Testery The Testery was a section at Bletchley Park , the British codebreaking station during World War II . It was set up in October 1941 under Major Ralph Tester . 4 founder members were Tester himself and 3 senior cryptographers were Captain Jerry Roberts , Captain Peter Ericsson and Major Denis Oswald . 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 decrypting methods to break Tunny traffic . Within one year of its foundation , the Testery had deciphered 1 . 5 million texts by these methods . By the war ' s end in Europe in May 1945 , the Testery had grown to nine cryptographers , a team of 24 ATS , a total staff of 118 , organised in three shifts working round the clock . The logical structure of the Tunny system was worked out by mathematician Bill Tutte ( William Thomas Tutte ) in the Spring of 1942 . Tunny had 12 wheels , and was more advanced , complex , faster and far more secure than the well - known 3 - 4 wheeled Enigma machine . The Germans were convinced that the Tunny cipher system was unbreakable . Tunny was the cipher system which carried only the highest grade of intelligence : messages from the German Army Headquarters in Berlin and the top generals and field marshals on all fronts . Some were signed by Hitler himself . Tens of thousands of Tunny messages were intercepted by the British and broken at Bletchley Park by Captain Roberts and his fellow codebreakers in the Testery . These messages contained much vital insight into top - level German thinking and planning . After the Testery had been breaking Tunny for a year by hand , the Newmanry became active from July 1943 under Max Newman . Mathematicians in the Newmanry used machine methods to speed up breaking Tunny . Early on , a machine called ( Heath ) Robinson was produced , to help speed up one stage — breaking of the chi wheels , but the Robinson was slow and not reliable . Fortunately , in February 1944 a new machine called “ Colossus ” became operational ; it was the world ' s first electronic computer . Colossus was designed and built in only ten months by Tommy Flowers of the G . P . O . ( Post Office ) . This had far greater capacity and speed than the Robinson and so the whole breaking process became much faster . The Colossus was essential for making the very fast counts needed to work out the “ de - chis ” , but the psi - wheels and motor - wheels were still broken by hand in the Testery . The Testery was hand code - breaking Tunny for 12 months before the Robinson machine was produced and for 19 months before Colossus operated . With the help of the Newmanry , the Testery broke up to 90 % of the traffic given to them to work on in the Colossus period . The information provided by Tunny enabled the Allies to ascertain German movements , saving thousands of lives at critical junctures such as D - Day and the battle of Kursk in the Soviet Union . General Dwight D . Eisenhower gave the best summary after World War II . He said that " Bletchley decrypts shortened the War by at least two years " . Tunny played a very important role in all of this , a war which was costing at least 10 million lives a year . A great deal of this was down to Bill Tutte . The story of Enigma ( declassified in the 1970s ) is well known , but the story of Tunny , Germany ' s top - secret cipher machine , was only declassified a few years ago . Most of the cryptographers in the Testery died before they could tell their stories . Fortunately , for the first time , on October 25 , 2011 , a BBC Timewatch programme titled ‘ Code - breakers - Bletchley Park ’ s Lost Heroes ’ is about Testery , Tunny , Bill Tutte and Tommy Flowers : http : / / www . youtube . com / watch ? v = JF48sl15OCg & feature = related By the war ' s end in Europe in May 1945 , the Testery had grown to nine cryptographers , a team of 24 ATS , a total staff of 118 , organised in three shifts working round the clock .