Hazard Warning Flag

Warning flags were used to mark the locations of unexploded bombs and other possible hazards.

Sergeant Joan Mortimer was awarded the Military Medal for her bravery in marking unexploded bombs at RAF Biggin Hill on 30 August 1940. She was working in the armoury when the raid of 30 August started. During the raid, she stayed at her post, operating the switchboard. Once the all clear had sounded, she began marking the unexploded bombs. ‘This airwoman displayed exceptional courage and coolness which had a great moral effect on all those with whom she came in contact.’ Official citation, 1940