New Alan Turing Film

[CCIP]

Although there is an interesting note on Sink the Bismarck! on Wikipedia...

http://en.wikipedia.org/wiki/Sink_th...rical_accuracy

Direction finding and traffic analysis showed that on 25 May, Bismarck stopped talking to Wilhelmshaven and started up with Paris, and Shepard committed to the belief that Bismark was headed for the French coast. The radio switch from Wilhelmshaven to Paris might have been a routine shift caused by Bismarck's crossing a meridian. Nonetheless, Shepard's hunch was soon proved correct when, by good luck, a Luftwaffe Enigma transmission was sent and intercepted and decoded at Bletchley Park, saying that Bismarck was headed for Brest to repair an oil leak.

So perhaps there's a bigger role Bletchley Park played than I gave credit for. The Luftwaffe intercepts were certainly decoded much more quickly than the Kriegsmarine ones. Still, it seems that the key decision in finding the Bismarck was taken on the grounds of DF rather than reading any of the messages, and the content of its own transmission to Paris was not known, at least certainly not until after the Luftwaffe message was read.

I think it's great that the story of Bletchley Park has now become much better known and movies are being made about it. At the same time, one should also not forget the Admiralty's very effective DF network, which was pretty much of equal importance and effectiveness in the Battle of the Atlantic as the crypto work at Bletchley Park.