"It's always felt distinctly downhill from the Snow Hill sidings to the

south end of City Thameslink station.

However, we've got drivers on that route reading this group; perhaps
they can comment."

The overall gradient from Farringdon to the bottom of the bank to
Blackfriars is probably about level, but with some lumps and bumps...

From Farringdon, there's a bit of a dip and then a hump around the exit
from Smithfield Sidings. This falls down, as you can feel, into the
start of City Thameslink platform.

There is then a more gradual hump through the length of the station,
dipping down again just at the bottom of the bank before rising
sharply. This is from memory, I think its about right!