Chennai: Sleuths from the National Investigation Agency (NIA) are yet to complete inquiries into an attempted sabotage of railway infrasturcture near Chennai last week and two more incidents targeting railway infrastructure have been reported in the past 48 hours, raising concerns about coordinated attempts to disrupt rail operations. This marks the third such incident in four days.
On Sunday, the loco pilot of the Tirupati-Puducherry Express narrowly averted a potential disaster near Melpakkam, close to Arakkonam. As the fully packed train approached a turnout section, he noticed a signal anomaly and immediately alerted the signal maintenance team. Upon halting the train and inspecting the track, he found stones and iron rods deliberately placed between the rails at five separate locations.

These obstructions were positioned at critical points near turnout zones, where point machines — electromechanical devices that physically shift movable rails (switches) — set the path of trains based on the signalling system. “Once the route setting command is issued through the electronic interlocking (EI) system, the point machine is activated to lock the movable rails into position. However, the presence of foreign objects can prevent the switch rails from closing properly, leading to a point failure. Thanks to the EI’s automatic detection and alarm system, the anomaly was flagged, allowing immediate intervention,” said a senior Southern Railway official.
A similar sabotage attempt was reported on Saturday at Patravakkam near Ambattur, causing significant delays to several long-distance express trains. Following these incidents, Southern Railway has intensified track patrolling, especially along the Chennai-Arakkonam corridor. In addition to routine early morning patrols, special teams have been deployed to carry out continuous inspections during the day.
While mere placement of stones may not easily derail a train, acts such as the removal of bolts — as seen in the Thiruvalangadu incident last Friday — pose far greater risks.
Railway police said that tampering with vital track components, such as stretcher bars and locking bolts in point machines, typically requires specific technical knowledge and specialised tools. Investigators are probing whether miscreants with online access to railway technical manuals or training materials were involved.