A mountain railroad (pt 3)
Now that I've figured out how the PV&T climbs out of the Connecticut River valley into Vermont, I've started thinking about the climb out east through Lyme, NH, and on into the White Mountains. My original plan (after looking at the historical map collection at the University of New Hampshire) was that the PV&T would go north from Lyme and work around to the north of Mount Cube, and then work east to the vicinity of Ashland. This turned out to be, um, an interesting bit of mapping, because even though the White Mountains aren't the Yalps, they still are, um, mountains, and going north of Mount Cube means that the PV&T would be spending a lot of time either going up and down really scary mountain grades or spending a lot of money digging long tunnels.
There really are no reasonable routes through the mountains here. Once you get east of Lyme you're faced with the New Hampshire state rock in large vertical masses. But, if you follow Grant Brook into the mountains, and do some short (2-500 ft) tunnels where the grade becomes completely laughable, you can reduce the climb to the east to an "easy" mix of 3% and 4% grades up to Reservoir Pond (1300ASL) and then by a combination of an easy 2% grade and an ~1 mile tunnel under Cummins Pond, an equally "easy" descent into the Baker River watershed (via North Dorchester), which is far better than the up, then down, then up, then down route that going north of Mount Cube would be.
I'd imagine that the Parsons Vale Line went through quite a few surveyers trying to get this line built without having to put in a rack section. And by the time this section was finished and ready to start eating helper engines for breakfast, quite a few chief engineers would no doubt be driven to strong drink and/or illegal drugs.
But, when this triumph of enthusiasm over common sense was done, the Parsons Vale had a very direct route from Portland, ME up to Montreal, PQ, and could bring enough trains across the line so that it wasn't abandoned as soon as the loggers stripped every tree off nearby hillsides. It helped that during the early years the bulk of the traffic coming off this division was logging traffic, which either went east to lumber mills in Rummey, or west to mills along the Connecticut River, and by the time the line had converted into a full-fledged bridge line the railroad could afford to buy and station enough banking engines to get the through freights through.