1. Traffic control system (TCS) or centralized traffic control (CTC) is a block system under which train movements are authorized by block signals whose indications supersede the superiority of trains for both opposing and following movements on the same track. FRA 236.828

2. Signal control – train movements are controlled by signal indication, usually by a dispatcher at a remote location via codeline, modem, or data radio.

Definitions

 Control – A request sent from the dispatch office for an operation of a device at a control point.

1. A request for a switch to throw or a signal to clear.

2. This is either a direct request from the dispatcher or an automated request from the control computer. (A stored route)

Indication – The information sent from the control point conveying the events that occur at that control point.

1. A signal clearing or track circuit becoming occupied.

2. This is initiated by any change of a condition monitored at the control point.

Vital circuits – circuit that directly affects the safety of train operation. (For example, a signal or switch control circuit)

1. Controls are routed through vital relays, which check the integrity of the signal system, before allowing a signal to clear or a switch to throw.

Non-vital circuit – A circuit whose failure would not cause an unsafe condition to exist. (For example, a control or indication circuit) Indications are used as a graphical representation in the dispatch office, to allow the dispatcher to “see” what is occurring in the field.

In CTC territory, trains are governed by signal indication.

1. The dispatcher controls trains by determining which signals to send a request to clear.

2. Signals are interconnected so that no two signals will be allowed to clear into the same block between control points in opposite directions.

Sequence of Events of Events

1. Dispatcher requests an operation of a component at a control point.
2. Control is sent via the necessary communications device.

3. Control is received at control point.
4. Vital circuits are checked and, if safe, the operation is completed.

5. Control point sends indication to dispatcher.
6. Indication is displayed on the dispatcher console.

Dispatch Office

1. Dispatch offices have evolved from toggle switches, push buttons and light bulbs to computer workstations with “point and click” interfaces and graphical displays.

2. Dispatchers select a device to control and the computer determines the means to send that request to the field
control point.

3. The control is then sent via modem, microwave, data radio or any combination of communication devices.

4. Indications are received from the field control point, interpreted, and displayed as an image for the dispatcher.

In the dispatch office are a variety of troubleshooting tools available to the signal department employees.

1. Data recording of dispatcher requests and keyboard commands.

2. Data recording of controls and indications from the “codeline”.

3. Monitoring capabilities for on-site personnel.

“Office logic” may be used to prevent unsafe controls from being sent from the dispatch office.

1. For example, if an eastbound signal is requested the computer would not allow a request for a switch to throw in that route.

2. This is not a fail-safe system.

3. This is not used to replace the vital logic of the field control points.

Field Control Point

1. The control point receives the control from the dispatcher.
2. Vital circuits are checked for conflicting signals, signals “in time”, switches in correspondence, etc.

3. If it is safe to operate device requested, the operation occurs – switch throws, signal clears, etc.
4. When operation is completed, the control point sends an indication to the dispatch office, updating the office of the current conditions at the control point.

In addition to the vital controls available to the dispatcher are useful tools for the signal personnel.

1. Remote control of switch heaters. (Snow melters)
2. Remote indication of power failure.

3. Remote indication of fire or break-in.
4. Dispatcher availability of a maintainer call.

Signals at control points are absolute signals

1. Signals normally display a stop indication until requested by the dispatcher or control operator.
2. An automatic block system (ABS) is used between control points.

3. Block occupancy indications are sent to the dispatcher or control operator from the adjacent control points.
4. Hand-throw switches in a control point or in the block between control points must be protected with an electric lock or an exiting signal.

Centralized Traffic Control Summary

1. CTC allows for a safe, efficient, and cost effective means of controlling trains.

2. CTC increases track capacity and train speed by expediting train movement by lining routes and clearing signals prior to a train’s arrival at a control point.

3. CTC allows a single dispatcher or control operator to manage a large section of track, interconnected signals and control points.

4. CTC allows a redundant safety system to prevent unsafe requests from being sent to the field control point.

Introduction to Centralized Traffic Control, Signal control,  Control, Indication, Vital circuits, Non-vital circuit,Sequence of Events of Events, Dispatch Office,Field Control Point,Signals at control points are absolute signals

Introduction

1. Public Information Display System (PIDS)
2. The purpose of PIDS is to display at station concourses and platforms on-line information about scheduled train arrivals and departures and other general purpose messages (normal and emergency) such as smoking is prohibited, evacuation messages etc.
3. It displays information in any combination of English text, Hindi text, numerals, animated graphics, punctuation and symbols in real-time.

Operational Control Center

OCC Theatre

FOTS

                                                     Stations

SCR                                                 SCR                                             SCR
Display Boards                     Display Boards                         Display Boards
Display Boards                     Display Boards                         Display Boards
Display Boards                     Display Boards                         Display Boards
Display Boards                     Display Boards                         Display Boards

PIDS/PAS functional blocks

It consists of the following functional blocks:

The Operational Control Centre (OCC).
1. The OCC is the global control centre for the PIDS/PAS system.
2. From the OCC system wide control of SCRs is possible.

The Station Control Rooms (SCR).
1. The SCR is the local PIDS/PAS installation exists in each station.
2. It manages the local PIDS/PAS system of that station.

Operational Control Centre
FOTS

Master                      OCC LAN                         PIDS/PAS
Clock                                                                          Server

AT S Central                                        PIDS/PAS
Server                                                      MMI

SCADA                                                   PIDS
Server                                                   Backup

PAS
Backup

Operational Control Center Configuration

PIDS/PAS Server

1. The central server is located in the OCC. This server, with the necessary back-up and redundancy modules is connected, via the central router to the central ATS server, to the Local ATS servers, to the SCADA server, and to the Master Clock unit. The PIDS central server is common to the PAS central server.

2. The central server is composed of two machines configured as a Windows NT cluster, with shared disk storage. When one machine fails, the services are automatically started on the backup machine, which reads the state information from the shared disk array.

3. The central server and the station servers are synchronized via the clock distribution system.

Master Clock
The Master clock provides for the system wide time synchronization.

ATS Central Server
The ATS server sends information on train arrivals and departures to PIDS local ATS servers.

SCADA Server
The SCADA server receives and manages  alarms generated by PIDS/PAS.

PIDS/PAS functional blocks

PIDS/PAS Servers
The two servers at a single station are symmetric: one is active, and the other is on hot stand-by. Both systems receive all the external events and update the local state, but only the active system sends output to the displays or loudspeakers. Both systems are constantly monitoring each other for a failure. When one system fails the other automatically takes on the active role. When the changeover occurs an alarm indication (alarm pop-up window and audio signal) is shown on the active MMI.

Submaster Clock
The Submaster Clock provides a local backup for the system clock in case the latter is unserviceable .

ATS Local Server (LATS)
The local ATS server receives and manages ATS data from the central ATS server.

The Main Window of PIDS/PAS Application

The main window is divided into different areas by function. Selection area Current Station area Alarm area

The Display Boards Tree (3)

This panel allows us to select or deselect display boards, in order to, send a message.

The Display Boards Tree (4)

The Alarms Panel (7)

The Alarm Panel displays alarms for:
  Equipment alarms.
Display boards.
Public Address Zones.

Communication with other systems.
1. Internal PIDS alarms (i.e. disk full).
2. Operational alarms (i.e. message priority conflict).

OCC/SCR Synchronization

Public Address System(PAS)

PAS provides broadcasting of voice messages to passengers / staff in all stations, depots and OCC. It can also be used for emergency evacuation broadcast in case of emergencies.

1. The PAS announcements are co-ordinated automatically with PIDS for Real Time Passenger Audio Broadcast.
2. PAS support :

3. Messages announcements in HINDI and English or any combination of these languages.
4. Different Live or Recorded announcements to separate Zones or Group of Zones simultaneously within a station.

5. Announcements from Designated Hand Portable Radios to a set of pre-defined Zones at each station.

Four Major Types of Messages

Fixed Message
-Smoking is prohibited in the entire station.

Pre-formatted with data to be added.
1. This station is…………
2. Due to ……..failure, the arrival of the trains shall be
delayed.

Instantly recorded messages.
Live audio broadcast.
1. According to situation, such as for crowd management
in case of accident.

Message Priority

1. Instantly created / pre-formatted message relating to emergency like fire etc from the SCR.
2. Instantly created / pre-formatted
message relating to emergency like fire etc from the OCC.
3. Train arrival / departure related messages triggered automatically by the TC&S system.

Alarms (Major & Minor)

1. Loss of the entire PIDS facilities at a location.
2. Loss of clock synchronization.
3. Power supply unit failure.
4. Loss of one side of a display board.

5. Message priority conflict.
6. Failure of communication link between OCC and station
PIDS.
7. Loss of both sides of a display board.

PIDS alarms and their possible causes.

Components of PAS

Codec
Telcommander
Amplifiers
Gate Keeper
Zone-8 M
Noise Level Controller (NLC)
Loudspeakers

Codec

Codec is a device that encode and decode the information from digital to analogue signals. It does this by using two Xchanger cards (one is master, located in the OCC server and other is slave, located at each station client server).

Telcommander

Its main task is to interface the Radio System via the PABX, allowing the portable Radio units to address the PAS.

Amplifiers

Signal sources like microphones, CD players, cassette DAT and MiniDisc recorders, do not have the capacity to produce enough energy to directly feed a loudspeaker. It is therefore necessary to use an amplifier that transforms the low power signals of the signal sources in signals with sufficient power to feed the system loudspeakers.The numbers of amplifiers are variable according with the number of physical zones used in each station. The standard procedure is to install one amplifier by zone, and n loudspeakers per zone

Gate Keeper

This equipment is used as an amplifier and loudspeaker controller that performs the
following tasks:
1. Detect and replace any malfunctioning amplifier.
2. Inform the status of each amplifier and possible cause of failure.
3. Distribute the audio signal directly to the loudspeakers.

Zone 8 Selector

1. Dispatch messages to the required zones, respecting the priority scheme between terminals.

Noise Level Controller (NLC)

The human and traffic conditions affect the levels of background noise. Therefore, in order to deal with this issue carefully, the
system will adjust the volume of the announcements to a higher level than the background noise, by using the NLC and NLC sensors.

Inspection of electrical installation – (1) The Commissioner shall inspect the following for electrical installations on the metro railway proposed to be opened for the public carriage of passengers, keeping in view the essentially of services and safety of passengers, namely:-

(a) protection systems of substation.
(b) earthing and bonding of installation.

(c) electromagnetic interferences to ensure that these are within limits. and
(d) essential services to ensure that these would run in case of major break downs.

(e) (i) electrical clearances.
(ii) implantation of masts or third rail and other structures.
(iii) caution and danger notice boards for public.

(iv) assurance Registers signed by various metro railway staff of their knowledge of working in electrified traction area.
(v) maintenance facilities and manpower. and

(vi) fire fighting measures.
(vii) measures provided to control stray current and corrosion of steel reinforcement of the structures, provision of shrouds in case of third rail DC traction system.

(f) Any other item, as he may consider fit for safety of passengers.

(2) During inspection particular attention shall be paid to the safety and operational aspects of the train movements and to see that staff are in possession of statutory rule books; instruction books, registers, forms, etc. and the Operations, Electrical, Permanent Way, Signalling and Train Control and Telecommunication staff are fully acquainted with the duties to be carried out after electric traction is introduced.

Inspection of rolling stock – The Commissioner shall inspect the following items of the rolling stock proposed to be used on the metro railway keeping in view the safety of travelling public on metro railway system proposed to be opened, namely:- 

(a) important systems like traction, braking etc.
(b) safety items like dead-man handle or vigilance device, door operations, etc.

(c) facilities for evacuation of passengers in case of emergencies.
(d) system of operation and train control. 
(e) fire prevention measures.

(f) communication between Train Operator and passengers. and
(g) any other item, as he may consider fit for safety of passengers.

Inspection of Signalling and telecom facilities – The Commissioner shall inspect the following items of the signalling and telecom facilities keeping in view the safety of travelling public, proposed to be used on metro railway system proposed to be opened, namely:-

(a) fail-safe features of the signalling system.
(b) Signal and Telecommunication installations satisfying the requirements of electric traction. and
(c) any other item, as he may consider fit for the safety of the passengers.

Inspection of facilities for relief of passengers in emergencies – The Commissioner shall check the following facilities for relief of passengers in case of emergency namely:-

(i) in-house facilities and preparedness to combat emergencies.
(ii) communication and arrangements with outside relief agencies.

(iii) availability of competency certificate with metro railway officials connected with the metro operations. and
(iv) any other item, as he may consider fit for safety of passengers.

Inspection of electrical installation, Inspection of rolling stock ,Inspection of Signalling and telecom facilities,Inspection of facilities for relief of passengers in emergencies

Power Supply and Traction Arrangement:- Switching on, and off, of traction and power supply distribution (1) All traction and power distribution systems shall remain live at all times and shall only be switched off when necessary for maintenance of the equipment or protection of other maintenance activities.

(2) Traction supplies shall be switched on and off as per instructions of the Traffic Controller: Provided that in case of emergency after giving information to the Traffic Controller, Traction Power Controller shall be authorised to switch off the power.

(3) All traction and power distribution systems which have been switched off shall be adequately earthed before any maintenance or repair work is undertaken.

(4) All maintenance work on high tension distribution network shall be undertaken with the permission of the Traction Power Controller who shall ensure maintaining adequate power supplies for the operation of the Metro Railway network under the condition prevailing at that time.

(5) Emergency Trip System, where provided – (a) The Emergency Trip Switches will be used for switching off the traction power supply on the line of the particular sections near the Emergency Trip Switch in case of any emergency;

(b) The Emergency Trip System switches are installed at each end of platform in stations, at station control rooms and at cross passages in tunnels. After activating an Emergency Trip System an individual signal is sent to Supervisory Control And Data Acquisition system, and according to a tripping scheme and logic provided, the Supervisory Control And Data Acquisition system shall switch off relevant circuit breakers and send signals to indicate that the track section is de-energized.

Access – (1) All points of potential access by the metro railway employees or public to high voltage equipment shall be kept locked and suitable warning notices displayed therein.

(2) All switch gear and other high voltage equipment shall be fenced off and shall be accessible only to authorised staff and access to the live equipment shall only be permitted when the equipment has been switched off and earthed as laid down under
special instructions.

(3) No person shall work on high voltage equipment, or DC traction equipment or switch such equipment by local control unless he is properly trained and certified to perform such duties and possesses a valid certificate of competency and he shall also obtain the permission of the traction power controller before undertaking such work and the procedure for obtaining; granting and cancelling of such permission shall be laid down in special instructions.

(4) No person shall work closer than two meters to a live conductor.

Arcing and Fire – (1) If any member of staff observes fire, smoke, arcing or fusing in the vicinity of the overhead line equipment or third rail equipment, as the case may be, he shall inform the Traffic Controller or Station Controller as quickly as possible and request power to be switched off from the section of the line.

(2) The Traffic Controller shall instruct the Traction Power Controller to switch off the power to that section of line before taking further action to investigate the occurrence.

(3) The Traffic Controller shall also instruct the Station Controller at the nearest station to check if the fire or arcing has been extinguished.

(4) On the basis of report of investigation and confirming rectification of the fault, Traction Power Controller shall re-energise the section and may advise the Traffic Controller to resume train services.

Inspection and maintenance of electrical way and works – The electrical way and work shall be inspected and maintained regularly in accordance with the provisions of the Metro Railway Traction Manual and special instructions, by official nominated for the purpose and in accordance with the duties assigned to them.

Issue of Caution Order – In case of breakdown of overhead equipment, or third rail equipment, as the case may be, when it is necessary for a train to proceed cautiously, the Traction Power Controller shall arrange for issue of caution order in accordance with the procedure in force.

Protection of the trains in case of Traction system failure or breakdown – Whenever a Train Operator finds that his train cannot proceed further on account of Traction system failure or breakdown the Train Operator shall follow instructions laid down in sub-rule (2) of rule 50.

Permit to work adjacent to or involving Electrical equipment –(1) Works adjacent to electrical equipment or involving any parts thereof shall be carried out only by authorised employee of the Metro Railway.

(2) No works under sub rule (1) shall be undertaken unless an authorised electrical person has given a permit to work and in addition, nominated a qualified representative of the electrical branch of Metro Railway, where necessary, in accordance with the Special
Instructions, which shall lay down the detailed procedure of obtaining, granting and cancelling of the permit to work ensuring utmost safety.

(3) The Authorised Electrical Person shall not issue such permit to work without the consent of the Traction Power Controller who in turn, shall keep the Traffic Controller informed when train movements are affected. Whenever such work is likely to affect any other installations, the work will be carried out as per Special Instructions.

(4) Before commencing any work within two meters of Overhead Equipment or Third Rail or its associated cables and equipment, a permit to work shall be obtained from an Authorised Electrical Person.

(5) The maintenance and operation of Electrical Traction Installations in emergency conditions shall be carried out after obtaining permit to work as per procedure contained in Special Instructions. 

Works at Stations – (1) No maintenance work, affecting safety of train operation, shall be carried out at any station without Engineer’s Possession and until permission has been granted by the Station Controller.

(2) All works in public areas shall be securely fenced to prevent access by the public.

(3) The maintenance staff, as per special instructions, shall report to the Station Controller before starting work and again before leaving the station and the Station Controller shall record the time and location of their work so that they be warned of any emergency arising on the station.

(4) Any maintenance work on a station which requires fire alarm or fire suppression equipment to be isolated shall be done only with the permission of the Station Controller.

(5) The maintenance staff shall be responsible for their own protection and for raising the alarm in case of fire in the area which has been isolated and shall also be responsible for restoring normal function to the isolated equipment informing the Station Controller on completion of their work.

(6) No maintenance work which requires the complete shut down of the fire alarm or fire suppression systems of public areas shall take place during the hours in which the station is open to the public.

(7) No maintenance work, which requires the use of ladders or scaffolding, shall take place within the fixed structure dimensions laid down in the schedule of dimensions from the platform edge during traffic hours. 

Control over movement of Trains & Development of signals.

1. This mode has its own inherent problems.

2. Trains cannot be steered away as in the case of other transports.

3. They are required to follow one another in the same direction on track, as otherwise for every vehicle separate parallel paths are to be provided.

4. Control over movement of Trains & Development of signals.
5. Railway locomotion, therefore, though more efficient, brings in problems of “Control over movement of Trains”.

Railways Signalling adopts two methods for controlling over movement of train:

–Time interval method
–Space interval method

Time Interval Method

1. In this method, trains are dispatched in the same direction at a fixed interval of time, irrespective of the status of earlier dispatched train.

2. Where the speeds and weights are low, it is not difficult for a following train to stop short of the train ahead, which has stopped.

3. With higher speeds and heavier loads, the distance required to stop a train is longer, and at this longer distance, the driver cannot definitely decide whether a train in front has actually stopped or not.

4. This makes it difficult for the driver of the following train to run his train at desired speed.

5. If all trains run at the same speed and are required to stop at the same place for the same duration, a certain amount of control can be exercised by having a definite time lag between the trains from one stopping place to another.

But in the case of Railway, this is not practicable as –

(a) Different types of trains like, Express/Mail, passenger, high-speed freight and low speed freight shunting trains are run.

(b) The speeds of all the trains are not same.

(c) The terrain of the country is not same everywhere.

(d) The brake power, hauling capacity, load of train is not same for all trains; and

(e) The stopping places of all trains are not the same.

Hence, it is not possible to control the movement of trains under the “Time interval” method.

A better method of control the “Space Interval Method” is therefore more commonly adopted.

Space Interval Method

1. In this method of “Control over movement”, the length of track is divided into sections called “Blocks”. The entry of a train into the ‘block’ is controlled in such a way that only when it is free, a train can be allowed to enter it. This means that between two consecutive trains, there is a definite space interval.

`A’ and `B’ are two block stations. Under the Absolute Block System controlling the movements of train between `A’ and `B’ is such that, Station `A’ can allow a train to leave his station towards Station `B’ only when the line clear is obtained from Station `B’. Station `B’ is supposed to give the “line clear” for a train to approach towards `B’ only, when the whole block section is clear of trains. That is, when the previous train has cleared the block section as well as the adequate distance beyond the block section.

2. This system of controlling train movement is more commonly known as “BLOCK SYSTEM or BLOCK WORKING ”.

3. So with the two controlling points and intercommunication, it is possible to control the entry of a train into a block only when it is vacant.

Signaling in Metro Operations

1. Such constraints of railway working is observed more prominently in metro system of working as:

2. The frequency of trains (Headway) is very high. 

3. Availability of lines for operations on main line are very limited (only one line for up direction and only one for down direction).

4. The crossing stations are limited and as the trains are worked in a closed loop, a delay to one train is potentially a delay to entire system.

5. Such challenges can only be met by adopting the most advance technology of railway signaling for working of trains on a metro system.

Signals – (1) The signals to be provided for controlling the movements of trains on the metro railway shall be, –
(a) Cab signals.

(b) Fixed line-side signals (where provided). and
(c) Hand signals for shunting purposes.

(2) The signalling and train control system shall be Continuous Automatic Train Control type and shall permit different modes of train operation depending upon its design, namely-

(a) automatic mode, where provided;
(b) automatic reversal mode (if provided):

(c) coded manual mode;
(d) run on sight mode, where provided;

(e) restricted manual mode; and
(f) cut-out mode, where provided.

(3) Under special circumstances and during initial stages, train services on the metro railway may be run with the approval of the Commissioner under Approved Special Instructions, by any of the following systems of working. namely:-

(a) Automatic Block System.
(b) Absolute Block System.

(4) The requirements of the various modes of train operations given in sub-rule  (2) above shall be in accordance with provisions laid down in Metro Railway General Rules, 2012 and the approved metro railway standards.

(5) The signalling and train control systems provided on the section shall be optimum for the planned level of safety and requirement of traffic.

(6) The design of signalling and train control system shall be such as to enable the driver to easily distinguish between various modes of train operation.

(7) The locations of trains running on the section and aspects of the signals, where provided and in use and, shall be displayed in the operations control center and the relevant station control rooms.

(8) The fixed line-side signals, where provided but not in use, will have specific indication to that effect.

Points – (1) All points on passenger lines shall be power operated.
(2) The point operating mechanism on passenger lines shall be of non-trail able designs.

(3) Spring points shall not be used.

(4) Move able crossings and move able diamond crossings on passenger lines shall be provided with complete facing point equipment of approved type.

Interlocking – (1) The operation of signalling gears shall be automatic or from a panel or key board or any other approved means enabling operation of routes and also individual operation of points and signals.

(2) The apparatus provided for operation of points and signals shall be interlocked for all passenger running lines.

Track Circuits – All passenger running lines shall be equipped with means of continuous detection like track circuit, axle counters, or other suitable means, to detect the presence or absence of a vehicle.

Sidings – Sidings shall be arranged in such a manner that shunting operations upon them shall involve the least possible use of, or obstruction to, running lines.

Provision of isolation at stations – (1) All passenger line shall be isolated from all sidings connected there to.
(2) Isolation may be accomplished by –
(a) connection to a long line or siding. or

(b) provision of a short dead end siding. or

(c) provision of trap. or
(d) any other authorised means of isolation.

Note: when a trap is provided, the trap switch should be located with the heel of the switch in rear of the fouling mark and preferably on the straight. The switch should be in the rail away from the line to be protected.

Emergency Communication – Necessary means of communication, like mobile radio communication, shall be
provided to enable the drivers to contact the operation control centre and station control room in case of an emergency.

General – The standard of safety of signalling and train control system provided shall be in accordance with the Approved metro railway standards or recommendations of the European Committee for Electrotechnical Standardization or it’s equivalent national standards/international standards, as the case may be.

Necessary measures like protective devices or design features shall be adopted to safeguard signalling and train control, and telecommunication installations against the harmful effect of electromagnetic inference, stray current and earth leakage current, etc. of 25KV AC, or 750 V DC, or other traction systems as adopted on the section.

Absence of cab signaling

(1) Failure of the cab signaling shall initiate an irrevocable emergency brake application.

(2) The Train Operator shall report the occurrence to the Traffic Controller and seek instructions.

(3) The Traffic Controller shall verify as far as practicable from indications on his diagram that the problem is not caused by a track side fault or another train and if no cause is apparent, he shall instruct the Train Operator to select the Restricted Manual mode or Run On Sight mode, and try to move ahead exercising utmost vigilance so that he may stop short of any obstruction.

(4) If the train still does not move, the traffic controller shall authorise the Train Operator to operate the Cut Out switch and to proceed in Cut Out mode of control to asuitable station, exercising utmost vigilance so that he may stop short of any obstruction. At the next station, passengers shall be detained and the train worked to depot or asuitable siding.

Failure of fixed Signals 

(1) If a Train Operator observes that a fixed signal is not displaying any aspect, he shall stop his train and seek instructions from the traffic controller by radio.

(2) All concerned staff shall then follow the provisions of sub-rules (7) to (10) of rule 21 and Sub-rule (1) to (4) of Rule 22.

Failure of route setting

(1) If a route through an interlocked area cannot be set automatically or by manual control from the Operations Control Centre, the control of the area shall be passed to the local Station Control Room.

(2) If the route cannot be set from the Station Control Room signaling control panel or work-station, the Traffic Controller shall instruct the Train Operator to secure his train and wait for instructions.

(3) The Traffic Controller and the Station Controller shall examine the indications for the points and if indications at the station and at Operations Control Center agree that all points are set correctly and locked, the traffic controller may instruct the Train Operator to select Run On Sight mode or Restricted Manual mode, as the case may be, and proceed at reduced speed such that he can stop short of any obstruction. Once cab signals show a proceed indication, Coded Manual mode shall be resumed; and if the train is equipped with Automatic Train Operation, then Automatic Mode may be resumed.

(4) If any point indication is missing or shows the points set for the wrong direction, or there is a discrepancy between the indications at the station and in Operations Control Center, the station controller shall examine the position of the points himself. If they are lying in the wrong direction, he shall manually set the points with the crank handle from the station control room and the points shall be secured with a clamp and padlock and the train instructed by hand signal to proceed, and if after travelling some distance, a proceed indication is received by the train running on Restricted Manual mode, the train shall automatically upgrade to the Coded manual mode of control and the Train Operator shall inform the Traffic Controller. the train is fitted with Automatic Train Operation, Automatic Mode of the control may be resumed.

(5) The Station Controller, after examining the position of the points under sub-rule (4), shall then return to the station and report to the Traffic Controller that the route remains secured and any subsequent train may be instructed by radio to proceed.

(6) In depot, the Depot Controller may instruct the Train Operator by radio to proceed if– 
(a) point indications for all facing points in the route show the points as set and locked in the correct position;

(b) any points not showing an indication shall be traversed in the trailing direction only if the points are trailable.

(c) If points for which indications are not available, have to be traversed in the facing direction, the Depot Controller shall ensure that the points are set manually and secured in correct position with the clamp and padlock before authorising the train to proceed .

ATS is at the Heart and Brain of various Systems operational in DMRC.

1. Acts as an Intelligent Interface where one can see all trains running in real-time in the entire network from a remote central location.

2. ATS is a Central and Key unit making the job of Operation and Maintenance easier and faster by its automatic nature.

3. ATS is fully automatic and needs no manual intervention in all the Operational tasks besides ensuring safe and efficient Train Operation.

4. It eases the job of Operation and Traffic Controllers to a great extent. Station Controllers are not bound to sit in front of MMI as system is regulating train movement according to scheduled Time Table from Central level (OCC). They can also look after different tasks related to passengers services which adds to the efficient utilization of our workforce.

5. Even Traffic Controllers in OCC are not bound to monitor the MPD/MMI continuously. Therefore ATS reduces the workload of ATC/SC’s to a great extent.

6. As a link and Source of information for Passenger Information, Radio and SCADA.

7. ATS is central and the most vital body having an interface with all the major units of Signalling and Telecom.

ATS Functions

1. To monitor and control the traffic through MMI.
2. To perform automatic route setting, and automatic train regulation.
3. To monitor & regulate train movement continuously.

4. To display information on PIDS.
5. To generate schedules.
6. To generate alarms & events.

Monitoring and Controlling the Traffic

Central
Local
Depot

PIDS/PAS information is provided by ATS System.

PLAYBACK

Every event is recorded automatically by the System and can be run on Playback as and when required. 

Train Hold Management Restricted in ATO and Advisory in ATP

The following ‘train hold’ functions are available:

Global Train Hold (for a line): It is a single command issued for all platforms at a time. It will hold ALL trains at their next platform arrival.

Platform Train Hold: A command issued for a particular platform. It will hold ALL trains at that platform arrival.

Automatic Train Hold: It maintains that at one time there is only one train between two stations inside a tunnel. Useful in avoiding conflict and bunching of trains.

Skip Stop Management Restricted in ATO and Advisory in ATP

To skip a station ‘N’, the command must be sent before the train leaves the previous station.
The following Skip Stops are available to the ATS operator,

Station Skip Stop: When a station (all platforms) is closed, this stop is applied for the indicated station, Useful in Fire.

Train Skip Stop: When a train is going to depot, without taking any passenger (for a specific platform), this state is applied for the next stations following the actual train position.

Work on service buildings and structures in the vicinity of live equipment –The Metro Railway employee required to carry out work on service buildings and structures in the proximity of Overhead Equipment shall exercise special care to ensure that tools, measuring tapes, and materials are not placed in a position from which they are likely to fall on or make contact with electrical equipment.

Sectioning and siding switches –(1) Sectioning and siding switches installed in the Traction system shall be operated only by such officials as are authorized to do so by the in-charge of the Traction system.

(2) No switch affecting the feed to the main running line or loop line shall be closed or opened without permission of the Traction Power Controller and the detailed procedures for opening and closing of sectioning and isolating switches shall be as per the Metro Railway Traction Manual.

(3) All operations of section or isolating switches, when completed, shall be reported to the Traction Power Controller in all cases.

Warning to staff and public – (1) All electrical equipment shall be regarded as being live at all times and consequently dangerous to human life, save and except in cases where the electrical equipment has been specially made dead, isolated and earthed as per instructions contained in the Metro Railway Traction Manual.

(2) caution notices, as specified in Schedule I appended to these rules, shall be prominently and permanently fixed near all vulnerable places to warn staff and public to exercise due caution.

(3) No person shall climb on the top of rolling stock, or go under the rolling stock in case of Third Rail DC Traction, when these vehicles are located beneath the Overhead Equipment or adjacent to the Third Rail except when the Overhead Equipment or Third Rail is made dead and earthed in accordance with Special Instructions and the person required to climb on the roofs of passenger cars or to go under the same, shall obtain a permit to work as per rule 78.

Alterations to Track – Before any alteration to alignment or level of electrified tracks is commenced, due notice shall be given to those responsible for the Overhead Equipment or the Third Rail, as the case may be, so that the Overhead Equipment or Third Rail may be adjusted using specified gauge to conform to the new conditions of track.

Additional rules for electrified Sections –Special Instructions, if any, for working of trains on electrified sections shall be issued .  

Rules applicable to Overhead AC Traction Equipment only – (1) Tripping of circuit breakers of Train in Neutral sections – (i) Unless otherwise allowed by special instructions, the Train Operator shall coast through the neutral section, duly switching off power and necessary indications boards as specified in Schedule II appended to these rules, wherever required, shall be provided to guide the Train Operator to switch off and switch on the power.

(ii) The Indication boards shall be provided at five hundred meters and two hundred and fifty meters in advance of the neutral section and additional boards shall be provided just short of and immediately after the neutral section to indicate to the Train Operator the points where he shall open and re-close the circuit breaker on the electrical multiple unit.

(2) Tower Wagon or Catenary inspection Car –(i) The movement or working of tower wagon or inspection car or any other vehicle with pantograph raised shall be as per the Special Instructions.

(ii) No tower wagon or inspection car shall be driven except by an authorised person and no person shall be so authorised, unless he has knowledge of the section on which tower wagon or inspection car is to operate in addition to being conversant with the operation of tower wagon or inspection car.

(3) Working of ladder trollies – (i) Ladder trollies shall be considered as work trains and their movement on the main line track shall be governed by rule 33.
(ii) The ladder trollies shall work during Engineer’s Possession only and their operation shall be supervised by a suitable traction distribution official as prescribed in Special Instructions.

Rules applicable to DC Traction Third Rail equipment only – Switching ‘OFF’ and ‘ON’ of Traction power. – (1) Traction power shall ordinarily remain ‘ON’ and shall be switched ‘OFF’ during traffic hours for a specified section by the Traction Power Controller or through the Authorised Employee immediately after informing the Traffic Controller in emergencies, like:-

(a) to stop serious arcing or fusing;
(b) to stop train in unusual circumstances; and
(c) when flood water overflows the drains. 

The Traction Power Controller shall issue emergency power block as per prescribed procedure, to the Authorised Employee. The Traffic Controller shall also inform all concerned that train movements on the affected section have been stopped.

(2) When the cause of ‘Switching OFF’ is over, the employee who has taken emergency power block will inform Traction Power Controller to that effect and cancel the emergency power block.

(3) Before switching ‘ON’ the current, the Traction Power Controller shall obtain the permission of Traffic Controller who shall confirm from the Engineering and Signaling officials that the track is safe and free from any obstructions before permitting energisation of third rail. Thereafter, traffic controller will resume the traffic.

Procedure for preventing admission of electric rolling stock into or over sections of track with dead or earthed overhead lines or third rail 

(1) In order to prevent electric rolling stock from being admitted into a track or a crossover for which overhead equipment or third rail equipment, as the case may be, is made dead or for which a permit to work is to be issued, suitable measures shall be enforced to block setting of such routes.

(2) The levers or slide or push buttons of signals and points governing movement of electric rolling stock shall be suitably protected and if the points and signals are locally operated they shall be clamped and padlocked in their normal position and the keys shall be kept with the Station Controller or Depot Controller as the case may be.

(3) These protective measures shall not be withdrawn until the Station Controller or the Depot Controller, as the case may be, receives a message from the Traffic Controller and acknowledges the same, and the Traffic Controller shall not issue a message unless he has received a message from the Traction Power Controller cancelling the power block.