Killaly, John A. (1766–1832), surveyor and canal engineer, was born in England. He may have worked for some time on several English canals before settling in Ireland as a surveyor. He initially did some freelance work for the Grand Canal Company, but his work sufficiently impressed the directors to warrant his appointment as assistant engineer (1794–8), in which capacity he worked on the completion of the canal from Lowtown to Tullamore. These first years proved a type of apprenticeship in engineering, for by the time 1798 came about, the directors agreed that Killaly had progressed from being a ‘mere measurer and surveyor’ and become the ‘complete superintendent of all kinds of work’ (Skempton, 384). Accordingly, he was appointed the company's chief engineer (1798–1810), and went on to become one of Ireland's most successful home-trained engineers.
Killaly saw to the construction (1798–1800) of the Grand Canal near Edenderry (perhaps the most difficult part of the route because of the extensive bogland), surveyed a line of canal from Monasterevin to Mountmellick, and supervised the extension to Shannon Harbour (completed 1803). In recognition of his work, the company awarded him a silver cup and 200 gold guineas (1804). He supervised the repair of various canal leaks (1804–5), surveyed a potential Ballinasloe line, and reported (1810) on the commercial viability of the company's Doonane collieries in eastern Queen's Co. (Laois). Owing to a series of cutbacks, Killaly formally left the company in 1810 but continued to serve as a consultant on future projects.
In 1803 Killaly was one of several engineers appointed under the directors general of inland navigation, a post that allowed him to remain with the Grand Canal Company and to take on other government assignments. During his tenure with inland navigations, he inspected the state of the Shannon navigation (1810), compiled a comprehensive report on the state of inland navigation in Ireland (1811), and advised on the Corrib, Lagan, Newry, Suir, and Erne navigations and on the Lough Allen canal (1810–21). When the directors of inland navigation appropriated the Royal Canal in 1813, Killaly was asked to survey the line; he designed the Whitworth aqueduct to carry the canal over the River Inny, Co. Longford (1814–17), and superintended its completion to the River Shannon (1813–17). Government loans facilitated the extension of the Grand Canal, so Killaly was hired as consulting engineer for the construction of the Ballinasloe (1824–8) and Monasterevin–Mountmellick (1827–31) branches, during which time he also surveyed a line of navigation for the Ulster Canal (1825). His son Hamilton Hartley Killaly (below) was chief engineer on all three projects.
Although he was best known as a canal engineer, Killaly's renowned talent and ability meant that his opportunities were not restricted to inland navigation. He had a private practice in Dublin with James Oates, and when Ireland was struck by famine (1821–2) he was appointed engineer for Co. Clare, the southern section of Co. Galway, and the northern part of Co. Tipperary as part of a government-organised public works scheme. He arrived in Clare in June 1822, and by July employed 9,434 men on relief works. From 1822 to 1828 he supervised the construction of 107 miles of road (mostly in Clare), including a road from Ennis to Kilrush, a thirty-six-mile coastal road, and the Bealaclugga bridge over the Annagh river, Co. Clare (1824). Towards the end of his life he laid out plans for the Loughrea–Derrybrien road and collaborated with Hamilton Hartley in designing a wet dock in Galway. He died 6 April 1832 at his residence in Williamstown, Co. Dublin; his remains were placed in St Patrick's cathedral, where his wife erected a large memorial in his honour.
Killaly married (late 1790s) Alicia Hamilton (d. 1837); they had three sons, two of whom became engineers. One of these, Hamilton Hartley Killaly (1800–74), engineer and civil servant, was born in Dublin in December 1800. He received a BA (1819) and an MA (1832) from TCD and served his engineering apprenticeship under his father. Thanks in part to the latter's influence and reputation, he was appointed chief engineer on the extension of the Grand Canal to Ballinasloe (1824–8) and from Monasterevin to Mountmellick (1827–31); he designed the Barrow aqueduct (completed 1831), worked briefly on the Ulster Canal (1830), and was chief engineer to the Galway harbour board (1832). On establishing himself as a competent engineer in his own right, he was appointed consulting engineer to the newly revamped board of works (1831–3). In 1834 he moved to Canada, eventually settling in Ontario, where he worked on the Welland Canal (1838–40). Soon after he was appointed chairman of Canada's board of works (1840–46) and briefly served as a member of the assembly and of the executive council (1841–3). However, he was dissatisfied with the political aspect of the post and his estimates tended to fall short of actual costs, so when the board was reestablished as the department of public works he did not stay on as chairman (1846). He later worked as assistant commissioner of public works (1851–9), and while his reputation as an engineer was solid, he was often criticised for his poor financial administration. He took part in several governmental commissions, including one on Canadian naval bases (1861) and a second on Canada's fortification and defence (1862). He retired in 1862, and died on 28 March 1874 in Picton, Ontario; he was buried in the family plot in St Mark's anglican church, Lincoln county, in the township of Niagara. He was remembered as a portly, genial gentleman who was often expensively but bizarrely dressed in wrinkled or dirtied clothing, sporting odd or misshapen hats. He had a well-known dislike for politics and an uncertain temper, but he was admired for his superlative engineering skills and his unflagging capacity to enjoy life. Killaly married (1833) Martha Jane Handy; they had three sons and two daughters. He was the first president of the Canadian Society of Engineers.