Technology will reduce operational time and enhance safety.
The railways is going slow with the implementation of modern signalling systems though they can almost double line capacity and throughput in one-tenth of investment in tracks.
The financially-troubled Indian Railways has not been able to keep pace with the fast increasing demand from passenger and freight traffic as most trunk routes do not have the line capacity for additional trains.
Railway officials say that lines on high density routes are almost choked. The sanctioned signalling works of Automatic Block Signalling (ABS) for 2,000 km of tracks — Mumbai-Ahmedabad; Delhi-Howrah; Delhi-Ambala; Agra-Bina sections — and many others are moving at a slow pace. These works, which were sanctioned over five years ago, are yet to be commissioned.
Of the 54,257 broad gauge route km of the Indian Railways, 18,606 km is double line and the rest is single line. Only about 2,020 km, inclusive of suburban network, is covered by Automatic Block Signalling, which forms about 10 per cent of the double line network. In comparison, China has 90 per cent of double-line sections with ABS.
According to a study done by Bharat Salhotra, general manager (finance and IT) of Dedicated Freight Corridors Corporation, modern signalling can improve line capacity and throughput. Salhotra, as Director of Long Range Decision Support System (LRDSS), did a study on signalling in the Ministry of Railways.
According to a senior railway official, “There is an urgent need to provide Automatic Block Signalling on all the double line sections and on the single line sections as well; investments on additional tracks can be postponed.”
This technology, if accompanied by Centralized Traffic Control, will reduce the operational time of signalling systems at stations by using computers and eliminating manual operation, reducing running time of trains. CTC can operate 20-25 stations or more so as to optimise track use.
In this system, the signalling systems of all stations are controlled from a remote control office through computers. In India, this system is present only in Delhi Metro, which is running metro operations with high throughput and safely. The running time will also be minimised. Systems such as Auxiliary Warning System (AWS), which warns the driver if he exceeds the speed limit, can further increase throughput.
Some countries in Europe use a combination of Cab Signalling and other technology, which automatically gives the driver a safe speed to proceed, and the locomotive automatically stops if the driver exceeds that limit.
ABS is being used by Mumbai suburban railway, which handles 1,300 trains on the central line and 1,100 trains on the western line daily. “The cost estimates for this technology is Rs 60 lakh for a route km for double line section against Rs 5-6 crore investment in building 1 km of the track. Against the construction time period of a stretch of track of eight-10 years, signalling would take two-three years. For implementing the system, the terminal capacity has to be suitably augmented too,” added the official.
If the railway management focuses on implementing the system, the works for automatic signalling can be executed in two-three years or earlier. Line capacity will get enhanced from two-2.7 trains an hour now to over five trains per hour, in each direction.
Usually, a rail line is divided into block sections between stations situated 15 to 20 km apart in the non-suburban sections, including the loop lines at the stations. Instead of conventional block working, which permits only one train at a time in the block section of 15-20 km, ABS splits the block section into smaller subsections of 1 to 2 km. Signals are automatically operated once the train occupies the track through track circuits or axle counters. Once that block subsection is clear, the next train is automatically given the signal to enter the subsection. Hence, line capacity is optimally used and a safe distance between trains is maintained.
The railway official said, “Right now, there is a lot of speed difference among the trains running on main trunk route. The implementation of ABS in the suburban sections provides high line capacity of 15-20 trains per hour as trains are running at almost the same speeds. But ABS execution in mixed traffic will be less than 15-20 trains per hour and can be six-10 trains per hour which is still more than double the existing capacityof two-2.7 trains per hour which is achieved by reduction of running time, thus providing better wagon and locomotive turnaround.”
In Sweden, with the provision of ABS and CTC in mixed traffic wherein the maximum permissible speed of freight trains is 100 kmph, passenger trains 130 kmph, intercity express trains 160 kmph and for superfast trains it is 200 kmph, the capacity of more than 10 trains per hour is achieved
ABS is functional in the non-suburban sections of Indian Railways in Palwal-Mathura (81 km); Vadodara-Ahmedabad (100 km) sections. The Palwal-Mathura section, which is considered as the most congested trunk routes of the railway carries mixed traffic of varied speeds of 96-100 trains each way in 24 hours without any problems.
A senior railway official said, “There is an internal opposition in the railways against progress in signalling systems and introduction of ABS due to the fear that there will be a surplus of station staff. The operations team and engineering team fear that they will lose power if drastic improvements in signalling happen. The Fifth Pay Commission had recommended the post of Member, Signalling and Telecom, but it never took off.”
