Tag Archives: Turing

A failure of our Times: No recognition for Tutte

The story of Lorenz and Colossus is relatively unknown compared to Enigma and the Bombe, and it is for this reason that I commend The Times’ feature on Colossus (Technology Review, 23rd September 2013).  However,  I cannot help but be disappointed by the failure to afford recognition to Bill Tutte.  It was Tutte who deduced the logical structure of the Lorenz cipher, which enabled Tommy Flowers to design Colossus.


Colossus Feature (c) The Times

In the feature it states: “Without having seen a Lorenz machine, the Brits worked out how it operated…”  Tutte’s achievement has been described as one of the greatest intellectual feats of World War Two, so to refer to Tutte’s accomplishment as “the Brits worked out how it operated” is incredibly inadequate.

This reinforces the perpetual problem of Tutte’s breaking of Lorenz receiving far less recognition than the breaking of Enigma.  It’s a real shame that the article doesn’t go that little bit further and give Tutte the credit he deserves.

The article is worth a read (despite minor inaccuracies) and is available on-line, where you can also do a little code-breaking.  Be sure to turn up your volume to make full benefit of the impressive sound effects http://www.thetimes.co.uk/tto/public/colossus/  

Why not visit The National Museum of Computing at Bletchley Park where you can see a rebuild of Colossus Mark II and learn more about the work of Tutte?



Author: Claire Butterfield


The Turning of the Tide

Almost all the literature about the achievements of Bill Tutte, the Bletchley Park code breaker who cracked the German Lorenz code in 1941, a code vastly more complex and strategically more significant than the well known Enigma that the Polish and then Alan Turing cracked, says that he was credited with contributing to shortening the Second World War in Europe by up to two years, saving countless lives.  Some attribute this saying to General (later President) Eisenhower, the Supreme Allied Commander, and some even to Churchill himself. No matter, but how could such an incredible achievement be made by just one man, or even a small team?

After the entry of the USA into the war in December 1941, many believed that eventual victory was inevitable.  What was far from certain is when that would be.  Churchill even feared that it could take until 1950.  He knew it would take years for the formidable American economy and industrial capability to transform onto a war footing, and he was fearful of a premature engagement in Europe that could result in defeat by the battle-hardened German armies.  The Battle of Kasserine Pass in February 1943 when Rommel’s Afrika Korps routed poorly led and untested American troops in Tunisia proved his point.  Similarly, the disastrous Dieppe landings in August 1942 had shown how inadequate forces could not hope to land on strongly defended coastal positions.

Bill Tutte’s achievement enabled the Allies to read the signals traffic between Hitler and his prime operational headquarters, giving invaluable information about German strategic intentions and capabilities.  Churchill and Roosevelt had realised at an early stage that Russia held the key to defeating Hitler and, as well as providing the Russians with prodigious amounts of war equipment, the supply of strategic information to them was critical.  The surrender of German forces at Stalingrad in the winter of 1942/3 allowed the Russians to move onto the offensive.  Hitler was determined to crush them and to avenge the defeat at Stalingrad.  In July 1943, 3000 German tanks faced almost twice that number of Soviet heavy armour at Kursk, 280 miles South West of Moscow, in the largest engagement of armour ever to have taken place.

Although heavily outnumbered, the German tanks were far superior in armour and fire power.  However, delays in German arrivals allowed the Russians to prepare formidable defences and to concentrate their forces.  Moreover, German misgivings about the forthcoming battle led to much signals traffic using the supposedly invincible Lorenz code machines.  Thanks to Bill Tutte, the British were able to read this traffic.  (British radio technology was far ahead of that of both the Germans and Russians, neither of whom could believe signals traffic in Russia could be intercepted in Britain.)  The British were able to give their Russian allies almost the complete German order of battle, leading to a stunning Russian victory which they rightly called the Turning of the Tide.  General Zhukov, the Russian commander, was so impressed with the information he had been given that he thought the British must have had a mole in the German Headquarters, which in effect we did.

Afterwards, the Russian advance into Germany and eventually to Berlin was unstoppable, but it did ensure the engagement of up to 100 Divisions of crack German troops with countless tanks and aircraft on the Eastern front for the rest of the war.  This massive diversion of German resources allowed the successful Allied invasion of Normandy on 6 June 1944, but only after intercepted Lorenz traffic had satisfied Eisenhower that Hitler was convinced that the invasion would come at the Pas de Calais.    The final defeat of Nazi Germany in May 1945 can be linked directly to the work of Bill Tutte.

Ironically, it was mistrust of the Russians that led to Bill Tutte receiving no recognition or award for his war winning achievement.  We never admitted to the Russians that we had cracked the Lorenz code.  After the defeat of Germany, the Russians used captured Lorenz machines for their own coded messages throughout the early days of the Cold War, without realising that British security services could read the traffic.  To have recognised Bill Tutte’s achievement would have given the game away.  It was not until nearly 50 years later, after the collapse of the Soviet Union, that his story came out.  Even now, much remains secret.

You can donate via https://mydonate.bt.com/charities/billtuttememorialfund

Author: Richard Fletcher