An exercise swung into operation in May 1959 to prepare Larne for the aftermath of a nuclear bomb.
The two-day operation was ordered by the Civil Defence and carried out by more than 20 members of the Larne Sub-Area Corps personnel from Belfast and Lisburn.
Local units of St. John Ambulance and British Red Cross Society and auxilary fire and rescue service joined the exercise.
They were asked to react to a mock emergency following a ficticious nuclear explosion outside Belfast and a supposed second attack from a submarine directed on a convoy near The Maidens lighthouse.
The exercise was controlled from the Larne Borough Council headquarters at Gardenmore House.
A mock hospital was set up at the town hall.
“Operation A1” was the first of its kind in the area.
A report in the Larne Times suggested that the operation was similar to one which would be necessary in an area of heavy damage and fall-out.
Communication was by wireless, as telephones were assumed to be out of operation. Meals and overnight accommodation were provided at Parochial Primary School.