Moriarty was born in County Kerry, Ireland, the second son of Commander Merion Moriarty, R.N. Staying behind to complete his education when his parents migrated to Australia, he completed a Bachelor of Arts and then Master of Arts at Trinity College, Dublin, was engaged as a cadet on the construction of the Isle of Portland breakwater and became a member of the Institution of Civil Engineers. He was articled as a pupil to William Morgan, in the firm of Acraman, Morgan and Company, of Bristol, during which he assisted with the design and construction of a number of steamships including “Little Western”, “Avon”, “Severn”, and a large steam yacht built for the Austrian Government, the “Archduke Frederick”. Moriarty then worked under Sir John Macneill on railways back in Ireland, and passed the examination for County Surveyor in the Board of Works. In 1848 he migrated to New South Wales, initially being employed as assistant in the Surveyor-General's Department undertaking survey work in Queensland under Sir Thomas Mitchell. In 1852 he commenced private engineering practice in Sydney. Moriarty married Leila Helen, née Geary, in Brisbane on 18 May 1853.
Engineering career
Between 1853 and 1855 he held the position of engineer and surveyor for the Steam Navigation Board and from 1855 to 1858 was engineer on the Hunter River improvements. He was then appointed Engineer-in-Chief for Harbours and River Navigation with the NSW Department of Works from 1858 to 1859. While in the military, in the 1850s, he undertook external commissions for the Penrith Nepean Bridge Co. and the first Pyrmont Bridge in 1866. In 1855 Morarity was Engineer Surveyor for the Hunter river improvements and in that capacity made soundings and mapped the Hunter River at the Port of Newcastle which were developed into a plan to improve the entrance to the sea by constructing extended breakwaters and river control walls as well as develop the port faculties to improve the export of coal. In particular, Morarity is noted for his involvement in the construction of the Dyke a river training wall on the western bank of the Hunter river at Newcastle which was developed into a coal loading facility and basin equipped with hydraulic cranes for loading coal and an associated rail link. In 1862 Moriarty was made commissioner for roads and engineer-in-chief. He was a Sydney Water Supply Commissioner in 1868, president of the Hunter River Floods Commission in 1869-70, and also responsible for water supply schemes for Albury, Bathurst, Hunter Valley towns, Wagga Wagga and Wollongong. Moriarty was made responsible for the Clarence River Entrance Works between 1862 and 1889, where he proposed short breakwaters and rock training walls.. However, this was not entirely successful as sandbars formed near the opening. Moriarty argued with the harbour engineer John Coode about the cause and remedy, but when Moriarty went on leave prior to his retirement, his successor, C.W. Darley, implemented Coode's scheme. Part of the remaining north training wall is still called “Moriarty’s Wall” in recognition of his role.
Personal interests
Moriarty also had a military career as lieutenant in the Volunteer Artillery, and as a captain from 1869. He was also involved in the board for inspecting and maintaining supply of colonial warlike stores, the commission on defence from foreign aggression and was a Captain of the Engineers Corps Volunteer Rifles in 1871-73. Outside of professional activities Moriarty was also a Philosophical Society councillor, member of the New South Wales Linnean Society and a member of the Royal Sydney Yacht Squadron. He retired from engineering positions on 31 December 1888 and returned to England, where he died at Southsea, Hampshire, on 18 September 1896, leaving an estate worth £5800.
