Train accidents
Lately there have been a series of serious train accidents resulting in the death and injury of passengers and material losses for the Railway Company running into hundreds of millions of rupiahs. I have been involved in the investigation of train accidents since the early 1950's and headed the investigations into the why's of one of the Djawatan Kereta Api's worst mishaps, the Trowek accident in 1957, with 102 people killed. After that I have analyzed tragic events like the Bintaro accident, the Citayam accident, the Trowek accident in 1996 and many others.
Although all those accidents were a result of different causes, one thread of observation is true in all those accidents: those tragic mishaps were not caused by an error of one person, nor were they caused by a single equipment failure. They were caused by a combination of one or more mechanical failures and one or more human errors. In other words, one mechanical error or one human error could not have caused the accidents to happen. They happen because of multiple errors occurring at the same time.
An error by the engine driver (engineer) can always be corrected by an alert assistant driver. When a driver falls asleep, the train is designed to stop automatically. A faulty action of a station master can not be executed because of the prevention by interlocking devices, provided of course that the interlocks are working properly. The whole operating system of a railroad, whether it uses Central Operating System (CTC) or Automatic Block System, or a completely manual system is designed for multiple layer safety protection. The systems are designed so that one human error or one equipment failure cannot cause an accident (especially a collision).
So why did the accidents happen? It is unlikely that different individuals make a mistake at the same time and safety features fail to work at the same time also. But like the Peter principle said: In engineering, anything that can happen will happen.
Like at the Citayam accident, the safety interlocks have been defective for a long time. The technicians who were supposed to check these have been neglecting them for a long time. Then the train controller gave the green (go) signal to a train without proper clearance from the next station. He could not have been able to move the signaling handle if the interlocks were working properly.
An additional fact came to light that the train controller was not the duly installed train controller. To make a long story short, more than one person made a mistake, technical maintenance was lacking and general supervision was not optimal.
The Bintaro accident was basically caused by the same errors. The 1957 Trowek accident was caused by human errors and a malfunctioning parking brake system. The 1996 Trowek accident was caused by failure of the mechanical brake and the electrical brake system and the lack of proper instruction and supervision by supervisory personnel. The tragic thing of almost all of these accidents is that the well designed rules of safety, are partially ignored daily.
DJOKO SOEJOTO
Bandung