There was an incident in the early days of the Berlin Wall when the driver, fireman and many of the passengers of an East German train used it to escape to the west, by not stopping at the last station in the east:
http://www.chronik-der-mauer.de/index.php/de/Start/Index/id/1320426.
According to an article about it in one of the railway enthusiasts' magazines a few years ago (if I remember it correctly), a) the passengers had to lie on the floor to avoid the risk of getting shot by the border guards, and b) the guard wasn't in on the plot, so to prevent him stopping the train the locomotive crew didn't connect the continuous brakes, which apparently made him suspicious, but not suspicious enough to take action -- I'm not sure why, but that's what the account said. Brakes are mentioned in the interview with the driver that you can listen to on the site that the link takes you to, but it would need someone with better German than mine to understand what is said about them.