When I built the layout shelf in the garage I made all the supports the same height. This was a mistake because the garage floor slopes down towards the front of the house, or the “south” end of the layout, so there is a gradient uphill from Resurrección to Rio Paleta. Here the line levels out a bit because some packing was needed to get the Rio Paleta and Frog Rock modules to match.
This isn’t really an issue because the FCPyF is meant to be in the Andes, which are not actually famous for being, erm, flat. There are high plains though, so the track levelling out over the bridge at Rio Paleta is assumed to be just such an area. At the south end the gradient eases once past Resurrección and is actually dead level in the south staging yard.
Operationally this means that smaller locos can struggle when going uphill and any accidental uncoupling when northbound can result in stock running away, often at alarming speeds, just like a real mountaineering railway!
An old Tri-ang gradient post partly hidden behind the MoW shanty at Resurrección marks the bottom of the climb but I didn’t have a corresponding sign to use at Rio Paleta so there’s a bodged hand written version attached to the station instead. The theory being that the original post was demolished by a derailment and hastily replaced by a locally made sign nailed to the building after one of the train crews complained to management.
It reads “NIVEL / 1 EN 50” which is not particularly steep by Andean railway standards, but that’s probably because the Pampas and Fernandez was engineered by the British.