Process Safety And Railroads
The end of a year is a time for reflection. As I look back at 2023 I see that I was increasingly interested in the application of process safety management principles to railroad operations.
At first sight, there seem to be few similarities between the safety of trains and the safe operation of chemical plants, refineries and offshore platforms. One of the biggest differences between the two industries is that trains operate in the public arena, whereas most process facilities are inside a fence of some kind, or are remotely located.
Yet the principles of risk management and process safety management can be used to analyze the problem of train/automobile collisions.
The accident shown in the following Virtual Railfan YouTube video is representative.
The sequence of events, which occurred than half a mile from where I live was as follows:
A car turns left at the railroad crossing and gets stuck between the tracks.
The driver and the passenger get out of the car and move away from the scene.
0:27 (after a time delay)
The emergency services arrive.
The barriers come down ― a train is on its way.
A full-size freight train appears. Notice how the police car backs away from the inevitable accident.
The train is going slowly, but is unable to stop. It hits the car.
The train comes to a stop. No one is injured, but the car is probably wrecked.
There are many process safety-related lessons that this incident suggests. Here are two of those lessons.
Remove the Hazard
Accidents such as this inevitably lead to comments on the lines of, ‘The car driver should have been more careful’. Yet the best process safety action is always to remove the hazard ― it is the only way that risk can be reduced to zero. In this case the way to do this is to design a system in which trains and automobiles do not occupy the same space at the same time, either with a tunnel or a bridge. Unless this is done, some collisions are inevitable. Trevor Kletz is famous for saying, “If a tank’s not there it can’t leak”. A paraphrase of this statement would be, “If a train’s not there it can’t hit a car”.
In a recent post, Decision-Making in an Emergency, we talked about the importance of moving away from an accident scene before the situation gets worse. In this case, the driver and passenger in the car did the right thing ― they got away. We can always replace the car, but we cannot replace those people.