The problem is that I don't know when the next train will go through that section.
How can I know that?
Pretty well anything running west of Montreal (mainline wise) will be busy...the corridor towards Dorval is busy. Probably a train every half-hour or so, at peak times. Sometimes more, sometimes less. At least, it was like that the last time I was there.
If I call the CN, will they give me the info, or will I be treated as a potential terrorist?
The only CN number most people would have access to would be a toll-free number for customers or soon-to-be customers. And, as was said earlier, most people at CN have no idea where trains are on the line. Your best bet would either be MOW guys somewhere along the line, or RTC. Sometimes, talking to MOW guys will work, sometimes not. The only way to get through to RTC is by phoning...which I know wouldn't go over well at all.
Do freight trains have a regular schedule?
To some degree, yes. I'll touch on that in a minute.
Talking to anyone you see trackside (easier in a more rural environment) would be the best thing to do right now. Investing in a Canadian Trackside Guide (CTSG) would be a wise idea, too, as it lists all the subdivisions and frequencies for TStBy, RTC, Engineering, and track occupation for said subs. A scanner would allow you to listen to those frequencies (totally legal, by the way). The rubber antenna that comes with the scanner would be more then enough for what you want to do right now. As you get into it more, you can invest in more and bigger antennas to listen further away. I've got 3 antennas on order right now. Two for home and one for the car.
CN doesn't have a fixed schedule, all the trains are run as "extras". That said, most trains depart their terminals at a usual time, but that can vary by several hours.
No, they don't. CN runs most of their trains as numbered trains (ie: Q149-11-12), which means they're not extras. Some of the numbered trains (usually locals) run as Work trains, but it's rare for CN to run extras. Aside from one hi-pri Intermodal just before Christmas (the first in a decade for that train, I’ve heard), the only extras that run down this way are EMD motive power movements from London to a pier in Halifax for exportation. Don't confuse an extra train with an unscheduled train, as they are two totally different things. The same can be said for many railroads.
You're partially right, however...CN doesn't have a fixed schedule, nor does any freight railroad. Schedules are a luxury known only to the likes of passenger service. CN does, however, have approximate times when trains leave their home terminals and guesstimates as to when they'll arrive, given sufficient padding and an assumed track speed. Many things can foul that, though. And some trains have priority over others, which can throw the travel time off when a lesser-priority has to meet a hi-pri, which can cause delays.
Turkey, hopefully this has been of some help to you.
AR