Candy, Joseph Phelan (1895–1960), engineer, was born in Derry 7 July 1895, one of the sons among at least three sons and two daughters of James Candy, stationmaster at Waterside railway station, and his wife Mary Catherine (née Gribbon). The family lived at the Station House, Waterside, Derry. Educated at Waterside Boys School and St Columb's College, Derry, Candy studied engineering at QUB (1914–17) and graduated B.Sc. (1917) and M.Sc. (1922). Between 1917 and 1920 he received his practical training under John Millar, and during the first world war he served in the Royal Engineers on railway construction.
In 1920 Candy joined the Great Eastern Railway, initially in the London area and later as assistant docks engineer at Lowestoft harbour. Responsible for the reorganisation and operation of a dredger fleet, he gained invaluable experience in coastal protection before being appointed personal assistant to the chief engineer at Liverpool Street. The amalgamation of the railway companies in 1922 diminished his career prospects and prompted his departure to the Public Works Department in Burma (1925–31). There he held senior positions in the dredging and irrigation departments, carrying out investigations in the Irrawaddy Delta. In 1931 he became chief engineer and manager of the Tilbury Contracting and Dredging Co. (Egypt) and thereafter was involved in many major projects in Egypt and Palestine.
After returning to Britain Candy had a series of short-term contracts and a brief, but painfully memorable, period of unemployment prior to his appointment in 1934 as chief engineer, commissioners of public works, in Dublin. Under his control the engineers' branch of the Office of Public Works carried out the construction of the airports at Shannon and Dublin. As a member (between September 1938 and July 1940) of the drainage commission, Candy oversaw the completion of the first four catchment schemes (Brosna, Glyde and Dee, Feale, and Nenagh) at a cost of £4 million and initiated work on a further seven schemes. During the second world war he organised the nationwide distribution of turf to deal with the fuel crisis. He was president of the Institution of Civil Engineers of Ireland (1948–9) and a director of P. O'Kane & Co., Foyle Street, Derry.
During much of his later life Candy suffered from ill health, exacerbated by the sudden death of his wife and two younger brothers. Devoted to his work, he was direct and brusque. He was married to Agnes O'Kane of St Columb's, Buncrana, Co. Donegal, and they lived at Ros Rua, 74 Trimleston Park, Booterstown, Co. Dublin; they had no children. Candy died 13 March 1960 at the Burlington Clinic Nursing Home, leaving an estate valued at £33,801. He was buried in the Derry city cemetery.