by Gerald Boerner


JerryPhoto_8x8_P1010031 The Allies had a secret weapon during World War II: the codebreakers of Bletchley Park. This country estate, outside of London, housed the Government Code and Cypher School where codebreakers were working on reading Nazi communication that used the Enigma Machine. These codebreakers, led by mathematician Alan Turing, were able to “crack” the code for the various military units in the Wehrmacht, especially the five-rotor submarine codes.

These codebreakers were essential for several reasons. In the first place, they let the Allies win the “Battle of the Atlantic” against the submarine “wolf-packs”. This allowed Britain to maintain supplies of essential goods before the U.S. entered the war. In the second place, they allowed the Allied high-command to know how troops were being deployed just before D-Day. Finally, the codebreakers built early computers, including the Bombes and the Colossus, that facilitated their codebreaking and prompted the development of computer technology that blossomed after the war.

Were it not for these “geeks” and “propeller heads”, we might well be under the rule of Germania today.  GLB

[ This is Part 4 of 6 ]


“Ronald Reagan used to alarm his Soviet counterparts by saying that surely they’d both unite against an invasion from Mars.”
— Christopher Hitchens

“The responsibility of commanding the invasion fell to me, and the task was assigned to my Army Group.”
— Gerd von Rundstedt

“Poverty is relative, and the lack of food and of the necessities of life is not necessarily a hardship. Spiritual and social ostracism, the invasion of your privacy, are what constitute the pain of poverty.”
— Alice Foote MacDougall

“One year after the United States led the invasion of Iraq, the country remains extremely dangerous not only to our troops, but also to the stability of the world.”
— Jay Rockefeller

“Social Democratic and trade union organs have approved of the illegal invasion of Belgium, of the massacre of suspected guerrillas, as well as their wives and children, as well as the destruction of their homes in various towns and districts.”
— Clara Zetkin

“So the reason that the Bay of Pigs failed was that the original promise made by Eisenhower was not kept by the subsequent Administration. It allowed hostile air to wipe out the approaching invasion force.”
— E. Howard Hunt

“Poland, of course, was the key country. I remember Stalin telling me that the plains of Poland were the invasion route of Europe to Russia and always had been, and therefore he had to control Poland.”
— W. Averell Harriman

“So, one of the things I was doing with the aliens in The Quiet Invasion was creating that advanced society which had ideas about morality and proper use of natural resources that were radically different from ours, as the Europeans were from the American Indians.”
— Sarah Zettel


Operation Overlord (D-Day): The Codebreakers

Enigma-rotor-stack Operation Overlord was the code name for the operation that launched the invasion of German-occupied western Europe during World War II by Allied forces. The operation commenced on 6 June 1944 with the Normandy Landings (commonly known as D-Day). A 12,000-plane airborne assault preceded an amphibious assault involving almost 7,000 vessels. Nearly 160,000 troops crossed the English Channel on 6 June; more than 3 million troops were in France by the end of August.

Allied land forces that saw combat in Normandy on D-Day itself came from Canada, the United Kingdom and the United States of America. Free French forces and Poland also participated in the battle after the assault phase, and there were also minor contingents from Belgium, Czechoslovakia, Greece, the Netherlands, and Norway. Other Allied nations participated in the naval and air forces. Once the beachheads were secured, a three-week military buildup occurred on the beaches before Operation Cobra, the operation to break out from the Normandy beachhead, began. The battle for Normandy continued for more than two months, with campaigns to expand the foothold on France, and concluded with the closing of the Falaise pocket on 24 August, the liberation of Paris on 25 August, and the German retreat across the Seine which was completed on 30 August 1944.

Bletchley Park: Government Code and Cypher School

Bletchley_Park Bletchley Park, also known as Station X, is an estate located in the town of Bletchley, in Buckinghamshire, England. During World War II, Bletchley Park was the site of the United Kingdom’s main decryption establishment, the Government Code and Cypher School. Ciphers and codes of several Axis countries were decrypted there, most importantly ciphers generated by the German Enigma and Lorenz machines.

The high-level intelligence produced at Bletchley Park, codenamed Ultra, provided crucial assistance to the Allied war effort and is credited with having shortened the war by two years, so saving many lives. However, Ultra’s precise influence is still studied and debated.

Bletchley Park is now a museum run by the Bletchley Park Trust and is open to the public. The main manor house is also available for functions and is licensed for ceremonies. Part of the fees for hiring the facilities goes to the Trust for use in maintaining the museum. Since 1967, Bletchley has been part of Milton Keynes.

Wartime History

Turing_flat The cottages in the stableyard were
converted from a tack and feed house.
Early work on Enigma was performed
here by Dilly Knox, John Jeffreys and
Alan Turing.

Five weeks before the outbreak of World War II, in Warsaw, Poland’s Biuro Szyfrów (Cipher Bureau) revealed its achievements in decrypting German Enigma ciphers to French and British intelligence. The British used this information as the foundation for their own early efforts to decrypt Enigma.

The "first wave" of the Government Code and Cypher School (GC&CS) moved to Bletchley Park on 15 August 1939. The main body of GC&CS, including its Naval, Military and Air Sections, was on the house’s ground floor, together with a telephone exchange, a teleprinter room, a kitchen and a dining room. The top floor was allocated to MI6. The prefabricated wooden huts were still being erected, and initially the entire "shooting party" was crowded into the existing house, its stables and cottages. These were too small, so Elmers School, a neighbouring boys’ boarding school, was acquired for the Commercial and Diplomatic Sections.

Station_X_bletchleypark Original listening equipment
in the ‘Station X’ room

A wireless room was set up in the mansion’s water tower and given the code name "Station X", a term now sometimes applied to the codebreaking efforts at Bletchley as a whole. The "X" denotes the Roman numeral "ten", as this was the tenth such station to be opened. Due to the long radio aerials stretching from the wireless room, the radio station was moved from Bletchley Park to nearby Whaddon to avoid drawing attention to the site.

Listening stations – the Y-stations (such as the ones at Chicksands in Bedfordshire and Beaumanor Hall in Leicestershire, the War Office "Y" Group HQ) – gathered raw signals for processing at Bletchley. Coded messages were taken down by hand and sent to Bletchley on paper by motorcycle couriers or, later, by teleprinter. Bletchley Park is mainly remembered for breaking messages enciphered on the German Enigma cypher machine, but its greatest cryptographic achievement may have been the breaking of the German "Fish" High Command teleprinter cyphers.

The intelligence produced from decrypts at Bletchley was code-named "Ultra". It contributed greatly to Allied success in defeating the U-boats in the Battle of the Atlantic, and to the British naval victories in the Battle of Cape Matapan and the Battle of North Cape. In 1941, Ultra exerted a powerful effect on the North African desert campaign, against the German army, under General Rommel. General Auchinleck stated that, but for Ultra – "Rommel would have certainly got through to Cairo". Prior to the D-Day landings, of June 1944, the Allies knew the locations of all but two of the 58 German divisions on the Western front.

When the United States joined the war, Churchill agreed with Roosevelt to pool resources. A number of American cryptographers were posted to Bletchley Park and were inducted and then integrated into the Ultra structure, being stationed in Hut 3. From May 1943 onwards there was very close cooperation between the British and American military intelligence organizations.

Conversely, the existence of Bletchley Park, and of the decrypting achievements there, was never officially shared with the Soviet Union, whose war effort would have greatly benefited from regular decrypting of German messages relating to the Eastern Front. This reflected Churchill’s concern with security, and his distrust of and hostility to communism, even during the alliance imposed on him by the Nazi threat.

The only direct action that the site experienced was when three bombs, thought to have been intended for Bletchley railway station, were dropped on 20–21 November 1940. One exploded next to the despatch riders’ entrance, shifting the whole of Hut 4 (the Naval Intelligence hut) two feet on its base. As the huts stood on brick pillars, workmen just winched it back into position while work continued inside.

After the war, Churchill referred to the Bletchley staff as "My geese that laid the golden eggs and never cackled".

Enigma Machine

Enigma An Enigma machine is any of a family of related electro-mechanical rotor machines used for the encryption and decryption of secret messages. The first Enigma was invented by German engineer Arthur Scherbius at the end of World War I. This model and its variants were used commercially from the early 1920s, and adopted by military and government services of several countries—most notably by Nazi Germany before and during World War II. A range of Enigma models were produced, but the German military model, the Wehrmacht Enigma, is the version most commonly discussed.

The machine has become well-known because, during World War II, British and American codebreakers were able, following pioneering Polish work, to decrypt a vast number of messages which had been enciphered using the Enigma. The intelligence gleaned from this source, codenamed ULTRA by the British, was a substantial aid to the Allied war effort. The exact influence of ULTRA on the course of the war is debated; an oft-repeated assessment is that decryption of German ciphers hastened the end of the European war by two years.

Though the Enigma cipher had cryptographic weaknesses, in practice it was only in combination with other factors (procedural flaws, operator mistakes, occasional captured hardware and key tables, etc.) that those weaknesses allowed Allied cryptographers to cryptanalyze so many messages.

After the War

At the end of the war, much of the equipment used and its blueprints were destroyed. Although thousands of people were involved in the deciphering efforts, the participants remained silent for decades about what they had done during the war, and it was only in the 1970s that the work at Bletchley Park was revealed to the general public. After the war, the site belonged to several owners, including British Telecom, the Civil Aviation Authority and PACE (Property Advisors to the Civil Estate). GCHQ (Government Communications Headquarters), the post-war successor organisation to GC&CS, ended training courses at Bletchley Park in 1987.

The local headquarters for the GPO was based here and housed all the engineers for the local area together with all the support they needed. The Eastern Region training school was also based in the park and later part of the national BT management college which was relocated here from Horwood House. There was also a teacher-training college.

By 1991, the site was nearly empty and the buildings were at risk of demolition for redevelopment. On 10 February 1992, Milton Keynes Borough Council declared most of the Park a conservation area. Three days later, on 13 February 1992, the Bletchley Park Trust was formed to maintain the site as a museum devoted to the codebreakers. The site opened to visitors in 1993, with the museum officially inaugurated by HRH the Duke of Kent, as Chief Patron, in July 1994. On 10 June 1999 the Trust concluded an agreement with the landowner, giving control over much of the site to the Trust.

Bombe-rebuild A project to construct a working replica of a
bombe is nearing completion.

The Trust is volunteer-based and relies on public support to continue its efforts. Christine Large was appointed Director of the Trust in March 1998. On 1 March 2006, the Park Trust announced that Simon Greenish had been appointed Director Designate, and would work alongside Large in 2006, taking over on 1 May 2006.

In October 2005, American billionaire Sidney Frank donated £500,000 to Bletchley Park Trust to fund a new Science Centre dedicated to Alan Turing.

A team headed by Tony Sale has undertaken reconstruction of a Colossus computer at The National Museum of Computing, which is also located within the park. Another team, led by John Harper, has undertaken a rebuild of the bombe. On 6 September 2006, the Trust demonstrated that the Bombe was back in action.



Background and biographical information is from Wikipedia articles on:

Wikipedia: Operation Overlord…

Wikipedia: Bletchley Park…

Wikipedia: Enigma Machine…

Web Sites and Blogs:

Brainy Quote: Invasion Quotes