NATMAP SURVEY BEACONS IN GOOD CONDITION

AFTER 46 YEARS

 

Canning Stock Route Traverse Survey Station Inspection Report 2010

 

Background

As an aside during a recreational trip along the Canning Stock Route in July – August 2010, several survey control stations were inspected on the Well 35 to Halls Creek geodetic survey traverse.  These survey stations were established and observed (by theodolite and tellurometer) in 1964 by a Natmap field party led by Reg Ford (RA Ford B.E.M [for meritorious Natmap service]).  This observing/beaconing party followed (but in reverse direction) an earlier reconnaissance of the traverse route by Natmap’s HA (Bill) Johnson.

The 2010 inspections were carried out at the request of Paul Wise, retired former Natmap senior surveyor.  The inspections were made on an opportunity basis; apart from NM/F/203, no out of the way search attempts were made to locate stations that could not readily be seen from the stock route track.  In the case of NM/F/203, the inspecting party detoured a few kilometres north from the Well 43 Billowaggi turn off to locate this station prior to returning to the along the wells route.  Equipment relevant to the inspections was: a Magellan eXplorist 600, hand held GPS receiver and Canon Digital IXUS 80IS, 8.0 megapixel, camera as well as 1:250,000 scale topographic maps.  GPS coordinates were observed at each station and terrestrial images captured.  The inspecting party comprised: former Natmappers: Laurie McLean (1969-1988) and Lawrie O’Connor (1966-1972) together with Dave and Lorraine Uren (Dave and Laurie served together as national servicemen in Vietnam during 1967-68).

Stations Inspected

Although a prominent land mark, this station was not plotted on the map.  Instead, the map plotted NM/F/2026 which was a recovery mark in the inter-dune valley to the north of the main station (beacon).  The relationship between the two marks was not known until the station summary was obtained and examined after the stock route trip was over (attached at end of photos section).  NM/F/2026 was neither sighted nor looked for.  The decision to plot the recovery mark rather than the prominent land mark (beacon) seems curious from a vehicle traveller’s perspective.

·      NM/F/201 was inspected at about 4:00pm (WST) on Saturday 7 August 2010.  Coordinates observed with the GPS unit held against the beacon centre pole were: 21 degrees 23.101 minutes South 125 degrees 49.495 minutes East.  Map sheet used: 1:250,000 NTMS: SF51-08 Percival, Edition 2.  Station Condition: All structural elements were observed to be in good order ie metal vanes, centre pole and bracing struts.  While the map indicates the track (so called Canning Stock Route) passes to the east of the station, in fact the main track was a couple of hundred metres or so to the west, a good bush camping site was located on the northern side of the sand hill on which this station was situated.

·      NM/F/203 was inspected at about 11:30am (WST) on Sunday 8 August 2010.  Coordinates observed with the GPS unit held against the beacon centre pole were: 21 degrees 11.921 minutes South 125 degrees 54.660 minutes East.  Map sheet used: 1:250,000 NTMS: SF51-08 Percival, Edition 2.  Station Condition: All structural elements were observed to be in good order ie metal vanes, centre pole and bracing struts.  .

 

 

Comment

Most of the survey stations inspected had a Landgate standard survey mark warning plate attached to one of the bracing struts.  Due credit must be accorded to the Natmappers who established these stations some 46 years ago.  These stations provided an important element in Australia’s national geodetic survey all those years ago.  They still stand as prominent land marks on isolated features in the harsh environment of the Great Sandy Desert; each one a monument to the skill and diligence of its creators.

 

Laurie McLean

8 September 2010

NM/F/198 (Courtesy L.McLean)

NM/F/199 (Courtesy L.McLean)

NM/F/201 (Courtesy L.McLean)

NM/F/203 (Courtesy L.McLean in picture)

NM/F/210 Crown Head from Well 48 (Courtesy L.McLean)

Observing at unknown CSR site in 1964 – beacon is lying on the ground prior to erection (Courtesy J.Combe – see Note at end)

NM/F/210 with satellite receiver over RM1 (Courtesy A. Porteous)

Example of Recovery Mark – Reg Ford in picture (Courtesy J. Allen)

Station position indicated during HAJ recce (Courtesy HAJ collection/Des Young)

Example of Recovery Mark – Bob Goldsworthy in picture (Courtesy OJB)

 

 

 

Coordinate comparison GPS on GDA datum v Station Summary on AMG datum.

Consistent difference of about 150m (5 sec) is indicative of datum difference.

COORDINATE COMPARISON

POINT

GPS

SS

DIFF GDA-AMG

NM F 198

21d 48m

41.70

46.73

-5.03

125d 34m

28.62

23.94

4.68

NM F 199

 

 

21d 38m

31.80

36.88

-5.08

125d 45m

58.50

53.84

4.66

NM F 201

 

 

21d 23m

6.06

10.98

-4.92

125d 49m

29.70

25.12

4.58

NM F 203

 

 

21d 11m

55.26

60.25

-4.99

125d 54m

39.60

35.01

4.59

 

 

Note:

Laurie’s investigation arose from his earlier trip when he showed me a photo of one of the trigs alongside ‘the Canning’ and we observed its good condition and wanted to know more. Reg Ford’s 1978 report “The Division of National Mapping’s part in the Geodetic Survey of Australia - activities based on the Melbourne Office, 1951 – 1969” provided the detail, like those who undertook the work listed below:

Halls Creek - Well 35 Traverse WA

 

R.A. Ford              Senior Tech. Officer Grade I

J. Allen                  Field Assistant (Survey)

D. Hutton              Field Assistant (Survey)

F. Combe              Field Assistant (Survey)                         

J. Combe              Field Assistant                                        

W. Bannerman      Field Assistant                                        

R. Francis              Field Assistant

C. Golya               Field Assistant

K. Snell                 Field Assistant

J. Coles                 Field Assistant WRE

E. Graefling           Field Assistant WRE

J. Driscoll              Field Assistant WRE

 

When Laurie mentioned his 2010 trip I requested he investigate the trigs in more detail, if possible.

This investigation showed that not only are the trigs in good condition, they have not suffered from any significant vandalism even though they are obviously visited by travellers of the Canning.  Hopefully this is a sign of respect by those travellers, for those who undertook the work, in such a remote place.

The stability of the sandridges is also indicated. There is little sign of erosion around these objects. The Recovery Marks were established as it was feared that over time the station on the sandridge would move or disappear and would have to be ‘recovered’ at some time in the future. It would now seem that the elements have affected the Recovery Marks leaving the main stations to continue to stand tall after 46 years.

Paul Wise

26 September 2010