I do find the stock duckies are pretty poor in the VHF range, they are just so short. If the rail guys are using stuff like 5 watt handhelds and there are much for obstructions in your way I expect the five mile range would be considered max. It wouldn't take much to improve your range though. Even a length of coax attached to the ceiling, or even the second floor if you have one, with about 18 inches of the sheild peeled away at the upper end will make a quickie antenna that should be "tuned" to the 160ish range.
As far as the example of my tower and the VHF transmitter at 45 miles away, the calculator says I should only have about 29 miles line-of-sight, but I obvioulsy get farther. I think it may have something to do with the fact that the transmitter is on terrain that is higher than me and effectively higher than it seems on paper. If the trains you were trying to hear were on top of some higher terrain too you may get better range also.
Try some experiments, you may be surprised.
A mag-mount antenna set on top of your fridge or a cookie sheet could net you some surprising results too.