I think the Germany Navy machines had four rotors, and the Wehrmacht/SS machines had three.
Thanks. It took several hours to rewire during ‘end of month’ prep for the Navy’s version. Pretty sure it was discontinued shortly after 1981.
Our version used 10 out of 20 rotor set and fir set switched coupled with a mechanical rotor stepping scheme. By 1950’s we used the KLB-47 which used 10 out of 20 rotors and attachable stepping rings. In fact these were commercially sold by Teletype Corp. But they were far more complex in that they included not only the aphabet but also number as several special characters.
The CSp-2900 unit with a skilled person could accommodate a badly garbled message and decode it. That was impossible with the KLB-47.
Everything is digital now and far more complex then the DES standard.