It was certainly entertaining watching loco-hauled departures, especially the VSOE.If we are recalling the past then a mention for the now closed Folkestone Harbour station.
Trains starting from there had over a mile at 1 in 37 before stopping at Folkestone East (formerly Junction) to reverse. If the sea was rough or low sea mist then it was greasy rails to contend with. In the days of steam it must have been interesting even with banking locos.
I think the most difficult ascent I recall was when a pair of the Gatwick pool 73/2s were allocated with, for whatever reason, both on diesel power. The pace was so stately I walked up the Tram Road at the same speed as the train!