Sunday, April 18, 2010

Bletchley Park #3

Showing a few examples from Bletchley's large collection of WW II code machines.

This is a standard 3-rotor ENIGMA machine, like the ones used by the German army.  Note the Steckerbrett (plugboard) at the front that added more possible electrical paths for determining substitute characters for those typed on the keys.  This greatly complicated decipherment.

Bletchley has one of the world's few surviving "Abwehr" ENIGMAs, as used by the German military intelligence department. It has four rotors instead of three, but lacks a Stecker. This may be the machine which was stolen in 2000, leading to a (fortunately) rather badly organized ransom attempt. Offers to pay the ransom were unanswered, and finally the machine was sent (anonymously) to a BBC journalist, minus three of the rotors. These turned up later, when an arrest was made in the case.

This imposing collection of heavy metal shows the notorious 12-rotor Lorenz machine, with associated tape reader and teleprinter. The setup was used to encrypt and decrypt the teleprinter communications at the higher levels of German command. Colossus was built to attack this encryption, with considerable success.

Finally, this isn't a code machine at all.  It's a vintage (late 1950s) K.W. "Vanguard" ham radio transmitter with 30 watts.  These were typically built from kits sold by a British company.  This particular old rig is at one of the operating positions set up by the Milton Keynes Amateur Radio Club upstairs in B Block.  The antenna tuner on top is modern.

Hope you liked my photo trip to Bletchley Park.

All photos Copyright © 2010 Hugh Stegman