Since the topic has strayed a little into emergency stops,Big Jim is correct on how fast your going .The stop is generally smoother at a faster speed,but like mentioned certain circumstances make changes in the reaction of the effect when doing so.
I’ve only been 60 mph top speed,when running a train and some how never went into emergency at that speed.
At 50 down to 10 mph I have several times . I’ve had different scenarios like busted air hose,air hose dragging on a crossing coming apart,I’ve had on four occasions the main brake pipe that runs the length of a car simply fall off do to age or what ever,but to get back ,the speed and curvature makes the difference that I’ve experienced in the ride quality if you might say,the train has when an emergency brake application occurs either by the train initiating it or the operator.
I had 18 loaded “ECP” coal cars spread the rail once coming out of Devils Neck curve on NS’s Wayne Branch ,near the end of a 100 car train going 10 mph and I never felt it tug,lurch, nothing until it slowly started dragging my speed down until I notched out of the throttle and brought my train to a stop.
And I guess at the last minute the car ahead of the 18 derailed cars broke the knuckle and pulled the electric cable and air hose apart and finally put my train in emergency .