Improbable rail modelling
When doing a line profile for the PV&T, I've found a few amusing irregularities. The railroad comes down into the Connecticut river valley at East Thetford, VT, and when going to the west it needs to climb about 500 feet in about 7500 crow feet.
Even with the usual round of handwaving about rope inclines replaced with banking engines replaced with the 1913 electrification (about the only way I can justify streetcar-like inclines on a mainline railroad), it turns out that in my world the Madison incline in Indiana is not such an extraordinary thing after all.
The New Hampshire side isn't much better; I can work the railroad around to the north of Mount Cube, but it's still going from ~400 feet ASL to about ~1200 feet ASL in about 10 miles. For a logging railroad (like the Beebe River railroad which I've made into part of the LW&C) it would be okay, but for a mainline railroad it's definitely a case of "THIS RAILROAD NEEDS TO BE ELECTRIFIED OR IT WILL DIE".