On the 29th of March 1922, the British arms ship the Upnor was seized by members of the Cobh company . The ship was returning to England with its second load of of arms out of Cork harbour and towing a drey behind it . A plan was hatched to seize the Upnor as she rounded Roches Point. However, British gunboats accompanied the Upnor to the sea and plans to get on board her were abandoned. Later that night a large tug boat was seized by the Cobh company under captain Michael Leahy.
It set sail and reached Upnor late that night on the open sea. There was no destroyer insight and she was hijacked and brought into Ballycotton harbour as pre-planned.
A number of days before the arms ship departure from Haulbowline transport was a quiet around Cork city and neighbouring towns. One hundred and thirty six lorries vans and cars plus their drivers were brought to Knockraha. The vehicles stretched from the village to Balinagoul Cross. Food was acquired from O’Connell’s in Carrigtwohill, everyone in the village helped out.