TWELVE German airplanes dropped high-explosive bombs over Glasgow on December 10, 1939. The bombs caused considerable damage, and casualties were carried from buildings on stretchers.

Fortunately, it was just an exercise (the real thing would, sadly, follow later).

The surprise test of the city’s civil defence organisation was put together by Glasgow Corporation’s emergency committee. The entire plan remained a secret right up until the moment when notices were suddenly handed to chief air-raid wardens in the central and eastern districts.

The notices had, the Glasgow Herald reported, “been written up with a wealth of imaginative incident, and told of the destruction of buildings and bridges, works and business houses, and the injuries of pedestrians in the streets”. People were trapped in one district; in another, there was escape of acid. In a third, mustard gas had been discovered in a creamery. Fires were burning fiercely.

Some 10,000 members of civil defence groups took part in the exercise, including not just the ARP but also auxiliary fire services, first-aid and ambulance corps, demolition and rescue squads, special constabulary, decontamination squads, too, as well the Royal Engineers.

In each district, Home Office "umpires" checked how long it took for the head wardens to react to the emergency and for the other organisations to be called to the scene. Their findings were to be collated by the Home Office’s Sir Ian Bolton, who would report on any weaknesses to Glasgow’s Lord Provost.

Air-raid sirens were to be tested across the city in the week ahead.