'Fail
The relay room in the Indian Railways has a double-locking system. One key is held by the station incharge, while the other is kept by the signalling staff. In addition, there is an electronic interlocking system that ensures the smooth operation of trains. Because these systems are not accessible to the general public, railway officials suspect that any tampering or malfunctions may have been intentionally caused by individuals who have the knowledge and access to these machines.
News18 spoke to a number of railway officials, including those from the signalling department, and they assured that it is a "fail-proof" system and it cannot malfunction on its own.
"We are the fourth largest railway network in the world. Indian railways is operating at least 13,000 express trains per day and an equal number of goods trains. One has to understand that if there was an issue in our system, then these accidents were frequent. But we know this is the worst in the last two decades," a ministry official told News18.
Another Railway official, who does not wish to be named, said the signalling system used in India currently is at least two decades old and it is because of this advancement that there is a drastic drop in the accident and fatality rate.
"In 2002-03, 16 collisions took place and there were 218 cases of derailment killing 418. The accidents per million train kilometer was 0.44. Now, in 2022-23, there were six cases of collision and 36 cases of derailment. The accidents per million train kilometer have dropped to 0.037. These numbers show that in the last two decades how advanced the system has become," the official added.
Relay rooms are sensitive set-ups with safety installations and directly related to train operations. All the signaling cables from the rail track terminate in this room. These are air conditioned with minimum human intervention.
It houses all signaling cables connected to the Assistant Station Manager panel to give a clear picture of the track to operate the room.
There are two locks on the relay room. The keys are either with the station master – for the lock called as operating lock – or with the signal maintainer or signal supervisor – called S&T lock. The key of the operating lock is handed over to only S&T staff, as and when needed.
The officials further explained that if the key is handed over to the S&T staff, it has to be recorded with reason in the relay room register. Both S&T staff and the station incharge on duty have to sign on this register. Also, before handing over the key, the section control should be informed about this.
The rule also says that the key of the relay room cannot be kept with other keys in a bunch and it has to be single. Time and again, orders have been issued to ensure minimum opening of the relay room. If and when opened, it should be for a minimum possible time.
"These rules are not new. As far as I can recall, these orders have been followed since 2005 at least," the official added.
On being asked when and why these relay rooms are opened, the officials said it is opened for routine maintenance by signal maintainer (once a week), by JE Signal (once a month) and Senior Section Engineer, Signal (once every quarter), inspection of officers at various levels as and when required. The rooms are also opened in case of signal failure, they added.
"So, firstly it is not possible that any one can simply walk up to these rooms. These are highly secured. And if by any chance, even a say 0.1 percent, any random person managed to enter these rooms, they will not be able to operate the machine. These machines are operated by skilled people," the first official said.
They explained that in a room full of machines and wires, one can only know how to manipulate if they have experience of dealing with such systems.
So, both the officials said that, the malfunction (if it was) has to be a properly planned, with intention.
"Nothing is 100 percent. But since it is so secure, it cannot be manipulated by just one person. It is my personal opinion that it was proper planning that needed more than one person," the second official said.
A third official explained that the system is not just fail safe but also error proof.
"We are calling it a fail-proof system as if there was any issue, all the signals in the route will turn red. That means all trains will stop and there will be no movement at all. It won't happen that the trains will continue to move even if there are glitches. Also, since there was already a train on the loop line, the only route left for the Coromandel express was the main line. It is not possible that two trains are on the same track," the official from the Eastern Railway explained, adding that for situations like these, there is automatic block signalling.
Indian railways follow two major types of signalling systems. First is the absolute block system. In this there is one train in between two stations at a time and the second train is permitted to enter only when the first train clears the block section.
An advanced version of this system is the automatic signalling where signals are provided continuously after around 1-1.5 km and there can be one train in between two signals. This enhances the line capacity to a great extent as more trains can be run within the same route using the existing track.
It is used in busy sections of Indian Railways. Further, it allows many trains in between two stations, depending upon the number of automatic signals provided.
However, another official added that if the things mentioned so far are not there, another possibility could be that the wires were damaged somewhere around the site, as mentioned by Jaya Verma Sinha, Member of Operation and Business Development, Railway Board on Sunday.
"It is totally possible that someone has done some digging without seeing the cables, as she had said. But here also, the question that still remained unanswered was why it was showing a green signal on the central control panel. Since it is a fail-proof system, signalling on the entire section would have been impacted and not just one part of it," they said.
While the exact reason for this disaster, that took over 270 lives is yet to be revealed, the movement of trains on the route have been restored and the official report of the investigation is awaited.