Number 90 posted:
However, you cannot do it with AC locomotives. If the train moved forward at all, then the AC locomotives would unload. Not sure if there were AC locomotives in use in this instance.
Tom, I know what you're talking about. I have held a train back with the engines in reverse while charging the brake pipe, and it was with AC power. The trick is just not to move forward.
Same thing happens when trying to start a train on an uphill...if you don't grab enough power, and she starts to roll backwards, it'll unload after 3-ish mph. One day, I had a particularly miserable freight train...both in terms of power, air, weight, weather, etc. I had to dig pretty deep before knocking off the air while pulling away from a stop on an uphill. One engine in the consist (exConrail Dash8) decided to kill itself while doing this, and the normal throttle position to get the train moving became not enough to hold it. Once we started moving backwards, everything unloaded and it felt like we were going 900 mph backwards. Luckily, the train was so long, we were still stretched through the last absolute signal, and we really only coasted back about an autorack-length...but it felt like a mile until the air I grabbed took hold. The conductor was yelling "dump it, dump it!"...I yelled back "YOU dump it, 'cuz you're walking it!".
