smallspy
Senior Member
Platforms don't have to be perfectly flat, but they need to at least be somewhat flat: +/- 0.3%.not necesserily. It really depends on how steep it is. A bigger concern is if they leave in a 100m long piece of track to have a straight enough platform.
The grade in that area is something like 4%. Thus you need to have a vertical transition curve from the steeper grade to the section of flat, and another vertical curve back to the grade. This means that the portal will actually get pushed out something like 2 or more platform lengths from its currently projected location. I haven't done any measurements, but this might actually put it so far east to be too low to cross the Don River.
Dan