Back in the 70's my brother and I were standing in the vestibule looking out the dutch door of an eastbound Broadway Ltd. when the train came apart at speed. We were looking out the dutch door at the moment and were quite impressed at how quickly the train came to a halt, along with a very strong smell of brake shoes. We were not at the point of the break, and even though the immediate sudden decelaration was notable, holding the grab irons kept us on our feet. The front of the train continued on for quite a distance before slowing to a stop.
A memorable and thrilling experience also in the 70's occurred at night when we were both again at the dutch doors on the City of New Orleans. This was double track territory and our train was changing tracks regularly, while weaving around freights. One of those track changes was made at higher speed than the rest, catching us off guard. Our car made a violent jerk as it slammed into the opposite track switch, accompanied by a sharp cracking sound and sparks. All previous and following track changes were at a somewhat reduced speed, but they were obviously high speed designed switches.
By the late 80's all the fun had been taken out of riding and I have only rode Amtrak once since 1988.