He was educated at the Manchester Grammar School, and completed his chemical training at Owens College.

[1] When Firth College, Sheffield, was opened, Thomas Carnelley was appointed Professor of Chemistry and Physics.

In 1905 he was elected Secretary of the Midland Institute of Mining, Civil, and Mechanical Engineers.

As its general secretary died in 1907, this position was offered to O'Shea, which he assumed on 2 September 1908 and held until his death.

This experience of active service led to his being placed in command of the University contingent, which was formed in 1911, a position he retained for eight years.