Alfred D. Tudhope was the son of John Tudhope, cabinet minister and mining magnate, and his wife Mary G.M. Pears. Alfred was educated at the Grahamstown Public School and the Diocesan College, Cape Town. He passed the matriculation examination of the University of the Cape of Good Hope in 1880 and, continuing his studies at the Diocesan College, the university's Survey Certificate Examination in 1882. The next year he was appointed as draughtsman and assistant engineer on the Midlands System of the Cape Government Railways. He soon resigned from this post and after working briefly for the firm A.E. Murray of East London, joined the survey for the Indwe railway in 1884. He next became second engineer for the extension of the railway to Kimberley. After passing his final survey examination in 1886 he was admitted as a land surveyor in the Cape Colony and was engaged to set out the Cape Central Railway to Ashton. Moving to Barberton he became resident engineer to the Pigg's Peak Gold Mining Company in July 1887, but soon returned to the Cape Government Railways to do survey work and in 1889 became assistant engineer for railway construction from Norval's Pont to Bloemfontein.
Tudhope resigned his post in 1893 to visit England and upon his return set up in private practice in Cape Town. From 1896 he was again employed by the Cape Government Railways. In 1897 he reported on a preliminary examination of the Transkeian Territories and a survey of the region between Indwe and the Natal border, with a view to the construction of a railway. In 1904 he was promoted to resident engineer on the Midland section, stationed in Port Elizabeth. Upon the formation of the Union of South Africa he was appointed superintendent (maintenance) of the South African Railways and Harbours in July 1910, stationed in Cape Town. He retired as maintenance engineer in 1923. Subsequently he was a member of the initial committee of the Town Planning Association of the Cape Province.
Tudhope was a member of the (British) Institution of Civil Engineers and of the (South African) Institute of Government Land Surveyors. In 1902 he became a foundation member of the South African Association for the Advancement of Science. At the association's annual congress in 1908, held in Grahamstown, he presented "Some notes on underground water" (Report, 1908, pp. 133-138), dealing with the quality and chemical analysis of water obtained from railway boreholes. He was also an early member of the Cape Society of Civil Engineers (founded 1902), served on its council during 1909-1910, and in 1912 was elected president of its successor, the South African Society of Civil Engineers. In 1902 he married Ada Price, with whom he had five children.