Interlocking System in Indian Railways
Current Situation:
- The Coromandel Express collided with the stationary goods train from behind due to “configuration” of the track, according to recent comments made by the railway minister, causing the three-way train catastrophe in Odisha.
- According to the minister, the configuration of the track upon which everything runs underwent such a change. When it comes to speedy operation and “locking” of point switches, the electric “point machine” is a crucial piece of railway signalling equipment.
- It is crucial to the safe operation of trains. Train movement will be significantly hampered by the failure of these devices, and dangerous conditions may occur from any installation-related flaws that are not fixed.
What does the railway term “interlocking” mean?
- A key safety mechanism utilised in the operation of train movements on railway tracks is interlocking in railway signalling systems. It guarantees that train movements proceed without interference from one another, avoiding accidents.
- An interlocking system is made up of three basic parts: the point, the track occupancy sensing devices, and the signal. These three elements’ operations are coordinated by the interlocking system to govern train movement.
What purpose does each of these three key elements serve?
- To show the condition of the track in front, signals (which are lights in the colours green, red, and yellow) are set along the tracks.
- Electrical circuits called track circuits, also referred to as track occupancy sensing equipment, are used to identify the presence of trains.
- Trains can switch tracks at points.
What are the points’ workings?
- The wheels of a train are guided by the points, which are movable rails, towards either a straight or a diverting route.
- They are often situated where two tracks that are headed in separate directions converge. The point is fixed in place once the direction of a train has been established. As a result, once a direction has been established, the point cannot change it until the train has past.
- A computer screen (or numerous screens) that display the full image of the station layout as well as the live (real-time) movement of trains on tracks, the signals, and the location of the points serve as the system’s digital interface. All trains operate in this configuration, everywhere. Data logger is the name of this computer interface.
The system detects whether a track is occupied in what way?
- Track occupancy sensors come in a variety of designs. Typically, sensors that detect the passage of wheels on rails are put on the tracks.
- Axle counters are another name for them. To ascertain if the entire train has passed by, they count how many sets of wheels or axles have crossed them.
How is the setup of the entire system?
- The interlocking system, which is managed remotely from the station, is fed with a “sound logic” of what constitutes safe train running.
- A pointsman would physically operate the point to alter its direction for an arriving train and to lock it in previous times, when technology was more primitive. After making sure that the track is clear of any obstructions, someone would then manually flag a green signal for the train. The driver would follow the flag while moving forward.
- Only about 100 minor stations still use manual levers to operate these points out of the 7,000 or so stations in the Indian Railways network today. Even though the fundamental logic of the rest is based on tried-and-true standard operating procedures for safety, the rest work electronically.
- In the case of the Coromandel Express, the logic in the computer would be that the signal to the train should be green if the Up line, on which the Coromandel was located, is empty, if the point is directed to the Up line, and if it is locked for the Coromandel.
Is this system secure?
- The system will attempt to halt the approaching train if any one of the three elements (signals, points, and track occupancy sensors) does not match the overall “safe” logic given into the computer.
- This means that the signal will automatically turn red, alerting the approaching train that something is wrong and that it should stop, if the point is not locked, not set to the proper direction, and/or the sensing equipment detects that the track is not clear.
- A system that errs on the side of safety is what is known as a “fail safe” system.
Who manages and oversees the interlocking signals system, and how?
- Typically, trained employees from the railways’ signalling and telecommunications department—commonly referred to as “signallers” or “signal operators”—operate and maintain the interlocking system.
- They are in charge of establishing the signals, keeping an eye on the track circuits, and ensuring that trains travel safely.
- Worldwide, interlocking systems are employed in railway networks. Although signalling techniques and technologies differ between nations, the fundamental idea of avoiding incompatible train movements does not.
Can this system be manipulated?
- Any machine is “prone to failure even if it runs smoothly 99.9% of the time, but digging work may snap cables, wear and tear and short circuit etc. can cause failures,” as Railway Board Member (Operations and Business Development) Jaya Varma Sinha stated on Sunday. These things don’t typically occur. However, any system has a.1% chance of failing for any reason at any time.
Conclusion:
- In order to improve safety, the committee recommended that tracks and signalling systems be modernised. According to the Bibek Debroy Committee (2015), this will reduce the likelihood of such incidents in the future. There is still a need for further technological modernization of the railway.
- Along with it, mock experiments and ongoing skill-development programmes are needed to raise railway employees’ awareness levels and reduce the possibility of human error to zero.
