Survey of International Border between West Irian and the Territory of Papua and New Guinea



Senior Surveyor, Department of Lands, Surveys and Mines, Port Moresby,

with a supplementary chapter on the surveyors involved by R. G. Matheson, Surveyor-General




This paper gives a brief summary of the history of the border between East and West New Guinea, and an account of the marking of fourteen points along that border by a joint Australian and Indonesian Survey Team.




Australia has only one international border, that between Papua and New Guinea and West Irian. At various times over the past half century, attempts have been made to define this border, but up until 1966 it was left virtually unmarked. This paper will be mainly concerned with the efforts of Australian and Indonesian survey teams, during 1966 and 1967, to fix a series of major markers along the border from the north coast to the south coast.


During the last 150 years, the territories have been administered by several countries over different periods, and negotiations between these countries as to where the border should lie have been long and pro­tracted. Attempts were made to have the border follow some natural features but other than where the border follows a section of the Fly River, these attempts failed. Currently, the border is defined as being the southern portion from the south coast to the Fly River as that meridian which passes through the middle of the mouth of the Bensbach River, the northern portion from the north coast to the Fly River as the meridian of 141 degrees east longitude and the central portion as the waterway (Thalweg) of the Fly River.


This definition allows for a very simple metes and bounds description of the border, but until such time as it is finally marked on the ground, its whereabouts are vague and the administering of people living in its vicinity creates many problems.


During the period when the two countries were administered by the Dutch and Australian governments, areas of population bounded by natural barriers and by ethnological changes were administered by one government or the other. After the Indonesian government took over West Irian, the uncertainty of political relations and the fear of relaxation of health regulations, amongst other things, accentuated the need for the border to be clearly marked on the ground. As will be seen from a description of the terrain given later, this will be a mammoth task.




The border cuts across the most diverse types of country including mangrove swamps, sago swamps, tropical jungles, extensive lakes, rugged limestone, and high mountain ranges, sometimes influenced by snow.


Commencing at Wutung on the north coast, the border rises from sea level to an elevation of 5,000 feet in crossing the Bougainville Moun­tains and then drops again to about 500 feet at the Moso River, all within a distance of 6 miles, and all covered in dense tropical rainforest; then the border crosses over the Kohari Hills, which rise to 3,000 feet and are heavily timbered, before entering the low swampy plains of the Bewani River. From the Bewani River the terrain again rises abruptly in the Bewani Mountains with its rugged limestone cliffs and peaks reaching up to over 5,000 feet. A short descent to Waris and then into the extremely rough limestone Border Mountains, with their huge sink holes, sheer cliffs, razor edged pinnacles, and dense tropical vegetation.


After leaving the Border Mountains, the border runs across almost 40 miles of the low flood plains of the Sepik River before commencing the huge ascent over the Star Mountains. These mountains are awe-inspiring with their 13,000 foot peaks, vertical cliff faces of thousands of feet, huge landslides falling for a thousand feet or more, dense rain forests on the slopes, moss forests higher up, their alpine grasslands where occasional falls of snow occur. From here to the west can be seen Mt Juliana with her permanent cap of snow.


From the Star Mountains, the border descends through broken ranges to the hilly country around Ningerum, then to the swampy low­lands of the Fly River. After leaving the Fly River, the border crosses some 15 miles of lakes before entering the heavy rain forests of the headwaters of the Merauke River. Moving south, the country changes to open savannah around Sota, then into the marshy swamps of the Tarl River and finally through mangrove swamps to meet the south coast at the mouth of the Bensbach River. All in all a horizontal distance of some 450 miles of surveyors' nightmares.


Brief History of Administering Governments


As mentioned earlier, the peoples of New Guinea have been admin­istered by numerous governments during the last 150 years.


Prior to 1828, the shores of New Guinea had been visited by various traders and explorers. In 1828, the Dutch established a settlement at Fort du Bus and proclaimed sovereignty over the southwest coast. Then in 1848, the Netherlands Indies Government laid claim to West New Guinea (west of 141st meridian) in the name of the Sultan of Tidore. In 1884, a British protectorate was proclaimed over the southern shores of New Guinea. This colony, known as British New Guinea, was handed wholly to Australia in 1906 and was re-named Papua. Also in 1884, the Germans raised their flag on the north coast and claimed Kaiser Wilhelmsland (German New Guinea). In 1914, Australian forces occupied German New Guinea and in 1920 a mandate was conferred by the League of Nations on Australia for this territory. The Territory of Papua and the Trust Territory of New Guinea were administered separately by Australia until 1949 when they were united for administrative purposes. Between 1942 and 1945 much of the country was occupied by the Japanese. In 1962 a United Nations Temporary Executive Authority replaced Dutch administration in West New Guinea, and in 1963 Indonesia assumed full administrative responsibility for this part of New Guinea, which is now called West Irian.


This continual changing of the administrative powers controlling the various parts of New Guinea have made continuity of the survey of the borders most difficult.


Brief History of Border Surveys prior to 1966


Only survey work carried out on the border between West Irian and the Territory of Papua and New Guinea will be discussed here. Con­siderable survey work was carried out on the border between German New Guinea and Papua but that is not the concern of this paper.



As explained earlier, the Dutch initially had claimed all land west of the 141st meridian, and that meridian in theory was the border from the south coast to the north coast.


In the early 1890s, marauding head hunters from Dutch New Guinea were raiding tribes in British New Guinea near the south coast. The position of the 141st meridian was not known so in 1893 a joint British-Dutch expedition went to the south coast to attempt to establish this meridian on the ground. The expedition landed at the mouth of the Bensbach River and took astronomical observations. The results of these observations put the mouth of the Bensbach River at 141° 01' 47.9" east longitude. Investigations showed that there were no natural features at the position of the 141st meridian that would make for easy identification so it was agreed to make the border, the meridian passing through the middle of the mouth of the Bensbach River from the south coast north to the Fly River. In exchange for this 01' 47.9" strip of country Britain was to get the country contained between the Fly River and the 141st meridian. The border north from the Fly River was to continue on the 141st meridian.


The next attempt at border marking was on the border between Dutch New Guinea and German New Guinea. In 1910 a joint Dutch and German expedition carried out extensive mapping of the country from the north coast to the Sepik River in the vicinity of the 141st meridian. It was hoped from this mapping to establish a border that would coincide with natural features and thus be easily recognizable in the terrain. As a result of this mapping the Dutch submitted proposals for a natural border but had not reached any agreement with Germany when Australia took over control from Germany. Subsequent discussions with Australia as to the adoption of a natural border never reached any finality, probably due to a rumour that there were oil deposits in the border vicinity.


After a series of incidents involving Australian patrols, Dutch patrols and migrating natives along the north coast, Australian surveyor A. G. Harrison, in 1928, took observations at Wutung village on the north coast and placed a concrete cairn inscribed:


"Lat    2 35 28

Long 141 0  13.5

The Dutch border is 400 metres west"


He marked the 141st meridian south to the Moso River, where he placed a second border mark. Surveyor Harrison's survey was done unilaterally and the marks placed were never adopted as constituting the boundary.


In 1933, a joint Australian and Dutch expedition established another mark on the north coast. In 1936 the respective governments agreed that the boundary along the 141st meridian should be a true north and south line running through this monument.


It is of interest to note here that the Australian surveyor on the 1933 expedition, a Mr A. A. Chauncy, agreed with Mr Harrison's observations made in 1928. In 1966, the Australian survey team again observed at Harrison's mark at Wutung and agreed in longitude to within 1 second of arc with Harrison. In 1936, the Dutch had triangulated from an astronomical point at Hollandia, a distance of some 20 miles. They differed in longitude with Chauncy by 398 metres. No further border survey work was then carried out until after the 1939-45 war.


In the period from the end of the war up until the Dutch left West New Guinea more efforts were made to finalize the marking of the border. Firstly the Australian and Dutch governments jointly agreed to undertake air photography of, and survey and map a strip, about 20 kilometres wide centred along the boundary. Australian and Dutch surveyors, by astro fixes and connecting traverses, agreed on a meridian for the middle of the mouth of the Bensbach River. These observations determined that meridian to be 141° 01' 07" east longitude. During 1962, a joint Australian and Dutch survey team established marks where the meridian of 141° 01' 07" east longitude intersected the Fly River at latitude about 6° 54' south and where the meridian of 141° 00' 00" east longitude intersected the Fly River at latitude about 6° 19' south.


The aerial photography was not completed before the Dutch handed over but was later completed by Australia and a series of reconnaissance maps of the border area was published by the Division of National Mapping. To help in the compilation of these maps, surveyors from the Papua New Guinea Department of Lands, Surveys and Mines took astro fixes in all villages along the border where there was doubt as to which side of the border they lay.


Now once again there was a change in administration with Indo­nesia taking over West Irian and another lapse in the progress of the marking of the border. During this particular period Australia, in late 1963, attempted to further define the border by erecting notices on roads and tracks crossing the border. These notices which carried the inscrip­tion "New Guinea International Border (approximate position only)" were positioned solely by reference to the reconnaissance maps produced by the Division of National Mapping and allied aerial photography. The placing of these notices was a unilateral action and led to political embarrassment when one notice was removed by an Indonesian patrol and when an Australian survey party attempted to replace it, the party was arrested by an armed Indonesian patrol and forced to abandon the project.


1964 Djakarta Meeting


First proposals for the permanent demarcation of the border by Australia and Indonesia were discussed at a meeting of survey authorities from both countries held in Djakarta from 31st July to 4th August, 1964. Australian delegates to this meeting were Mr B. P. Lambert, Director of National Mapping, Mr R. G. Matheson, Surveyor-General, and Mr J. C. Macartney, Senior Surveyor, both from the Papua New Guinea Administration. The proposals resulting from this meeting subsequently received the approvals of both governments and have been the basis for the survey operation to date.


The most important factor resulting from this meeting was an agreement on a technical description of the border meridians. These were that the 141 degree east astronomical meridian be accepted as the border between the north coast and the northern intersection of this meridian with the Fly River and that the astronomical meridian passing through the present middle of the mouth of the Bensbach River be mutually determined and adopted as the permanent border between the south coast and the southern intersection of this meridian with the Fly River.


This meeting also recommended that the border meridians be established astronomically at fourteen points from coast to coast and that the respective border meridians on the ground be permanently accepted as the geodesic joining adjacent border monuments.


The way was now clear for the border survey to proceed once again and the Survey Division of the Department of Lands, Surveys and Mines, Papua and New Guinea prepared a survey team to carry out the task.


1966 Canberra Meeting


It was almost two years before the Indonesians were able to attend a second meeting at which final arrangements for the method of conduct of the survey in the field were agreed upon and an actual date for the commencement of the survey made firm. This meeting was held in Canberra in May, 1966, and the survey actually got under way in June of that year.


The first part of the survey was the establishment of the fourteen meridian markers described above. This was completed in two stages, six markers being placed during an expedition in 1966 and the remaining eight during an expedition in 1967.


Survey Operations


Composition of Teams - It was agreed that the total number of personnel in the two teams should be balanced and that the teams be made up as follows:


Clearing team -

One survey officer.

Four labourers.

One administration officer for liaison with local population.

Medical personnel as considered necessary.

Four security personnel consisting of one commissioned officer and three others.


Survey team -

Observing team up to seven personnel including observers, assistants, and labourers.

Three security personnel.

Medical personnel as considered necessary.


Programme of Operation




A joint reconnaissance team made an aerial inspection and selected sites as near as practicable to the meridian at which the astronomical observations would be carried out. The sites were selected on major rivers at the approximate latitudes agreed upon at the 1964 Djakarta meeting. The choice of the sites on rivers was done for several reasons, namely: easy initial access by helicopter landing on the river bed; provision of water supply for use by the survey teams; provision of water and materials with which to construct the concrete markers; and finally, because most of the movement of people in these areas is along the rivers.

Preparation of landing, camping, and observing sites


It was the job of the clearing party to go into a proposed site and prepare a helicopter landing area, erect a full camp and clear a site at which the astronomical observations would be taken. The accompanying security team and liaison officer made the initial contact with any indigenous people in the area. At one site the local people had never before seen white people and the landing of the helicopter plus white people caused them quite some concern.


In the first instance, the clearing party would be landed, by heli­copter, on some suitable place in the bed of the river. The party then waded ashore, and with chain saws, prepared a helicopter pad adjacent to this site. These initial landings by the helicopter were most interesting as they sometimes involved vertical descents between trees hundreds of feet tall. The camp site was then cleared and the camp erected and finally the astronomical observing site was cleared.


Once the site was completed the survey team moved in, the previous camp was broken and moved forward to the next site in a leapfrogging action.


Survey procedures


Independent astronomical observations and traverses were carried out by both teams in the establishment of the meridian markers. Each team carried out their astronomical observations at separate points, theoretically on their respective sides of the meridian. They then traversed to a common point where their resulting co-ordinates for that point were compared and meaned if they agreed within the prescribed limits of accuracy. Traverses were then run to the meridian and a site for the meridian marker positioned. Once again, the traverses were compared and meaned should they agree within certain limits of accuracy.


Limits of accuracy


The astronomical stations had to be determined by both sides with an accuracy (mean square error) of plus or minus two seconds of arc.


In the case of a discrepancy of not more than 4" in the values of the common points as computed from the Indonesian side and the Australian side, a weighted mean was accepted as the conventional longitude/latitude. If the results differed by more than 4" the position of the points was to be redetermined by both sides until the results agreed within the pres­cribed limits.


In the traverse run to establish the common points and the meridian markers, the orientation (initial and final azimuth) had to have an accuracy of one minute and distances measured to an accuracy of 1 part in 1,000. These traverses were calculated on the International Spheroid.


Survey Methods


It was agreed that both teams could be free to select their own observational methods and stations for radio time signals. Latitude observations were corrected for refraction only, these corrections being in accordance with pressure and temperature readings. Longitude observations were corrected only for travel time of radio signals and where an impersonal micrometer eyepiece was not used, a personal equation correction of 0.09 seconds of time to the east was applied.


The Indonesian Surveyors used several methods of observations during the course of survey. They commenced by using a Wild T3 theodolite with astrolabe attachment and stars were timed crossing the circle of 60 degree elevation in each of the four quadrants. This time was recorded by one pen of a chronograph. The chronometer, radio time signals, and identifying marks being recorded on the other three pens. They used time signals from JJY or WWVH.


The Indonesians experienced difficulty due to misting of the surface of the mercury in the astrolabe attachment so then reverted to position lines using a Wild T3. They only used stars which they could visually identify using a star chart. As there was seldom large areas of clear sky, this method also proved difficult.

Finally, they accepted the offer by Australia to supply them with electronically precomputed star predictions and they then determined longitude by Almucantar pairs and latitude by meridian transit pairs in a similar method to that used by the Australian surveyors. A Wild T3 was again used by the Indonesians and a correction for personal equation of 0.09 seconds of time applied.


The Indonesians calculated their results in the field and carried out their traverses using the T3 for bearings and subtense bar for distance measurement. Azimuth for these traverses were determined by stellar observation.


The Indonesians appeared to have no knowledge of simple theodolite traversing and had never seen anything like the typical Australian five chain band.


The Australian Surveyors used the method of observing Almucantar pairs for determining longitude and meridian transit pairs for latitude, about twenty pairs in each case being observed over three or more nights. The following equipment was used for these observations:


Kern DKM3A theodolite with impersonal micrometer eyepiece.

Mercer mean time chronometer, with contacts making and breaking each half second and missing the 59th second.

Labtronics time signal receiver, type 21, with six crystals on frequencies 5, 5.425, 7.515, 10, 12.005, and 15 megacycles per second.

Labtronics chronograph.

Favag chronograph, 2 pens, with one input modified to take radio time signals.

Stop watch.

Barometers and thermometers.

Star predictions which had been electronically computed.


In the observations for longitude the stars were timed moving across an Almucantar circle of 35 degrees elevation, within 10 degrees of the prime vertical. Using the moving wire micrometer eyepieces of the Kern DKM3A, the stars were tracked across the Almucantar circle, contacts from the micrometer being registered on one pen of the chrono­graph and contacts from the chronometer being registered on the second pen of the chronograph at the same time.


Corrections to the chronometer were got by finding pulses from radio time signals and the chronometer to the trace on the cathode ray tube of the chronoscope where the difference was read to 5 milliseconds. The full second was checked both by ear and on the chronograph tape.

For time signals, the Australian station VNG was used whenever possible, alternatively WWVH was used.


A double Horrebow bubble was used to apply corrections to times of crossings of the Almucantar circle.


The east and west stars of each pair were observed within 20 minutes of time of each other to minimize refraction errors.


For latitude, altitudes were read to pairs of north and south stars crossing the meridian. A north star being paired with a south star transiting within 4 degrees of altitude and twenty minutes of time. The alidade bubble was moved before each pointing to a star, the bubble read, and a correction applied to the observed altitude. Stars were observed with altitudes of between 50 degrees and the zenith.


During the 1966 expedition, after the completion of observations the data was forwarded to Canberra where it was processed through the CSIRO computer. The results were radioed back and the full printed computer output was mailed back. During the 1967 expedition, the Australian surveyors reduced their observations in the field.


After agreement was reached with the Indonesians on the co­ordinates of a common point, the Australian surveyors traversed to the meridian using a Wild T2 theodolite and either a 100 metre or 5 chain steel tape. Azimuth for these traverses was determined by solar observations.


At the site where the observations were taken, concrete pillars measuring 20 cm x 20 cm and 60 cm high were set in concrete foun­dations.


On the north face of the Australian pillars was inscribed:





(BAS = Border Astro Station)


In the north face of the Indonesian pillars a marble slab was set and this was inscribed:




(TA = Titik Astro)


Recovery marks were placed at suitable positions about these pillars.


The meridian points were marked by a monument in the form of a truncated pyramid being 40 cm square at the top, 60 cm square at the base, 160 cm high and set on a concrete foundation, 1 metre square and 1 metre in the ground. Where materials were available these monuments were constructed of solid reinforced concrete. Where materials for making concrete were not available, the monuments consisted of an aluminium angle frame, sheeted with thick aluminium plate.


The monuments were inscribed as follows:



Latitude (on the north face)



Survey (on the east face)



Survey (on the west face)



The monuments were set in a clearing of 50 metres radius and recovery marks were placed at suitable positions about them.



The construction of the meridian monuments was always a joint effort with both teams providing man power and materials. These were always happy occasions on the survey, for although the work was arduous, the sense of achievement of completing another mark overrode the physical discomfort.




After the placing of the marks at each station, white cloth strips were laid about the marks in the form of a cross and the marks photographed from the air at heights of 300 ft, 1,300 ft, 3,000 ft, and 10,000 ft. This was done for identification on survey photography previously flown at 25,000 ft.


The taking of these photographs was a thrilling experience, par­ticularly from 10,000 feet as the helicopter had no door and the operator had to lean out holding the camera which weighed 15lb.




While most of the survey staff of the Department of Lands, Surveys and Mines have been associated with the border investigations from time to time, this paper is specifically concerned with the recent project resulting from the 1964 Djakarta conference. Until this conference work on the border was made under considerable hardship - no heli­copters, long patrols through the jungle carrying a minimum of camping equipment, and the bare necessities in the way of instruments and radio equipment.


The situation changed radically when the international project was planned. There was now no shortage of equipment and it was essential that the two parties which worked together "balanced". As the Indonesians required a security force to guard their personnel in such an isolated area, it was necessary for us to supply an equal number of police (these were the only armed personnel on the project incidentally). Similarly with other staff categories, equal numbers were supplied by both sides.

To organize these relatively large teams the approach of each country was quite different. The Indonesians appointed a surveyor to take charge of the actual observations, but other units - transport, security, etc., were each under independent control. We appointed a senior surveyor to take overall control and responsibility, and supplied him with survey, security and District Administration staff, helicopters, etc., to assist in accordance with his overall planning, subject only to their own professional obligations.


The Indonesian surveyor in charge was Dr J. Soenarjo, the Principal of the School of Astronomical Surveying in Bandung. He was assisted by pupils about to graduate from that school. Just prior to the end of stage two of the survey, Dr Soenarjo accepted a position in Saudi Arabia, and was replaced by Captain Tawil. The Indonesian surveyors proved accurate and efficient as the comparison of results will prove. The spirit of co-operation exhibited by them at all times was a major con­tribution to the success of the project.


Our officer in charge was Mr J. C. Macartney, a senior surveyor of the Department of Lands, Surveys and Mines. John proved an ideal choice for this task because of his understanding, among other things, of the fairly sensitive diplomacy required in such an operation. This was probably the first serious joint project by Australians and Indonesians, and was in an area where some embarrassment at diplomatic level had occurred. We are proud that the operation proved an important diplomatic success.


The first three observations were made by Mr D. P. Cook of the Division of National Mapping.  David was familiar with the sophisticated equipment used and Mr Lambert generously made his services available, as well, of course, as assisting in other ways too numerous to mention. David was replaced by Senior Surveyor Bruce Willington, from Wewak, who completed the remainder of the observations.


All other personnel - Australian and New Guinean - contributed willingly to the operation, but the responsibility rested most heavily on the officer-in-charge, and his observing team, including the two assistant surveyors, Erben and Edmonstone. The weather was not always kind, and an example of its effect occurred when the observing teams, Indo­nesian and Australian, were left at 12,000 feet in the Star Mountains for three weeks while weather prevented the return of the helicopter. The helicopter arrived the day the emergency rations ran out.


This doesn't end the survey, of course. There is still the major task of linking up these fourteen points over some of the most difficult country in the world. Then we are faced with the maintenance and preservation of marks against tropical jungle, winds and snow, and annual floods.


There is not much chance of surveyors working themselves out of a job in this country.



Indonesian Survey Team



Survey Mark


Extract from the discussion on this paper at the congress.


On being asked by Prof. J. V. Mackie how the monuments were to be connected, Mr Macartney replied that the Division of National Mapping had plotted the meridian on a series of aerial photographs and maps produced from this photography. However the control of this mapping was of a low order and the geodesics joining the monuments were being replotted. The maps thus prepared would be submitted to the respective Governments for ratification. Further ground marks between the monuments are to be placed later when required. The method to be used in the placing of these marks has not yet been determined.




MACARTNEY J.C. The Australian Surveyor, December, 1968, Vol. 22, No. 4 pp 249-262.

Reprinted with permission.