Doyne, William Thomas (1823–77), railway engineer, was born in April 1823 at Old Leighlin, Co. Carlow, second son of the Rev. Thomas Doyne and Sophia Doyne (née Armstrong). At the age of 16 he entered the University of Durham and studied engineering for a year. In 1840 he was articled to Edward Dixon, resident engineer of the London and South Western Railway. He later worked with Robert Stephenson before being appointed as the managing engineer of the Rugby–Leamington line (1847–51). He was elected as an associate of the Institute of Civil Engineers in 1849 and as a full member in 1851, as a result of a paper he submitted on the stresses experienced by railway-bridge beams.
During the Crimean war (1854–6) he was the engineering superintendent in charge of the Army Works Corps (AWC), a body of civilian engineers and navvies sent to the Crimea to build a road system and carry out general engineering duties for the army. He arrived in the Crimea in August 1855, and by October had 1,000 AWC personnel, 8,600 troops, and 1,000 Croatian labourers working on a road system; it was ready for use by 10 November 1855 and was later described by an English traveller as the best road system in Russia. The next two years were spent in Ceylon as the chief engineer of a railway construction scheme before his moving to New Zealand (1858), where he was employed surveying sites for possible rail lines. In February 1861 he was asked to supervise the construction of the Launceston–Deloraine railway, the first in Tasmania. While the project was notable for some fine pieces of engineering, such as the King's Bridge on the South Esk, it was realised in 1869 that the work would run vastly over budget. The press vilified him, and he sued for libel without success. The committee of inquiry that followed censured Doyne for leaving the work in the charge of his partners, while absent on other business.
Despite this setback, he continued to find work on major engineering projects. He had opened an office in Melbourne in 1866 and concentrated his business on mainland Australia. He was appointed as a consulting engineer to the government of Western Australia (1869), and worked on the Hobson's Bay dredging scheme (1871). He also supported the campaign to found the Homeopathic Dispensary (now Prince Henry Hospital), Melbourne. In the course of his career he published several papers including The causes which have retarded the construction of railways in India (1860) and Report on the plains and rivers of Canterbury, New Zealand (1864). He died at St Kilda, Melbourne, 29 September 1877. The Institute of Civil Engineers described him as ‘a clever painstaking engineer, good mathematician, geologist and analytical chemist’.
He married (1853) Helen Cox in London. They had one son and two daughters.