Role of the Signalling & Telecommunications Department
Elements of Safety in Train Operation
- Safety in train operations
- Punctuality of running of trains
- Optimum utilization of line capacity
- Passenger amenities
- Manufacturing of specified signalling items
- Providing telecommunication infrastructure for :
- Safe and efficient operation of trains
- Administrative voice and data circuits
- Passenger Reservation System (PRS)
- Unreserved Ticketing System (UTS)
- Freight Operation Information System (FOIS)
- Crew Management System (CMS)
- Coaching Operating Information System (COIS)
- Management Information System (MIS)
- Management of Railways Corporate Wide Information System (RAILNET)
Track circuiting is a basic safety device used in signalling systems. It monitors occupancy of a section of track and prevents clearance of signal in the event of the track section being occupied by another train. This is a fail-safe device, which in the condition of its failure prevents the signals to be cleared.
It is another important safety device used for detecting presence of train in a track section. This device counts the number of train axles entering and exiting through a track section and controls the associated signal.
It is an arrangement to control the entry and exit of train in a section called block section between any two adjacent stations. This maintains space interval between two following trains. It provides safety by preventing the second train to be sent into the section between the stations unless and until the previous train has cleared the section.
Driver to Guard communication
Driver to Guard communication has been provided for running trains using VHF walkie-talkie sets, for better co-ordination in controlling of the train.
Interlocking is a mechanism to check the route the train is going to traverse before clearing the signal and to prevent the clearing of signal when it is unsafe for the movement. It eliminates human error and ensures safety in train operations. Two types of interlocking arrangements are in vogue depending on the size of the station yard.
Panel interlocking is provided for smaller yards. It is a signalling system, which assures the best standard of safety and eliminates the accidents arising out of human errors. This has been provided at 484 stations over South Central Railway.
Route Relay Interlocking
Route Relay Interlocking is provided at major junctions and yards where large numbers of train movements are required. It is available at four major junctions/yards viz. Vijayawada, Kazipet, Secunderabad & Dornakal stations in South Central Railway.
Safety at Level Crossing Gates
All the level crossing gates in the station area and other important gates in the route are controlled by the signals. These gates are called interlocked gates and provide best safety for the road users. Provision of telephone communication at manned level crossing gates is a safety tool to ensure closure and opening of gates at appropriate time. On this railway all the manned level crossing gates have already been provided with telephone communication facility with the controlling stations. Statistical details of the level crossing gates are as under:
There are 908 interlocked level crossing gates over south central railway. All these level crossing gates are provided with telephone connectivity with controlling stations
Modern Signalling Systems
South Central Railway has adopted the state of art of interlocking technology in the form of computer controlled interlocking for the first time on Indian Railways. Thirty eight stations on the South Central Railway have been provided with solid state interlocking. The first system was commissioned on 10.07.1994 at Kavali station in Vijayawada division. It cuts down installation time and future modifications to cater the need of traffic can be implemented easily.
Digital Axle Counters
South Central Railway has been the test bed for Digital Axle Counters. To start with the state of art Digital axle counters imported from Germany have been provided between Moula-Ali and Cherlapalli railway stations. These axle counters are compact and highly reliable. The Digital Axle counter based Block proving called BPAC is provided in 195 block sections over various locations in Vijayawada, Secunderabad and Guntakal divisions using indigenously developed Digital Axle Counters.
Second Distant Signal
For improved visibility of signals and small reaction time of the drivers to control trains especially at high speeds second distant signal is mandatory. It increases the confidence level of the drivers and gives them sufficient time to control the trains at high speeds. This has been introduced on Rajdhani route between Balharshah - Kazipet - Vijayawada - Gudur, Kazipet - Secunderabad sections, of South Central Railway.
Intermediate Block Signalling (IBS)
IBS is provided on trunk routes to increase line capacity by splitting the block section into two parts. Two trains can be accommodated in the Intermediate Block signalling section improving the throughput. There are 94 Intermediate Block sections on South Central Railway.
Automatic signalling is provided in suburban and high density traffic sections to increase Line capacity. In this system signals are provided at almost every kilometer. 77 route kilometers are provided with Automatic signaling in Secunderabad and Hyderabad Divisions on South Central Railway.
Light Emitting Diode Signals
The conventional Filament type signaling Lamps are replaced with Light Emitting Diode (LED) to enhance the reliability & the visibility of the signals. LED signals are provided in 546 stations. Hyderabad, Nanded and Guntakal Divisions are fully provided with LED signals. -
Data Loggers are microprocessor based systems for logging the progression of important signalling & interlocking events taking place at stations. 532 Data loggers are installed at stations provided with Route Relay Interlocking/ Panel Interlocking / Electronics Interlocking. Data loggers help in diagnosis of signal defects.
Intergraded Power Supply (IPS)
SMPS based Integrated Power Supply Systems are being provided for Signalling Installations. By providing these systems, various voltages required for signalling sub-systems can be derived form IPS alleviating the need for battery banks. There are 394 IPS systems provided on S.C. Railway.
Providing basic telecommunications facilities for the Railways vast transport system is the responsibility of the Signal & Telecom Department. The telecommunication facilities provided on the Railways are broadly categorized in to three areas of applications.
- Train Operation
-Data Communication for Railway Information Technology Applications
- Administrative Communications.
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Telecommunication for Train Operation
Provides omnibus communication circuits on ofc and Quad cable and overhead telecom wires for operation of trains and other supporting activities of train control. The omnibus circuit provides telephone communication between the station-masters and the control centre at the divisional headquarters. Other omnibus circuits are also provided for other supporting train operations, including remote operation of 25 KV AC power supply systems required for electric traction. Emergency communication facility is provided along with the track throughout the route for the drivers and guards of the running train to communicate to the control centre at the respective divisional headquarters during emergencies.
a) OFC & MW Communication
1) Optical Fibre Communicationsystem is the backbone of Railways Telecommunication Network. The short-haul STM1 equipment of 155 Mbps capacity is provided at every station along the fibre network. The short-haul STM1 network is protected by long-haul STM4 / STM16 self healing ring network provided by RailTel. There are 352 STM 1-s installed.
The fibre network carriers Voice, Data & Multimedia services for various applications.
2) Microwave communication
Railways has its own microwave infrastructure for long haul communication circuits in addition to providing short distance telecom circuits as a support to over head & cable network for train control and voice communication for sub divisions and important activity centers.
The OFC & MW communication system meets the entire need of voice and data communication circuits of the divisions and the zonal headquarters.
b) Data Communication
Data communication circuits for computerized Passengers Reservation System (PRS), Unreserved Ticketing System (UTS), Crew Management System(CMS), Freight Operation Information System(FOIS), Coach Operation Information System(COIS), Management Information System (MIS) etc. and in-house E-mail facilities are provided by Signal & Telecom branch.
c) Telephone Exchanges
Telephone Exchanges are provided at various divisions and other important locations- for Railways internal Communication requirements.
1) Closed User Group
Mobile Communications are Provided to officers and supervisor staff in SCR . Recently CUG Mobile phones are also provided to loco pilot, assistant loco pilot and guards of all Divisions. Total mobile numbers provided are 12914.
Signalling & Telecom Infrastructure
Route Relay Interlocking
Colour light Signaling
(i) RE Telecom cable
(ii) Quad cable
382 Route Kms.
5104 Route Kms.
Overhead telecom circuit
174 Route Kms
25 W VHF sets
At all 556 block stations of S.C.Railway
At all 556 block stations of S.C.Railway
UTS/PRS Data Channels
The Signal & Telecom Department provides various passengers amenities for the benefit of travelling public.
Public Address System (Microprocessor based) is provided at various stations to announce the arrival & departure of trains and other information required by travelling passengers. This facility is available at 191 stations on this Railways.
Train Arrival Departure Information is provided through Rail Sampark Centralized Service 139
Train Indication Boards are provided for indicating the train timing and platform numbers at 97 important Railway stations.
Coach Indication Boards are provided for indicating the- coach position of the train on the platform at 79 important Railway stations.
Platform Clocks are provided at 418 stations on this Railways including GPS based platform clocks at 110 stations.
BSNL Telephones have been provided at all 556 Railway stations.
RAILNET infrastructure provides Corporate Wide Information System for Indian Railways. The network connects all the 16 Zones and 6 production units. All the 6 divisional headquarters i.e Secunderabad, Hyderabad, Vijayawada, Guntur, Guntakal & Nanded of South Central Railway are connected to RAILNET.
Recently, the Headquarter and the divisions have been migrated from leased line point-to-point WAN links to IP MPLS VPN network provided by M/s RailTel Corporation of India Ltd. The network provides Management Information System, Electronic Data Interchange and enables sharing of information among various units of Railways. Internet service has been provided through this network. The HQ network is provided with a Mail Server and a Web Server.