North to south reversals, where the train approaches Euston from
Bank, are not especially difficult ... North to south reversals,
where the train approaches from Camden and then returns to Camden,
might be a little more involved.

This wasn't a typo -- the first "North" means "northbound", while the
second one is in the sense of "north wind", right? grin
--
Mark Brader, Toronto | Any company large enough to have a research lab
| is large enough not to listen to it. --Alan Kay