Alfred Ernest Snape, civil engineer and academic, was the son of the printer Alderman Joseph Snape and his wife Agnes Mary, born Stockbridge. He was educated at the Manchester Grammar School. As a City of Manchester Technological Scholar he continued his studies at Owens College, Manchester, and was awarded the BSc degree with first class honours in engineering (1900) and the MSc degree in engineering (1905) by the Victoria University of Manchester. From 1900 to 1909, equipped with an enquiring mind, he gained extensive experience working as an assistant engineer for the Rochdale and Southampton municipalities and the London County Council, and as resident engineer to the Norwich City Council. He became an associate member (later a member) of the Institution of Civil Engineers in 1906 and was a Fellow of the Royal Sanitary Institute. In 1910, aged only 29, he was appointed as professor of civil engineering at the South African College, Cape Town (from 1918 the University of Cape Town), succeeding Professor Henry Payne*. He held this position until his death in 1946. The University of the Cape of Good Hope admitted him to its MSc degree on the basis of his British qualifications in 1910.
In 1911 the government asked Snape to report on technical education in South Africa, which he did after visiting educational institutions in different parts of the country. His findings were published by the government in the form of a Bluebook entitled Report on technical instruction in the Union (1911). He was primarily a teacher, rather than a researcher, providing his students with a thorough professional training which helped to reduce the lingering prejudice against university trained engineers in a time when some engineers still qualified through an apprenticeship. However, during his last few years his courses had become outdated. He was particularly interested in town planning, was a foundation member (1932) and president of the Town Planning Association, and was a member of the commission whose work led to the Township Ordinance No. 33 of 1934.
Snape became a member of the Cape Society (from 1911 the South African Society) of Civil Engineers shortly after his arrival, served on its council from 1911 until his death, as honorary secretary for 1912-1913, as president in 1916, and as editor of its Proceedings from 1915 until his death. From 1942 to 1945 he was the South African representative on the council of the (British) Institution of Civil Engineers. He became a member of the South African Association for the Advancement of Science in 1910. By 1917 he was a member of the Royal Society of South Africa. When the British Association for the Advancement of Science met in South Africa with its South African counterpart in 1929 he served as one of the joint vice-presidents of Section G (Engineering) of the British Association and read an unpublished paper on 'University training in structural design and practice'.
During his first few years in South Africa Snape published several papers: 'Practical notes on tunnelling' (Minutes of Proceedings of the Cape Society of Civil Engineers, 1910), 'Methods of construction and prime costs' (1911), 'Tests on suction gas plants' (1912), and 'The parabolic reinforced concrete arch' (with A.N. Henderson, 1915) in the Minutes of Proceedings of the South African Society of Civil Engineers; and 'Principles of sewage disposal' (1911) in the Journal of the Royal Sanitary Institute. For some time he was co-editor of the journal Architect, Builder and Engineer (published from 1917 to 1941). In later years he contributed three papers to the South African Survey Journal: 'The education of a surveyor' (1924), 'Aerial mapping' (1925), and 'Our units of measurement' (1930).
Snape was an active member of the (Anglican) Church of the Province of South Africa. During World War I (1914-1918) he served as director of the Disabled Soldiers' Vocational Training Institute. He was awarded the King's Silver Jubilee Medal in 1935. In 1913 he married Eleanor Mary Hambidge, with whom he had a son and three daughters. After his death the University of Cape Town named a new civil engineering building in his honour. In 1953 the Cape Town branch of the South African Institution of Civil Engineers instituted the Alfred Snape Memorial Lecture to commemorate his life and work.