Australian Dictionary of Biography

Gerald Harnett Halligan (1856-1942), hydrographer and civil engineer, was born on 21 April 1856 at Glebe, Sydney, son of Irish parents Gerald Halligan, clerk, and his wife Mary Ann, née Harnett. His father later became under secretary of the Department of Public Works. Gerald junior was probably educated at Fort Street Model School and on 1 August 1871 joined the Department of Public Works. In July 1889 he was appointed chief surveyor of the harbours and rivers navigation branch and was for many years in charge of all borings relating to harbour and bridge construction works in the colony. He introduced practical innovations to improve techniques in boring.

At the invitation of the Royal Society, London, in 1898 he joined the third scientific expedition to the Pacific atoll of Funafuti in the Ellice Islands. Assisted by two experienced departmental foremen, he supervised deep borings into the coral from a stage rigged over the bows of H.M.S. Porpoise. In 1899 he was appointed hydrographic surveyor and in 1911 inspecting engineer (later reclassified as supervising engineer), in which capacity he served the department until he retired in 1918.

Halligan made a lifetime study of tides and currents and their effects. He was particularly knowledgeable on the formation of sand dunes and on the control of movements of sand and sediment in channels and harbours, becoming an international authority in oceanography. He was a member of the Royal Society of New South Wales in 1880-1942 and of the Linnean Society of New South Wales from 1897, and a fellow of the Geological Society of London in 1900-29. In 1911 he was one of three Australians to address the Institution of Civil Engineers in London on the bar harbours of New South Wales, and put forward several novel theories which aroused considerable interest.

His advice was sought outside New South Wales—in 1918 Halligan advised the Tasmanian government on the problem of sand drift on to agricultural land on the north-east coast. In 1922, on the suggestion of his friend Professor Sir Edgeworth David, he made a hydrographical examination from the air of Lake Eyre in South Australia. He compiled a number of maps for the oceanographic section of Pan Pacific Science congresses in 1923 and 1929. He published many papers, some in association with Edgeworth David, in scientific journals.

He had married Harriet Victoria, sister of the artist W. C. Piguenit, at Petersham, Sydney, on 3 November 1881. She died in 1919 and on 26 April 1922 at St Peter's Church of England, Wahroonga, he married Sarah Albina, née Genders, the widow of W. H. Twelvetrees, geologist to the Tasmanian Mines Department; both marriages were childless. For much of his life he lived at Hunters Hill. Halligan died on 23 November 1942 in hospital at Killara and was buried in the Roman Catholic section of Northern Suburbs cemetery.