Bletchley Park rebuilds the bombes -- code crackers that won the war

Make Blog has a great roundup of links and coverage for the opening of Bletchley Park's recreation of the Polish "bombe" code-cracking devices that were instrumental in breaking the German Enigma cipher in World War II. Bletchley's curators gathered all the surviving scientists from the original effort to lead the project, and the result is beautiful and inspiring.

Bletchley Park is a national treasure. Every visitor to Britain should go.

During World War II, British brainiacs helped save their country and defeat the Nazis. Recently, the equipment they used has been rebuilt and the surviving members got together for a reunion.

The rebuild project appears to be a maker's delight: code, electronics, old-school manufacturing, and rapid prototyping all wrapped up in a world-changing quest to win the war.

Code cracker remade


  1. And let’s not forget the contribution of Alan Turing…and his fate.

    Even today, we are reminded of his contributions to everyday computer science by “Captcha”s.

  2. My grandfather worked at Bletchley Park during the war, and went to his grave without ever revealing what he did there.

  3. That’s odd, not a single mention of Alan Turing in a post about Bletchley and Enigma? For shame Cory, what are you now, Fox News? :P

  4. Turing didn’t work on the bombes – that was the Polish crypto team. Turing worked on Colossus, and if you read to the end of the post, you’ll find that I’ve blogged rather a lot about Turing, Colossus and Bletchley.

  5. (The Polish mathmos used group theory to crack Enigma, but I don’t believe they ever built any machines. In fact they were never even told that Bletchley existed…)

  6. The Polish team copied an enigma and got it to the Brits.
    The bombes couldn’t keep up with the possible encode combinations of the improved enigma machines. But the Germans did some really dumb things. There was always a preamble noting awards and promotions that was common to all daily transmissions. If they broke the low level code sent to picket ships in the north Atlantic they had a leg up breaking the enigma coded message due to the common text.
    Turing needed delay lines to use results for logical adds etc. They were glass tubes with a mixture of water and alcohol. A ministry developed a technical spec for the liquid to give to potential vendors. Turing was using gin right out of the bottle. My kind of guy.

  7. #5:

    Dirk Rijmenants’ Enigma simulator is fantastic, it’s a great program. All his work is really, really impressive. He doesn’t only make simulators for the Enigma machine, there’s a whole series of them.

    Working out how mechanical ciphers work is a how-to I’d pay to see.

  8. I agree and would love to visit the site but with everything I’ve read about the surveillance culture in England I think I’d be vary about going there.

    And Alan Turing should be a national hero, there and here

  9. Lee, I know some English people who refuse to come to America because they don’t want to be fingerprinted at the border.

    Civil liberties infringement is bad, sure, but don’t let it mess up your life.

  10. Actually, Bletchley Park just feeds the myth of MI5 codecracking invincibility – it’s a psyop. Phil Zimmerman and Steve Wozniak destroyed “code cracking” by introducing a) better, cheaper computers, and b) mathematically sound encryption for the masses. If the CIA could crack anybody’s code, they wouldn’t have resorted to waterboarding.

  11. The word bombe is Polish. The Biuro Szyfrów (the Polish intelligence bureau) built the first bomby to decode German Enigma messages during the ’30s. In 1938, just prior to the invasion of Poland, the bureau gave copies of the Enigma and its encrypting rotors to French and British intelligence, then destroyed all records of their operations, and their equipment.

    So, the original devices were Polish, hence the name, but the bomby at Bletchley were British designs, by Turing, using the same principles.

  12. As Nelson says, Turing did indeed have everything to do with the British bombes. The Poles did the first versions, based on the work of Marian Rejewski and others, but what Turing did is that he came up with a superior way of cracking the Engima, and he did indeed design bombes based on his principle. But it is true, the Poles are often forgotten, and they deserve a boat-load of credit that generally goes to the Brits.

    Cory is wrong about Colossus though. Alan Turing had very little to do with that, it was designed and built by other people working at Bletchly Park. No doubt they were influenced by his ideas regarding Turing machines, but he wasn’t actually involved in building those.

  13. “British Brainiacs” Is a beautiful term. Sad that we loose perspective about the power of our brains. Good brains are still in demand . For some strange reason they tend to cluster around death. Have you ever seen the beauty inherent in a hydrogen bomb? Could not be without bombe.

  14. #1
    It’s already been done, and is at Bletchley also. They have it breaking real WW2 Lorenz ciphers for when visitors come round.
    I was there yesterday for the National Cipher Challenge prizegiving and saw both the Colossus rebuild and the Bombe rebuild in action. I believe they were explained in Simon Singh’s “The Code Book”, but I’ve forgotten what I knew.

  15. #23 Bad post . The museum for Nuclear Weapons is in New Mexico U.S.A. Unlike Bletchley park few local craftsmen were called in to build the main frame. The beauty of the Bomb is in the metallurgy. Not readily accessible to brainiacs. Maybe by 2050 if we haven’t used it, we can honer a new group of brains. I hope.

  16. kind of wish a British anti-surveillance underground would name itself “Turing’s Children”

  17. Please continue to evolve. I trust our children. I believe our children are smarter, more wisdom filled, and mentally more proficient than the generation ahead of them. Any generation ahead of them. I can’t think of a healthier attitude toward them for maturation and trust in themselves. Support from their elders is best served by looking up to them, Instead of looking down on them.

  18. I apologize. My previous post was meant for the string two up from this one. Same stuff tho.

  19. Three in a row is probably going to get me expelled. What happened with your guest blogger comments? I started there and suspect a rookie . Please assure him that public discloser is a brutal process. Loving your brain has to be one of the first causalities in evolving. The rest is just Loving stuff.

  20. ya i was gonna mention that too – but couldnt figure out how to send a message directly to a moderator

    1. E-mailing me is the best way to deal with urgent issues. That way, I’ll hear it ding if I’m over at XTube or Cats In Sinks.

  21. #31. Don’t bother. Connecting in cyberspace is like a popcorn fart. Moderators occupy a position. The position soon becomes a drag. The nearest stand in becomes your best friend. Authorizing postings to your Dog works . The new game is in trying to figure out the species of Dog that is the stand in. I think boingboing is partial to yappey little fluffballs. Good recipes abound on how to cook dogs. Problem is they got no meat on em.

  22. Bletchley Park is arguably the most fundamental, historial site in the UK. The work carried out by the code-breakers and the other 12 000 people who worked there shortened WW2 by two years, possibly saving 22 million lives. It was also the birthplace of the computer. Tommy Flowers and his team invented Colossus: the first programmable computer, there during WW2.

    I also urge you to visit Bletchley Park. It is an amazing place, with something for everyone, from The National Museum of Computing, to the Toy Museum, to the Colossus and Bombe rebuilds and much more. Entry is £10 for a pass which gives you a year’s free access to everything on site, remarkable value.

    Bletchley Park is under threat due to lack of funding. There have been several recent funding successes mainly thanks to English Heritage and Milton Keynes council, but Bletchley Park needs another £9 million to survive. Please support the campaign to save Bletchley Park. More details at

  23. I see the vintage Typex, and i think, “wow, a secret message from Jula Child may have been decoded on that very machine!”

  24. 3 points here:
    1.) I can not believe how so many of you know so much about what seems to be an obscure little sidebar detail of WWII, an occurance that probably pre-dates all of you. Not to diminish the significance of code breaking- I’m saying I stand in awe of your knowledge of this (and lots of other) stuff.

    2.) fltndboat: “#34 None of which floats.”
    A sore subject for you, I suppose. When do we get to see your flattened boat? And

    3.) Antinuous, does the cat in the sink have to be alive?

  25. Just a note for those unfamiliar with the counterpart effort in the United States; (and a plug for my hometown, Dayton, Ohio!) the US also produced a derivative design of the Polish bombe- it was refined and semi-mass produced (around 100+ bombes) in Dayton, Ohio by the National Cash Register Corporation (NCR); the effort was led by NCR Engineer Joe Desch. A description of this effort in greater detail has been published under the title of “Dayton Codebreakers” (on Amazon, both in book and a 1-hour documentary film) and a short description on Wikipedia at:

    This isn’t to minimize the effort of the British or Polish work; just to inform readers that the US was also able to contribute to the brute-force effort of codebreaking by manufacturing the bombe’s (Britain’s effort to make the Bombe’s suffered from material and engineering design shortages)

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