As these teletypes were quite slow (typically 50 baud) and mechanical, the procedure was for line shifts to always be CR CR LF. The reason for this is to allow for the carriage (printing head) to have time enough to move to the start of the line before the line feed.
This was enforced in the procedures, so you might end up with a rejected message if you did not do it properly.
When computers were introduced in the various networks, ITA2 was converted to ASCII and some of these restrictions were relaxed a bit.
https://www.radiomuseum.org/r/siemens_fernschreiber_t37.html https://www.cryptomuseum.com/telex/siemens/t100/index.htm https://www.camion-militar.com/spa/item/ART02979.html
There were also other makes, like Olivetti.
They were connected to various networks, e.g. military, the civil Telex network or the ICAO AFTN network.
https://en.wikipedia.org/wiki/Telex https://en.wikipedia.org/wiki/Aeronautical_Fixed_Telecommuni...
They all used a 5 bit character set Baudot/ITA2: https://en.wikipedia.org/wiki/Baudot_code (I can still read a paper tape message directly from the reel)
As these teletypes were quite slow (typically 50 baud) and mechanical, the procedure was for line shifts to always be CR CR LF. The reason for this is to allow for the carriage (printing head) to have time enough to move to the start of the line before the line feed.
This was enforced in the procedures, so you might end up with a rejected message if you did not do it properly.
When computers were introduced in the various networks, ITA2 was converted to ASCII and some of these restrictions were relaxed a bit.