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Bletchley Park Photos
November 2004



Bletchley Park holds a remarkable place in world history. It is where the British, with important pre-war help from Poland, broke through the Enigma and Lorenz ciphers and read enormous amounts of German military and diplomatic radio traffic during World War II with profound results.

Bletchley Park is located in the small English town of Bletchley which is located in Milton Keynes on a main north-south rail line about 50-miles northwest of London midway between Cambridge and Oxford universities. The area also had excellent telephone and teletype connections, was outside London in an obscure place, and was also centrally located between the two major universities that were to provide many of the required cryptography personnel. These were all important factors just before the beginning of the war that lead to its selection when it was established by the Government Code and Cipher School (GC & CS) in 1939.

Bletchley is the secret location where the British housed their cryptographers during the war when they penetrated and read enormous amounts of Enigma and Lorenz enciphered German military and diplomatic traffic that was transmitted by radio during the 1939-1945 period. The high-level intelligence that resulted from the decrypted intercepts was codenamed ULTRA and was a very closely guarded secret by the Allies. The only other secret of similar magnitude and impact during World War II was the American Manhattan Project that lead to the development of the Atomic Bomb which decisively ended the war in August 1945. About 12,000 people are estimated to have worked at Bletchley by the end of the war.

The impact of the work completed by the people at Bletchley Park was enormous on the outcome of World War II and on world history. Many historians estimate that Bletchley shortened the war by at least two years and saved millions of lives. For example, ULTRA enabled the Allies to know the German Order of Battle in specific detail before and during the D-Day invasion. Before D-Day, ULTRA allowed the Allies to monitor and control the effects of their complex deception plans that convinced Adolf Hitler that the invasion of Festung Europa would target the Calais region of France rather than Normandy. Both of these events helped assure the success of the massive D-Day assault. Thousands of similar examples, large and small, existed throughout the war.

However, perhaps the most important strategic victories that were enabled or even caused by ULTRA happened earlier in the war when the Allies were much more vulnerable than later. The Battle of the Atlantic, where German U-Boats threatened to starve England out of the war, was finally abandoned by Germany in early 1944 largely, though certainly not completely, because of the work of Bletchley. The victory by the Allies in North Africa in 1943 was also speeded along and made inevitable by ULTRA. D-Day would almost certainly never have happened when it did if England had been knocked out of the war or if the Axis Powers had not been driven out of North Africa in 1943.

However, the main turning point of the war in Europe was, undoubtedly, the Axis defeat during the Battle of Stalingrad in 1943 (probably the bloodiest and largest single battle in human history - and certainly one of the most important). After Stalingrad, though it was perhaps not very apparent to most people for some time, defeat for Germany was almost inevitable as the Red Army relentlessly ground its way west toward Berlin obliterating everything in its path. At the same time, America began to finally bring its enormous industrial and military might to bear on the NAZIs in Europe.

It can easily be argued that the most important long-term impact of Bletchley Park was that by enabling the Normandy landings in France to happen when they did, the Red Army was able to only reach west to the Elbe River and no further. Without ULTRA, D-Day almost certainly would never have happened in time and the Soviet Union with its Red Army would probably have reached all the way to the Atlantic just after the Americans, and the British, would have ended the war in Europe by dropping the atomic bomb on Germany rather than on Japan. With only Red Army troops on the ground in continental Europe, the Soviet Union almost certainly would have quickly pushed west all the way to the Atlantic before the end.

Post-war global history would have been radically different. The Cold War might never have happened with all of Europe under undoubtedly firm Soviet control. After all, would it have been realistic for the U.S. to have overcome that situation (think Hungary 1956 where NATO was unable to help the Hungarians after the Soviet invasion -- but on a continental scale). Arguably, one possibility would be that all of Europe would probably be Soviet and the Soviet Union still intact even today. One likely outcome of such a post-war situation could easily have been a cataclysmic hot global nuclear war (1955?) with no winners whatsoever - only losers - rather than the Cold War that lasted almost half a century.

It is impossible, of course, to know for sure the probability of the correctness of such alternative historical theories. But one thing is certain -- History would have been different if Bletchley Park and its activities had not existed.

Bletchley Park is also tremendously important to the world because of the foundational technological work that was completed there. The first electronic Digital Computer was invented at Bletchley by the brilliant engineer Tommy Flowers (see photo) which was based on theoretical work by the mathematician Alan Turing. Even though the machine - Colossus - was not really a complete general purpose stored program computer in the modern sense (e.g., it was not Turing Complete), it was the first electronic data processing machine ever built. The long-term fallout of that work radically transformed the world forever.

Bletchley Park is a remarkable place.


As a cryptographic engineer and a reader of history, I have an interest in the history of cryptography and the early days of machine computing and was able to visit Bletchley Park in November 2004 after business in London. I traveled to Bletchley (the small town where Bletchley Park is located) by train from London and then spent two interesting days over a weekend wandering and prowling about the famous Huts where Turing and the others worked their history altering magic over half a century ago.

I had some terrific luck with the usually not very helpful English winter weather by having a gloriously clear day after one day of cold rain and fog. The clear sunny skies helped some of the photography a bit.

See for a detailed map of wartime BP (Bletchley Park) to help stay oriented. The map has been pinched (as the Brits say) from Tony Sale's site at www.codesandciphers.org.uk.

The following photos (all 2272 x 1704 pixels) are copyrighted by Jack Harper but are free to be used for any purpose by anyone as long as there is accompanying attribution to this website at www.frobenius.com/bletchley.htm (click on the Thumbnails).


Bletchley Station Sign
Bletchley is on the main line from Euston Station in London. Travel time is 55-minutes and trains travel about every 20-minutes.

Bletchley Station.
The station is of modern construction and appears perhaps 20 or 30-years old. It is almost certainly not in its original WWII state.

Entrance to Walkway to Bletchley Park.
Bletchley Park is a short 5-minute walk from Bletchley Station. Leave the station through the ticket office toward the west and walk across Wilton Avenue until you see the sign "Bletchley Park & Wilton Avenue". Walk along the pathway which is just outside the southern boundary of the park.

Southern Boundary Security Fence.
A high and, apparently, WWII era security fence still protects the southern edge of Bletchley Park. This is one of the concrete fence posts.It has clearly grown up with weeds and tall grass over the past half-century.



Walking Path.
The path is perhaps 100-meters long to the main gate.

More Security Fencing.
These fence staves appear to be of more modern construction.

Minor Entrance.
Some sort of secondary entrance with concrete posts.

Still More Walkway.
Keep Going...



Main Entrance with, even today, a Security Guard.

The Mansion.
The Bletchley Park Mansion was built in stages during Victorian times and is a strange combination of Victorian Gothic, Tudor, and Dutch Baroque. Admiral Sir Hugh Sinclair, Director of Naval Intelligence, head of MI6, and founder of the Government Code and Cypher School (GC & CS) purchased the property in 1938. He then allowed the British Government to use the property. GC & CS moved into the Mansion in 1939.

Bletchley Park Mansion.
The Mansion served as the primary administrative offices for the entire park during the war.

Bletchley Park Mansion.
Another shot.



Bletchley Park Mansion.
Another shot.

Bletchley Park Mansion.
Another shot.

Bletchley Park Mansion.
Another shot. Hut 4, responsible for translation and analysis of naval decryps, was just a few meters south of the Mansion (just off to the left of the Mansion in this photo).

Bletchley Park Mansion.
Closeup from the north-east. A German bomb, perhaps aimed at the Bletchley Train Station, fell not very far from the Mansion during the early days of the war and shifted Hut 4, just to the south, on its foundation.



Bletchley Park Mansion.
Closeup facing north-west. In 1939, a radio room was built in a turreted tower at the top of the Mansion on the south side (not in photo) that was used to maintain radio contact with British Embassies in Europe during the 1939-1940 period. Its designation was Station X. However, the radio room was removed in early 1940 so as not to draw attention to Bletchley Park and its purpose.

Tree between the Mansion and the Lake.
This view from the Mansion shows the famous Sequoia Tree by the Lake. A radio aerial wire was strung from the Mansion to the top of the Tree at the beginning of the war when BP was known as Station X.

Tree between the Mansion and the Lake.
This photo taken from the Lake shows the giant Sequoia Tree in front of the Mansion.

Stable Yard Sign.
Walking from the Mansion toward the Stable Yard, is this sign.



Path to Stable Yard.
Walk from the Mansion past the post office toward the Stable Yard.

Stable Yard.
The stables were converted to motor car garages at the beginning of the war. Above the stable/garages, can be seen the pigeon loft (yes, pigeon loft) where carrier pigeons were kept that were airlifted to Occupied France to carry messages back to Bletchley from the French Resistance. Before the war, this area was used to store horses and their various accoutrements etc before GC&CS moved in.

Bungalow or Cottage.
These three linked cottages were, before the war, from left to right, the house for the head coachman, the corn store for the horses, and the tack room respectively. The tack room is not visible in this photograph.

The right-most cottage, the former Tack Room.
The earliest work by Turing at BP was completed here which is where the first break into Enigma happened in early 1940.



Memorial Plaque to Rejewski, Rozycki, and Zygalski (English half).
Enigma was first broken into by these three Polish mathematicians just outside Warsaw.

Memorial Plaque to Rejewski, Rozycki, Zygalski (Polish half.
In July 1939, the Poles, realizing that the war would soon start and that they would be overun, transferred their knowledge of Enigma to the British and French at a secret meeting near Warsaw in July 1939. This large bronze plate commemorates their work and importance.

Churchill's Tennis Court.
PM Winston Churchill, believing that the cryptographers needed a bit of on-site R&R, ordered this tennis court to be built - undoubtedly the only court built in England during the war.

Turing Bombe Rebuild Plaque.
The Bombe was the machine designed by Turing and his team and was based on ideas from the Poles to break into Enigma. A group of British enthusiasts, chaired by John Harper (no relation to this webpage author), are rebuilding a Bombe - a massive undertaking. An American built Bombe can be seen today at the NSA's National Cryptologic Museum near Washington, DC.



Bombe Rebuild Team Plaque.
An impressive number of volunteer people completing an impressive task...

Bombe Rebuild.
Many, many thousands of feet of wire and tens of thousands of solder joints.

Bombe Rebuild.
An electro-mechanical maze...

Bombe Rebuild.
I think that the cable ties on the wiring harness on the left are not original - cable lacing would have been used in the original during the WWII era (/whine)...



Bombe Rebuild.
An impressive effort...

Bombe Rebuild.
..ibid..

Bombe Rebuild.
..ibid..

Bombe Rebuild.
..ibid..



Bombe Rebuild.
A view from the front of the machine.

Bombe Rebuild.
You can see the Enigma rotors -- the Bombe was the equivalent of 36 Enigma machines operating at extremely high speed to buzz through possible solutions in parallel until a stop was encountered.

Faux-Bombe.
Very Pretty but, unfortunately, not real. This Bombe is a mockup that was built for the fun but historically inaccurate film Enigma a few years ago.

Faux-Bombe Rotors.
A closeup of the rotors on the mockup - obviously, on close examination, not real. They sure are pretty though.



Faux-Bombe Rotors.
Another view.

Two Movie Stars.
Two Faux-Bombes side by side.

Enigma Rotor Plaque (Real).
Numerous exhibits of Enigma artifacts exist at BP.

Enigma Rotor with Wiring.
Enigma Rotor with internal Wiring exposed. The wiring determined the encipherment performed by the single rotor and was first worked out by the Polish mathematician Marian Rejewski in Warsaw when he was in his early 30's.



Enigma Rotor.
Most Enigma machines had three rotors that enciphered/deciphered plaintext. However, the Enigma machines used by the Kriegsmarine (German Navy) used four which made naval traffic much more difficult to read.

Enigma Rotor.
Another view.

Enigma Rotor.
Another view.

Enigma Rotor.
Yet, another view.



Rotor Box.
German airforce/Luftwaffe and army Enigma machines had five rotors to select from whereas the German Navy/Kriegsmarine, which was far more security conscious, had eight rotors in its repertoire.

Plaque on Four-Rotor Naval Enigma Machine.
Traffic enciphered on the Four-Rotor machine was much more difficult to read.

Four-Rotor Naval Enigma.
Four-Rotor machines are more rare than the three-rotor version. Four-Rotor machines may also be seen at the National Cryptologic Museum near Washington, DC and at the U-505 exhibit at the Chicago Museum of Science and Industry.

Fragment of Colossus.
Colossus was the electronic machine used to decipher traffic encrypted by the German Lorenz machine which was much more secure than Enigma. I would argue that the photo of Turing in the display really should be replaced by a photo of Tommy Flowers, the engineer that actually designed and built Colossus though based on ideas by Turing. Flowers actually designed and built the machine with help from several others.



Fragment of Colossus.
PM Winston Churchill ordered that all (except for two) of the Colossus machines be broken up and destroyed at the end of the war.

Fragment of Colossus.
The fact that the Allies read Enigma and Lorenz traffic during World War II was a closely guarded secret for 30-years.

Placard on TypeX Crypto machine.
The TypeX was a cipher machine built by the British that was based on the German Enigma but was much more secure.

TypeX Machine.
Example of TypeX at Bletchley.



Placard on German Lorenz Cipher Machine.
The Lorenz was a cipher machine designed by the Germans for high-level strategic communications at the CORPS (equivalent) level and higher. The British called the machine and its traffic Tunny and almost immediately reverse-engineered and understood the machine because of an error by a German operator just after it was introduced into operation.

Example of Lorenz at Bletchley Park.
This particular Lorenz machine was captured from Field Marshal Kesselring's communication's staff at the end of the war. The design of the Lorenz was considerably more secure than that of the original Enigma. Colossus, built by the British, was the world's first large-scale electronic computing system and was built to read Tunny traffic.

Placard on Lorenz Teleprinter.
Unlike the Enigma, Lorenz was a teletypewriter cipher and used an automatic keyboard and printer.

Example of Lorenz Teleprinter at Bletchley Park.
The Lorenz machine employed twelve rotors compared to the three or four used with Enigma.



Alastair Denniston's Passport.
Denniston was the first head of GC&CS (from 1919 until 1942). In July 1939, Denniston and two others (Dilly Knox and Humphrey Sandwith) went to Poland where the Polish Cipher Bureau transferred everything they knew about Enigma to the British which had a profound impact on World War Two. This is the passport used by Denniston for that trip.

Typical British Shortwave Radio Listening Station from the Y Service, a chain of wireless intercept stations scattered across Great Britain.
The receivers are American-made National HRO units. The HRO was extremely well designed by the brilliant radio engineer James Millen and made its first appearance in 1935 with a retail price of $230 - an enormous amount of money for a radio during the Great Depression. The intelligence community of the Allies preferred HRO receivers during WWII because of their superior sensitivity and selectivity.

Another View.
National HROs.

Another View.
National HROs are classic receivers and are available on eBay today for a few hundred dollars.



W/T Wireless Form of the period.
W/T (or Wireless Telegraphy) Form with received enciphered German traffic.

Placard on U-Boat Replica.
Submarine replica is 1/5th Scale - Used for the movie Enigma.

1/5th Scale Replica of MkVII Submarine.
Used for the movie Enigma.

Another Replica.
Conning Tower etc - Used for the movie Enigma.



Placard on Hut 8.
Alan Turing's Hut.

Hut 8.
Turing's Hut.

Hut 8.
View through the Window (Not open to the Public).A Lot of history is in there...

Hut 11.
Hut 11 is where the Bombes that deciphered Enigma traffic were operated.



Entrance to Hut 11.
The interior of Hut 11, which is made of brick and concrete unlike most of the other huts which are wooden, is quite small - perhaps 20 x 30 feet (~6 x 9 meters). Hut 11 was actually quite massive with bomb-proof walls two-feet thick.

Another View of Hut 11.
It was, apparently, extremely noisy and hot inside when the Bombes were in operation.

Placard on Hut 6.
Interpretation Center.

Hut 6.
This hut housed the effort to break into German Airforce and Army Enigma traffic. The brick wall used to extend some distance upward to help protect against bomb blast.



Hut 4 - Naval Intelligence.
This hut housed the effort to break the Naval Enigma. During the war, a near miss of a German bomb (from the only stick of bombs dropped near Bletchley) shifted Hut 4 off its foundation. Workmen pushed the hut back into place and work continued. These days, it serves as a cafeteria/canteen just to the south of the Mansion.

H Block - Lorenz and Colossus.
Location of Tony Sale's current Rebuild Effort for Colossus.

H Block.
Another View.

Sign in front of B Block.
National Codes Center.



Placard on front of B Block.
...Former Naval Intelligence.

Entrance to B Block.
Walkway.

Another View.
Walkway.

Another View.
Houses, today, the Bombe Rebuild.



Side View of A Block .
From the west - Naval Intelligence.

Placard inside A Block.
Amateur Radio Station GB2BP.

GB2BP Radio Aerials.
Probably a 20/15/10-meter tri-band beam antenna. All amateur radio operations were shut down during the war. This antenna was erected long after the war by local enthusiasts.

A Block and B Block from across the lake from the south.
B Block was also used for Italian Air & Naval and Japanese code breaking.



Looking west across the lake toward the Mansion.
The famous Sequoia Tree is visible. In the early days, when BP was Station X, a longwire antenna was strung from a gable of the Mansion to the tree.

Ducks on the Lake.
That's George on the left and Fred on the right. Not sure about the others :)

Yet More Ducks.

Walkway between Huts.



http://www.frobenius.com/bletchley.htm -- Last Revision: 20 March 2006
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