Files contain documents regarding storage of explosives at Explosive Fog Signal Stations. Included are details of: quantities of explosives each stations, storage and security conditions (September 1917) ; police escort when transporting explosives (February 1919) ; stocks of explosives to be reduced to a minimum (May 1920) ; police or military protection for explosives in unaffordable (August 1920) ; discontinuance of Fog Signals at mainland Fog Signal Stations (January 1921) ; reduction of explosives on board Lightships (June 1921). Correspondents include Headquarters, Irish Command, British Army ; Inspector ; Lord Lieutenant; Under Secretary Dublin Castle ; Admiralty.

Files contain documents regarding Raids on Mizen Head during and after the Irish War of Independence. The Raids were carried out by the Irish Republican Army. The purpose of the Raids were to seize explosives used for firing explosive Fog Signal. Included below are extracts from reports by J. J. Treeby, Principal Keeper and J. J. Duggan, Assistant Keeper: summary of Police Reports as to the storage of explosives at Fog Signal Stations around the coast of Ireland ; 16 May 1920: Station raided 1.35 am and all ammunition removed. Telephone cut ; 31 July 1920: Station raided by armed and masked men who removed 2200 charges and 2000 detonators. Irish Lights advise against replenishing stock ; August 1920: Possibility of having to discontinue Explosive Fog Signal. Inspector suggests temporary reed horn signal and purchase of Acetylene Gun Signal ; 1 July 1921: station raided by 5 armed men. Telephone wires cut and complete instrument carried off ; 1 January 1922: stable broken into by persons unknown and several scaffolding planks carried off.