An engine room artificer was a fitter, turner, boilermaker, coppersmith or enginesmith in the early days of steam-powered warships. Usually working under an engineer officer, they were able to read and write, competent in the workings of engines and boilers, and trained in the maintenance and operation and uses of all parts of marine engines. ERAs were the senior maintainers and operators of all warship mechanical plant. Around 1916 ERAs could also be placed in charge of small ships as an engineering officer and were also EOs of the watch on destroyers and below for which they received rapid advancement to CPO and extra charge pay of 1/- per day on attaining their "ticket" By the 1950s, ERAs were apprentice-trained as boilermakers, coppersmiths, fitters and turners, although boilermaker and coppersmith skills were largely becoming redundant trades and the remaining trades, fitters, turners and metalworkers, together with shipwrights and mechanicians expanded by cross-training to undertake most of the Royal Navy'soperational maintenance and the running of all mechanical equipment including steam, diesel and gas turbine main machinery. By the 1950s, ERAs spent their first 16 months at HMS Fisgard in Torpoint, Cornwall and the next 8 terms at HMS Caledonia in Rosyth, Fife before completing their 5th yearat sea or in dockyards with the fleet. During this long training time their duties with the RN often moved beyond the world of engineering and into the world of combat and leadership. In the 1960s, nuclear power operation was added to the résumé of a considerable number of ERAs, as first HMS Dreadnought and then an increasing number of nuclear-powered submarines came into service. Late on in that decade, the long established title of engine room artificer was changed to marine engineering artificer, MEA in short. The rationale for this change of title was said by MOD to better represent the true technician ability of the ERA. The modern MEA is a qualified engineering technician with an in-depth knowledge of all the ship's engineering equipment, including main engines and auxiliary engine room equipment. An ERA is also involved with the calibration of the various measuring instruments on a naval ship. The Irish Naval Service continues to use the term 'engine room artificer' for marineengineering technicians who wear a distinctive propeller insignia.