The Nema, also spelled NEMA, also known as the key-pusher machine (T-D), is a rotor cipher machine from Switzerland. The acronym “NeMa” was formed from “Neue Maschine” and refers to the successor to the German key machine Enigma.
The Nema was used for military and diplomatic purposes. There was a version for training purposes, a version that was never used in wartime and a version for embassy radio.
GC Wizard knows the versions for training and wartime use.
The device was developed by Hugo Hadwiger, Heinrich Emil Weber and Paul Glur as a successor to the German Enigma K, which was used by the Swiss army during the Second World War. The Nema was manufactured in 640 units by Zellweger AG in Uster from 1946. The designation T-D (Tasten-Drücker-Maschine) was also used for the labeling of the devices and in the operating instructions.
In the Swiss Army, the Nema was largely replaced by the KFF-58/68 crypto-radio teletypewriter from the end of the 1950s. The Nema was used in embassy radio until around 1976. It was declassified in 1992 and the army sold several examples to collectors in 1994.
The first difference to the Enigma concerns the number of rotors. In addition to four normal rotors, called contact rollers on the Nema, the reflector is arranged to rotate. The reflector (on the left in the picture) is called the reversing roller on the Nema, as on the Enigma, and the red roller (on the right in the picture) is called the entry roller. The improvement over the Enigma lies in the feed system of the rollers. Whereas the Enigma feeds the rollers like a counter, with the Nema the feed of each contact roller is controlled by its own feed roller. Each time a button is pressed, several rollers move simultaneously.
At least three different sets of rollers with different “windings”, as the Swiss called the roller wiring, were used on the embassy machines (reversing rollers A, B and T).
The training machines are equipped with the following rollers: Contact rollers A, B, C, D and advancing rollers 16, 19, 20, 21, 23/2.
The war machines have the contact rollers A, B, C, D, E, F and the progress rollers 12, 13, 14, 15, 17, 18 and 22/1.