Schuko was the preferred and official Irish standard for plugs and sockets for quite a long time. It's still referenced in the wiring standards and national electrical standards.
Basically what happened was that the ESB (Electricity Supply Board) adopted the original Schuko system in the 1920s as it fitted into the the 220V 50Hz system that they had standardised on by 1927.
The UK system was not considered as there was no single UK standard i.e. the old round pin UK system had at least 6 different types of incompatible plugs and there were various voltages in use in the UK before they finally settled on 240V 50Hz in the 1960s! Then moved to 230V 50Hz to harmonise with the rest of Europe.
Schuko and 220V was pretty much a mature and stable standard by the late 20s, so it made a lot of sense to adopt it. It was widely used in other European countries even by that stage.
During WWII it became impossible for Irish electricians to get their hands on Schuko fittings as they all came from Northern continental europe i.e. Germany, Netherlands, Scandinavia etc.
Ireland's electrical market size possibly didn't make it worth anyone's while to manufacture electrical fittings locally, so UK fittings started to appear. So, you begin to see the UK 15A round pin plug and socket system appearing in homes in the 1940s and into the 50s.
Schuko came back again after WWII, but at that stage there was a mess with a mixture of old UK round pin and schuko sockets.
The UK was in the process of abolishing the use of the old round pin system which was very cumbersome and had a lot of problems i.e. umpteen different types of plugs etc and was moving to the current rectangular pin system used today.
BS1363 was specifically designed to be totally incompatible with its predecessors so that it would force a standardisation on a single safe system.
Ireland had a slightly different mixture of standards, but it made sense for us to do the same thing and get rid of the mix.
Both countries were in a similar position and wanted to get rid of a "system" that was poorly standardised and relied heavily on the use of adaptors in the home.
e.g. in the UK it was impossible to plug a 5amp plug into a 15amp socket without an adaptor, yet these fittings all co-existed in homes and offices! So, if you tried to plug your vacuum cleaner into the socket in the kitchen it might not have fitted.
Also, it made sense as we share a land border with the UK so, had we continued to use Schuko we would have had 2 different plug/socket systems on the Island of Ireland.
Today, IS401 (BS1363) plugs are required to be fitted to all appliances sold in the Republic of Ireland and the BS1363 socket system is the default standard in homes and offices. You won't really find anything else in use at this stage.
However, the Schuko system is still referenced in the modern wiring standards and can crop up in special uses e.g. if we need to connect something >13amps.
It's also still referenced in the official irish guides to how to wire a plug!
Ireland never moved away from German wiring practices though. We do not use ring circuits, rather we use 16 or 20amp radials to power socket outlets and the Siemens originated "diazed" or "neozed" cartridge fuse system was always used on our distribution panels rather than the UK system. This is the same as the fuse system found in most of Northern Europe (except France and the UK)
It's weird though, I think we're possibly the only country to have used Schuko and actually dumped the system. Most countries have standardised on it having moved away from older national standards.
http://www.esb.ie/main/energy_home/plug_safety.jsp
