Steam locomotives running on autopilot on long trips, lose pressure from the boiler through the safety valves and the activity cannot be continued. It should not happen since the autopilot is supposed to correct any inconvenience, and the circular train in ideal conditions.

[Jorge Luis Gonzalez]

A passenger train runs a long journey with autopilot activated. When you stop at a station, you lose steam through the safety valves, and when you restart the gear, the boiler pressure starts to drop to the red level and you cannot continue the march.