Andre, I'm sure it's not used in today's time, back a way's it was. I don't know what rail lines do today. Rules, as you know are continuously changing. Most of my experience, is from the 70's thru the early 90's. KCS, will do anything and so will short lines. Ha Ha, as I'm sure you know. The FRA, got more into it, after Helena, Montana's incident involving a bottling issue where the train run away. That was on a steep grade I think in the late 80's right in the middle of town. I don't know the details, but the issue in Canada where the oil cars got away, really charged the issue. Besides all that, how well did my memory work ?