1. TCAS – Indian Railway Train Control SystemBy
Mahesh Mangal
Sr. ED/Signal/RDSO
26 July 2014

2. Train Protection system on IR

3. Auxiliary Warning System at Mumbai
Working in Mumbai suburban since 1986.
Track Magnet based system working in Mumbai suburban area (329 RKm), where trains run at a Headway of 3 to 4 minutes
Opto coupler to interface & collect signal aspect
This system is now getting obsolete and we have now developed a advance system which is interoperable with existing system.

4. Train Protection & Warning System(TPWS)
System is installed on Chennai – Gummidipundi section of SR, Nizamuddin – Agra section of NR/NCR and on Metro Kolkatta.
Works have been sanctioned for suburban section of ER, SER, SR & auto signalling sections (3330 RKM, 2362 onboard, Rs cr).
TPWS specification is based on proven European Railway Traffic Management System (ERTMS) Level-1 configuration.
Even though the system is working, but lot of time has been taken for customizing and it has not been possible to use system on trains running at more than 120 kmph.

5. Anti Collision Device (ACD)
Installed on 1800 Kms of BG section of N.F. Railway in the year
It is GPS based non signalling system.
Train transmit their location and track ID and if a dangerous event like collision is likely to occur, automatically apply brakes and prevent the collision or minimize the impact of collision.
Prevents head on/rear/side collisions.
Provides station approach warning to drivers.
Provides warning to road users at LC gates.
Detects parting/jumbling of trains.

6. GPS Satellites
UHF Data Radio Modem
GPS Receiver
Loco ACD
Loco ACD
I R
I R
To detect track ID in station, deviation count theory used results in wrong identification and cause false alarm resulting in operational and other problems. As such, not been found effective and has not been proliferated.

7. Experience of IR with existing TPWS
Requires lot of data entry at the start of train which is inconvenient for existing loco pilots.
Braking is not optimized for mixed rolling stock on IR.
Intermittent update of MA results in un-necessary brake intervention whenever signal aspect is updated on approach.
Needs lot of cable and trackside electronics which are failure prone.
The procedure for train trip or start is cumbersome and any customization is not possible.
No protection is available in case on non interlocked working.
Does not provide facility of SoS which is considered essential as there are many collisions on IR due to derailment obstructing other track.

8. Development of Indigenous system
RDSO started about 2 years ago to develop TCAS to take care the problems of ACD installed on NFR.
However, in this period, not only the system developed takes care this problem but it also provides Automatic Train Protections(ATP) features as available in advance Train Control systems like ETCS L1 & L2.
Multiple sources with interoperable product are developed with IPR being shared by firm and RDSO and cost of system is expected to be much lower than ETCS and only marginally higher than ACD.

9. Comparison of ETCS & TCAS
Feature
ETCS L-1
ETCS L-2
TCAS
Cab Signalling
Yes
Line side signal
Required
Optional
Continuous supervision
Continuous update No
Suitable for Auto signal
Trials to be conducted shortly
Collision prevention (independent of Signalling)
SOS feature
SIL-4
Vulnerability to theft
Easy to operate 9

10. TCAS - System configuration
GNSS/
GPS
Radio
Communication
Loco
TCAS
Station
RFID READER 10

11. Features of TCAS Automatic Train Protection(ATP) FEATURES
Detection and Prevention of SPAD
Full cab signalling with Display of signal aspect, movement authority, target distance and speed
Continuous train control
Protection for Permanent and temporary speed restriction.
Detection of roll back
TRAIN COLLISION FEATURES
Head On
Rear End Collision
Side On Collision 11

12. Additional features to improve safety
SOS from Loco and Station
Derailment Alert with auto generation of SOS
Automatic and Manual Brake Test
Continuous horn while approaching LC gate or gang working.
Detection of unusuals in interlocking like signal cleared for occupied line or train entered in wrong line etc. and controlling the train.
Live display of train movement with their speed, location and any unusual in control office.

13. STATION EQUIPMENT
Station TCAS – Gathers signaling inputs & loco inputs and transmits signaling inputs to Loco TCAS
Radio- For communication with Locos
SMI – Station
Master Interface
GPS – For time
synchronization 13

14. LOCO EQUIPMENT
Loco unit – Gathers inputs from RFID tags, speedometer and Station.
BIU – Brake Interface Unit
DMI – For In-cab display of signal aspect, TCAS status, alarms and alerts, SOS buttons.
Radio & Antenna- For communication with stations and other Locos
RFID Reader- To read RFID tags
GPS and GPRS 14

15. ON TRACK EQUIPMENT
RFID Tags provided in block section at every 1 km and station yard for each track and signals.
Used for track identification, correction of location of train and identifying train direction. 15

16. Status of present development
Work for undertaking extended field trial on 250 RKM section with 40 locomotives sanctioned.
Section in Secundrabad division identified for trial.
Section divided in three sub sections. Contract already awarded to 3 firms.
TCAS
Territory 16
Wadi

17. Status of present development17

18. Status of present development
Two firms have successfully developed the system. Field trials have been done by for 5-6 months.
It has been also possible to achieve interoperability of product developed by two vendors.
Third Firm (Awarded the developmental work in Nov-2013) has also tested their onboard equipment.
Trial done on 4 stations with 4 Locos on 32 km Route-km, with Brake Interface Unit and most of the important features with interoperability tested. 18

19. Scenarios tested in recent trials
In Cab Display of Signalling related information such as Movement Authority, Target Speed, Target Distance, Signal Aspect etc.
Brake Test : To assess braking characteristics of train
Prevention of SPAD
PSR and TSR
Loop line speed control
Prevention of collisions in block section
SoS from loco and station
LC gate warning
Control of train for certain interlocking abnormalities. 19

20. Current status
After these trials, firms have manufactured the final equipment and type testing is in progress. The installation at stations, track and locomotives likely by Sep, 2014.
Extended trials with 40 locos and on 250 kms sections will commence within 3 months.
The present system being developed is suitable for absolute block signalling and RDSO is also working to upgrade this equipment later for automatic signalling.
Lab for testing interoperability and offline testing of various scenarios has been setup at RDSO. 20

21. Trial Video (10 Mins)

22. THANKS