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Typex modified as an Enigma

Typex Machines were normally used by the British to send intelligence information between units in a secure form. These machines were much more secure than the German Enigmas and there is no record of them ever being broken.

However at Bletchley Park they were also used in the Decoding Room to decipher German messages once the setting for a given network had been found. In this application they were configured as three wheel Enigma machines. This meant certain modifications and it is these that we have reproduced so that we can repeat what went on in the decoding room.

 

The photograph above shows a Bletchley Park Trust Type 23 Typex before modification.

The modifications, none of which changed anything on the original machine were:

  1. A selection of plugboard to allow stecker plugging

  2. A selection of plugboards to act as reflectors

  3. Five new wheel inserts wired to represent the normal Enigma Wheels

  4. Five new wheel progression rings – with notches as in the Enigma wheels

  5. Five ‘straight through’ inserts. Two for use and three for maintenance purposes

Above are some of the parts for the new plugboards ready for final assembly

Above left is an original Typex wheel and insert with a progression rim removed for measurement.

On the right is an example of a new insert made by the team. We also made new progression rings to match those above but with notches where the original Enigma one would have been.

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