Engine Room Artificer
In the early days of steam-powered warships, usually working under an Engineer Officer, an Engine Room Artificer (ERA) was a fitter, turner or boilermaker, able to read and write and was 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.
By the 1950s, ERAs were apprentice-trained as boilermakers, fitters, turners, pattern makers or Metalworkers, although boilermaker and pattern maker 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's operational 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 (4 terms) at HMS Fisgard in Torpoint, Cornwall and the next 8 terms at HMS Caledonia in Rosyth, Fife before completing their 5th year at 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 bullets 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 Engineroom Artificer was changed to MEA (P), this abbreviation (or even an acronym) stands for Marine Engineering Artificer (Propulsion). The rationale for this change of title, seen by most serving and former ERAs as paperwork for paperwork's sake, was said by MOD to better represent the true technician ability of the ERA.
The modern MEA (not ERA) is a qualified engineering technician with an in-depth knowledge of all the ships engineering equipment, including main engines and auxiliary engine room equipment.