In message , Marcus Fox
writes

I thought of Harrow last night, and it is pretty far out on the edge of the
underground, so is unlikely to have been part of the underground as long as
the central parts. However, people were using harrows well before 1952 I
believe, so it is unlikely to be mentioned in the context of a disaster.

Well, the "harrowing of hell" was mentioned by Aelfric, c. 1000AD
(although the concept was said to be much older), and that's quite a
long time before the railway got to Harrow

--
Paul Terry