The reason for the gradient on the Thameslink route at Farringdon, though, is to get underneath the Met and Circle at the Ray Street Gridiron. Presumably built that way so that the City Widened Lines could be on the north side of the Circle at Kings Cross and St Pancras, enabling the links to the Great Northern and Midland to run in.
The surprising thing at Farringdon is there used to be, in freight train days, a banking loco to help push southbound freights up the hill to Ludgate Hill. But the banking loco spur, the site of which is still visible, was immediately beyond the west end of the Farringdon platforms, so the climb up from Ray Street was not covered. I would think if the freight loco could manage that climb up (which looks about 1 in 30), then it could manage the continuation to Ludgate Hill.
This long climb is only to get up to the level of the river bridge. Is Farringdon (or Ray Street) below river level? I did read that Ray Street, quite apart from the recent water main burst there, was a regular point for flooding; the Underground kept one of their old steam locos on long term, fitted with a steam pump, to come and pump out floodwater, principally there.
Long ago, possibly Victorian times, the promoters of a notably undulating railway scheme argued in Parliament that the ups and the downs just cancelled each other out, so the effort required was the same as if level. The committee chairman then observed dryly that therefore the Scottish Highlands must be excellent territory to build a railway across.
Are there other stations with a steep down into the station and then back up the other side to get away?
Totnes sort of qualifies, steeply down Dainton Bank into the station, then equally steeply up Rattery Bank the other side. Inevitably, for non-stop trains, both are quite notably curved. Apparently on a Warship taking this at speed it was something like a Disneyland ride.
