Ordinary Seaman Sheean joined the Royal Australian Navy in 1941 and served as an Oerlikon anti-aircraft gun loader in the corvette HMAS Armidale. On 29 November 1942, Armidale sailed to Timor to support the Allied troops there. On 1 December, Armidale came under Japanese air attack. A severely wounded Sheean was last seen strapped to his gun and firing at the aircraft as the ship sank. He received a Posthumous Mention in Despatches for this action.
In 2011, Sheean was listed in the Terms of Reference for the Inquiry into unresolved recognition for past acts of naval and military gallantry and valour. The following link is to Chapter 17 of the Report of the Inquiry which focusses on Sheean:
The Tribunal received 21 written submissions regarding Sheean: