The codebreakers at Bletchley Park were indebted to the Polish secret service for helping break the Enigma code and for smuggling an Enigma machine to them just as war broke out.

At the entrance to the courtyard of houses seen in yesterday’s post lies a memorial to three of these Polish contributors. In Polish and English it commemorates, “the work of Marian Rejewski, Jerzy Różycki and Henryk Zygalski, mathematicians of the Polish intelligence service, in first breaking the Enigma code. Their work greatly assisted the Bletchley Park code breakers and contributed to the Allied victory in World War II.”

Nearer the main museum building is this memorial to those who worked at Bletchley Park. The letters read, “WE ALSO SERVED.”

Reverse of memorial:-

World War 2 wasn’t all technology driven.

One of the exhibits at Bletchley Park featured the contribution pigeons made to message carrying.

The pigeons were parachuted into occupied Europe using contraptions like this:-

Information board:-

Memorial to a pigeon winner of a gallantry medal. They also served:-

There were few facilities at Bletchley Park other than the working spaces. They did have a tennis court and there was the possibility of picnics etc on the lawns.

To simulate this outdoor loudspeakers at the modern museum play voices as if there’s a tennis match or picnic going on.

Some of the workers lived (just slept probably) off-site but there was some accomodation for others.

These buildings enclosing a courtyard were beyond the tennis court:-

Side of building to left above:-

There was a lovely stained glass window in the side wall here:-

Other side of courtyard:-

In courtyard to right of arch in photo above:-

Arch into courtyard:-

Most of the work at Bletchley Park was carried out in huts.

Hut corridor:-

Room with security reminder poster:-

The famous “Careless Talk Costs Lives” slogan and First Aid box:-

Another room in one of the huts:-

Alan Turing’s office:-

Statue of Alan Turing, made in slate. (This is situated in the main building, where most of the Enigma machines are displayed.)

It wasn’t merely European languages that were decoded during WW2. Japanese codes were also broken. One of the decoders taught himself Japanese in weeks to help do so.

These two exhibits refer to the efforts in Japanese.

Index Cards for Japanese words:-

Captured Japanese flag:-

This irreverent cartoon referring to BP (Bumph Palace; aka Bletchley Park) is about all the paperwork etc involved in the war effort:-

Most of the endeavours at Bletchley Park were devoted to the decipherment of messages encrypted by machine – most famously the Enigma; but others were more imprortant to crack

An Enigma machine:-

Enigma machine with explanation:-

A cabinet of Enigmas:-

Remains of a Hungarian Enigma machine dug up from the earth somewhere in Europe:-

4 Rotor Enigma machine:-

Enigma + diagram:-

Hagelin Encryption Machine, Italian Naval cypher machine. Plus a German hand cypher sheet:-

The enigma was cumbersome to use, requiring three operators, the typist, the noter down and the telegraphist – and required a similar number of personnel at the receiving end.

The Germans began to produce more complicated machines – with more encryption rotors and a faster transmission system.

Lorenz T 32 Encryption Machine. Amazingly Bill Tutte managed to work out how this machine worked only from the form of the messages it encrypted:-

Siemens & Halske T52 Cypher Machine. Messages were typed in and encrypted automatically then transmitted by teleprinter to be decoded by the reverse machine at the other end. (The use of ordinary teleprinter letter encoding in this system was a weakness that the decoders were able to exploit):-

One of the rooms here had an exhibition devoted to Bill Tutte, whose mathematical expertise helped to crack the fiendish Lorenz cypher (called Tunny by the codebreakers.) Tutte managed to describe how the Lorenz encryption machine worked without ever having seen an example of one.

The mansion is really lovely inside.

Entrance hall:-

Library:-

Ornamental plastered ceiling:-

Another ornate ceiling:-

One of the rooms has some lovely wood panelling:-

Tiling on wall:-

Windows onto park:-

This notice records the Bletchley Park’s staff’s feelings at first decoding an enigma message:-

This is a replica bombe, the proto computer used to find ‘matches’ for Enigma encoded messages, leading to their decoding.

Every five minutes or so the replica simulates the operation of the originals. It’s very noisy. One of the huts elsewhere on the site housed several of these machines. Imagine the din!:-

Colossus was the first electronic computer; used at Bletchley Park to help decode enemy messages:-

The surroundings at Bletchley Park are fairly scenic.

There’s a lake:-

In the first photo above you can see the mansion, here photographed from near the lake:-

Close-up of mansion (stitch of three photos):-

The grounds have some mature trees. This one seems to be destroying the building it’s now growing through:-

This one stands on its own:-

If the workers ever had any spare time there could have been worse places to relax in.

Bletchley Park near Milton Keynes (very near) is famous for the codebreaking efforts of its occupants during World War 2.

As a museum though it is so much more. It is one of the best I have ever visited. We spent nearly the whole day there.

And it is not devoted merely to the breaking of the Enigma (and related) WW2 codes.

The recommended route through on our (Covid distanced) trip took us first into the section covering Bletchley Park’s Great War predecessor – the famous Admiralty Room 40.

An amusing exhibit was this one of a magazine Room 40’s denizens produced for themselves to document their activities:-

Room 40’s workers were the “brightest and best”:-

This exhibit lists the members of Room 40 who went on to the Government Code and Cypher School, Bletchley Park’s predecessor:-

I also liked the cover of this book on the Battle of Jutland:-

These document the German Naval bombardment of Scarborough:-

Room 40’s greatest achievement was the decoding of the Zimmerman Telegram:-

Its contents, with its invitation to Mexico to invade the US and promise to reward it with US territory, were the major reason the US entered the war against Germany.