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Derailments Caused By Emergency Braking?

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In George Hilton’s article called SLACK, he discusses the incredible impact force when slack runs in during an emergency application of a 100-car train.  He cites an impact force of 468 foot-tons occurring wherever the force reaches its maximum potential.  But I am not completely clear on his analysis, or how often this maximum run-in occurs. Does every emergency application that occurs while pulling with slack stretched lead to a slack run-in?  On one hand, the run-in seems logical because the brakes are applying from front to rear.  So trailing cars will run up against a gathering resistance as the head end cars set up and slow. However, the run-in process takes time, and this time has to factored against the time it takes for the emergency application to propagate from front to rear.  And the run-in time itself depends on the rate of deceleration of the head end.  And not only does the emergency application take time to activate front to rear, but it also takes time for each brake to fully apply once it is activated. So, when an emergency application is made, it sets off a wave of brake application from front to rear, and potentially, a wave of slack run-in from front to rear.  I can see how the brake action might stay far enough ahead of the slack to stop its the run-in before it reaches the end of the train.  I suppose the makeup of loads and empties would have a big effect on how it all plays out. I wonder what that dynamic model would look like with a 100-car train of equally loaded cars, running 60 mph on straight, level track, and dynamiting from the head end.  What would the slack status be once the train stopped?
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