Re: Amtrak near hit
Author: Dr Zarkoff
Date: 02-19-2021 - 10:31
> Would the train have skidded to a stop or do brake systems have a non-skid feature that manipulates brakes to prevent skid?
Just about all lightweight passenger cars built after about 1935 had/have a slip-slide control system, particularly if they were equipped with disc brakes (freight cars don't have slip-slide control). The older systems do function in emergency, but I don't know about the newer all-electronic systems. I strongly suspect these do, because when a wheel slides, it looses a great deal of braking power, and the idea in emergency is "maximum braking effort".
> What would PTC have done with that?
RR signal systems, of which PTC is one variety, are designed to detect track conditions, not things like motor vehicles foul of the track. To equip it to do so would be a whole new, extremely large can of worms because vehicles can foul the track just anyplace, not just crossings.
> Can Amtrak Cascades can do an emergency stop without getting flat wheels on all the cars?
Probably, but it depends on rail conditions (wet leaves, grease, oil, etc. on the railhead).
> That would be a pain to turn all those wheels on a lathe.
Not with a wheel peeler, just time consuming.