Behind the lines

Keeping the Metro running all day long without a glitch requires not only regular maintenance of trains and tracks but also constant monitoring of the system during operational hours. TOI visits the Metro's operations control centres and maintenance depots to find out how it pulls off the feat daily

As you walk into the room barefoot, lights are flashing on a giant screen even as a man talks into the system, keeping a close eye on another screen with multiple CCTV images from different stations flashing. It's a Tuesday morning at Shastri Park and business as usual as Delhi Metro engineers monitor the two giant screens that reflect the trains running on line 1 (Dilshad Garden to Rithala) and line 2 (Jehangirpuri to HUDA City Centre).

With almost 100 trains running on the network, the operations control centre or OCC is the nerve centre of the Delhi Metro. From here, every aspect of the Delhi Metro system is monitored—the time-table, speed, security, traction or electricity, the trains, auxiliary equipment like air-conditioning and ventilation system in underground tunnels, and even the crowds in the station. When the train stalls in the middle of the track, it's from here at the OCC that engineers try to investigate what's gone wrong in the system. Says a Delhi Metro official, "The OCC has engineers from rolling stock (trains), signalling, traction and all other relevant departments who can identify and isolate any problem that may occur in the system. Only if the problem can't be solved from the OCC, do we send a team to the location of the problem." With a fully automated rail system, it's not surprising that Delhi Metro regards the OCC as its nerve centre. Delhi Metro's trio of systems keeps the net-work running—ATP (automatic train protection), ATO (automatic train operation) and ATS (automatic train supervision). "The time table, along with the route and other safety parameters like minimum distance between two trains, is fed into a computerized system. It's this system that runs the trains on the network...the train operator is the second line of op-eration, as he or she only ensures that the train is running on time, or when a fault occurs in the system," says the Delhi Metro official.

Each train has a special identity, called the train ID. Of this, the first part is the destination code while the second is the train number. The screen at the OCC tracks the movement of the train through the track circuits—which are like electrical nodes which send the information to the OCC. These are placed at intervals of 20m along the track. With no lag in the real time location of the train and the OCC circuit, every minute movement of the train is monitored by the system. The ATC (automatic train control) system, which controls the route of the train, works in tandem with the ATS, which interfaces between the train and the line side equipment like the track circuits. Together, the system moves the train from one station to the next, ensuring that a minimum speed is maintained. When a problem occurs—like when the track circuit "drops", the train is navigated manually, as it falls off the OCC grid. Other common problems that crop up on the Delhi Metro network include the OHE mal-functioning or doors not closing in the trains. Says the Delhi Metro Rail Corporation official, "In such cases, we have to manually close the door or repair the OHE. A team is sent to the spot to address the issue, though the problem is identified in the OCC." When stations get too crowded, it's again the OCC which controls the frequency of the trains. "To manage the crowds, we may introduce another train into the system, which will be sent directly to the crowded station, without stopping at any other station. This option is also fed into the system," says the DMRC official. Increasing the frequency is another option, again controlled from the OCC. In under-ground stations, if a train is stopped, it's from the OCC that the air ventilation system and lights are switched on. The ATS also ensures that only one train is running between stations in the underground section, for safety reasons.

Incidentally, the two OCCs - at Shastri Park and Metro Bhawan - have the ability to back up each other, ensuring continuity and seamless monitoring.

Anda sedang membaca artikel tentang

Behind the lines

Dengan url

http://sehatputihgigiku.blogspot.com/2013/04/behind-lines.html

Anda boleh menyebar luaskannya atau mengcopy paste-nya

Behind the lines

namun jangan lupa untuk meletakkan link

Behind the lines

sebagai sumbernya