Australian Dictionary of Biography

Gordon Thomas Colebatch (1910–1998), civil engineer, was born on 10 July 1910 at Semaphore, South Australia, second of four children of English-born Walter John Colebatch, agricultural superintendent and acting principal of Roseworthy Agricultural College, and his South Australian-born wife Hazel May, née Richardson. Gordon was educated at the Collegiate School of St Peter and the University of Adelaide (DipAppSci and BE, 1932). He earned Blues in cricket and football in his final year at university.

After graduation Colebatch secured employment with the State Engineering and Water Supply Department, carrying out design work for Mount Bold Dam and the River Murray barrages, and then supervising the construction of two sewerage treatment works. At the same time he completed (1937) an associate diploma in industrial chemistry at the South Australian School of Mines and Industries. In 1936 he joined the Hydro-Electric Commission (HEC) in Hobart where he worked on canal and pipeline design and model-testing for the Tarraleah Power Development. On 8 April 1939 he married Barbara Carlyon Angove, a trained masseur, at St Peter’s Church of England, Glenelg, Adelaide.

Having been commissioned (1939) as a lieutenant, Royal Australian Engineers (RAE), in the Citizen Military Forces, Colebatch joined the Australian Imperial Force on 10 June 1940. In World War II he served in the Middle East (1941–42) with the 2/9th Field Company, RAE, and on the headquarters of I Corps; and in Papua, New Guinea, and Bougainville (1942–45) on the staff of New Guinea Force and as commander of the 11th Field Company (April–October 1943) and the 3rd Divisional Engineers (October 1943-July 1945), rising to lieutenant colonel in December 1943. He was mentioned in dispatches for his service in Papua and New Guinea. Proximity to a bursting Japanese shell in September 1943 left him with tinnitus and some permanent hearing loss.

During the campaign in South Bougainville (1945), Colebatch’s ‘able planning, energy, and drive’ (NAA B883), in directing the construction of roads, bridges, and airfields, and the clearance of mines and booby traps, was crucial in keeping lines of communication open to the forward areas. ‘His pleasant personality, courtesy, and unfailing co-operation’ gained him ‘the respect and goodwill of all’ (NAA B883). For his efforts he was appointed OBE (1947). Back in Australia, he was transferred to the Reserve of Officers on 16 November 1945. He would serve as colonel commandant of the RAE in Tasmania from 1975 to 1979.

In 1946 Colebatch returned to the HEC. Faced with Tasmania’s severe power shortage in the postwar period, he developed plans for a series of dams and power stations along the Derwent River. Five years later he was appointed chief civil engineer. He reported to (Sir) Allan Knight, commissioner of the HEC, and worked alongside the chief electrical engineer to deliver a series of major projects. In the twenty-three years that followed, nineteen power stations were commissioned. Civil works he oversaw included twenty-eight large dams and over forty smaller dams, and the associated tunnels, canals, and pipelines. He had overall responsibility for the civil engineering branch, but relied on his capable deputy, Harry Thomas, to handle investigation and design, while he concentrated on construction.

Colebatch encouraged innovative dam construction. He was proud of his ability to get his engineering staff and construction personnel to work collaboratively, and was indebted to his military service for developing his organisational and administrative skills. His department established a world-wide reputation for its expertise in the design and construction of dams, and associated civil works. Examples of its innovation included reducing the concrete required for the Catagunya gravity dam by using steel cables to anchor it to its foundation, and the purchase of Australia’s first tunnel boring machine, which considerably increased the speed of excavation.

Towards the end of his career, Colebatch helped to plan the Gordon River Power Development scheme. He oversaw the in-house design of the 140-metre Gordon Dam, the highest arch dam in Australia. Associated works included preparing for the inundation of Lake Pedder. The flooding of the lake was controversial; the United Tasmania Group, the first ‘green’ political party in the world, was formed in response by protest groups. Colebatch recalled that while he was ‘concerned at the loss of the original Lake Pedder,’ he believed that ‘the enlarged lake would also be very beautiful and on a much grander scale’ (1992, 18).

Active in professional associations, Colebatch had joined the Institution of Engineers, Australia in 1931. He chaired the Tasmania division in 1951, was national president in 1961, and became an honorary fellow in 1991. He had also joined (1961) the Institution of Civil Engineers, London, represented the HEC on the Australian National Committee on Large Dams (chairman 1967–70), and was a vice-president (1966–69) of the International Commission on Large Dams.

After retiring in 1974 Colebatch became a foundation member (1976) of the newly formed Institute of Arbitrators, Australia. During the 1980s he resolved disputes, mainly between building contractors and councils or government departments. Recalling the assistance he had received as a student, he also mentored engineering scholars at the University of Tasmania. He was appointed AO in 1982 and OBE (civil) in 1988. Survived by his wife and their son and four daughters, he died in South Hobart on 29 May 1998 and was cremated.