Plenty of good answers from a previous thread about what was going on in Ireland at the time (though it's 3 years old and accordingly may not be held to as high standards as current AskHistorians answers):
/u/clarkyisafox
In short, Ireland (the republic, not Northern Ireland which was a part of the UK and thus at war) was neutral during the war, though many Irish did fight for the British military.
The British managed to convince the Irish government of the real possibility of Germany invading Ireland, and the two states coordinated Plan W as a counter-invasion plan in the event of German invasion.
Germany indeed had a plan for a potential invasion of Ireland, called Operation Green, that would be launched to support Operation Sea Lion, the proposed invasion of Britain. Neither invasion ever took place however, as Germany turned its attention to the USSR after not being able to achieve air-superiority over the British in the Battle of Britain.
So to answer your question, the Irish military, especially in the years 1940-1942, would be preparing for potential invasions from aggressors in the conflict in which they were officially neutral in. Some of those preparations included training against paratrooper tactics, expanding the air-force, and training units in guerilla warfare tactics such as dynamiting bridges to slow down a potential German invasion.