Locopilots have urged Southern Railway to drop action against the motorman of an Electric Multiple Unit (EMU), who flagged a major signal failure and averted a disaster in Chennai Division on March 5.

The case relates to an incident reported between Ambattur and Avadi stations, when Automatic Signal S192 displayed a ‘Double Yellow’ aspect, authorising an approaching EMU to proceed even though the line was occupied by two other trains.

After spotting the trains stationed on the same track, motorman K. Karunakaran halted the EMU just short of the signal, preventing what could have been a major accident. He photographed the scene on his mobile phone and alerted higher authorities.

A multi-departmental committee, comprising senior railway officers, that probed the safety lapse held the local technician responsible for the signal failure. The committee also holds Mr. Karunakaran “blameworthy” for not following the rules.

Multiple signal failures

The All India Loco Running Staff Association (AILRSA) members have given a memorandum to the Divisional Railway Manager, Chennai, and other senior railway officials, saying the inquiry into the incident pointed to multiple failures in the signalling system.

The signal failure was due to defective LED indication, unauthorised resetting of the system, and failure of diagnostic and alert systems. It was also established that the system was not working in a fail-safe manner and that signal S192 displayed erratic and contradictory aspects. The root cause of the incident is purely system failure.

The motorman of train no. 43221 faced a dynamic and abnormal situationon line. Initially, the signal showed caution aspect even though two trains were present in the section ahead. Recognising this abnormality, the motorman stopped the train. Subsequently, the signal changed to danger aspect, which indicated that it may have normalised.

The signal was inconsistent. “Hence, the motorman had to take decisions based on the changing anspects and actual conditions observed on track,” the association said.

The inquiry committee fixed the blame on the motorman citing provisions under Subsidiary Rules 3.74(i). However, this rule said that when a signal is flickering or showing irregular aspects, it must be treated as showing the most restrictive aspect. It also provides that when the signal becomes steady and remains so for 60 seconds, the loco pilot shall act according to the steady aspect. But in this case, the signal was not continuously defective. It showed changing aspects and subsequently became steady.

No clear instructions

The motorman had acted in accordance with the rules. “It is also submitted that there are no clear instructions, either in rules or in training, regarding the procedure to be followed after restoring a signal from an abnormal or defective condition. While instructions exist for passing defective signals, there is no guidance on how to deal with situations where signals behave erratically, and then regain steady aspects,” the memorandum said.

In the absence of clear guidelines, fixing the blame on the motorman was not justified as he had displayed a high level of alertness. He noticed the contradiction between the signal aspect and the actual train position and stopped the train, and avoided a potentially unsafe situation. “He did not rely blindly on the signal, and exercised caution. Even after starting, he proceeded with restricted speed, keeping the situation under observation. Such conduct is in the interest of safety. If such actions are treated as blameworthy, it will discourage running staff from reporting signal abnormalities, and lead to loss of confidence in the signalling system,” it said.

The crew depended entirely on signals for safe operation, and when signals behaved abnormally, their judgement and vigilance became the last line of defence. Railway signalling system was designed to be fail-safe. “When the system gives wrong indications or behaves inconsistently, the responsibility should lie on system failure and maintenance issues rather than on the end user.”

Published - July 20, 2026 12:02 am IST