Career
He founded and supervised a section named the Testery for breaking Tunny (a Fish cipher). The Lorenz cipher machine had twelve wheels, and was thus most advanced, complex, faster and far more secure than the three-wheeled Enigma. Lorenz was used to encipher top-secret messages between German Army Headquarters in Berlin, and the top generals and field-marshals on all fronts, including Adolf Hitler himself.
Before World World War II, Tester was an accountant who had worked extensively in Germany and as a result was very familiar with the German language and culture.
He held a senior position in the accountancy division of Unilever. On the outbreak of war, he worked for the British Broadcasting Corporation Monitoring Service which listened in to German public radio broadcasts.
Recruited to, and during later 1941 was the head of a small group working on a double Playfair cipher used by German military police. Testery set up in July 1942 under Major Ralph Tester and the three other original founding members, cryptographers and linguists were: Captain
Jerry Roberts, Peter Ericasson and Major
Denis Oswald, all four were fluent in German. The Testery was a section at, the British codebreaking station during World World War World War II lieutenant was set up in October 1941 under Major Ralph Tester. All four were fluent in German.
From 1 July 1942 on, this team switched and was tasked with breaking the German High Command’s most top-level code Tunny after Bill Tutte successfully broke Tunny system in Spring 1942.
The Testery used hand methods, working on a German hand cipher to break messages enciphered on TUNNY Fish (cryptography) traffic. Messages broken by hand reached 1.5 million places within one year of its foundation.
By the war’s end in May 1945, the Testery had grown to nine cryptographers, out of a total staff of 118 organised in three shifts. A former Testery senior codebreaker and shift leader Jerry Roberts, recalls that, "The imperturbable, pipe-smoking Tester spoke fluent German, but did not pretend to be a codebreaker.
The atmosphere in his unit was always positive and friendly, and the personnel were well selected—Tester seemed to find the right niche for everybody.
Thanks to Tester"s influence the work of the Testery was very well organised."
Towards the end of the European war, Tester was part of a TICOM team, a mission sent to Germany to discover information about their communications technology, including TUNNY machines. After the war, Tester returned to Unilever. Ralph Tester, linguist and head of Testery (not a codebreaker)
Jerry Roberts, shift-leader, linguist and senior codebreaker
Peter Ericsson, shift-leader, linguist and senior codebreaker
Victor Masters, shift-leader (not a codebreaker)
Denis Oswald, linguist and senior codebreaker
Peter Hilton, codebreaker and mathematician
Peter Benenson, codebreaker
Peter Edgerley, codebreaker
John Christie, codebreaker
Jack Thompson, codebreaker
Roy Jenkins, codebreaker (later moved on to wheel setter)
Tom Colvill, general Manager
By the end of the War, the Testery had grown to nine cryptanalysts, a team of 24 ATS, a total staff of 118, organised in three shifts working round the clock.
