Yeah for sure. You can be called in at anytime and they're really not going to care what you're doing. Be prepared to miss events and such. Also, depending on the job, there's no set time. There might be a time RANGE but no SET time, so yeah. I hear Union Pacific is hiring, though. I hear they're not easy jobs, at all.
Ear plugs are a MUST. Buy multiple pairs. If you're out in the yard without them, you're fucked.
Be prepared to move around every couple of years. If you're lucky though, you wont have to.
Ehh, thats all I can remember for right now.