1. Singapore Downtown Line (SIGNALLING - SIRIUS)
18 November 2016
Singapore Downtown Line (SIGNALLING - SIRIUS)

2. DUAL SIGNALLING SYSTEM
CBTC
FBSS
High Availability of Unmanned System
Avoid Major Disruption
Two Signalling System (CBTC, FBSS) which allows transition between them in Unmanned Operation
Transition in unlikely events of FBSS is also done seamlessly

3. DESIGN OVERVIEW

4. ONBOARD TRAINBORNE DM1 T-CAR DM2 Legend: ATP radios (X2)
APR Readers (X2)
ATP Pick Up Coils (X4)
Train Data Management System (X1)
Driver Machine Interface (DMI) (X2)
Dopplers (X2)
Event Recorder (X1)
Bearing Sensors (X2)
ATC Cubicle (ATP+ATO)

5. ONBOARD TRAINBORNE - ATC
PSU
ATC Cubicle
Automatic Train Protection:
1. 2oo3 (Triple Redundancy)
2. Responsible for the safety-related
Automatic Train Operation:
1. Hot Standby
2. Allows train to move and operate in AM (driverless)
ATP
ATO

6. SIGNALING SYSTEM: CBTC SIRIUS
CBTC: Communications Based Train Control
Radio based train control system (Redundancy)
ATC Trackside: Block Processor (BP)
BP will take control of a specific CBTC operating area BP
2oo3
Leaky Coaxial (LCX)
Ethernet Switch
RADIOS
Channel A (diff. Freq)
RADIOS
Channel B (diff. Freq)
TRACKSIDE
SER

7. CBTC - MOVEMENT AUTHORITY
SAFETY MARGIN
CBTC
CBTC
Issued MA
Calculated MA

8. CBTC – ATC TRACKSIDE (BP) HANDOVER
BP Handover Boundary H A BP BP
AREA 2
AREA 1
CBTC 1 2
In the event, if one radio is faulty, the train will be able to do the handover with one radio. Two radios are installed on board the train for redundancy.
End of Handover Process
Start of Handover Process

9. CBTC - CREEP
Both ATO lanes are down, CREEP functionality can be used for unmanned operation to the next station.
TDMS and ATP will move the train safely to the station.
ATO
CBTC
PLATFORM 1
Reset EB remotely
DEGRADED MODE: Unable to reset ATO lanes manually.
Train is in the middle of tunnel and moving in unmanned operation, no CSO are present in the train. Unable to move the train manually in RM or CM.
Most effective way is to activate creep mode and move the train to the platform. In the meantime, a CSO will be activated to the platform to standby.
Instead of traction power off or on to send a CSO on board the train in the middle of the tunnel to rescue it. 2
Creep command
OCC

10. SIGNALING SYSTEM: FBSS
FBSS: FALL-BACK SIGNALING SYSTEM
Traditional system
Secondary method used
Continuously provided by the use of track circuit, FS2550
Onboard Trainborne equipments are compatible
PURPOSE: Increase availability of unmanned operation, FBSS is always available.
Traditional system which is already in used since NS& EW lines in Singapore.
Priority: CBTC, FBSS acts as a redundancy system.
Normal Operation:
Nevertheless, even though train is still moving in CBTC, track codes are always provided. Train will still be detecting the codes transmitted.
Loss of CBTC is unpredictable and FBSS is always on standby.
The principle of having FBSS

11. FBSS – TRACK CIRCUITS FS2550
How are track codes transmitted?
Transmitter (SER)
ATP Pick Up Coil (Train) Rx Tx
Direction of Travel (XB)
Direction of Travel (BB)
[De-Energised Relay]
[Energised Relay]
Bi-directional Track Circuit
Brief Introduction
Tx will send the track codes and the ATP Pick Up Coil in the train will read the code.
Before sending the track codes, there is a receiver, Rx required, to detect trains occupying the track circuit.
Rx will always be the start of the direction of the travel. Unless route is set, Rx and Tx will switch based on the direction of travel?
In any case when the relay is faulty, track codes will still be transmitted but only in the direction of travel. (XB bound, XB direction). For opposite direction of travel, track codes of 0/0 will be given even though route is set. MOVE IN RM if required!!

12. FBSS – TRACK CIRCUITS FS2550
Carrier Frequency
Track Circuit Separation (Jointless)
CARRIER
FREQ
TYPE P1
4080 Hz V P2
4320 Hz K P3
4560 Hz W P4
4800 Hz L P5
5040 Hz X P6
5280 Hz M P7
5520 Hz Y P9
6000 Hz Z
Direction of Travel (XB) V W M L
Track codes include both Carrier Frequency and Modulator Frequency.
Track circuits are separated by electronic means, the use of carrier frequency. JOINTLESS.
The frequency varies with the different type of channels, V.. K.. W.. L.. X..
Based on the design, the track circuit is fixed with it’s own channel. This can be seen in the transmitter.
Adjacent track circuits required different channels to separate the track circuits. Y X L K
Direction of Travel (BB)

13. FBSS – TRACK CIRCUITS FS2550
2.Modulator Frequency
Interlocking (WESTRACE MKII)
Track Code Output Module (TCOM) used
Generate Speed Code
Maximum and Target speed
SIEMENS
MODULATOR
FREQ
SPEED CODE
Max. / Target M1
28 Hz
81/81 M2
32 Hz
81/71 M3
36 Hz
71/71 M4
40 Hz
71/55 M5
44 Hz
55/55 M6
48 Hz
55/42 M7
52 Hz
42/42 M8
56 Hz
42/18 M9
60 Hz
42/0
M10
64 Hz
18/18
M11
68 Hz
18/0
M12
72 Hz
0/0
M13
76 Hz
M14
80 Hz
Modulated frequencies provided externally by the TCOM.
The frequency varies with different speed code.
Speed codes will then be sent from the TCOM to the transmitter and read by the ATP pick up coil in the train.
The speed codes include both the maximum and target speed.
Depending on the route set, the speed code given to each of the track circuit are configured accordingly to the control table.
Longer routes, speed codes given will be higher and shorter routes, speed codes will be lower.
Doors opening and closing code

14. FBSS – TRACK CIRCUITS FS2550
POWERED
UNPOWERED
RELAYS
OVERVIEW
SIEMENS RX TX TX
Tuning Unit
TCOM RX TX RX
Tuning Unit
SER
TRACKSIDE

15. Transition of CBTC to FBSS
In any unlikely EVENTS, will the train fall back from CBTC to FBSS.
Loss of ALL Trackside Radios (X2)
Loss of ATC Trackside (X2 BP lanes)
Loss of FULL Onboard Trainborne Radios (X2)
Loss of both APRs / APR readers (X2)
Loss of both Dopplers (X2)
Loss of both Bearing Sensors (X2)
Loss of two consecutive APRs, train will fall back to FBSS, but if only one APR is loss, train will still remain in CBTC.
For Dopplers and Bearing Sensors, these are categorized under Sensors. In any case in which, one doppler and one bearing sensor are failed, train will still be able to move in CBTC. If either BOTH Doppler or Bearing Sensors failed, train will fall back to FBSS.
These are a few cases that will affect the signalling system to fall back to FBSS.
**On the next slide we will show the behaviour of the system if the train happened to fall back to FBSS.

16. Transition of CBTC to FBSS
1. Movement of train (Entering Platform)
CBTC
FBSS
18/18 1
18/0 2
0/0 3
42/18
18/18
PLATFORM
42/42
0/0
18/18
18/0
EOA
SVL
Train was travelling at a speed of 65kph with speed codes given continuously even through train is in CBTC.
EOA= MA given by the BP, which will impact the maximum speed of the train.
SVL is the OL + EOA
EB will be automatically normalised and only for this special case that is configured this way.
Speed codes given are configured based on the control table. The track circuit before the red signal will be 0/0.
Two conditions are required to stop at the platform:
Speed code of 2/2
Stopping Point Information configured in the APR.
Even though the platform track circuit is 0/0, speed codes will drop slowly to ensure smooth stopping.
The sequence of track codes when entering the platform will be 18/ /0 followed by 0/0..
Stopping Point Information
Route is set to the signal ahead.
Train is moving in AM CBTC.
Train will stop nicely and align with the PSDs.

17. Transition of CBTC to FBSS
2. Doors cycle (Opening & Closing)
FBSS 5 3
Speed codes: 0/0
Speed codes: 81/81 7
FM13 (0/0)
FM12 (0/0) 4
Dwell Time: 28s, 45s, 60s
CBI
In the event that the train stopped in CBTC, train and psd doors are opened, BUT so coincidentally, train fall back to FBSS.
What will happen?
Don’t worry, it applies the same for track codes, FM12 and FM13. It will be provided to the train continuously and CBI will activate FBSS enabled once FBSS is detected.
Once the route set, without completing the door cycle, the speed code will still remain as 0/0 for safety.
Signalling Switch
PSD
HW/TW Unit 1 6

18. Transition of FBSS to CBTC
Establish of communications (Train & BP)
SER BP 1
Initiate of Communications 4
Train Accepted 2
Configuration Determination 3
Registration Position Report
Before generating the first MA for the train, the system has to ensure that there are no obstacles ahead. This process is called PCA.
3 different methods are used.
FBSS
71/55
55/55
55/55

19. Transition of FBSS to CBTC
Proof Clear Ahead process (PCA)
Signal
Track codes
OBSTACLE
FBSS
CBTC
18/18
0/0
18/0
0/0
0/0
0/0
OBSTACLE Rx Tx

20. Transition of FBSS to CBTC
OVERVIEW OK OK
NOK OK
AREA 1 BP BP
AREA 3 BP
AREA 2 1
Establish of comms + PCA
CBTC
FBSS
CBTC
81/81
81/71
71/71
71/71
71/55

21. Movement of MULTIPLE trains
- (CBTC + CBTC)
- (FBSS + CBTC)
FBSS 2
CBTC 1
18/0
0/0
0/0
Last position reported
**Verify the speed codes with Grant
Safety Factor
Better headway can be achieved!

22. Movement of MULTIPLE trains
- (CBTC + FBSS)
Protection Envelope Activated
CBTC
FBSS
CBTC
18/0
0/0
0/0
Last position reported
MA shortened

23. CONCLUSIONS