Railway authorities are investigating a major safety issue reported in Adra division of South Eastern Railway where the signal of a line in ‘green’ turned ‘red’ after the passage of a train in the adjacent track.
A Junior Engineer who noticed the unusual incident at Ispat Nagar railway station immediately wrote to the Signal & Telecommunication officials in the zone explaining the sequence of events which led to the signal in one track cleared for passage of train automatically turning to danger position, railway sources said.
Highly unsafe
He wrote that around 7.47 a.m. on October 8 at Ispat Nagar station, run-through signal (green) was given simultaneously on two lines. But after one train passed the signal and hit the track circuit, the signal of the other line automatically turned to danger position (red). “It is a highly unsafe case on part of signalling,” he said in an alert message.
Railway sources said that a preliminary probe revealed a defect in the design of the circuit. The advance starter signal was suspended to ensure the safety of trains and immediate rectification work was ordered to minimise impact on train movement and punctuality, the sources said.
Senior railway officials said that the signal mix up could not have been a sudden phenomenon but would have happened on many occasions in the past and was merely noticed by the Junior Engineer on the particular day. “It is sheer luck that there was no unfortunate incident involving this design defect so far…in the normal course track circuits and signalling mechanisms are checked in every section once every three years,” a railway official said.
Very rare
According to a former Principal Chief Signal & Telecommunication Engineer such design defects causing signals to fly back to danger are “very rare”. If signals turned to danger suddenly, the Loco Pilot of an approaching train with a mindset to pass through the station would have to apply sudden brakes and that could lead to a derailment.
“Signal and circuit designs are checked at three levels at the drawing and approval stage. Before loading into the system software, senior railway officials visit the company manufacturing the circuit to look for any errors. After that, there are multiple levels of checks during field testing…I wonder how this was missed out and not noticed over the years,” he said.
Signal issues made it to the headlines after a suspected signal fault led to one of the worst railway accidents in recent years involving two express trains and a goods train at Bahanaga Bazar railway station in the South Eastern Railway on June 2 which left about 290 passengers dead and over 900 injured. Another train accident occurred in Adra division on June 25 when two goods trains collided after the Loco Pilots of one freight train allegedly slipped into “microsleep”.
