Signalling system on Blue Line under pressure: DMRC

The corridor — among the top two busiest in the entire Metro network — was conceptualised as a small stretch between Dwarka and Barakhamba Road. It was later extended to Indraprastha, Noida and Vaishali in the East and Dwarka on the West, leaving its signalling system overburdened.

Metro officials said though advanced technology was used on this corridor, the signalling system installed by Siemens turned out to have a longer recovery period as compared to other corridors. Of the existing corridors, the signalling systems on Lines 1 and 2 were put in place by Alstom, on Lines 5, 6 and 7 by Bombardier and on Line 8 by Nippon. The Airport Express Line is the only other corridor that has the Siemens system. As it has a lower ridership and only six trains, snags have been more manageable.

“At the time of planning, we did not know that the extensions would be so much. The signalling system by Siemens was brought in following an open tender… However, it was not ready for such heavy passenger load…,” Sharat Sharma, director (operations), DMRC, said.

Adding to the problem, Blue Line has an overhead electrification (OHE) line that is exposed to external vagaries. “The line runs through densely populated areas. Whenever it rains, roof sheets, clothes from neighbouring houses, kites and even lightmasts fall on the OHE. In East Delhi, the performance of electronic cards on the line was affected due to high pollution in the area. We had to use protective coating on them. In West Delhi, the butcheries in R K Ashram and Jhandewalan draw vultures and birds. As a result, the line is covered with nests and droppings. These problems are not faced on Line 2 (Samaypur Badli to HUDA City Centre) that is mostly underground and has a similar ridership pattern,” he said.