If you lie betwen the tracks, unless you are VERY thin, you are definatley as good as dead.
I have worked for CSX since 98'. prior to that i trained at EMD and Academy of Industrail Technology as a locomotive mechanic (mainly engines), also took classes at GWU for Cab signal and train control systems. I then worked for a private company that services EMD engines. I also worked for Sperry Rail service for 2 years as an operator/mecahnic. I have a private company now where i basically provide maintenece information for EMD engines when they need repair and parts identification. I have service manulas and operators manuals for about 200 different locomotives. I scan or fax the pages as needed to the customers.
On the Alertor question, as Kat said , its just a light/beeper that you have to constanly reset or the trian brakes will apply and the power will shutoff. Some of our older units still have "Dead man" pedals but they no longer install them since people would bypass them with Flagsticks and brake shoes anyhow, plus, you can fall asleep with your foot on the pedal anyhow. Suprisingly enough, Alertors are NOT required by law. And if a Locomotive has one, it does not have to work. That scares me since if one of my fellow knucklehead engineers falls asleep coming at me, i am dead. EVERYONE falls asleep while running a train at one point or another. I have made trips at night where my conductor slept the entire time. Without an alertor and cab signals, NOTHING will stop the train but me, and if i fall asleep, thats the end of that. UP had a bad accident a few years ago that was supposely caused by the train crew of one train both being asleep and they went right through a stop signal and into the side of another train. Its a serious risk. I have had nights where i could not keep my eyes open. The only thing that kept me awake was the fear of death.