Indian Railway Chapter 3: Signal and Telecommunication

Signal and Telecommunication Department

• Responsible for safe train operations and maximizing the utilization of fixed and moving assets
• The department is headed by Member-Electrical and assisted by Additional Member (Signal) and Additional Member (Telecommunication)

Performance Efficiency of Signalling Assets

• Modern signalling systems play a key role in enhancing safe and reliable train operations
• The Corporate Safety Plan (2003-2013) aims to upgrade and modernize signalling systems
• The plan targets the reduction of signal failures per 1000 Zonal Integrated Signal and Telecom Units (ZISTUs) from 13.19 to 5.28 by 2013

Audit Findings

• Signal incidence per 1000 ZISTU is a key performance indicator to monitor signal incidents
• However, the basic units assigned to Signal and Telecom (S&T) equipment for ZISTU calculation have not been revised for four decades
• The audit found that the signal incidence per 1000 ZISTU was not a fair indicator of signal incidents due to the non-standardized units and yardsticks
• The audit also found that the signal incidence per 1000 ZISTU was not within the tolerance limit in 10 out of 16 Zonal Railways

Effectiveness in Monitoring Signal Failures

• The signal failures per 1000 ZISTU have declined, but the decline is mainly due to non-revision of weights for various S&T equipment and yardsticks
• The audit found that the signal failures per 1000 ZISTU were not comparable across Zonal Railways due to the adoption of different basic units and yardsticks

Performance of Signalling Equipment

• Mean Time Between Failures (MTBF) and Mean Time to Repair (MTTR) are norms to measure the performance of signalling equipment
• The audit found that the norms for MTTR had not been issued by the Ministry of Railways
• The audit also found that the MTBF and MTTR of signalling equipment varied widely across Zonal Railways and brands

Utilization of Data Loggers

• Data loggers are devices that monitor real-time events and record the functions of track circuits, points, signals, and axle counter signals
• They have the capability to perform statistical analysis, predict faults, and generate failure reports
• The audit did not mention the utilization of data loggers in the railway system.### Data Loggers in Network
• Railway Board expressed concern in July 2010 about the lack of utilization of data loggers due to:
  • Lack of involvement of staff
  • Improper upkeep of the device
  • Absence of Annual Maintenance Contract (AMC) with Original Equipment Manufacturers (OEMs)
  • Poor follow-up in case of failures
• Data loggers play a crucial role in analyzing the causes of accidents

Provision of Block Proving by Axle Counter (BPAC)

• BPAC reduces dependence on human element in train operation and enhances safety
• Railway Board reiterated instructions in November 2009 to provide BPAC in all A and B routes in a contiguous manner
• Audit observed that 830 stations in A and B routes were without BPAC/Absolute Block System (ABS)

Non-Provision of Integrated Power Supply System

• Reliable power supply system is vital for a robust Signalling system
• Railway Board issued instructions in September 2009 to ensure availability of adequate power supply for signals at all stations
• Audit observed that provisions of Integrated Power Supply (IPS) system were incomplete in many zones

Analysis of Signal Failures

• There is a significant correlation between safety and reliability of assets
• Details of causes of signal failures during 2008-09 to 2011-12 are:
  • Equipment failure
  • Lamp fusing
  • Cable failure
  • Relay failure
  • Point machine failure
  • Fuse blown off
  • Power equipment failure
  • Bad maintenance
  • Track Circuit Failure
  • Block Instrument failure
• Block Instrument failure was the single largest cause of signal failure

Availability of Dissimilar Signalling Equipment on Same Route

• Signalling infrastructure of the same standard in all sections of a particular route is important for maximum utilization of existing railway lines
• Audit observed that 26 sections across the Zonal Railways did not have signalling equipment of similar standard
• Existence of equipment with dissimilar standard has safety implications

Replacement of Dated Signal Equipment

• Replacement of old and ageing assets through upgraded modern signalling system is essential for achieving a collision-free system
• Audit observed that there were shortfalls in provision of modern signalling equipment vis-à-vis targets in the Corporate Safety Plan (2003-2013)

Age Profile of Signalling Assets

• Audit test-checked age profile of assets like signalling equipment/machines, point machines, relays, battery chargers, signal transformers, and cables
• Out of 93 signalling equipment, 64 items (69 per cent) had outlived their prescribed life and were yet to be replaced

Operation and Maintenance

• Corporate Safety Plan laid stress on preventive maintenance for preserving the longevity of the equipment
• Audit observed that there were shortfalls in adherence to maintenance schedules in many stations

Efficient Utilization of Training Facility by S&T Personnel

• The Ministry stated that the shortfalls in maintenance schedule primarily arose on account of shortage of trained manpower
• Audit analyzed the data on training course conducted by the Indian Railway Institute for Signal Engineering and Telecommunication (IRISET) and the ten Zonal Training Centers
• Audit observed that there was under-utilization of training slots in many zones

Accidents due to Collision

• CSP (2003-2013) envisioned that the Indian Railways should attain a Collision-free status by ensuring completion of all safety-related works
• Audit observed that the average number of collisions per annum had come down, but human error of judgment and non-observance of the rules were the major causes of accidents

Conclusion

• Indian Railways need to revisit the basis of measurement of signal failures in view of the ongoing modernization of the signalling systems
• Addressing manpower and training issues is essential for ensuring better preventive maintenance and achieving a collision-free environment