COLOSSUS THE TRUE STORY

There are many more myths around Colossus than there are accurate stories. Tim Danton unravels the mystery with the help of a professor, engineers and historical records

- Tim Danton

On 1 September 1939, Post Office engineer Tommy Flowers found himself in Berlin to take part in a European conference about telephone systems. Germany invaded Poland the same day.

Flowers and a fellow British delegate went to the British embassy to let them know where they were staying. “The young man at the embassy... looked at us and said, ‘You people must be mad, there’s going to be a war in a few days’,” Flowers said in 1998. “Which surprised us a bit.”

The British duo spent the next day with their German counterparts on the committee, trying to play it cool, but the next morning the embassy called to say they had to catch the next train out or else. A tense eight-hour journey through Germany followed, but the men were back in London by 8am on 3 September.

It had been a lucky escape for both men. Many British citizens unfortunate enough to be in Germany on the day Britain declared war were detained at internment camps until VE Day in May 1945. It was an even luckier escape for the British war effort, because without Tommy Flowers there would have been no Colossus – and without Colossus, the Allies’ path to Germany would have cost many more lives, on both sides.

GPO staff in the telephone exchange at the Ministry of Information in 1941

INSERT Colossus wouldn't have been built without the genius of Tommy Flowers

A new type of encrypted message was received by teleprinter in 1940

Flowers and valves