In article , Mark Brader
writes
Right. The deep-level lines
[...]
marketed themselves as being a New And Improved kind of underground
railway, and the word "tube" was featured in this marketing.

In due course the older lines electrified and got rid of their steam
locomotives,

This implies that it was after the tubes were built.

In fact, the key parts of electrification of the subsurface lines were
done in 1905-6. At this point the Central, part of the Northern, and the
Waterloo & City were open and the Bakerloo was about to open. The
Piccadilly and the Charing Cross branch of the Northern were still under
construction.

--
Clive D.W. Feather, writing for himself | Home:
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