomes simply a new watercourse.

 

b) On infrequently used deep tracks in flat sandy areas where every wind, puts sand on the move, these deep tracks fill up with the finest sand. With no traffic to consolidate this loose sand, it is soon much easier on the vehicle to get out of this deep, very fine sand and travel outside the track.

 

The whole success of making useful and lasting but infrequently used tracks in arid areas with light soils depends on the following:

 

Bombardier used by National Mapping in 1965

 

a) Cut the surface as little as possible and only scrape enough to level the surface reasonably; smashing and throwing aside, or spreading the sandfilled or small antnested spinifex bushes which make the travelling so slow and rough.

 

b) Avoid channelling deep long straights on slopes where the water can gather speed, volume and destructive power. A few very slight bends may help this on long slopes.

 

c) Avoid high banks of spoil as much as possible, by light cutting, and, if at all possible, by burning the spinifex. Burning spinifex is easy when in season, or just after seeding, and when the bushes are thick and the wind right, but it is far from easy at many times to get a running fire. Burning spinifex immediately improves the going, but after a few weeks the sand held in the bushes blows away, to improve going even more.

 

d) If a grader is used so that the spoil can be thrown either side, this spoil on a side slope should always be thrown on the low side. If on the high side water will bank up against the wall, break through, and channel deep gutters across the road every few yards, in the very first rain, especially before the surface consolidates, and there­after with every subsequent heavy fall.

 

e) If easy turns can be made, deep ruts will be avoided at corners.

 

Recovery mark and base line

 

The main purpose of the above track notes has been to let your parties know the great saving in time, repairs and money to your operations, if tracks are put down initially, and cut in the lightest possible manner, so that stormwaters can flow over them with least interruption and channelling.

 

They may be confused thought that the new beef roads are going down as high built-up sand tracks, with channels each side and a good camber to shed the water. These beef roads are well-used well-maintained and over 100 feet wide, shedding the water, which cannot saturate back to the centre to form a quagmire and cut up, as happens with the normal narrow track, 20 ft wide or less whose side gutters and walls on any flat, firmer, heavier ground hold the water to retain a morass long after the untouched, adjacent ground is dry or are channels of destruction on any slope.

 

A scraper was used by National Mapping along 100 miles of track on the Callawa to Well 35 traverse in 1962, as well as the recovery marks for its survey stations.

 

It cost £36, was made so it could be unbolted for transport, and even behind the Bedford, in flat and undulating going could form 15 to 20 miles a day of track, which immediately was far freer-running than the usual churned-up sand bog of most sand track makers whose result requires weeks of vehicular use plus the right amount of rain to consolidate.

 

8.    Vegetation

 

This area is no desert in the normal conception of a Sahara-like wilderness of live sand.

 

Practically the whole of it is clothed in spinifex, and undoubtedly some day will be grazed all over, when tracks and waters are down and cattle can be moved in and out quickly by cattle trains amongst the areas where the thunderstorms have fallen. This spinifex softens and improves with proper burning, and any burning carried out to make better tracks is more likely to improve than harm the spinifex.

 

The going in the flats between sandridges is generally open and good, though there are some flats of much rougher sanded spinifex,

 

Near Well 45, there was rough outcropping limestone and patches of rough teatree scrub, but this was the only such area encountered.

 

In the flats, small Grevillea (6'-7'), Hakea (6'-10'), various Eremophila (4'-), various bushy or spindly Acacia (4'-10') grow in a scattered manner, amongst the generally complete cover of spinifex. Only four patches of Mulga (Acacia aneura) were seen from Callawa to Well 45, three of the patches having recently died in the drought and with the leaves still on them. Near one patch, just East of Percival Lakes, big Eucalypts 25 ft high had just died, the heavier soil near the residual country there, drying out much more than when coved in sand, of course.

 

In the low tableland country from NMF178 to NMF180 many beautiful white-barked Eucalypts were growing. This section had had good rain, the spinifex was in head and it was the best pastoral area seen.

 

Fine stands of Desert Oaks (Casuarina decaimpana) are at Well 35, at Well 36 to Well 37 and further East, and on the Southern side of Lake Tobin. As with the coastal sheoak species, Desert Oaks appear to indicate shallow water.

 

Extensive stands of those magnificent trees were passed between Wells 50 and 51, and also about 30 miles West of Billiluna, on the track to Tonka Springs.

 

Of arresting interest are the number and size of the Eucalypts which grow on the sides and crests of most of the sandridges through the area traversed from NMF176 to Well 35 and on to Well 45, the flats between the rides being relatively bare of such tress.

 

Some of them are over 50 foot high, and 20" thick in the trunk. They are obviously responsible for some drifts 40 foot high, and so steep and knife-edged that the angle of rest of the sand seems impossible - these drifts will occur at times as tops right on the crests of some of these sandridges. Yet it is obvious from the size of the trees, and from examination of photographs, nearly 16 years old, just how stable those sandridges are. On one wind-scoured sandridge between Wells 41 and 42, roots 1" thick were seen 50 yards from their parent tree.

 

It is astonishing but it is presumed these big trees get all their water by precipitation from the infrequent rains which fall on and penetrate the sandridges, the loose sand however, retaining the moisture which would be lost by capillary action in firm loam or clay. This seems borne out near Well 45, where the sandridges become lower, and devoid of big trees, which then grow in the flats, but presumably reaching water, judging by the teatree and limestone indications.

 

No rain sufficient to make the spinifex flower seemed to have fallen between Wells 35 and 45 in the first 9 months of 1962 at least, and the area was very dry. North of Well 42 (Guli Tank), the spinifex in places was almost black-dry, very thick: and dead-looking. No fires seemed to have been through it for years, with the aboriginals now almost entirely at Balgo Mission.

 

In crossing sandridges, much depends on what type of season there has been immediately previously. If it has been a good season, the sand will be firmer, and herbage will also cover and help bind it, allowing easy crossings, which previously might have been difficult or impossible.

 

9.    Aboriginals

 

Smoke rose suddenly about 3 miles from the truck one after­noon, near Percival Lakes, but no natives were seen on approaching the area. There was a big mound of Desert Oak cones at Well 36, which looked fairly recently brought there, and recent footprints of two natives were seen in the soft damp mud, on one part of Lake Tobin.

 

These were the only fairly recant signs of aboriginals noticed on the entire trip.

 

Trees from which coolamons (carrying dishes) had been cut were very frequent, and several small caves, with paintings were found, but time did not permit examination of every likely cavity.

 

Grinding stones were on many of the high sandridges.

 

10.  Animal and Bird Life

 

Every Well had its cloud of Diamond Sparrows fluttering round it, and, as mentioned, with many drowned and floating on its surface.

 

Galahs were floating drowned in Well 36, and there were 20 or more galahs flying round Guli Tank, which was about 2 or 3 foot only below the surface.

 

There was also a very mangy fox staring balefully, till the truck was about 20 yards off, than slunk away. It was lying in wait for the galahs as they came in to drink and feathers showed it had unfortunately had one success.

 

In Lake Tobin, just 30 or 40 yards from the edge, amongst a lime­stone and mallee clump was a rabbit burrow, from which one of its inmates was seen foraging amongst the Desert Oaks in the moonlight. It is possible the burrow reached water, or else the rabbits got sufficient moisture from nearby samphire.

 

Dingo tracks wore seen on many occasions on the sandridges, but never sight or sound of the animals themselves.

 

No kangaroo or wallaby tracks were seen near the Stock Route between Wells 35 and 50, but presumably these dingoes obtain sufficient lizards and nocturnal rodents as their food.

 

Other than the Diamond Sparrows and Galahs near the Wells, the only other sign of bird life was 10 miles South of Well 48, where a medium­ sized hawk was seen sitting on the ground.

 

Scraper used by National Mapping in 1962

 

Although there is little daylight movement in the hot weather in Central Australia at any time, it is thought drought conditions had affected the fauna appreciably, as compared with normal numbers.

 

11.  Scraper for Track Making in Sandy Going

 

Top framework is of 4" x 2" channel iron, constructed for unbolting for transport.

Cutting blades of 10" x 2" hardwood, shod along the bottom and outside bottom with 2" angle iron.

Prow is iron shod.

10" x 2" x 30" wooden rudders prevent swing in rough spinifex.

 

Bondwood platforms carry sandbags, and it is important to adjust those bags according to the roughness of the spinifex - that is how solid the spinifex is with sand or small ant nests, and so that the scraper has just sufficient weight to smash and smooth these without digging a deep channel or making heavy pulling.

 

The length of towrope is important to avoid digging in. When smoothing sandridges, experiments should be made with the length of towrope and weight of bags. It is likely that little weight should be placed on the nose, and that a short towrope is used.

 

If dragged over boulders, the scraper will most likely be wrecked, especially at any speed and if weighted.

 

If a one way scrape is made, a useful track is formed at once, but if some traffic can use it and then a second unloaded scrape is made, a fast excellent track is formed.

 

Although this scraper can be readily towed behind a 3 or 5 ton truck, such as a Bedford, in flattish and undulating going, such vehicles should not be used in an attempt to drag the scraper over sandridges.

 

Some type of tractor is essential for sandridge smoothing as explained previously.

 

Heavy trucks will find fairly steep sandridges difficult or impossible, even if smoothed and cleared by a scraper or grader, but 1 ton 4 wheel drive vehicles will cross steep sandridges quite readily, if good smooth run can be made at them, with no turns to avoid secure, sandfilled bushes.

 

Any turning below the top of a sandridge, as a vehicle loses its speed, is what prevents most crossings.

 

A straight run to the top, at least, is important - even if a slight turn is necessary on top to avoid an obstacle, or to obtain a two way crossing down the other side.

 

Where areas of heavy sandridges have to be crossed, unless there is considerable and daily traffic, deep cutting by bulldozer to reduce the grade for 3 ton and heavier trucks will give no lasting benefit.

 

In one day, a big wind, can put several feet of fine, loose sand over the track, making it impassable to heavy trucks, and difficult even for 1 ton vehicles, probably necessitating mechanical packing by repeated attempts.

 

A caterpillar type of prime mover seems essential for heavy trailers to cross most sandridges, but in preparing the surface over a sandridge (no matter whether for a caterpillar or 1 ton truck) the last disturbance to the soil is likely to give the longest use.

 

Unless there is a definite terrace, a track square across the ridge at the best crossing is important, with just sufficient smoothing and clearing the surface of bushes and bumps for a clear, fast run.

 

                                                                             H. A. Johnson

 

 

 

 

 

This document was originally signed by H. A. Johnson as can be seen in a copy of the original below. However it did not include the photos. These have been added to illustrate the text and come from Reg Ford’s Geodetic Activities Report.

 

 

 

In February, 1954, Colonel H.A. (Bill) Johnson, Officer in Charge of the Royal Australian Survey Corps Training School at Balcombe, Victoria, joined the National Mapping Office as a Senior Surveyor in charge of geodetic surveys.

 

During 1961, H.A. Johnson became Supervising Surveyor, Geodetic Survey Branch and held that position until early 1968 when he retired from that position. He remained with National Mapping as a Surveyor Class 1 in a temporary capacity, working under the Director on field revision of various 1:250 000 scale maps.