Some of the oldest trig stations in NSW are in Sydney’s north, which was extensively surveyed in in the early 1880s. The Trigonometrical Survey of New South Wales commenced in 1867 with the selection of the first baseline at Lake George, with most of the trigs in Sydney’s north constructed in the early 1880s. The history of these trig stations was extensively documented by Tony Dawson in Guide to the Historic Trig Stations of Sydney’s North (2007).

Early Surveys and Land Grants

While the rugged terrrain of Sydney’s north meant it avoided development in the first decade of Sydney’s colonisation, by the early 1800s the first portions of land were granted. In 1807 James Meehan surveyed a parcel of land for William Gore and Isaac Nicholls, and in 1814 a 400-acre allotment was given to Daniel Mathew at what is now Roseville. Between 1814 and 1821 (before retiring in 1822), Meehan mapped the coast and lagoons between Barrenjoey and Manly Beach, with 17 land grants being made in this area.

Arriving in Sydney in 1827 as the deputy Surveyor General, Major Thomas Livingstone Mitchell undertook a more systematic approach, adopting trigonometrical principles to divided the colony into counties and parishes. (A year later with the death in May 1828 of John Oxley, Mitchell became the Surveyor General, remaining in charge of the Survey Department until he died in 1855.) Supported by a team of surveyors, Mitchell divided the colony into nineteen counties and mapped Sydney’s north as far as Church Point. Despite these efforts, even by the 1870s the parish maps were still fairly inccurate, with warnings such as “The position of the Railway Line from Homebush to Waratah as shown hereon is only approximately correct due to the inaccuracy of the map”

A new approach is needed

In January 1855 William Thomas Denison arrived in Sydney as the new Governor-General, and quickly concluded that the Surveyor-General’s Department needed a drastic overhaul. He found that the lack of any permanent reference maps meant that the cadastral mapping system was unreliable: in many cases boundaries were incorrect and portions of land encroached each other, sometimes by a significant amount. Despite Mitchell’s “trigonometric approach”, Denison’s Commission of Enquiry found that the previous surveys “could not have any claim to the character of of a ‘trigonometric survey’ in the correct and ordinarily received acceptation of the term“. By the early 1860s, stations used for triangulation were established in the Albury area, and in 1869 Lake George was selected as the most suitable location to establish a Base Line that would extend across the colony.

A formal Trigonometric Survey is established in the north

In December 1880, Pittwater Trig on Tumbledown Dick Hill (the highest point on the Lane Cove Range) was built by Thomas Charles Swannell, a piling overseer. Over the next few years, Swannel and his team built over 80 trig stations across Sydney’s north – most of them substantial stone cairns up to two metres in height. Most of the trig sites were high points along the main ranges, which were often challenging to reach. Before the trig station could be built, the hill or high point had to be cleared of trees.

At the same time as Swannel was building the trigs, connecting these into a network (which would form the basis of accurate maps) was the job of the Trigonometric Branch. First class stations were used for large-scale triangulations – forming triangles with sides up to 60km in length – while the more numerous second-class and third-class stations were used for lcoal surveys. During the 1880s much of this work was done by Frank Burdett, who made extensive surveys around the Hawkesbury River and Cowan Creek, and played an important role in the survey of the Parish of Manly. His legacy is witnessed by the many arrows cut into the rock as survey marks, although he also used the newly established trig stations as reference points.

Summary of original Sydney North Trig Stations

The trig stations below were listed in the 1895 Register for the Trigonometric Survey of NSW and the 1891 Register for the City of Sydney.

Name Number Built Location Height Condition
Addison TS594 1882 33°41’11.4″S 151°15’30.7″E 200m Partly destroyed
Allison TS620 1882 33°40’17.0″S 151°08’33.7″E 195m Destroyed
Arden TS638 1882 33°38’02.9″S 151°15’03.4″E 206m Damaged
Arthur TS649 1882 33°38’53.5″S 151°11’47.5″E 192m Good
Bangalley / South Head TS4135 1882 33°37’24.5″S 151°20’28.3″E 116m Damaged (new trig 1976)
Bairne TS681 1882 33°36’50.8″S 151°17’10.0″E 183m Good
Bantry TS728 1881 33°46’41.9″S 151°14’21.9″E 137m Good (restricted access)
Barbara TS734 1883 33°40’35.8″S 151°07’14.9″E‘ 183m Destroyed
Bare TS739 1881 33°43’03.7″S 151°13’08.3″E 195m Destroyed
Barrenjoey TS7220 1882 S33° 34.758′ E151° 19.716′ 104m Good
Barrenjoey Lighthouse TS10091 1882 33°34’48.7″S 151°19’47.5″E 102m Good (passive trig)
Bates TS784 1882 33°46’34.0″S 151°13’00.0″E 108m Destroyed
Beaumont TS801 1882 33°38’39.3″S 151°08’09.2″E 220m Destroyed
Belrose TS6324 NEW 33°43’03.4″S 151°13’08.7″E 207m Good (restricted access)
Bobbin TS1013 1883 33°40’12.7″S 151°09’42.1″E 180m Partly destroyed
Boundary TS1100 1881 33°42’27.2″S 151°12’12.1″E 189m Good
Bradleys TS1131 33°51’08.7″S 151°14’46.5″E 30m Good
Brown TS1184 1881 33°45’30.0″S 151°06’47.6″E 90m Destroyed
Bushranger TS1321 1882 33°39’48.7″S 151°19’04.4″E 103m Good
Carrol TS1421 1882 33°44’04.8″S 151°11’15.6″E 166m Good
Castlecrag TS10293 33°47’59.4″S 151°13’16.1″E 93m Good (trig plug only)
Carvossa TS1426 c.1881 33°48’20.9″S 151°10’35.6″E 100m Destroyed
Cliff TS1490 1882 33°34’52.3″S 151°14’03.9″E 184m Damaged
Cole TS1531 1882 33°35’06.3″S 151°12’23.3″E 201m Damaged
Cook TS1582 1883 33°41’58.2″S 151°07’35.2″E 201m Good
Cowan TS1672 1881 33°39’10.8″S 151°10’28.2″E 197m Damaged
Dee Why TS1796 1881 33°45’52.9″S 151°18’06.1″E 49m Good
Djarra TS1839 1883 33°35’28.4″S 151°09’21.3″E 210m Good (restricted access)
Dobroyd Point TS1840 33°48’28.3″S 151°16’08.7″E 91m Destroyed
Duffy TS1890 1882 33°40’37.9″S 151°12’53.9″E 210m Good
Edith TS1935 1883 33°45’12.4″S 151°10’34.3″E 124m Destroyed
Edwards TS1940 1882 33°35’07.6″S 151°13’02.8″E 184m Partly destroyed
Eliza TS1948 1883 33°45’35.5″S 151°10’11.2″E 111m Destroyed
Ellis TS1955 1882 33°38’52.9″S 151°13’44.9″E 195m Mostly destroyed
Ethel TS1985 1883 33°35’53.5″S 151°10’24.0″E 205m Damaged
Euro TS2005 1882 33°35’59.8″S 151°17’17.4″E 169m Good
Eva TS2012 1882 33°41’06.7″S 151°11’02.8″E 188m Mostly destroyed
Evelyn TS2015 1882 33°36’14.5″S 151°08’54.3″E 212m Destroyed
French TS2109 1882 33°44’15.5″S 151°13’14.1″E 175m Good (trig plug only)
Gordon TS2276 1881 33°46’25.1″S 151°08’41.2″E 70m Not Found
Gore TS5607 c.1880 33°49’16.1″S 151°11’08.7″E 101m Destroyed
Gundah TS2358 1882 33°37’43.0″S 151°07’31.1″E 222m Mostly destroyed
Gunson TS2380 1882 33°41’48.8″S 151°16’03.7″E 175m Good (trig plug only)
Hamley TS2399 1882 33°38’13.6″S 151°08’40.3″E 218m Good
Harnett TS2415 33°50’10.0″S 151°14’48.1″E 100m Destroyed
Harvey TS2427 1882 33°40’10.3″S 151°14’03.7″E 199m Mostly destroyed
Hecla TS2461 1882 33°36’23.3″S 151°08’05.5″E 225m Destroyed
Hungry TS2531 1882 33°39’18.7″S 151°13’39.4″E 197m Partly destroyed
Ida TS2548 1883 33°45’00.7″S 151°09’55.4″E 120m Destroyed
Jacomb TS2581 1883 33°41’00.8″S 151°09’41.3″E 166m Mostly Destroyed
Johnson TS2632 1882 33°38’57.6″S 151°16’57.3″E 120m Destroyed
Jones TS2636 1881 33°46’04.3″S 151°14’04.9″E 131m Good
L8 TS2780 33°49’20.0″S 151°13’06.4″E 70m Destroyed
Lix TS2868 1881 33°40’47.0″S 151°16’26.4″E 179m Good
Lloyd TS1871 1883 33°32’48.1″S 151°11’27.4″E 210m Good
Long TS2882 1882 33°38’13.7″S 151°10’37.2″E 206m Damaged
Long Reef TS2888 1881 33°44’29.4″S 151°18’53.4″E 36m Good (new trig 1972)
Lucy TS2904 1882 33°39’50.0″S 151°07’21.1″E 190m Good (trig plug)
Mcintosh TS3025 1882 33°39’55.4″S 151°16’43.0″E 165m Damaged
Maggie N/A 1882 33°41’48.4″S 151°16’09.4″E 205m Destroyed
Manly TS2962 1881 33°45’14.4″S 151°15’50.9″E 155m Good
McCarr TS3015 1882 33°39’07.4″S 151°15’40.7″E 191m Damaged
McComb TS6234 1881 33°47’01.5″S 151°15’29.2″E 81m Good
McCowen TS3018 1882 33°40’09.8″S 151°15’50.4″E 184m Good
Middle Cove TS10010 33°47’41.7″S 151°13’15.5″E 88m Good (trig plug)
Middle Harbour TS5550 1881 33°45’47.4″S 151°12’35.6″E 128m Damaged
Millicent TS3112 1883 33°35’05.8″S 151°10’45.7″E 230m Good
Mole TS5083 1883 33°42’33.8″S 151°11’21.8″E 176m Good (trig plug)
Narrabeen TS3329 1882 33°42’35.0″S 151°15’51.4″E 135m Partly destroyed
North TS3553 1883 33°43’19.5″S 151°10’50.6″E 165m Good (trig plug)
Northbridge TS2575 1882 33°48’26.0″S 151°13’35.9″E 88m Good (trig plug)
Obelisk TS3597 1809 33°49’08.4″S 151°17’37.4″E 72m Good
Peate TS3691 1881 33°40’18.0″S 151°06’29.1″E 212m Good (trig plug)
Pittwater TS6957 1880 33°41’08.5″S 151°14’03.1″E 218m Partly destroyed
Poppy TS3791 1882 33°37’08.2″S 151°08’49.8″E 220m Destroyed
Quarantine TS3818 33°48’54.1″S 151°17’55.5″E 105m Partly destroyed
Powell TS3792 1883 33°45’50.5″S 151°09’24.5″E 120m Destroyed
Ramsay TS3841 1881 33°43’44.2″S 151°17’32.0″E 100m Destroyed
Roach TS3914 1882 33°39’00.5″S 151°10’57.9″E 207m Mostly destroyed
Robertsons TS3920 33°50’54.6″S 151°13’58.1″E 10m Destroyed
Ryland TS3991 1882 33°41’36.7″S 151°11’41.9″E 187m Partly destroyed
Sandy TS4023 1882 33°40’53.8″S 151°11’58.9″E 198m Good
Smart TS4112 1882 33°44’18.0″S 151°09’09.2″E 160m Destroyed
Soutar TS4132 1882 33°44’31.8″S 151°10’26.7″E 130m Destroyed
Taber TS5929 1882 33°37’51.3″S 151°12’28.2″E 204m Mostly destroyed
Terry TS4323 1881 33°41’46.3″S 151°13’08.9″E 207m Unknown (private land)
Topham TS5653 1882 33°36’30.3″S 151°15’47.7″E 227m Damaged
Turimetta TS4478 1882 33°41’43.0″S 151°18’42.8″E 59m Good
Vize TS4551 1883 33°34’19.6″S 151°11’27.9″E 225m Mostly destroyed
Wallaroo TS4576 1882 33°36’30.3″S 151°15’47.7″E 194m Partly destroyed
Waller TS4580 1882 33°44’00.7″S 151°10’33.0″E 150m Destroyed
Want TS4609 1882 33°36’17.4″S 151°11’55.7″E 198m Partly destroyed
Waratah TS4625 1882 32°54’13.9″S 151°43’03.3″E 196m Partly destroyed
Wheeler TS4735 1881 33°43’54.7″S 151°15’25.1″E 145m Destroyed
White TS4745 1882 33°39’41.2″S 151°10’41.4″E 202m Partly destroyed
Wilkins TS4763 1882 33°39’23.6″S 151°12’07.9″E 195m Partly destroyed
Willunga TS4779 1882 33°37’05.4″S 151°15’30.8″E 232m Partly destroyed
Wright TS4861 1880 33°44’29.3″S 151°08’20.8″E 160m Unknown
Yatala TS4923 1883 33°36’46.5″S 151°09’35.6″E 220m Good