Peter Twinn facts for kids

Peter Frank George Twinn CBE (born January 9, 1916 – died October 29, 2004) was a British mathematician. He was a very important codebreaker during World War II. He also studied insects, which is called entomology. Peter Twinn was the first professional mathematician to be hired by the GC&CS. From 1943, he led a special team called ISK. This team was responsible for breaking over 100,000 secret messages from the German spy agency, Abwehr.

Early Life and Education

Peter Twinn was born in Streatham, a part of South London. His father worked for the General Post Office. Peter went to Manchester Grammar School and Dulwich College. After that, he studied mathematics at Brasenose College, Oxford. He even won a scholarship to study physics further after his first degree.

Breaking Secret Codes

Peter Twinn was the very first professional mathematician to join the GC&CS. This was a top-secret British organization that worked on breaking enemy codes. In early 1939, he saw an advertisement for a job and applied. He first worked in London, then moved to Bletchley Park. This was the secret place where many codebreakers worked during the war.

He worked with other famous codebreakers like Dilly Knox and Alan Turing. They focused on breaking the German Enigma codes. By early 1942, Peter Twinn became the head of the section that broke the Abwehr Enigma codes.

Joining the Codebreaking Team

Peter was studying physics when he saw the job advertisement. He remembered feeling a bit unsure about what to do next after finishing his university degree. The advertisement said they were looking for mathematicians, but it didn't say much more.

At that time, the world was very tense, and a big war seemed likely. Peter was offered the job with a good salary for the time. On his first day, he met Dilly Knox. Peter started as an assistant to Knox, who led a team of codebreakers at GC&CS.

Dilly Knox was a very smart codebreaker. He was one of the first British experts to work on the Enigma code. Most of the early GC&CS experts studied old languages. But as war got closer, GC&CS started hiring mathematicians, chess players, and even crossword puzzle experts. Peter Twinn was the first mathematician to join the team.

Knox liked to challenge new people. He gave Peter only five minutes of training. Then he told him to start working on the codes by himself!

Before World War II Started

Peter Twinn was the first British codebreaker to read a German military Enigma message. He got very important information from Polish codebreakers in July 1939. Peter said it was a small task and he didn't deserve much credit for it.

In July 1939, just before the war, GC&CS moved from London to Bletchley Park. The main house was used by staff. Many other buildings, called "huts," were built to hold all the people working there during the war.

Codebreaking During World War II

Understanding the Enigma Machine

The Enigma machine was invented a long time ago, in 1919. It was a special machine for secret writing. An engineer named Arthur Scherbius worked on these machines. He thought they would be great for sending secret messages.

At first, a company tried to sell the Enigma for business use. But businesses weren't interested. Then, in 1926, the German Navy looked at the machine. They liked it a lot and bought many of them. They kept the purchase of the Enigma machine a big secret.

The Enigma machine was complex. It had a keyboard, like a typewriter, with all the letters. Each letter was connected to three spinning wheels called rotors. Each rotor also had the 26 letters of the alphabet. Wires then connected the rotors to 26 lights.

When someone typed a letter, electricity went through the machine. The rotors would spin. Each time a key was pressed, the first rotor moved one step. After 26 steps, the first rotor completed a full turn. Then the second rotor would start to move.

When a key was pressed, a light would turn on. This light showed the coded letter. This coded letter was always different from the original letter. The lit-up letters formed the secret message.

To decode a message, someone would use another Enigma machine. It had to be set up exactly the same way. When they typed the coded letter, the light for the original message letter would turn on. This way, they could read the secret message.

To make the codes even harder to break, the rotors could be taken out. They could be put back in a different order. Also, the settings on the rotors could be changed every day. For example, one day the first rotor might be set to 'B', the next day to 'F'.

The military version of Enigma had a plug board. This was like an old telephone switchboard. It added another way to scramble the letters. This happened before the letters went into the rotors and after they left. The plug board had 26 holes. Wires and plugs connected pairs of letters. With three rotors and six pairs of letters connected on the plug board, there could be over 105,000 different combinations!

In December 1938, the Germans added more rotors, up to six. This made the number of combinations much, much higher. The Germans thought their messages were impossible to break. But Peter Twinn and his team proved them wrong.

About 10,000 people worked at Bletchley Park. The main group trying to break Enigma was small, only about ten people at first. Knox and Twinn were in charge.

The British codebreakers had worked on the easier commercial Enigma machine in the 1920s and 1930s. They had made good progress on the military version. But Twinn and his team were stuck. They couldn't figure out how the Enigma keys were wired inside.

In July 1939, just before the war, Knox and others went to Poland. Polish code experts shared important information about Enigma. They even gave the British replica machines.

The British learned that Enigma machines were wired alphabetically. 'A' connected to the first contact, 'B' to the second, and so on. This was shown in the original patent diagram. But Twinn and his team thought it was too simple to try!

In early 1940, Peter Twinn made the first big breakthrough into Enigma. This could have happened much earlier if they had just tried the simple alphabetical wiring.

Being able to read German secret military messages helped the Allies greatly win the war. This was largely thanks to the hard work of Peter Twinn, Dilly Knox, Alan Turing, and others at Bletchley Park. Alan Turing was a brilliant mathematician. He developed a machine called the "bombe." This machine helped speed up the decoding process by trying many combinations. This was a very important step for the codebreakers.

Breaking German Naval Enigma

Peter Twinn also worked with Alan Turing to break the German Naval Enigma codes. Their success helped Allied ships avoid German U-boats (submarines) in the ocean.

Leading the ISK Team

In October 1941, Dilly Knox solved the Abwehr Enigma code. A new team, called Intelligence Services Knox (ISK), was created to decode messages from the German spy agency, Abwehr. In early 1942, Dilly Knox became very ill. Peter Twinn took over running ISK. After Knox's death, Peter was officially made the head of the team. By the end of the war, ISK had decoded and shared 140,800 messages.

The secret information from these Abwehr messages was very important. It helped the Allies trick the Germans about D-Day, the big invasion of Europe. This was part of a plan called Operation Fortitude.

After the War

After the war, Peter Twinn continued to work for the government. In the late 1960s, he was the Director of Hovercraft in the Ministry for Technology. Later, he became the Secretary of the Royal Aircraft Establishment in Farnborough. In the early 1970s, he worked for the Natural Environment Research Council. He received an award called CBE in 1980 for his important work.

Peter Twinn also became very interested in entomology, the study of insects. He earned his doctorate degree from the University of London. His research was about how click beetles jump. He also helped write a book about the distribution of different types of longhorn beetles.

Peter Twinn loved music. He played the clarinet and the viola. He met his wife, Rosamund Case, at Bletchley Park because of their shared interest in music. They got married in 1944 and had a son and three daughters.