This is a just post-WW2 version of the French National Railways SNCF logo. These signs, made of inter-twined letters are usually associated with an earlier period of design. Traditionally, this type of sign is called a monogram.
One of the most famous of these signs is the crest for Glasgow Rangers Football Club. Indeed, this kind of logo is often used in the context of Edwardian sports clubs and schools. The letters look good woven as bullion style blazer badges, or on the fronts of your velvet slippers.
This is the kind of thing I mean.
This, below, is the classic SNCF logo from the end of the 1930s
And, this is the SNCF logo from the 1980s, designed by Roger Tallon. He was the industrial designer who shaped the French TGV trains. Here, he has used the double-line railway track lettering from the monogram at the top of the page. The rounded corners and the italic slope make it a little faster looking…