Flower Power and Colossus

Meet a 'Colossus' in the world of early encryption!

Have you ever built a computer before? It can be scary, but once you’re done, you have a PC that you can use and enjoy by yourself. However, do you think you have what it takes to build a computer to help win a war?

This is the job that Tommy Flowers had to do. Despite his name, he isn’t well-known for gardening; instead, he designed and built a machine that helped win World War 2.

Back when the war was waging, Germany was sending a lot of encrypted messages. They did this to protect their communications from being caught by the Allies. Back then, encryption was a big deal; it was hard to crack unless you had some really smart people to churn through all the code yourself.

The going was tough, so Tommy Flowers was brought on to make a machine that could do all the hard work for the army. The computer took eleven months to build, and it was given the name “Colossus.”

The Colossus was an early computer, but it wasn’t the first ever. There were a few machines before it that could automatically calculate things with minimal human interaction. However, the Colossus was both the first electronically-powered computer and the first one you could program.

It didn’t get the name ‘Colossus’ for nothing. Even by today’s standards, it was a beast of a machine. It featured 1,500 vacuum tubes to help it compute stuff, and it could process 5,000 letters a second; a lot faster than a human!

It also was a ‘Colossus’ in terms of space, too. After all, all those vacuum tubes have to go somewhere, and as such the computer was 7 feet tall, 17 feet long, and 11 feet wide. If a medium-sized giraffe laid down flat next to the Colossus, it would have been as long as its entire body!

However, all that work and effort wasn’t for nothing. By the end of the war, ten Colossus machines had been made, and they were staffed by 550 people. The machines had successfully churned through 63 million characters of German code and helped quicken the end of the war by a few months!

So, was Tommy Flowers regarded as a hero? Unfortunately, because the Allies wanted to keep this giant code-busting machine secret, they didn’t reveal the machine’s existence for a very long time. Even after World War 2 ended in 1945, the computers were disassembled bit by bit and kept secret.

Fortunately, however, the army decided to finally reveal the existence of Colossus in 1975 so people could see how it worked. And because Tommy Flowers wouldn’t pass away until 1998, he was sure to get all the recognition and thanks for bringing a terrible war to a quicker conclusion.

Learn More

Wikipedia Colossus article


The Colossus Mark 1


Tommy flowers


The codebreakers of Bletchley Park


Tommy Flowers and Colossus


Tommy Flowers Facts for Kids


The history of Colossus Computer


Early Electronic Computers


A brief history of encryption



  • Simon Batt

    Simon Batt is a UK-based tech enthusiast and all-around geek. His favourite things are cups of tea, cats, and new gadgets, even though they never mix well.

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