SIGNAL COMBINED FOR EXAM
Act means Railway act ,1989.
Block Back - Means to despatch a message from a block station to intimating to block station in rear on a double line,
Or
Next block station on either side on a single line,that the block section is obstructed or to be obstructed.
Shunt Key is the authority for the driver to shunt from Starter upto First Stop Signal of concerned block section.The key authorizes driver to pass Advance Starter at ON during shunting.
Block Forward -
Means to despatch a message from a block station to intimating to block station in advance on a double line,that block in advance is obstructed or to be obstructed.
Substitute for Adequate Distance -
1) Sand hump of approved design
2) Deraining switch under approved Special instructions
Minimum Equipment of fixed Signals In Automatic Block territory on single line-
Home and Starter
IB Section-
There are three Push buttons in IB panel.
PB 1- To reset Axle counter when IB Home passed at ON
PB 2- To reset Axle counter due to failure or improper counting.
PB 3 - To give co operation to the station at rear.
PB 1 or PB 2 used only with co operation of station ahead.This co operation is given by pressing PB 3 and indicated by white line near PB1 or PB 2.
There are four Indicators at IB panel.
K1 Indicator-
When a train passes IB at ON,K1 indicator appears and alarm sounds. This indication dissapears after normal restoration of circuits by using PB1 and Co operation from Station master.
K2 Indicator-
When train passes LSS and enters Axle counter section, K2 Indicator appears and alarm sounds.This indication disappear when as LSS knob is put back to Normal.
K3 Indicator-
When a train passes IB at OFF,K3 indicator appears and alarm sounds. This indication dissapears IBS knob is normalized.
K4 Indicator-
Appears when power supply of IB signals fails. Dissapears after restoration of power supply.
Census of LC gates-
Carried out for 07 days by Engg, Signal and Traffic.
Train,Road Vehicle,Bullock Carts and Tonga- 01 unit
Cycle Riksha/Auto Rikshaw- 1/2 unit.
Classification of LC gates-
Special Class- TVU greater 50000
A Class - 30000 to 50000
B Class - 30000 to 20000
B1 Class - 25000 to 30000
B2 Class - 20000 to 25000
C Class - all other LC gates.
Non Interlocking Work -
Working of trains when interlocking between signals and points/ track circuits/slots/slides/block Equipments etc.
Occasions for Non Interlocking working-
a) Overhauling of Lever frames
b) Remodeling of station/gauge conversion/doubling.
c) Introduction of PI/RRI
d) Replacement of worn out frames/panels
e) Cable Meggering
f) S&T/ Engg joints works.
Interlocking -
Four essentials of Interlocking
i) Setting of Routes
ii) Locking
iii) Holding
iv) Prevention of Conflicting movements
Standard of Interlocking-
Standard 1 - Upto 50 kmph
Standard 2- 50 to 110 kmph
Standard 3- 110 to 140 kmph
Standard 4- 140 to 160 kmph
Double distant is required on sections where goods trains have a braking distance more than 1 Km.
2 Months after Commissioning- Stipulated time period as per SEM for taking over the new signalling installation and associated gadgets by Divisional open Line.
20 percent - Spare conductors required in each main cable upto farthest points.
COA Software is used in Divisional Control Office for train control charting.
3.15 m - Thickness of MS Sheet used in manufacturing of Full location box.
Speed in A route -130 to 160 kmph
100 to 130 for Speed in B route.
SWR Revisions- 5 years , 5 corrections
Validity of competency certificate issued by Zonal training school- 4 years.
CSL -686 m
CRS - 715 m.
More than 20 route LEVER - ADSTE
Point testing- Once in month by JE/ SSE
Painting of signal post - 3 years.
Point machine from centre of track - 1600 mm
TLjb-1905 mm
LOCATION -2360 mm
Life of EI ,Axle counter,Ips - 20 yrs.
Kavach - 15 yrs
Track relay,QBCA-10 yrs.
ELB - 10 YRS
Led- 8 yrs.
Quad ,ofc - 25 yrs
No change of gradient within 30 m of point crossing
ABS, IB, DOUBLE DISTANT- GM SANCTION
LC CLOSURE - PCE SANCTION
RE ENERGISATION - EIG ( PCEE)
Catch Siding slip Siding- CRS.
Signaling plan and locking table shall be approved by JAG and above
Protection of lorry in single line-
600 m on both sides and three detonaters at 1200 m from place of obstruction.
Typical wiring diagram such as inter cabin slotting, auto signaling,track circuit, indication circuit etc.approved by Dy CSTE/ Sr DSTE.
Post 1--
Speed after Authority to proceed without line clear - 15 kmph.
Clearance of last row of relays from floor level on Relay racks - At least 600 mm.
Relay rack shall have space to accommodate Relays for future expansion- 15%.
Reliability-
Frequency of failure and network recovery time after a failure was measured.
In Case of total interruption of communication trans can be passed LSS with paper authority.
Terminal station comes under Special Class.
230 mm - Dia of Disc of markers.
Post 9-
Accident has been classified in categories from A to R excluding I and O.
Serious Accident -
Accident to a train carrying passengers which is attended with loss of life or grievous hurt to a passenger in the train or with serious damage to Railway property exceeding 2 Cr shall be deemed to be a serious Accident.
Train Accidents-
Divided into following parts
A) Consequential Train Accident - It is a Accident having serious repercussion in terms of human life,human injury, loss to Railway property or interruption to rail traffic. Train accidents are classified as -
Collision - All cases under category A-1 to A-4
Fire - All cases under category B-1 to B-4
Level Crossing- All cases under category C-1 to C-4
Derailment- All cases under category D-1 to D-4
Miscellaneous- All cases under category E1
B) Other train Accidents -
All other Accidents which are not covered in the above list.
Further classified as-
1) Yard Accidents:-
Accidents take place in Yard and does not involve a train.
2) Indicative Accidents:-
These are not Accidents but are serious potential hazards and include all cases of SPAD, Averted Collision,Breach of Block Rule coming under classification F,G and H.
Level of enquiry - Junior Administrative Grade Officer
3) Equipment Failures:-
All failures of Railway equipment. Coming under classification of J,K,L and M.
4) Unusual Incidents:-
These include cases related to law and order but not resulting into train accidents. Classified as N,P,Q and R.
Sabotage -
Means criminal interference with any part of working machinery of Railway to cause damage to Railway property other than train wrecking or attempted train wrecking.
Train Wrecking -
Wilful obstruction of or temporary with permanent way,Works or Rolling stock resulting in a Accident to train with or without loss of life.
Damage/Serious damage to property :-
Damage to Railway property = Rs 100 to Rs 3 Lakhs
Serious Damage to Railway property = Cost over Rs 3 Lakhs
Averted Collision:-
A Collision would have occurred either in Block section or in Station Limit between two trains or between a train and obstruction.
Following will not be considered as Averted Collision
a) If the distance between trains is 400m or more.
Breach of Block Rule
Means Breach any or rules mentioned in essential of the absolute block system ( GR 8.01).
Classification of Accidents -
I. Train Accidents
II. Yard Accidents
III. Indicative Accidents
IV. Equipment Failures.
V. Unusual Incidents
Classes of Accident-
Class A - Collisions
Class B - Fire
Class C - Trains running into road traffic,and/or traffic running into trains
Class D - Derailment
Class E - Other Train Accidents
Class F - Averted Collisions
Class G - Breach of Block Rules
Class H - SPAD
Class J - Failures of Engine and Rolling Stock
Class K - Failure of Permanent Way
Class L - Failure of Electrical Equipment
Class M - Failure of Sinalling and Telecommunication
Class N - Unusual Incidents
Class P - Casualities
Class Q - Other Incidents
Class R - Miscellaneous
PCOM - Authority to declare an accident as disaster
Five types of accident
1. Train Accident
2. Yard Accidents
3. Indicative Accidents
4. Equipment failure
5. Unusual Incident.
A B C D E - Train Accident + Yard Accident
F, G,H - Indicative Accidents
J,K,L,M - Failure of Equipment.
N,P,Q,R - Unusual Incident.
Class A - All types of collisions
Class B - Fire and blasts
Class C - LC gate Accidents
Class D - All types of Derailment
Class E - Collision on obstruction on passing over obstruction or passing over obstruction but safe.
Class F - Averted Collision Cases( Indicative Accidents)
Class G - Breach of Block Rule ( Indicative Accidents)
Class H - Train pass at danger( Indicative Accidents)
Class J - Failure of Engine
Class K - Pway Failure
Class L - Electrical failure
Class M - All S&T failures.
Class N- Train wrecking
Class P - Passenger Casuality
Class Q - Other Incident
Class R - Miscellaneous
ART has 30 sets of 5W VHFs
SPAD is the example of indicative Accidents.
All kind of Equipment failures , level of enquiry - Senior supervisors of respective departments
ART-
As per accident manual, target time for starting ART is 30 min in Day.
In the night it is 45 min.
Max speed of ART is 100 Kmph.
Inspection schedule equipment in ART by ADSTE/ DSTE - Quarterly once
ARMV( Accident Relief Medical Van)
Target time for starting of ARMV from Single exist siding is 25 min in both day and night.
Target time for turning out ARMV from Double exist siding is 15 min in both day and night.
Max speed of ARMV will be sectional speed.
First Priority for moving will be given to ARMV then ART.
Hooter
After Accident hooter will blow for 45 seconds.
Difference between two hooter is 5 seconds.
To cancel previous message Hooter of 90 seconds will blow.
Hooter code is repeated after 5 min.
For cancellation of ART/ ARME - One long siren of 90 Second.
Time after 1 hrs of Accident is called Golden Hour.
Serious Accident
1) If loss is more than 2 crores.
2) if there is human life loss
3) Very serious injury
Five types of accident
1. Train Accident
2. Yard Accidents
3. Indicative Accidents
4. Equipment failure
5. Unusual Incident.
A B C D E - Train Accident + Yard Accident
F, G,H - Indicative Accidents
J,K,L,M - Failure of Equipment.
N,P,Q,R - Unusual Incident.
Class A - All types of collisions
Class B - Fire and blasts
Class C - LC gate Accidents
Class D - All types of Derailment
Class E - Collision on obstruction on passing over obstruction or passing over obstruction but safe.
Class F - Averted Collision Cases( Indicative Accidents)
Class G - Breach of Block Rule ( Indicative Accidents)
Class H - Train pass at danger( Indicative Accidents)
Class J - Failure of Engine
Class K - Pway Failure
Class L - Electrical failure
Class M - All S&T failures.
Class N- Train wrecking
Class P - Passenger Casuality
Class Q - Other Incident
Class R - Miscellaneous
ART has 30 sets of 5W VHFs
SPAD is the example of indicative Accidents.
All kind of Equipment failures , level of enquiry - Senior supervisors of respective departments
ART-
As per accident manual, target time for starting ART is 30 min in Day.
In the night it is 45 min.
Max speed of ART is 100 Kmph.
Inspection schedule equipment in ART by ADSTE/ DSTE - Quarterly once
ARMV( Accident Relief Medical Van)
Target time for starting of ARMV from Single exist siding is 25 min in both day and night.
Target time for turning out ARMV from Double exist siding is 15 min in both day and night.
Max speed of ARMV will be sectional speed.
First Priority for moving will be given to ARMV then ART.
Hooter
After Accident hooter will blow for 45 seconds.
Difference between two hooter is 5 seconds.
To cancel previous message Hooter of 90 seconds will blow.
Hooter code is repeated after 5 min.
For cancellation of ART/ ARME - One long siren of 90 Second.
Time after 1 hrs of Accident is called Golden Hour.
Serious Accident
1) If loss is more than 2 crores.
2) if there is human life loss
3) Very serious injury
Recommended gradient in Station yard - 1 in 1200.
For New works
Any infringement from Schedule of Dimensions requires sanction of CRS.
Installation of Signals on Right Side - Approval of PCOM required (Special Instructions).
Clubbing of Two signals- Approval of CRS is must. (Approved Special Instruction)
Maximum height of low level platform- 455 m.
Stipulated days for completion of accident inquiry at zonal level - D +7 days.
D+90 days = DAR against officials held responsible to be completed.
CRS will submit enquiry report to
1. Railway Administration
2. Railway Board
3. Other commissioners of Railway Safety.
If CRS or CCRS is not in a position to enquire serious Accident, enquiry should be done at least by JA grade officers inquiry committee with DRM as accepting authority subject to review by CSO.
All Collision A1 to A4 - Committee of SAG officers, GM accepting authority.
Consequential unmanned LC gate Accidents shall be enquired by committee of Junior scale officers.
Manned LC gate Accidents- JAG OFFICERS Committee.
All Yard Accidents- Sr Supervisors, SrDSO accepting authority.
All case of equipment failure- Sr Supervisor level.
Distance from wall - 1 m
Post 10-
Minimum distance centre to centre of tracks.
I) For existing works - 4265 mm
II) For new works/ additions to existing works - 5300 mm
Minimum horizontal Distance from centre of track to any structure-
For Existing Works- 2135 mm
For new works/ additions to existing works - 2360 mm
Maximum Steepest Gradient in Station yard
A) Existing Works - 1 in 400
B) For new works and alterations to Existing Works-
Recommended gradient- 1 in 1200
Maximum ( steepest) gradient - 1 in 400
Steeper than 1 in 400 and upto 1 in 260 - CRS permission required
Steeper than 1 in 260 - Railway Board permission through CRS
For above purpose, a Station yard means:-
Station yard will be taken to extend-
i) On Single line to a distance of 50 m beyond stock rail joint of outermost points at either end of station.
ii) On Double line where multiple aspect of signaling is provided to a distance of 50 m beyond stock rail joint of outermost points. In the absence of point, from BSLB to LSS of each line.
For any deviation from SOD in new work, CRS sanction is required.
No part of signal without route indicator shall normally be higher than 5.2 m above rail level.
13 mm - Difference of wheel diameter between wheels of two adjacent axles of the same trolley for goods should be within 13 mm
POST- 12
System integrity testing( SIT) - This is a complete testing involving both indoor and outdoor signalling equipment for functional working and safety.To be done in a new installation, at every interlocking alteration or periodically once in five years.
POST--13
ATP( Automatic Train Protection)
Features of ATP are
1) Detection and Prevention of SPAD.
2) Cab Signalling with display of movement authority, target distance, speed and signal aspect.
3) Continuous train control
4) Prevention of speed restriction.
5) Detection of roll back
6) Blowing horn while approaching LC gate.
Track Side Equipment of ATP
a) RFID Tag
b) Stationary unit
c) Radio
As per RDSO Specification, RFID tag shall have minimum ingression protection level of IP 68.RFID tag is passive device.
Maximum distance between two normal tags in Block Section is 1000 m.
RFID tag provides specific static information to Loco kavach
On board Equipment of ATP
a) On Board Computer ( OBC)
b) RFID reader consisting of two RFID Reader in hot standby.
c) Driver Machine Interface( DMI), indications and non-resettable counters.
d) Loco radio units consisting of two Radio Modems in hot standby with seperate cables and antenna for each radio.
e) Pulse Generators( Speed Sensors)
f) Train Interface Unit ( TIU)
g) Interface to existing brake controls application of Normal/service/emergency brakes or interface to existing brake system directly.
h) Power supply arrangement.
I) Suitable Isolation arrangement for isolating the system.
KMS
KMS used for security of radio communication between stationary KAVACH and Loco Kavach. KMS is Key Management System.
In TPWS , movement Authority is updated at Balise locations.
RFID - Radio frequency identification
GPS
Purpose of GPS in Kavach System is Time Synchronisation of all molecules.
Important Information -
Station Kavach communicates with NMS through E1 interface.
In kavach LC gate Tag on main line is placed at 600 m distance before approach of LC gate for automatic whistling.
Movement Authority generated by Stationary KAVACH.
TCAS is designed two out of two Hardware with identical software.
Station TCAS and LoCo TCAS communicates with each other for every 2 second
Loco has two antennas, GPS antenna and radio antenna
Station TCAS has also two antennas, GPS antenna and radio antenna.
Signals are connected with station TCAS only.
There will be two RFID tag at one place.
There will be two RFID tag reader, one in front other in back in loco.
Movement authority -
Distance upto which the train is permitted to travel safely
Record of critical events need to be stored for 90 days.
TPWS has total 40 packets for track to train transmission.
Input data fed to OBC of LOCO TCAS through DMI is
1. Length of train
2. Wheel diameter
3. Deceleration factor
Stationary TCAS transmits data on F1 frequency.
Frequency used in TCAS
441.8 MHZ
456.8 MHZ
416.8 MHZ
466.8 MHZ
426.8 MHZ
Communication between Stn kavach and Loco Kavach - 1024 bits.
F0 freq - Loco kavach transmits in Block Section and in emergency it transmits
SOS,head on collision, rear end collision.
For sending SOS message - press SOS button and common button together
LTe modem - 24 v DC, 110 v AC
Stn kavach to NMS - E1 INTERFACE
LOCO Kavach- NMS- GSM interface
Stn Kavach - 6 RIU
OVRD mode - Allows Loco kavach to pass Signal in ON Aspect.
PTRIP mode - Operted after SPAD condition for Loco kavach
PSR- Permanent Speed restriction
TSR- Temporary Speed Restriction
EB - Emergency brake
FSB - Full Service Brake
Kavach- Max 250 kmph.
Communication Range in TCAS is 1.5km normally and in double distant terroritary, it is 4.5 kms
TCAS is ETCS level 2
TPWS has total 38 types of packets.
X tags provided at yard exit.
Loco kavach to NMS - GSM Interface
Vital computer - 24v or 110 v DC
SSP in Kavach - Static Speed profile
Duplicate RFID tag - 3 to 5 m
RFID tag marker-
1. RFID number
2. Type
3. Absolute location
Stn kavach to NMS - 5 to 7 Stn kavach in one E1 ring.
POST--17
ATP( Automatic Train Protection)
Features of ATP are
1) Detection and Prevention of SPAD.
2) Cab Signalling with display of movement authority, target distance, speed and signal aspect.
3) Continuous train control
4) Prevention of speed restriction.
5) Detection of roll back
6) Blowing horn while approaching LC gate.
Track Side Equipment of ATP
a) RFID Tag
b) Stationary unit
c) Radio
As per RDSO Specification, RFID tag shall have minimum ingression protection level of IP 68.RFID tag is passive device.
Maximum distance between two normal tags in Block Section is 1000 m.
RFID tag provides specific static information to Loco kavach
On board Equipment of ATP
a) On Board Computer ( OBC)
b) RFID reader consisting of two RFID Reader in hot standby.
c) Driver Machine Interface( DMI), indications and non-resettable counters.
d) Loco radio units consisting of two Radio Modems in hot standby with seperate cables and antenna for each radio.
e) Pulse Generators( Speed Sensors)
f) Train Interface Unit ( TIU)
g) Interface to existing brake controls application of Normal/service/emergency brakes or interface to existing brake system directly.
h) Power supply arrangement.
I) Suitable Isolation arrangement for isolating the system.
KMS
KMS used for security of radio communication between stationary KAVACH and Loco Kavach. KMS is Key Management System.
In TPWS , movement Authority is updated at Balise locations.
RFID - Radio frequency identification
GPS
Purpose of GPS in Kavach System is Time Synchronisation of all molecules.
Important Information -
Station Kavach communicates with NMS through E1 interface.
In kavach LC gate Tag on main line is placed at 600 m distance before approach of LC gate for automatic whistling.
Movement Authority generated by Stationary KAVACH.
TCAS is designed two out of two Hardware with identical software.
Station TCAS and LoCo TCAS communicates with each other for every 2 second
Loco has two antennas, GPS antenna and radio antenna
Station TCAS has also two antennas, GPS antenna and radio antenna.
Signals are connected with station TCAS only.
There will be two RFID tag at one place.
There will be two RFID tag reader, one in front other in back in loco.
Movement authority -
Distance upto which the train is permitted to travel safely
Record of critical events need to be stored for 90 days.
TPWS has total 40 packets for track to train transmission.
Input data fed to OBC of LOCO TCAS through DMI is
1. Length of train
2. Wheel diameter
3. Deceleration factor
Stationary TCAS transmits data on F1 frequency.
Frequency used in TCAS
441.8 MHZ
456.8 MHZ
416.8 MHZ
466.8 MHZ
426.8 MHZ
Communication between Stn kavach and Loco Kavach - 1024 bits.
F0 freq - Loco kavach transmits in Block Section and in emergency it transmits
SOS,head on collision, rear end collision.
For sending SOS message - press SOS button and common button together
LTe modem - 24 v DC, 110 v AC
Stn kavach to NMS - E1 INTERFACE
LOCO Kavach- NMS- GSM interface
Stn Kavach - 6 RIU
OVRD mode - Allows Loco kavach to pass Signal in ON Aspect.
PTRIP mode - Operted after SPAD condition for Loco kavach
PSR- Permanent Speed restriction
TSR- Temporary Speed Restriction
EB - Emergency brake
FSB - Full Service Brake
Kavach- Max 250 kmph.
Communication Range in TCAS is 1.5km normally and in double distant terroritary, it is 4.5 kms
TCAS is ETCS level 2
TPWS has total 38 types of packets.
X tags provided at yard exit.
Loco kavach to NMS - GSM Interface
Vital computer - 24v or 110 v DC
SSP in Kavach - Static Speed profile
Duplicate RFID tag - 3 to 5 m
RFID tag marker-
1. RFID number
2. Type
3. Absolute location
Stn kavach to NMS - 5 to 7 Stn kavach in one E1 ring.
POST --18
Codal life -20 years
DSU ( Digital Scanner Unit)
Each DSU contains 8 no of digital input cards. These scanner cards contain opto couplers and multiplexer.
Each input card - 64 Inputs
Total input capacity of one DSU unit is 512 inputs (inbuilt)
Display of digital inputs in 32 row 16 column display.
Maximum 7 nos additional DSUs can be can be connected to the system so digital input capacity is 4096.
All this digital inputs are scanned at rates of 16 m sec.
ASU ( Analog Scanner Unit)
ASU contains maximum 3 nos of Analog input cards. Each input card can be connected with 8 nos of Analog Inputs. Total input capacity of the ASU is 24 Analog input channels. Maximum 4 nos of ASUS can be connected to the system.Analog input channel capacity of the system is 96. All these Analog inputs are scanned at rate less than 1 sec.
RS 232 Serial Ports
At least 6 serial communication ports are provided for communication with other dataloggers, Central Monitoring Unit, Remote Terminal Unit,EI system, IPS system etc.
Power Supply
Normally 24V DC supply with battery backup is required for the system working.It can be given through DC DC converter of IPS or through SMPS charger with 80 AH battery with back up of 4 to 6 hours.
Storage - 10 Lakhs
Features
On line Relay status
On line faults
On line simulation
Remote monitoring of stations with help of stations with help of networking.
Inbuilt room temperature sensor
Software Objectives
Predictive Maintenance
Easy identification of failures
Crew discipline
Train charting
Data Transmission Speed between two data loggers - 57.6 kbps.
Data logger CMU -
Graphical user interface ( GUI) to retrieve data from all networked data logger.
Max distance between Datalogger and RTU connected to it - 3 km.
Signal Bobbing -
The time difference between ON ECR ( up to down to UP) is between 500 ms to 2 second, which should be counted as one and for satisfying the fault logic 2 to 3 times within 10 second.
Track Bobbing -
The time difference between TPR ( Up to Down to Up) is in between 50 ms to 1 second which should be taken as 1 count. For fault logic 2 to 3 counts should happen within 10 second.
Point Bobbing -
The time difference between NWKR/RWKR ( up to down to UP) is between 500 ms to 2 second, which should be counted as one and for satisfying the fault logic 2 to 3 times within 10 second with TPR up.
Point Burst -
The train arrives on tracks proving the sequence of track DN and Point setting in unfavorable position and then NWKR and RWKR both down for 120 second.
POST-19
For Existing Works-
Horizontal Distance of any fixed structure (upto 305 mm height), from centre of track - 1675 mm
From 305 mm to 4520 mm - 2135 mm.
Max height of any signalling gear between track lines - 64 mm.
SOD of the Signal -
SOD of a signal is measured from outermost part of the Signal.Outermost point is generally ladder.
For new work-
Rail level to 305 mm above rail level -1905 mm.
From 305 mm to 1065 mm - 2360 mm.( Distance of Signal Post from centre line of track)
From 1065 mm to 3735 mm - 2360 mm.
If implantation is correct,it should be written in Black colour with white background.
If implantation is less,it should be written in Red colour with white background. As per new SEM,if implantation is less,signal should be painted with alternate Red and White stripes at Loco pilot's eye level (3.65m),showing an arrow towads infringing track.
Signal post on platform- 4720 mm
Existing yard-
gradient is steeper than 1 in 400 and upto and upto 1 in 100 - Permission of GM through PCSO is required
If gradient is steeper than 1 in 100 - Railway Board through CRS.
New yards or New Work -
In Station Section, Maximum Gradient recommended is 1 in 1200.
For Single line, Station yard will be extended to a distance of 50 m beyond outermost points at either end of the station.( For purchase of maximum gradient Permitted).
In block section, Steeper than 1 in 400 and upto 1 in 260 -CRS
If steeper than 1 in 260 - Approval of Rly board required
For the purpose of Maximum gradient permitted in Station yard as per SOD, on a single line,a Station yard will be taken to extend to a distance of 50 m beyond outermost points at either end of the station.
1600 mm - Horizontal Distance of point machine
2500 mm - Normal implementation of OHE mast
POST- 20
Fully Charged lead acid Cell Voltage - 2.2 V, Gravity - 1220+/- 5
Discharged lead acid Cell Voltage- 1.85 V, Gravity - 1180+/- 5
Elctrolyte -Dilute Sulphuric Acid
Positive Electrode - PbO2, Negative Electrode - Sponge Pb
Input Voltage of SMR- (160-270) V AC
Initial Charging Voltage - 2.7 V/Cell
Initial Charging Current- 4% of capacity
Float Charging Voltage - (2.12-2.3) V/Cell
Boost mode equalizing charging - 10% of AH Capacity
In RE area-
Safety factor -1.5
Safe handling voltage - 400 V
Induced voltage in underground unscreened cable
1) On a single line section -for the catenery current of 800 Amps is 116 v/ km.
2) On a Double line section- for the catenery current of 1000 Amps is 95 v/ km
2 m from contact wire - iron mess required
Iron mess - separate earth less than 10 ohms.
Height of contact wire - 5.55 - 5.75 m from rail level
2360 mm is distance for signal implantation and OHE mast also
Contact wire and catinary are parallel
Height of Red Aspect -3.65 m.
Quad cable is jointed at every km and every joint should be connected with earth.In case of signalling cables , Armour is earthed in every location box,where it is terminated.
The minimum distance between two working earths must be 3 meter from each other.
Do not connect the Earthing of any block Equipment with any earth provided for other gears.
Induced voltage is normally AC.Earth return voltages are generally DC.
Do not open keep common battery set for two or more block Equipments.
Do not open the Earthing and connection of any part of block filter unit.
Ensure continuity of Earth bond before opening any insulation joint.
Ensure that max length of track ckt is within limit.
Provide B type choke at both feed and relay ends.
Do not disconnect any OHE bond provided on Single rail track circuit.
Approx 10 V AC will induce into 100m track circuits.
Cross bond is provided at 100m distance in Station Section and at 400m distance in block section.
In screened cable, two or three layers of metallic Armours are used. Due to this,Any induced voltage in Armour is not likely to reach the copper conductor but cost of the cable will also increase.It protects 50% of induced voltage.
In unscreened cable only one layer of metallic Armour is used and Earthing provided at Armour.Cost of unscreened is less compare to screened cable.Now a days only unscreened cables are used in signalling.
Only 6 quad is screened cable used in Railway and three layer Earthing is used.Currently used 6 quad is unloaded and unbalanced cable.
Depth of Discharge-
There is a limit laid down on extant of discharge which is known as DOD.
Permitted DOD
Flooded type Lead Acid cell - 70%
LMLA cell - 80%
VRLA cell - 50%
Capacity of Cell = (Load current × Backup time Permitted)/ DOD Permitted
Initial charging and boost charging - Constant current
Status Monitoring panel in IPS -
At 50%DOD - Start Generator
At 60%DOD - Emergency Start Generator
At 70%DOD- System Shut Down( System feed will cut , INVERTER Output will cut, but all DC DC converters continue
No of Modules for internal 24 V = n+2
No of modules for Relay external 24v or 60 v = n+1
As per RDSO Specification IRS: S 88/2004 Version 1.0 for LMLA cells - Frequency of topping shall not be earlier than six month.
LMLA battery to be charged with constant current.
As per RDSO Specification IRS: S 93/96,VRLA batteries shall be charged at a constant voltage of 2.25 V.
The current rating of Battery Charger= Load current+ AH/10 capacity of cell
As per ACTM para 16.4 to 16.5 of Appendix I
A) If any portion of a signal Post or its fitting falls within 2 meters of a 25 KV live conductor, or any it's metal part, such portion shall be protected by an iron screening solidaly connected to the structure.
If not, a Caution board shall be provided on the signal post at a height of 3 meters above rail level to caution the staff.
Normal height of contact wire is 5.60 m at support.
In tunnels and underneath bridges, contact wire may be as low as 4.58 m.
Normal height of catenary at its highest point is 7.05 m.
Maximum permitted length of direct feed of signal shall be as mentioned below -
Single track - 180 m
Double track - 220 m
In RE area,
with uncreened cable, max permissible length of parallelism of DC Circuit using QNA1/ QNNA1 line relay shall be restricted to 2.8 kms for Double line and 2.1 Kms for Single line.
Distance between The Signal and Mast in front of it - 30 meters
Minimum distance between RE mast and any signal -10 m
SGE lock and block Block Equipment suitable for RE territory.
TLB Block Equipment not suitable for RE territory.
Neutral Section -
Warning board before Neutral Section is placed at 500 m and 250 m in Advance.
700 m - Minimum Clearance of Signal Post or its fitting from live OHE conductor during the 2.2 KV anti theft measure charging.
910 m - Maximum distance between between point contractor and point machine( AC immunity 160V) in Single line RE Area
1100 m - Maximum distance between between point contractor and point machine( AC immunity 160V) in Double line RE Area.
1.5 - factor of safety
Vertical clearance from OHE - 320
Horizontal clearance from OHE - 270
In RE area
Single line - NTI,FM TYPE DADO ,UFSBI used
Double line- DLBI
Internal resistance of secondary cell - Shall not more than 2 ohms
Normal Working Voltage of RKT is 3.75 V DC.
When the current drawn by battery less than 3 to 7.5 percent of set charging current and voltage less than 2.4 v/ cell - Charger automatic goes to float.
Permanent magnet DC motor used in ELB.
Internal resistance of a secondary cell shall not be more than 2 ohms.
Power factor = True power/ Apparent power.
In Automatic battery charger,automatic changeover from Float to boost mode by sensing battery current.
Material in grid of maintenance free Lead Acid Battery is Lead Calcium alloy.
72 m - Normal distance between RE Masts on straight track .
By adding choke we can increase length of Track Circuit by 30 m.
POST--22
Resetting -
1. Block Section/ Auto/IB Section-
Preparatory Reset by both side ASMs.Will show clear only after matching 'count in ' and 'count out’ with passage of train.
2. Main Line/ Run through line-
Preparatory Reset by on duty ASM only. Will show clear only after matching 'count in ' and 'count out’ with passage of train
3. Point zone/ loop line/siding -
Conditional Reset by on duty ASM and another operating staff. Will show immediately clear after operation.
As per RDSO Specification, life of Digital Axle Counter shall not be less than 20 yrs
POST--23
IB Signal -
IBS is an arrangement made for increasing the section capacity by splitting of a relatively long block section into two portions namely Rear Section and Advance Section by placement of IBS at near mid of two block sections.
IB is used where distance between two block sections is equal or more than 10 kms.MSDAC is possible in IB Section.
IB signal should not be placed if Gradient is steeper than 1:80.
In case of IB signal, Separate set of ATs shall be provided,with automatic Changeover switch.
Rear Section i.e. " Station Controlled Intermediate Block Section" starts from LSS of rear station and ends at IBS including 400 m block overlap in that direction.
Advance section i.e. " Block Controlled Intermediate Block Section" starts from IBS and ends at Home Signal of Advance Station including block overlap in that direction.
Track sections in both Rear and Advance Section are monitored either by Axle counter or Track Circuit.
Train entry into Rear Section is controlled by LSS of rear station in that direction.
Train entry into Advance Section is controlled by IBS in that direction.
IBS block overlap of 400 m shall be seperately monitored.
Provision must be there to indicate that train has passed IBS at ON position.
Control of IBS lies with SM of station in rear.
A signal post telephone( SPT) or any approved type communication shall be provided with station in rear.
Resetting Operations in IBS-
Two types of resetting Operations
a) When a train passes IBS at ON position/ blank
b) When Axle counter fails. (PB 2 and PB 3 push buttons are used)
IBS system will permit only one train in the entire block section, when a train passes IBS at ON position or axle counter is not clear even after passage of train beyond axle counter section.
Procedure to be followed by Loco pilot to pass IBS at ON as per GR 3.75
a) If phone communication is available between IBS and rear section - Loco pilot shall stop his train in rear of IBS and contact SM of rear station on SPT, then pass the defective IBS,if authorised by SM.
b) If phone communication is not available between IBS and rear section - Loco pilot after waiting 5 min, can pass IBS at danger at a speed not more than 20 kmps. He shall be able to reduce speed to 8 Kmph in case of inadequate visibility.
Loco pilot will maintain restricted speed till he reaches advance station.
IBS in Double Line
1) IBS should be Interlocked with any of the approved means of block working for double line.
2) IBS should not be taken off unless line clear has been obtained from block station in advance.
3) DLBIs/ Block panel of BPAC etc pertaining to monitoring of advance section are placed at the rear and advance stations.
IBS in Single Line
1) Provision shall be there to establish direction of trafic for IBS in single line.
2) First direction of trafic shall be established and then line clear shall be obtained from Block station in Advance as per the established direction of trafic.
3) IBS shall not be taken off unless the line clear has been obtained from block section in Advance and direction of traffic is established.
4) IBS should be Interlocked with any of the approved means of block working for single line.
Note - IBS shall not be provided in a block section with steep falling gradients, unless the brake power is adequate to enable the trains being stopped at IB signal.
Boundaries of Track Section
(I) AS track section, which starts from the foot of LSS and ends at 400 m ahead of IB home signal.
(II) IB track section,from the foot of the IB home signal to 400 m ahead of the IB signal.
(III) BPAC section, from foot of the IB home signal to 180 m ahead of home signal of Advance Station.
In IBS with HASSDAC, the Axle Counter Evaluator equipment for second block section is provided at both the ends.
IB telephone is connected to rear station only.
IB is classified as class C station.
While passing IB signal at night ,speed must not be more than 8 kmph.
GR 3.75 - Procedure to be followed by Loco pilot to pass IBS at ON
POST --24
Earth is a Equipotential surface.
All power equipments along with suitable SPDs are to be connected to Earthing having earth Resistence less than 1 ohms.
LPZ ( Lightening Protection Zone)-
Outer Zone
LPZ 0- Zone where the threat is due to unattenuated lightening electromagnetic field.
LPZ 0 is sub divided into
LPZ 0A- Zone where threat is due to direct lightening.
LPZ 0B - This Zone is protected against direct lightening. Internal system will be subjected to partial lightening surge current.
Inner Zone -
Area inside structure
LPZ 1-
Zone inside structure where magnitude of surge current is reduced due to multiple parallel paths and isolating surfaces and or by installing SPDs.
LPZ 2..n -
Zone inside structure where magnitude of surge current may further reduced by current distribution and isolating surfaces and or by installing SPDs.
Surge Protection Device -
Class A -
This is provided with an external lightening conductor on top of the building, connected through a down conductor to ground ( Earth). By this arrangement 50% of lightening energy is connected to ground.
Class B - ( Stage 1 Protection)
Provided at input of Power Supply equipment.
(Power line protection at distribution level) against Lightening Eletro - Magnetic Impulse ( LEMP) & other higher surges provided at power distribution panels.
This is the first stage of protection provided before the equipment at mains distribution panel is called class B type.This device is spark gap type and operate on arc chopping principle and designed to handle pulses of 10/350 micro seconds.
It can handle 100Ka current between Neutral and Earth.
50 Ka current between all three phases and neutral.
It is provided with a 63 Amp fuse in phase line.
Class B SPD is connected between all three phases and the neutral also between neutral and earth.
Max protection is less or equal to 2.5 kv.
Class C- ( Stage 2 Protection)
(Power line protection at Equipment level)
This is second stage protection. This type of protection is provided against low voltage surges at equipment input level connected between phase and neutral.
This device is single high capacity variable ( MOV) which has following additional features.
Failure Indication when device failed.
Thermal disconnection of device when it starts having high leakage current due to aging/ handling several surges.
Potential free contact for remote monitoring
A number of MOVs in no case to be provided in parallel.
MOV is surge suppressor.
Response time of Class C is less than 25 n seconds
Class D- ( Stage 3 Protection)
Provided at Indoor and field equipment.
Protection for power/ Signalling/ data lines
All external power/ Signalling/ data lines (AC/DC) shall be protected by using class D type SPD. It consists of Varistors/ Suppressor diodes and Gas discharge tube with voltage and current limiting facilities.
Note- if power/ Signalling/ data lines ( AC/ DC) are carried through overhead wires or cables above grounds to any nearby building or any location outside equipment room,additional protection of Class C type shall be provided at such locations for power supply lines and Class D type for signal/ data lines.
MOV and Gas discharge tubes are used in Class D protection.
SPD in IPS-
IPS is provided with class B and Class C, two stage protection. Coordinated type B and C arrester shall be provided in a separate enclosure adjacent to each other in IPS room.This enclosure should be wall mounting type.
EI shall be shall have provision of accomodating 15% of I/Os in future.
During the alterations of stn yard only Application logic will be changed.
Capacitor microphone and carbon microphone require polarizing voltage.
Ribbon, Dynamic and Crystal microphones do not require any external voltage
All object controllers are connected through OFC only to EI.
Executive Software of an EI system is common to same model of same OEMs.
Changeover of EI system shall be done from Main to Hot Standby and vice versa once in Monthly under supervision of Sectional SSE/JE.
In an EI system, Protocol Converter is used to interface between EI and Datalogger.
Vital Output of EI -
Signal - HR, DR, UGR, COHR,HHR
Point - NWR, RWR,PCR 1, PCR( Point power Control)
Crank Handle - CHYR
Siding Control - KLYR
LC gate - LXYR
Vital Input of EI -
Signal- DECR, HECR,RECR, CO_HECR, UECR
Point - NWKR, RWKR
Track Circuit - TPR
Crank Handle - CHCR
LC gate - LXCR
SMCR
Non Vital Input of EI
Signal - GN
Point - WN
Siding - KLN
Gate - LXN
Crank Handle - CHYN
All route buttons
Common point Buttons - NWWN, RWWN,EWWN
Signal cancel Button - EGGN
Route Cancel Button - EUUYN, EUYN
Slot Buttons- GSBN, GSRBN
Panel/ PC key
Non Vital Output of EI -
All the indications
Pre Commissioning check list of EI will be verified by field ADSTE/DSTE and countersigned by SrDSTE or Dy CSTE.
System Architecture-
Two out of two Hardware Architecture with identical hardware and identical or diverse software.
Important points of EI
1) Only approved application logic with specified checksum shall be used in the EI system and this data and checksum shall be version controlled and preserved by Railway
2) The input and output cables shall be twisted to minimize EMI and EMC effect.
3) EI system shall be installed closer to Operator Room, preferably adjacent room.Track crossing should be avoided between main EI system and operator room.
4) Clean and dirty wiring shall be clearly segregated and routed in different enclosures/ladders and where this is not feasible, a minimum distance of 150 mm between clean and dirty wiring shall be maintained.
5) If clean and dirty cables need the cross at any place, then wiring should be arranged at perpendicular to each other.
6) Indicative type surge protection devices of appropriate class and rating shall be installed for all copper based external interface ports.
7) The connectivity between EI and sub system like Control Terminal,Control panel and object controller shall be planned with OFC cable to avoid damage due to surge and lightening.The OFC shall be provided in redundant manner to avoid failure due to cut/ damage in one location/ path.
8) Executive Software of an EI system is Common to same model of same OEM.
9) Changeover of EI system shall be done from Main to Hot Standby and Vice Versa once in on Month under Supervision of Sectional SSE/JE when there is no train movement.
10) Protocol Converter is used as interface between EI and Datalogger.
150 mm - Distance between clean and Dirty cables in EI installation.
3m - Minimum distance between two earth pipes.
Object Controller ( OC)-
Object controller is the equipment which drives the field function through conventional relay or directly through its own electronic circuitry.It also takes input from field.
Object controller are used as slave unit of Main system.
OC and Main system can be connected by copper cable or OFC or wireless.
Both Hardware and Software of Object controller must meet SIL 4 standards.
OC should be placed at maximum distance of 15 Kms from CIU.
Each OC is independent from Other.
Hardware used in EI -
Input cards - All the field relay contacts are connected to these input cards.
Field inputs - ECRs,TPRs,NWKRs etc
Panel inputs - GNs, UNs, NWN, RWN etc
Read back inputs - HR DR WNR WRR
Opto couplers are provided to isolate field optically from the system in input cards.
Processor Card -
Called central processing unit card of the system.
Provided with microprocessor,RAM,ROM,EPROM,EEPROM memory etc.
System software consists of the following
1) Executive Software programmed in system EPROMs
2) Application Software programmed in Data EPROMs.
During EI alteration Data EPROMs are to be replaced with new Data EPROMs as per new table of control.
For EI alterations EI Complier software is used.
Executive Software-
Common to all EIs for the same company manufacturing
Factory installed software
Cut off Vital supply voltage to output relays in case of unsafe failures.
Application Software -
Specific for each station.Different for different stations.
As per table of control of specific station.
Can be installed at site by signal engineer.
Vital Output -
DR HR WNR WRR CHYR KLR LXYR
Vital Input -
DECR HECR RECR UECR Co HECR NWKR RWKR TPR KLCR LXCR
Non Vital Input -
GN UN WN CHN LXN
Non Vital Output -
DGKE HGKE RGKE
EI shall have provision of accomodating 15% of I/Os in future.
No of physical ASR Relay is zero in EI.
As per RDSO Specification in big yards MTBF of all vital modules shall be more than 1 Lakh.
RDSO Specification for EI in big Yard ( More than 200 routes) - RDSO/SPN/203/2011
System availability ( operational Availability of Complete system) shall be 99.98% or better.
AC may be provided in PI/RRI having more than 100 routes.
FAT-
Performed with computer Simulation
Control table ( including Negative Testing)
Cross table ( Also known as Square sheet testing)-Conflicting movement testing.
SAT -
Logic and interlocking Testing:
1. Control table ( including Negative Testing)
2. Cross table ( Also known as Square sheet testing
Table )
Interface and Equipment function test
1. Intercommunication test between sub racks
2. Correspondence test.
EI system back up data of Minimum 10 lakhs or one month data.
TSAA - Technical System Application Approval
Both Cyclic time and response time must be less in EI system.
As per GOI RB letter 2021/ Sig/ 25 - Conf/5/ SSC dated 26.05.2021
Upto 100 routes - Centralized/ Distributed EI Can be provided with approval of CSTE.
100 to 500 routes -Distributed EI
More than 500 routes - RRI with Metal to Metal or Distributed EI
TSAA upto 200 routes - PCSTE approval required. TSAA must be prepared as per TAN.
Power Supply Arrangement for EI-
1) Input 110 V DC from IPS room to EI rack shall be provided with duplicate cable so that voltage drop is less than 1 volt.
This 110 v DC is directly given from EI to battery.
110 DC is connected to reliable UPS recommended by OEM,to get 50 V DC or 24 V DC or any other desired voltage by OEM.DC DC Converters shall be used in N+1 Configuration.
Reliability Parameters-
1.MTBF
2.Failure Rate
3. Failure probability .
Maintainability Parameters-
1. MTTR
2. Time for replacement
3. Time for preventive maintenance
Warm Standby Arrangement of EI - Only one system will switch on.
In EI system RTC of CPU system should be updated with external data logger.
NWR and RWR connected to read back.
10 Second- Time taken in EI to take longest route and display lowered signal
POST--25
Earth Resistance
Earth Resistance of an earth is sum of three separate resistances
a) The resistance of the conductor joining earth electrode to the installation.
b) The contact resistance between the surface of the earth electrode and the soil
c) Resistance of the body of soil surrounding the earth electrodes.
The first two resistances are negligible compare with third.
So resistance of the earth is primarily depends upon nature of soil and not by electrode itself.
d) Material used for a standard electrode system should be corrosion resistant.Under ordinary soil conditions, use of galvanized iron or mild steel electrode is recommended.
If soil corrosion is likely to be excessive, it is preferable to use either copper or copper clad electrode.
The electrode shall be free from paint,enamel or greese.
e) Earth tester normally used for measurement of earth resistivity comprises of the current source and meters in a single instrument and directly read the resistance value.
Resistivity of soil when checked by megger.
then resistivity of soil P= 2Ï€SR= 2*22/7*S*R
P = Resistivity of soil in ohm meters
S= Distance between successive electrodes in meters
R= Megger readings in ohms.
Regular Checks of Earth
1) Block earths and their connection shall be examined at intervals of not more than 01 month by JE/Signal and not more than 03 months by SSE/Signal incharge.
2) Block earths shall be tested for Resistance at intervals of not more than 12 months by Sectional JE/SSE.If the Resistance is more than 10 ohms, action shall be taken to reduce Resistance by providing additional earths in parallel.
(1) Rocky soil has high resistivity
(2) Resistivity of dry ground is more compare to moisture.
(3) Resistivity of cold ground is more compare to warm ground.
(4) Igneous rocks are more resistive compare to minerals.
(5) If we add salt content,Resistivity of soil reduce.
Resistivity of wet, moist and dry soil is 10,100,1000 ohm/meter.
All choose the soil with less resistivity.
Earth Resistance of the rod
R= 0.75× o/L if 25 <L/d <100
= o/L if 100 <L/d <600
= 1.2 × o/L if 600<L/d <3000
o = Resistivity of earth in Ohm.m
L= Length of the electrode in m
d= Diameter of the electrode in m
While Earth testing distance between Main earth and P2 electrode must be 50 to 100 ft. Similarly distance between P2 and C2 must be 50 to 100 ft.
Depth of additional two rods must be 30 to 50 Cm.
Top of the earth should be 30 cm above ground.
The electrode shall be directly driven upto depth of at least 2.5 m.If a rock is encountered at a depth less than 2.5 m,the electrode can be inclined by upto 30 degree from vertical.
Minimum seperation between two earths - 04 m as per telecom manual.
As per TAN of Earthing,
1) distance between Earth Electrodes shall not be less than 3 meter and not more than 6 metres.
2) Earth pit shall be installed 01 m from building wall.
3) Distance of 30 m shall be maintained between electrical earth and SnT Earth.
Minimum Clearance of equipment earth from earth of AT/ transformer should be 20 m.
Artificial treatment of Soil to reduce Resistivity-
A Earth pit of dia is 600 mm and depth is 2.5 m is to be formed. This pit shall be filled alternatively with layers of common salt and charcoal. Each layer of about 2.5 cm thick,upto height of about 20 cm from ground level.
Qty of salt = 1/200 of soil removed from pit.
For future improvement Calcium chloride and Sodium carbonate can be added
POST--26
All roads should be preferably cross the Railway line at Right angles. In special cases,when modification is required to suit the Road approaches, the angle of crossing should not be less than 45 degree.( pway manual =906).
Minimum width of Road- Special class -7.5 m,others -5.5 m
OHE Height of contact wire - 5.50 mts to 5.75 mts from Rail level.Under bridge it is 4.65 m.
This height can be reduced to 4.54 m if carriage department certifies that no rolling stock above 4.27 m height will move on that line
All interlocked level crossing gates should be kept 'Normally open to Road traffic’.( pway manual =907).
Periodical census once every three years. This shall be carried out for 7 days by Engg,traffic and SnT.
Train/ Four Wheeler/ Bullock Cart/Tonga - 01 unit.
Cycle Rikshaw/Auto Rikshaw - 0.50 unit
Spl class gates- TVU more than 50000
A Class gates- TVU 30000-50000 or Line Capacity utilization is 80% ( on Single line section) and no of Road vehicles more than 1000.
B Class gates - TVU 20000-30000., B class is further divided into two two sub groups
B1 Class - TVU from 25000 to 30000
B2 Class - TVU from 20000 to 25000
C class gates - TVU less than 20000
Spl class, A Class and B class gates are normally open to Road traffic while C class are closed to Road traffic. If gate is in Station Section, it must be Interlocked irrespective of its class. Communication must be provided to every gate irrespective of its class. All the gates whose TVU is between 20000 to 50000 ( Class A and B),must also be Interlocked as per new SEM.
IF C class gate is in auto Section or sub urban, it must be Interlocked.
All the road signals should be of three aspects. Hooter will be kept in between red and yellow Aspect. Hooter must be connected with boom CB ( 10 to 80 degree). Height of boom must be between 0.8 metre to 1 metre. Stop board must be of Red color and written with white. Dia of this board is 600 mm. This board will be placed on both main as well as sliding barrier.
Color scheme of boom whether electrical and mechanical alternate yellow and black. Length of each yellow or black strip is 300 mm.
One major drawback of MLB is its can not be operated from more than 150 m. That's why gate lodge is made within 150m from gate.
Minimum distance of lifting barrier from centre of nearest track is 3.5 m Minimum.( As per new SEM).
Minimum distance of height gauge from çentre of track is 8 m.It's height is between 4.65 m to 4.70 m from Rail level.
When gate is open, boom must be 80 to 90 degree.In closed condition it shall be 0 to 10 degree.
When gate is closed .clearance between the road surface level and the boom shall be 0.8 to 1m.
In mechanical gates,winch shall be located not more than 150 m from the gate and having clear visibility of the Road.
Emergency Sliding Boom must be outside lifting barrier.
Counter should be provided for logging gate man's extraction of Emergency key to open LC gate.
Road signal must be outside the height gauge.
Dia of stop board is 600 mm and disc having red reflector/ luminous strip facing the road traffic. Boom shall be painted with alternate yellow and black strips for both ELB and MLB. Length of each strip is 300 mm.Stop board must be placed on sliding barrier also.
Minimum two power supply is required at gate. If DG is placed it must be of 10 kva and with auto Changeover.
Arching Zone -Arching Zone of 25 KV is 25 cm. If anyone come in arching Zone, there are chances of getting shock.
Neutral Section- Neutral section must be located away from stop signals,level crossing gates and shall be on tangent track on level to the possible. The distance should be preferably 1600 m away on Section with up gradient upto 1 in 300 and 2500 m with higher gradient. Neutral Section shall be located on level tangent at least 400 m after stop signal and 200 m before stop signal.Demarcation has been given to Loco pilot before 500 m for information and at 250 m for lowering the pentagram.
At LC gates in , Approach Locking to be provided due to continuous track circuit available. In other sections dead approach with 60 sec time delay to be provided.
At every manned LC Gate , there should be distinct indication at 600 m ( One detonator) and 1200 m ( 03 detonators at 10 m apart) on broad gauge on either side to guide gateman for placing detonators
Visibility of Road Signal - 180 m.
Distance of gate lodge from from centre of track is 6 m.
Limit Switch of ELB is actuated by Nylon 66 Cams.
Max Length of ELB boom - 9.76 m.
POST--27
As per new SEM, Minimum length of Track Circuit is 26 m( Two rail length)
Glued joint Insulation Resistance- Not more than 25M ohms in dry conditions and not less than 3 k ohms in wet conditions.
Glued joint are to be replaced after 250 GMT ( Gross million Tonnes) of Movement of Traffic.
Stray Voltage- not more than 10 m Volt track circuit upto 100m. 100mV for track circuit more than 100 metres.
Stray current-
Not more than 10 mA for TC upto 100 Mts.
Not more than 100mA for length of TC is equal or above 100 mts.
B type choke for 25 KV AC RE Area- 120 ohm impedence and 3 ohm Resistence.
QTA2 - pick up voltage 1.40 v , pick up current should be 140 mA.Minimum Excitation is not less than 125% of rated pick up voltage.Maximum Excitation is not less than 300% of rated pick up voltage for plug in type Track Relay. Configuration 2F1B.AC immunity is 50V AC.
QBAT - pick up voltage 1.75V, max pick up current should be 175 mA.Minimum Excitation is not less than 122% of rated pick up voltage.Maximum Excitation is not less than 235% of rated pick up voltage for plug in type Track Relay. Configuration 2F2B.AC immunity is 80 V AC.
All the track Relay are of 9 ohms.
Percentage of release of track Relay not less than 68%.
Track relay sensitivity depends upon percentage release.
Max Length of Track Circuit - In Non RE, Max length of TC is 1000 mts in block section and 670 m in Yard for both type of Sleepers.Normally QT2 is used but QTA2 or QBAT can also be used in both cases.
In RE Area Stn yard,if Sleepers are PSC, Max Lenth of TC is 350 metres for QTA2 track relay. Max length can be increased to 750 m by using QBAT track Relay.
In RE Area Stn yard,if Sleepers are Wooden,Max Length is 450 m.QTA2 relay used.
In RE Area Block Section Max Length of TC is 450 metres for both types of sleepers.QTA2 any can be used.
Minimum Ballast Resistance -
4 ohms/ km for Block Section
2 ohms/km for Yard Section
For RE , Non RE both, Any Sleeper
Maximum Rail Resistance- For RE and Non RE both,
TC length upto 700 m -1.5 Ohms/ km
TC length more than 700 m - 0.5 Ohms/ km
So that total rail Resistance should be on lower side in both the cases.
Dead Section- In big Yard there is portion where train can not be detected.Max length of dead Section is 1.8 m because motor trolley is the shortest train and its length is 1.8 m.
SRJ ( Stock Rail Joint) - Where stock rail of Point joints ( between first and second sleeper).This joint may be fish plated or welded. Distance of first Glued from SRJ is minimum 13 m but practically it can not be achieved at all places.However there is no issue of safety due to this.
Highest TSR - 0.5 ohms for DC track circuit and for AFTC outside their tuned length
0.15 ohms for AFTC at the tuned portion.
Important Points -
1) QSPA1 is the first repeater of QTA2 or QBAT relay.
2) For replacement track of Starter Signal, Glued may be placed 0 to 3 m from Starter and HR of the Starter will be made slow to release so that CSR can be maximum.
3) For replacement track of Home and Advanced Starter Signal, Glued may be placed at 13 m because there is no issue of CSR at these signals.
4) In case of berthing track having multiple track circuits sections,it is desirable to show individual Indications of each track circuit on panel.
Creep - Movement of rails due to moving loads or increased braking load.
PSC Sleeper resistance - 500 ohms
POST--28
Plug in type Relay-
These relays are plugged in to pre-wired terminal boards.It works on electromagnetic principle. Each relay has a base electromagnet,armature,contact spring contacts, transparent cover and handle.A non magnetic residual pin is fixed on the inner face of armature,in all relay except magnetic latch relays.
When current is applied through the coil,it sets a magnetic flux through the bar magnet,core,L shape heelpiece and armature.
The flux causes armature to attract towards pole face. Armature picks up and front contact closes.The residual pin maintains small air gap in attracted position.When current interupts, magnetic flux collapse. The contact spring above the armature helps restoring to its full released position thus front contacts open.
Plug in type Relay consist of more than 25 varieties. Out of which about 12 variables are used on Indian Railway. These relay normally operate on 12,24 and 60 volt DC and can be provided with max of 16 independent contacts.
In front contact A1 A2, A1 is contact and A2 is Arm . In back contact A5 A6, A5 is Arm while A6 is contact. Contact is steady while Arm moves.
Polycarbonate material is used for relay cover of Q Series relay.
Non Fusible Contacts- A pair of contacts in which one contact element comprises non fusible material which presents practically no risk of welding of contacts.eg metal to carbon relays.
Carbon Contacts- Corbon in the expression ' Corbon to metal contacts ’ is used as general term covering graphite and compounds and mixtures of carbon and metals.
Metal Contacts - Metal in the expression ' Corbon to metal contacts ' and 'Metal to Metal contacts' is used as a general term covering the use of silver,silver cadmium oxide,tungsten, platinum or any other suitable material to an approved specification.
Track Relay - Track relay are relays which is directly connected across the rails of the track to detect occupation of track. E.g QT2,QTA2,QBAT.
Line Relay- Line relay are used for any other purposes other than track circuits such as HR, DR, NWKR. E.g QN1,QNA1
Dependent Contact- The condition in which a movable arm contact connecting front contact when the relay is energized and the same arm contact connects to a back contact when the relay is denergized.
Independent Contact- The condition in which the movable arm contact connects to either a front or back but not both.
Pickup Value(operate value)- The value of current or ampere turns which is just sufficient to close all the front contacts of relay under specified conditions.
Drop away Value ( Release Value)- The value of the current or ampere turns at which all the front contacts get open under specific conditions.
Wiping ( Self cleaning) contacts- Contacts designed to have certain relative motion,during the interval from instant of touching until completion of the crossing motion.
QNA1 ac immunity is 1000 V.
It's front contact will not make when AC rms voltage 1000V, 50 hz applied across relay coil.
It's back contact will not break when AC rms voltage of 300 V,50 Hz is applied across the relay coil.current 115mA.
Coil Resistance is 200 ohms
QBA1 - DC baised AC immunised relay, used for NR and BLR of TLBI.A Copper slug is provided on the armature for immunization and a permanent magnet adjacent to copper slug is provided on the armature for biasing.It does not operate if 20 times of the rated voltage is applied.It's specification is BR Spec No 932 A.used in Daido.
QTA2 - Pick up voltage 1.40 V and pick up current is 140 mA.
Minimum Excitation is 125% of rated pick up voltage.Maximum Excitation is 300% of rated pick up voltage.
Copper slug is provided on core to achieve AC immunity.Due to this Copper Slug , it requires more DC power to pick up.Hence it requires more time to pick up and drop due to copper slug.
It can be used upto 450 m track circuit in REc area with choke at both ends.
Coil Resistance- 9 ohms.
AC immunity- 50 V AC.
QBAT -2F/2B
Pick up voltage 1.75 v,Pick up current should be 175 mA.
Minimum Excitation is 122% and Maximum Excitation is 235% of rated pick up voltage
Coil Resistance- 9 ohms
AC immunity- 80 V AC.
It can be used upto 750m Track Circuit lengths with choke in RE Area.
QNN1 ( DC Twin Neutral Relay)
Both relay are independent from each other.
Coil Resistance 470 ohms.
QBCA 1 Relay - QBCA 1 relay contact can carry 30 amps. AC immunity of 1000v,50 Hz AC.Used to drive point motor. It is biased and AC immunised Relay used for heavy duty contact
2F 4B (30 Amp/ 3 Amp)
Coil Resistance- 250/910 ohm (24/50 DC)
Full pick up/ release- 19.2/2v DC (40/4v DC)
Contact Resistance- 0.1/0.2 ohm
It is similar to QBA1 Relay but two heavy duty contact.
For spark quenching, blow out magnets is provided.
Minimum front contact pressure is 56 grams instead of 28 grams. Specification no 943 A.
QSPA1 Relay -
BR specification 933A
Only this relay is permitted to be used as repeater for immunised Q series track relays,due to its slow to pick up character.
Provision of a Copper slug at Armature for AC immunity and a magnetic shunt between the core and the armature at the front contact make this relay slow to pickup by 540/600 seconds.less slow to release by 140/200 seconds and immune to AC
QN 1 Relay - Used for all control and detection circuit. Except in external circuits of AC RE area.
Coil Resistance-400 ohms
Specification no BR 930A
AC immunity for 300v 50 hz AC.Current is 60mA
QS3 Relay -
Works on low current, works on 12 v DC.
Coil Resistance 1000 ohms, current 12mA.
BR specification 930A
QB3 Relay -
Similar to QS3 Relay
It is biased Neutral line Relay. Two relays of this type is used in in parallel on tokenless block to detect line current polarity in place of polar relay.
Biasing stands good for 240 v DC.
QB 3 - 60 v dc, used in push button block instrument.
Contact resistance of Q series relay - 0.20 ohms
Relay arm contact - Silver oxide
Arm contacts are movable.
For biasing permanent magnets is provided on the armature along with Cu slug.
Armature get attracted when both magnetic forces, permanent magnet and electromagnet attract acting on same direction.Either of them alone can not attract armature.
In Biased relays Permanent magnet atteched on Armature and in Latch relay , permanent magnet attached to heel piece.
Metal to Metal Relay
K 50 Relay :-
K 50 Relay are available only in group units of different sizes.They are broadly classified as
Mini Group, Minor Group and Major Group.
Mini Group - 2 Neutral control relays or 2 Interlocked relays or ECR with power conversion unit
Minor Group-
Upto 15 relays.
Major Group -
Used only in RRI
Upto 30 relays.
Group Relay in Siemens interlocking
a) 2 Aspect Signal Group
b) 3 Aspect Signal Group
c) Shunt Signal Group
d) Universal Route Group
e) Point Group for PI
f) Point Group for RRI
g) Point Chain Group for RRI.
Non AC immunised Neutral Relays
These relays are available in 4F/4B , 5F/3B & 6F/2B contact configuration.Ohmic values of these relays are 1260 ohms, 1260 ohms,1840 ohms for 6F/2B.
Interlocked Relays-
These relays are available in 4F/ 4B, 5F/ 3B & 6F/2B contact configuration. The ohmic values of these relays are 615 ohms.
Current to pick up ECR = 108 mA/ AC 50 Hz
ECR Drop away current= 72 mA/ AC 50 Hz
Cable-
Laying -
1) Main cable laid parallel to track shall normally be buried at a depth of 1.0 m from top of cable to ground level.The depth shall not be less than 0.50 m for tail cables.
2) When cables are to be laid in Rocky area, depth of 1.0 m is not feasible.
3) Signalling cable must be separated from LT power cables by array of bricks or any other approved mean and from HT power cables a minimum 3 m seperation shall be maintained.
4) Where it is necessary to take the cables between tracks, it shall be carried in trunking/duct/pipe kept sufficiently below the ballast level.
5) Outside the station section, the cables should be generally be laid at not less than 5.5 meters from centre of nearest track.
6) Within Station section, the trenching to be done at a distance not less than 3 meters distance from centre of track.
Laying in RE Area
1) If the depth of cable is not greater than 0.5 m, then the minimum distance of 1 m shall be maintained between cable and OHE structure.
2) When the cable is laid at a depth greater than 0.5 m,the minimum distance of 3 m shall be maintained between cable and OHE structure.
If we can not maintain above distances, the cable should be laid in DWC/HDPE pipe/ Concrete Ducts or any other approved means for a distance of 3 m on either side of the mast.If we follow this procedure the distance between cable and mast may be reduced to 0.5 m.
3) Near Traction Sub Station and feeding post-
Minimum Distance between cable and any metallic part of OHE/ Earthing of sub station - 01 meter
4) Cable should be laid in Concrete or DWC- HDPE pipe/ RCC pipe for a length of 300 m on either side of feeding point.
5) The use of GI pipe or any form of metallic pipe is prohibited within a distance of 300 m from feeding post.
Spare Conductor-
Adequate spare conductors to a minimum 20% of the total conductors used in each main cable upto farthest point zone.
Beyond this there should be a minimum of 10% of spare conductors of the total conductors used.
No spare conductors are required if total conductors used is 3 or less.
Testing of Cables -
Periodical Testing
Main Cable - Every 2 years
Tail cables - Once in year
Spare Conductors - once in year
Cable markers distance - 20 m in station Section
50 in block section
20 percent Spare for farthest point.
Contact element of DC polarized relay 3 position is made up of Silver.
Cable Markers shall be placed at a distance of 20 m in Station Section and 50 m in block section for signaling cables.
B type Choke - S 65/83.
Polarized Relay - Dependent Contact.
Loop resistance of Signalling cables- 23 ohms per km.
10 Volt- AC Immunity of Polarised relay.
Micro ohm meter - Measure Relay contact resistance .
Screening factor of Signaling cable- 0.91
POST--29
Essentials of Interlocking ( SEM -7.6.1)-
Equipments provided for the operation and control of signals, points etc. shall be Interlocked and arranged as to comply with following essentials,
A) It shall not be possible to take OFF a Main stop signal or subsidiary signal, unless all the Points in the route, including overlap and Isolation (as applicable),are correctly set and locked and all interlocked level crossing are closed and locked against public,and all the relevant track circuits are unoccupied by vehicles and clear for the line on which the train will travel.
B) After such Signal has been taken off, it shall neither be possible to move any point in the route,including overlap and Isolation, nor to open any interlocked gates until the concerned signal replaced to ON.
C) It shall not be possible to take 'OFF' another signal which can lead to conflicting movement.
Route Holding (Approach Locking & Back Locking)-
A) The route ( including overlap, isolation as applicable),locked by a signal,shall be released normally on passage of train or by Emergency Route Release with specified time delay.For such route Holding, it is essential to provide continuous track circuit/Axle counter from Signal to end of the route at all class of stations.
B) Overlap shall be released with,either passage of train or with specified time delay on arrival of train on birthing Track or Emergency Route Release.
Approach locking is rear of Signal and back locking is ahead of Signal.For Home signal back locking is used and for Starter Signal both approach and back locking can be used
If the track ckt/Axle counter in rear of Home Signal is minimum 1 km and track detection is provided, we can use Approach Locking.After taking off a Home signal,if signal cancellation is carried out,signal will go to danger without any time delay but route will not cancel immediately because driver need some time to stop the train.in this case route can be canceled in two ways
1) If approach track/ Axle counter ( 1 km length) is clear, route will be canceled immediately without any time delay.
2) If approach track/ Axle counter ( 1 km length) is occupied, a timer of 120 seconds will start and after 120s route will be released and driver will get 120 s to control his train.
3) If approach track is not provided, it is called dead approach and route will be released after 120 s time delay after signal cancelation process.
Back locking tracks start from foot of the Signal to Last point zone track excluding birthing track.
For Home Signal., length of Approach track is 1 km. To avoid making a track ckt of 1km,we prefer Dead Approach Locking.
For other stop signals, length of Approach track is not mentioned so take sufficient distance according to need.
Approach Locking and back locking shall be provided for all routes governed by Main stop signals and subsidiary signals.In absence of approach track circuit, dead approach shall be provided with suitable time delay.
At LC gates in , Approach Locking to be provided if continuous track circuit available. In other sections dead approach with 60 sec time delay to be provided.
Continuous Track Circuit -
Where continuous track circuiting/Axle counter are provided, the occupation by a vehicle of any track circuited/Axle counter section shall also control the signals leading to same line and shall also lock the points on the route.
At Stations where points and signals are operated through Relay interlocking/ Electronic Interlocking, track circuiting/ Axle Counters shall be provided.
Note- If a signal is flashing at panel, it's route will come if other conditions are satisfied but signal will not lower.For cancellation of this route,you have to first cancel the signal then route will be cancelled through super emergency cancellation.
Length of overrun shall be 120 m.
Emergency Crossover point
It is located in either up or down side in double line section. Generally it is kept in Normal.Used in Reverse when we need to receive a train on common loop line. Platform line is made common loop to get the facility of receiving a train from both directions.
Interlocking and other safe condition are verified at initiation stage.
Conflicting Signals are proved in three stages.
Colour of Buttons-
Signal- Red
Calling On- Red with white dot
Shunt - Yellow
Route - Grey
Point,Crank Handle - Blue
Siding Control- Blue/ Black
Slot- Grey/green.
When train arrives on birthing Track, overlap Release after 120 seconds
Twin Single Line Block Working-
Starter is released by Advanced Starter.
Class A - No Station Section
POST--30
Siding Points on Passenger running lines outside station limits:- Facing Points:-SEM-7.4.12
1) The siding points on passenger lines outside the station limit shall be detected for permitting speeds of up to 50 kmph in facing direction.In case the detection is not provided, speed restriction of 15 kmph shall be imposed.
2) Where Siding Points are provided only with the minimum equipment specified in Para no. 7.4.12 (a), an appropriate speed limit over the facing points imposed for all trains passing over such Points in the facing direction only and an 'S' marker at the Points and a speed indicator at not less than 30 meters from the Points shall be provided, neither of which, need be lighted.
3) In addition a caution indicator shall also be provided at a distance of 800 m from speed indicator. If the sanctioned speed of the section does not exceed 50 kmph, the S 'Marker' at the points and the indicators need not be provided.
POST--31
SEM 7.5.1
Catch Siding is provided to protect the station section, if the gradient is steeper than 1 in 80 falling towards the station section.
Slip Siding is provided to protect block section if the gradient is steeper than 1 in 100 towards Block Section.
Normal permissible gradient for Block Section is 1:1200 and for Station Section is 1:400.
Reception of Trains in Catch Siding Stations-
(a) Either a minimum of two Stop Signals shall be provided in rear of the Catch Siding points or the First Stop Signal shall be at an adequate distance equal to Block overlap from the catch siding points.
(b) A train shall first be brought to a stop at the First Stop Signal, before the Catch Siding points are set for the main line and the reception signals shall not be taken 'OFF' unless the following conditions are satisfied.
(1) The line on which the train is to be received is clear and the train is to be received on the main line. (here main line means all running lines).
(ii) The points leading to the Catch Siding as well as all the Points required for a run through train are set for the main line Immediately after granting Line Clear to the Block station in rear.
iii) Line clear has been obtained from block section in advance.
iv) The gradients in the block section ahead are such that the train can be brought under control easily.
Interlocking of Catch/Slip Siding points with Block Instruments:- (SEM-7.5.4)
The interlocking shall be such that the key required to set the siding points is released from the instruments in the "Train Going to"/"Train Coming from" position and once the key is removed from the block instruments, the instrument gets locked in the relevant position. After movement of the train and the points are set for the Slip Siding/Catch siding and the "Train Going To" / "Train Coming from" key is released from the Points and brought back to release the instrument to Normal position.
Shunting on non isolated lines shall cease once Line Clear has been granted.
Where Slip Siding is located at the departure end of a Double Line Station, the interlocking shall be such that Points can be set towards the block section only when the block instrument is set to Line Clear.
Audible Indication: An audible indication shall be provided at the place of operation of Points as an aid to the Operating staff, indicating that the train has been received or dispatched and that the points shall now be normalized for the Catch Siding/Slip Siding. This indication would continue till the points are normalized for the Catch Siding/Slip Siding.
The following safeguards shall also, inter alia be provided in
the Station working Rules:(a) Shunting on non-isolated lines shall cease once Line Clear has been granted.
(b) Points shall remain set and locked for the Catch Siding until Home Signal has been taken 'OFF'.
(c) Before normalizing the block instrument the Station Master /Assistant Station Master, shall verify the complete arrival or dispatch of the train, even though he is getting an audible warning, which may be due to reception or dispatch of a complete train or part thereof.
Emergency key- An Emergency Key of the Catch/Slip Siding shall be kept in a sealed box under the custody of the Station Master. This is used for operating the Slip Siding/Catch Siding points when either the block instruments have failed, or when the train is still in the Block section and another train is required to be dispatched into the Block section.
Number of contacts in a circuit shall not exceed 45 Nos,due to voltage drop consideration.The voltage across R1 & R2 of a relay shall not be less than 22 V.
POST--33
Important facts -
1. There should be no change in gradient within 30 m in case of BG and 15 m in case of MG of the point.
2. For IRS point Stroke is 143 mm and opening is 115+_ 3mm.For IRS clamp type point machine maximum stroke is 220 mm.
3. For TWS Point stroke is 220 mm and opening is 160 mm.Tolerance is not mentioned anywhere.
4. Chipped/ Cracked Switch - Chipped length is the portion where tongue rail has worn out for a depth of more than 10 mm over a continuous length of 10 mm.If the total chipped length is 200 mm within 1000 mm from toe of switch rail, this switch rail will be called Chipped Switch.
6. Knife Edged tip- If thickness of tip is less than 2 mm over a length of more than 100 mm anywhere upto a distance of 1000 mm from its toe, then it is knife edged tip.
7. Vertical wear - It is measured at a point where tongue and stock rail are at same level.Vertical wear allowed is 8 mm for 60 kg
IRS Point Machine - throw is 143 mm ( 160 mm for TWS)
143 mm = 115 (opening) + 25 (gap at JOH) + 3 (idle stroke)
Normal Working Voltage-110 V DC
Minimum Working Voltage- 60 V DC
Normal Working current- 2-3 Amps ( 3 to 5 Amp for TWS)
Slipping Current/Obstruction Current-
A) Upper Limit- 1.5 to 2 times of Normal Working current
B) Lower Limit- Difference between Normal Working current and Slipping current shall not less than 0.5 amps
Minimum AC immunity- 160 V AC
Friction clutch movement is 270 degree. Mechanical snubbing is achieved in Friction clutch. Friction clutch slips from 10 to 15 seconds during Obstruction.
Mode of Locking - Rotary type locking ( only closed switch is locked) in IRS
In TWS, closed switch is locked through Rotary type locking and open switch is locked through fish tail so it is called clamp type locking.
Operation Time- 3-5 Second ( 5-6 Second)
Space between 3rd and 4th Sleeper - 685 mm for IRS (1 in 8.5 point)
695 mm for IRS (1 in 12 point) 745 mm for TWS point.
Test Load on Throw bar - 450 kg ( 550 kg for TWS)
Slipping Load - 580 kg ( 700 kg for TWS)
Stalling Load - 1000 kg for all Point machines
No of teeth in main gear rim is 92 teeth.
No of teeth in motor pinion is 12 teeth.
04 detection and 04 control contacts.
Test gauges 1.62 mm - Go test
3.25 mmm - maintenance purpose
5 mm - Obstruction test
Point machine /EPD should be provided at Min distance of 1060 mm from nearest C/L of track
Motor used is DC series split field motor. It means it's coils are divided into two pieces and connected in series ( two coils for Normal and two coils for Reverse) to enhance its strength. The quality of a motor,depends upon the insulation of its coil.
If this insulation is weak and after repeated operation, coppor conductor in touch each other and motor can burn.
That's why insulation of point motor should be 10 Mega Ohms for new motor.To check it, first we will megger between C and N terminals, then C and R terminals.Practically it will work for 2 to 3 Mega ohms also. In regular maintenance or inspection, meggering of motor is not required. It can be done if there is intermittent failure. Insulation is B grade Insulation. Design is C10 ( it will only operate for 10 s after giving feed).
SAE 30 oil is poured in reduction gear in once in six months.Quantity is 150 ml to 180 ml.
Facing point and trailing point- Same point can be facing of a train and trailing for another train according to their direction of movement.If the Train is entering into face of point ,then it is facing otherwise it is trailing.
Trailable or Non trailable point -
Maximum points are Non trailable. In these point we need to alter the position of point for Normal and Reverse trailing movements. We can not do both the movement in one position.In the trailable point, there is no need to change the position of point for trailing movement either from Normal or Reverse.In this case point is on loose heels which is not in practice now a days.
Stalling Load - It is minimum load at which Mechanical fuse ( Bearing Pedestral) breaks during trailed through movement due to pressure of wheel on closed switch. Breaking of mechanical fuse saves the other parts of point machine. Mechanical fuse is connected with throw rod and friction clutch. Value of Stalling Load is 1000 kg for both IRS and TWS Point machines.
Points are of two types 1/12 and 1/8.5.In 1/12 points, distance between Normal and Reverse rail is 1 m after movement of 12 m from toe of point.
In 1/8.5 points, this distance will be achieved after movement of 8.5 m from toe of the point. Curve on 1/8.5 points are more compare to 1/12 points.Length of crossover of 1/8.5 m point is 54 sleepers ( 33 m). Length of one sleeper is around 600 mm. Length of Crossover is from SRJ to ahead of crossing.
In 1/12 points, the length of crossover is 83 sleepers (55m).
In main line points only 1/12 point is permitted.
Maximum speed on 1/8.5 m point is 30 kmph for ordinary point and 60 kmph for TWS point.
Obstruction Test- Insertion of a 5 mm Obstruction between the switch rail and the stock rail of a Facing point, at approximately 150 mm from the toe of the switch rail to prevent the point from being locked is called Obstruction Test.
Minimum Clearance from bottom of rails and top of the ground connection is 25 mm.
Minimum Clearance of Check Rail
At Curve -44 mm
LC gate - 51 mm.
Minimum depth of space for wheel flange from Rail level -38 mm.
Minimum radius of curve -175 mm (10 degree)
Clearance from bottom of the rail for ground connection rods - 40 mm in RE area.
Point Indicator -
Show White when point are set for straight and Green when point set for Divergence.
Trap Indicator-
Shows Red when trap switches are open,Shows Green when they are locked.
POST--34
In TWS Point,Distance between tongue rail and stock rail at JOH is 60 m.This distance is 25 mm in IRS Point.When train moves on Point,it does some lateral movement.Due to this larger gap at JOH in TWS Point,wear and tear in wheel and tongue rail is very less compare to IRS Point.
TWS fitting are made for high speed (160 kmph).Stroke of TWS Point machine is 220m.
In IRS Point only closed switch is locked and Open switch is kept free but in TWS both switches are locked.Open switch is locked with Fish tail or clamp.
TWS is not suitable if curve is more than 2 degrees.
In TWS Point, throw is 220 mm
220 mm = 160 (opening) + 60 (gap at JOH)
Operating Data as per IRS :S 24/2002 - Amandement No 1
Motor DC series split field.
Throw of point machine -220 mm +4/-1
Time of operation (Max) -5.0 sec
Current Consumption- <_ 5.5 Amp
Rated Voltage- 110 V DC
Max Throw -550 Kg
Slipping load - <_ 700 kg
Stalling load (min) - 1000 kg
Threaded portion of Lock Rod is made of steel .
SSD( Spring Setting Device)
SSD of approved type shall be provided at JOH ( junction of Rail head).
SSD used in TWS is fitted between 13 th and 14 th sleepers
SSD is insulated from both rails.
SSD installation and maintenance is the responsibility of engineering department.
Opening
Out of 220 m throw, during first 60 mm throw closed switch rail get unlocked and open switch moves towards stock rail.
In next 100 mm throw both switch rail move simultaneously thereby open switch rail get closed and closed switch gets locked and open by 100 mm.
During final 60 mm throw, closed switch gets locked and open switch rail moves 60 mm further resulting total opening of open switch by 160 mm.
Provides direct locking between tongue rail and stock rail in closed and open position.
No strecher bar is used and both the tongue rails move independently of each other.
POST--35
SLB ( shunting limit board)
It is used in single line B class Station working in Absolute block system, where Advanced Starter is not provided and Shunting is permitted in front of Approaching train.Its distance is 180 m ahead of Home Signal and it is facing towards station.A white light on the board will lit both in day and night
Shunting in face of approaching train can be done only upto SLB.
Dimension of rectangular board is 600 mm×1000 mm.Height of the bottom of rectangular board is 2 m from rail level.On the post there are alternate band of Black and White, each 300 mm wide.
BSLB ( Block Station Shunting Limit Board)
It is used in double line B class station worked on absolute block system and placed 180m ahead of home Signal when first point is trailing or there is no point.
BSLB should be placed near Fouling Mark of the first point.Legend is facing towards station. A white light on the board will lit both in day and night.
Other Indication Boards
An indication board shall be provided at foot of gate signal if it is protecting more than one mid section LC gate with appropriate legend.
An indication board shall be provided at the foot of the IB Signal if it is protecting mid section LC gate with legend ' look out for LC gate when passing IB signal at ON.
Important points
One Block equipment can be Overhauled maximum two times in a S&T workshop.
POST--36
Station Limit- Area Between outermost points of Station.In Single line, it is from UP Distant Signal of to DN Distant Signal.
In Double line , it is from DN Distant to DN Advanced Signal and UP Distant to UP Advanced Signal.
Block Section-
In single line area between Advanced Starter of other Station and Home Signal including overlap is Block section.
In Double line area between Advanced Starter Signal of other station and Home Signal including Block Overlap
Station Section- Other than block Section is Station Section
POST--37
Automatic Block System
A) Automatic Block is a system in which movement of trains is controlled by the stop signals which are operated automatically by passage of trains past the signals.
B) The automatic stop signal which governs entry of train into an Automatic Signalling section is a multiple aspect colour light signal which is not dependent upon manual operation but it is controlled automatically by the passage of a train into, through and out of the automatic Signalling section which the Signal governs.
C) The line between two adjacent crossing stations shall be divided into a series of signalling sections and entry into each signalling section shall be controlled by a manual stop signal or Automatic Stop Signal which must assume ON position on entry of a train into the section and be maintained in that position until the train has passed clear of the next Automatic Stop Signal in Advance and also for an adequate distance beyond it.
D) No automatic signal shall assume OFF position unless the line is clear not only upto the next Stop Signal but also for an adequate distance beyond it.
If Next Stop Signal is Automatic , the this adequate distance is 120 m.
If Next Stop Signal is Manual or Semi automatic , the this adequate distance is 180 m.
E) The signal that governs entry into Block Section shall be Manual or Semi-automatic Stop Signal 🚦.
Manual Stop Signals
Fixed Signals which require manual control each time they are taken OFF are called Manual Stop Signals.Manual Stop Signal shall be manually operated signal which shall assume ON position automatically on occupation of the section ahead but shall assume OFF position only when they are operated.
Semi automatic Stop Signal
A fixed signal having both manual and track circuit control and which is capable of being operated either as an Automatic Stop Signal or manual Stop Signal, is called Semi automatic stop signal.
Important points regarding Automatic
1) passage of trains Duties of Loco Pilot and Guard when an Automatic Stop Signal on Single line is to be passed on Danger-GR 9.07.
2) Automatic signal Interlocked with a LC gate shall be provided with a yellow disc with letters G in Black and an A marker light.
3) The A marker shall be lit only when the gates are closed and locked against road traffic.
4) In 4 aspect automatic block section, one track section plus overlap is required to be clear to get Caution ( Yellow) aspect.
5) When a Loco pilot finds an Automatic Stop Signal with an A marker at ON. He must stop and in rear of Signal can pass this ON Aspect after waiting One minutes at day and two minutes at night.
6) Minimum 4 trains can be there at a time in a Automatic Section.
7) Overlap is 120 m for every signal in Automatic. For Home signal, it is 180 m as usual.
8) There is no Automatic signalling in Station Section.
9) Home Signal can be made Semi Automatic by placing illuminated A marker.This A marker will lit through a switch by Station Master when Home Signal fails and then this Home Signal will work like Automatic and driver will pass through it.
10) Immunisation of A marker shall prove that correct setting and locking of the points as required and ensures the back locking of routes.
11) Passing a Gate Stop Signal at ON in Automatic Signalling- GR 9.15.
12) If the A marker is extinguished, he shall sound the prescribed code of whistle to warn the gateman and bring the Train to stop in rear of Signal. After waiting 01 minutes in Day and 02 minutes in night. He shall pass the cautiously.
Essentials of The Automatic Block System on Double Line -
Where trains on a double line are worked on the Automatic Block System.
A) The line shall be provided with continuous track circuiting or Axle counter.
B) The line between two adjacent Block Stations are divided into series of Automatic Block signalling sections each of which is the portion of running line between two consecutive stop signals and the entry into each of which is governed by a stop signal.
C) The track circuits or Axle counter shall control the Stop Signal governing the entry into Automatic Block Signalling Section that the Signal should not assume an OFF Aspect unless the line is clear upto next stop signal in advance and adequate distance beyond it,The Automatic signal shall be placed to ON , as soon as it is passed by train.
D) In automatic territory where emergency braking distance is more than 1.0 km is to be catered for, 4 aspect automatic signaling shall be provided. If not provided, suitable speed restriction shall be imposed.
When a Gate Stop Signal is Semi Automatic Stop Signal and Protects Points
When a Gate Stop Signal is semi- automatic Stop Signal and protects point where exist in addition to the level crossing, it shall be provided with white illuminated letter 'A’ and white illuminated letter 'AG' against black background.The Indication of such Signal shall be as under-
A) When the gates are closed and locked against road traffic and points where exist are correctly set for main line and locked for route.- Only A marker lit
B) When LC gate locking failed but points are correctly set for main line - Only AG will lit.
C) If points not set - No marker will lit.
D) If both A and AG extinguished---Signal trated as Manual Signal
E) A and AG will not lit together
A warning board is to warn loco- pilot approaching a stop signal of a station.It is provided at a distance of 1.4 km in rear of the FSS.
Where inter distance between two signals is less than the distance required for warning board, the signals in rear shall either be controlled by the signal in advance or both the signals shall be combined.
Generally placed on left side unless there are special reasons to the contrary.
Goods Warning Board -
Height of centre of circle of goods warning board is 3.65 m from Rail level.The dimension of rectangular board is 1800× 530 mm.In Double distant terroritary, there is no need of this board. It gives a pre warning that either FSS of a Station or IBS or Gate Stop Signal will come after 1400 m.This distance may be increased suitably to cater for gradients.Its post is alternate yellow and black.
Detonator-
When engine explodes detonator, Loco pilot shall whistle intermittently and take every possible caution including reduction of speed as necessary,so as to have the Train well under control and be able to stop short of any obstruction on the line.
After passing 1.5 kms from the place where the engine exploded detonator,if his engine does not explode any more detonator, the Loco Pilot can resume Authorized speed and he should report the incident to the next station.
Indication Board-
Indication Boards are provided to give warning to loco pilot about changes in the type of Signalling or type of block working or automatic protection territory.
Important points -
1) An Indication board shall be provided at the foot of Gate Signal if it is protecting more than one mid section LC gate with appropriate legend.
2) An Indication board shall be provided at foot of the IB Signal if it is protecting mid section LC gate with legend Look out for LC Gate when passing IB at ON.
3) A board shall be fixed not less than 400m in advance of IBS Signal facing against the direction of traffic,to read "No backing without Permission ( GR -8.7.0)"
4) When the block working at one end of a Station is automatic and the other end is absolute, an indication board with suitable legend shall be provided at first stop signal of the Station. The legend on the board shall be Entering Absolute Block Territory or Entering Automatic Block Territory.
Point Indicator ( for Non Interlocked points)
They are provided at all points on the running lines which are not Interlocked with signals, unless position of points is otherwise proved.
Point indicator shall be of Target type.
1) When the point is set for straight line, the indicator shall display a white target by day and white light by night in each direction.
2) When point is set for diverging line, the indicator shall display the edge of the disc in the day and a green light by night in each direction.
3) At points where a green light would give a misleading indication to a loco pilot, a red light may be permitted under special instructions.
POST--39
Repeating Signal- (GR 3.16)
A Signal placed in rear of a fixed Signal for the purpose of repeating the aspect of fixed Signal in advance to the Loco Pilot of an approaching train is called a Repeating signal
A Repeating shall be provided with an R marker and shall be of-
a) banner type
b) a square ended semaphore arm,or
c) A colour light Signal
Repeating Signal is on different post from Main Signal.
Repeating Signal has two aspects, Yellow and Green.It shows Yellow when main signal is ON and Green when main Signal is OFF.
Exact location of Repeating Signal is decided by Signal Sighting Committee.
Co acting Signal -
No of Aspect of Main Signal = No of Aspect of Co acting.
No marker on Co acting Signal
Co acting Signal is on same post on Main Signal
POST--40
SEM 7.1.19 & GR 3.14
Shunt signal are two types -
Dependent and Independent
Shunting can be done only in jurdiction of Staion Master in Station Section . Speed during shunting should be maximum 15 kmph.
For shunt Signal, tracks,points and LC gates in the route are taken but points in the isolation and overlap are not taken.Birthing track is also not proved.Lowering of Shunt Signal will block conflicting movements of Main and Subsidiary Signal.
Shunt Signal will always come with arrow. White arrow with red background.
Route of the Shunt Signal is from foot of the Signal to Last point zone before birthing.
Implantation
(Rail level -1050 mm) - 2135 mm
Above 1050 mm - 2360 mm
Pilot on independent Shunt will always lit ( both in ON and Off )
If main signal is ON, then only Subsidiary Signal below it, can be lowered.
No Shunt on Home Signal.Shunt on LSS can be placed with permission of CRS.
Shunt movements as far as possible ,be controlled by Shunt Signal.
Outer, Home and LSS shall not be taken off for shunting purpose.
If a Shunt signal is placed below calling on or main signal,it shall not be capable of being lowered at the same time as the relevant stop signal.
If a Shunt Signal and calling on signal are placed below a stop signal.Then sequence of fixing from top will be
Stop Signal (Top)
Calling on
Shunt Signal ( Bottom)
Important points -
For Red LED, non blanking mode is used. LED will lit at site until illumination is upto 40% of normal illumination.
In other case LED will lit at site but ECR will drop if current drawn by Current Regulator is less than 40 mA.
LED - 199/2010
Main - 110 +-25%
Immunity level - 60 V AC
Red-60 LED
Yellow- 60 LED
Green- 30 LED
POST--41
Codal life of IPS is 20 years.
LMLA battery - 05 years
VRLA Battery - 04 years
Track relay- 12 years
Quad cable - 25 years
POST--42
1)The line on which speed is higher than 50 kmph should be isolated from all other running lines.
2) Passenger lines should be isolated from all other goods line and siding, irrespective of speed.
In any other case Isolation may be desirable but not compulsory.
3) If speed is less than 50 kmph, Passenger line is not required to be isolated from passenger line
4) Catch and Slip Sidings and sidings provided for isolation purpose only.
Isolation may be accomplished by – (as per SEM)
(a) Connection to another line or long siding;
(b) The provision of short dead end siding; or
(c) The provision of trap.
Means of Isolation
1) Sand humps, trap points or other approved means of Isolation shall be provided on all goods lines and sidings at the junctions with passenger lines, the normal setting being such as to prevent the passenger lines from being fouled.
2) At Interlocked layouts, means of Isolation shall be Interlocked with the relevant signals.
3) No trap point in Main line /Through line.Trap point can be placed in main line with permission of CRS ( under approved special instructions)
4) Sand hump is must after every four station.
If Sufficient distance is not available ahead of starter signal to provide signal overlap of 120 m,then a trap point is placed ahead of starter to achieve signal overlap
Trap indicator
Trap indicator shall be provided at all trap points on running lines which are not Interlocked with signals, unless the potision of trap points is otherwise proved.Trap indicator shall be of the target type.
Detailing Switch
Points leading to a short dead end and used solely for the purpose of trapping the running line or siding shall be treated as derailing Switch.
Indications
a) When the trap points or derailing lines are open, the indicator shall display a red target by day and Red light by night in each direction.
b) When the trap points or derailing lines are closed, the indicator shall display edge of the disc by day and a green light by night.Red light may also be permitted to indicate trap Closed position only.
POST--43
Factors affecting breaking distance:-(priority wise)
1. Train speed
2. Train Load
3. Gradient
4. Brake power
5. Types of brakes
6. Condition of Rail
7. Rail/wheel adhesan
Service Breaking Distance (SBD)
The drivers are normally supposed to apply brakes gradually, so that breaking may not cause discomfort to passengers. The breaking distance obtained with gradual application of brakes is called SBD or Normal Breaking Distance (NBD).
Emergency Breaking Distance (EBD)
When brakes are applied suddenly, the breaking distance required would be less but the rate of declaration may cause discomfort to passengers and in case of freight trains,may damage the consignments.The breaking distance with sudden appliance of brake is called EBD.
SBD is 1.2 times EBD
The inter signal distance is always based on Emergency Breaking Distance (EBD)
Reaction time
When driver approaches and observes a signal, he can not be expected to instantaneously react to the aspect of signal, but after some time. This time is called Reaction time.
When driver is in process of reacting to the Aspect of a signal, the Train is running at max speed and distance covered during this Reaction time is called Reaction distance (RD).
Reaction distance on Indian Railway is 200 m
Reaction distance plays a crucial role while determining the minimum visibility required for a signal.
Visibility of the Signal IRSEM- 7.1.11
All Stop Signals -200 meters except Distant.
Inner Distant- 200 m
For Distant -400 m
Where it is not possible to obtain 200 m of continuous Visibility of any stop signal ( due to site constraints), then suitable speed restrictions shall be imposed.
POST--44
Speed in Station Section
STD 1- up to 50 kmph
STD II - up to 110 kmph
STD III - up to 140 kmph
STD IV - up to 160 kmph
In STD IV, MACLS Signalling or Movement Authority anyone can be used.For others only MACLS.
In STD IV, MTRC ( Mobile Train Radio Communication) and TPWS both are mandatory and desired for STD II and STD III.
CTC ( Centralized Traffic Control) is not required for any one.Desirable for STD II,STD III and STD IV.
Advantages of CTC-
1) Better line Capacity
2) Time table Management
3) Automatic Route Setting
Flexibility is not the advantage of CTC.
For STD III and STD IV, Double Distant is Mandatory. On STD II,it is required in section where EBD is more than 1 Km.
Token working is permitted only in STD I.
There is no connection of S&T department with speed in block section.
Aspects of Signal-
2 Aspect - Red, Green
3 Aspect- Red, yellow, Green
4 Aspect- Red,Yellow, Green, Double Yellow
Aspect Sequence Chart is mentioned in SIP
Distant Signal -
If distant signal is no light, driver will stop and then move cautiously.
Normal Aspect of Double distant- YY
Normal Aspect of Inner Distant-Y
If speed is more than 110 kmph then double distant signal is required.
No good warning board in double distant territory.
In Double Distant Territory,
Double Distant has two aspects - YY and G ( Normal Aspect - YY)
Inner Distant are of three aspects.- - Y, YY , G ( Normal Aspect - Y)
In Double Distant territory if Distant Signal is Green ,it indicates that train will either stop at Main line or run through main line.
In all other cases , it will remain YY.
Inner Distant/Second Signal -
If inner Distant is Green, It is Confirmed that Home Signal will also be Green because there is no provision of Double yellow in Home Signal. If Home Signal is Green Main Line Starter will be Green and Train will go Run through only.
Aspect Control -
Distant and Inner Distant are automatically controlled by the Aspect of Home Signal.
1) If Home Signal is Red , Inner Distant is Yellow and Distant will be Double Yellow.Train will dead stop at Home.
2) If Home Signal is Yellow, inner Distant will be Double yellow and Distant will be Green. Train Stop at Main Line Starter.
3) If Home is Yellow with Route Indicator, Distant and Inner Distant both will be Double Yellow.The train will come on Loop line.Now if Loop line is Red, train will stop and if it is yellow, it will run through via Loop line.
4) If Home is Green, Distant and Inner Distant both will be also be Green and Train will run through on Main Line.
Route Indicator -
There are three types of Route Indicators
1. Directional/Junction type Route Indicator
2. Multi Lamp Route Indicator
3. Stencil type Route Indicator.
If Speed is more than 15 Kmph, Directional type Route Indicator is provided upto 3 diversions on any side of the main line, .
In Standard III, MACLS territory, Multilamp cum Junction type Route Indicator is provided for more than 3 diversions on any side of the main line, .
If Speed is less than 15 Kmph, Any Route Indicator of Approved Design may be used.
Multi lamp and Stencil are used if Speed is less than 15 Kmph.
Directional type Route Indicator can be used for any speed.
In Single Distant territory -
If Single Distant is Green, train will run through Main line.
Fuse capacity -250% of rated current.
Conflicting signal to signal locking is provided in at least three stages.
POST--45
Shunt Key in UFSBI
Shunt key can be extracted only when Block panel is in TGT or LINE CLOSED however shunting in TGT is not permitted.
For shunting in block section, shunting key to be removed in Line closed position and give to loco pilot as authority to enter in block section.
Before entering train into block section , SM will exchange private no with next block station.
Electromagnetic Impulse Counter-It is a six digit, 10 impulses per second minimum, 24 V DC non resetable type counter.
Buzzers -
Cedicom or Piezo make buzzers ( continuous and intermittent) working at 24 volts (+20%-10%) DC for audio alarm is provided to register the BELL CODE sent by other end SM & to register the occupation and clearance of each Block Section.
Block Telephone - This is provided for speech communication with SM at other end of Block Section. Separate block telephone is provided for Separate block section. Block panel has provision for hanging block telephone as Drg no RDSO/S 32019.
POST--46
Single line- Distance between outer most point and Advanced Starter is minimum 120 m and Distance between Advanced Starter and Home Signal is minimum 180 m.In this way Home Signal is 300m behind first facing point
Double line - Distance between Starter and Advanced Starter is minimum 120 m.No fixed distance between Advanced Starter and opposite Home Signal.Home Signal must be placed 180 m behind outer most point.
In Double line if first point is trailing then BSLB board is required. If first point is facing then no board is required.
Home Signal- Distance between Home signal and first facing point must be more than 180 m in both Single and Double line.When there is continuous steeper down gradient more than 1 in 260 towards station between Distant and Home Signal in Single Distant terroritary and between inner Distant and Home in Double distant terroritary
Starter Signal -Location of Starter is just beyond birthing track. All Starter signals will be released by Advanced Starter in new works.
Intermediate Starter Signal - Intermediate Starter Signal shall be placed clear of fouling marks in rear of the point,if any which it protects.
Starter Indicator - Very rarely used. For long/curved platforms,a Starter Indicator may be provided to repeat the Aspect of Starter for the guard. Starter Indicator exhibit 'No light',when concerned Starter is ON and yellow light when it is Off.
Calling On Signal -
Placement - Calling on Signal shall be placed below a stop signal governing approach of a train.Under approved special instructions( Sanctioned by CRS) it can be provided below any stop Signal except LSS.
It can not be provided on Advanced Starter in Any Case.
It can be provided on Starter Signal.
Important points for Calling On Signal
1) It will be placed above Shunt Signal and below stop Signal.Calling on and Shunt below it, can not be lowered together.Same way Calling On and Stop Signal can not be lowered together.
2) Calling on Signal can be lowered only after train comes to dead stop ( GR 3.13).
It will be OFF after time delay of 60 s after occupancy of calling on Track Ckt and lowering of signal for Reception Signal.
For Calling on below starter signal. No time delay is required for taking off calling On Signal however provision for ensuring that train has stopped shall be covered in SWR and to be ensured by operating staff.
3) Length of Calling on Track Ckt is equal to five rail lengths (65 m).Calling on Signal replaced to ON, when Complete train clears this Track ckt.
4) Calling on Board is placed at the start of Calling on Track Ckt joint ,rear of HOME Signal.When a train is received on Calling on, Loco pilot of train to move ahead with caution and be prepared to stop short of any obstruction.
5) If no Track ckt is failed or Birthing TC failed and we are receiving train on Calling on Signal,it's route will release automatically after complete arrival of train.
6) If Any other TC failed and we received train on Calling on, it's route will be released manually using Emergency Route Release with time delay of 120 Seconds.
7) Provision of manual route release of Calling on Signal should be included in concerned SWR.
Calling On signal requires
a) All the LC Gates to be closed and locked against road traffic.
b) All the points in the route and isolation are set and locked in required position.However points in the overlap are not proved in the Calling On Circuit.
C) No Track circuit is proved in Calling on lowering Circuit except Calling on track ckt.
Distant Signal -
If distant signal is no light, driver will stop and then move cautiously.
Normal Aspect of Double distant- YY
Normal Aspect of Distant-Y
If speed is more than 110 kmph then double distant signal is required.
No good warning board in double distant territory.
Under approved special instructions.a colour light Distance signal may be combined with the Last Stop Signal of a station in rear or with a IB Signal or a Gate Signal.
Inner Distant/Second Signal -
If inner Distant is Green, It is Confirmed that Home Signal will also be Green because there is no provision of Double yellow in Home Signal. If Home Signal is Green Main Line Starter will be Green and Train will go Run through only.
IB Signal -
IB signal is placed in the mid of two block sections.
IB is used where distance between two block sections is equal or more than 10 kms.MSDAC is possible in IB Section.
CSR is normally 750 m.
Arrow On the Right Side Signals-
SEM 7.1.4- Signals must be placed normally on left side of track.Where signals are placed right side, a arrow must be provided towards applicable line.
Arrow must be of white colour and background is red
Unused Signals-
For unused signals a rectangular cross bar of 1000 mm×100 mm is placed. (GR 3.18). Unused signal should not be in lit condition in any case.
Some Important facts -
1) Voltage range for Main Signal LED is 82.5 V to 137.5 V.
2) Voltage range for subsidiary signal LED is 88 V to 132 V.
3) Passenger warning board abolished from Railway
4) Normal Aspect of Home- Red
5) Height of Red Aspect is 3.65 m from Rail level.
Combination of Signals-
Permitted with Special spl instructions(CRS).
A Colour light Distant Signal may be combined with the LSS of a station in rear or with IBS or gate signal when distance between signals is less than 1 Km.
E.g.
Combination of Distant with gate signal
Combination of Advanced signal with Distant signal of next station.
GR 8.01 - Block overlap and Signal overlap.
BSLB - Class B double line Station,if the first point is trailing,BSLB will face towards staion.If a train is doing shunting , he can not cross BSLB,Crossing of BSLB means entering into Block section.BSLB will be placed exactly at FM.Home signal will be placed at a distance of 180 m from BSLB.
POST-47
Block overlap SEM .7.1.8-. 180 meter - Adequate distance ahead home signal only ( used for line clear).
(i) Where there is a continuous down gradient towards station steeper than 1 in 260 between Distant and Home signal in single distant territory and between Inner Distant and Home Signal in Double Distant territories, the Home signal may be placed at a distance of sum of Block Overlap and Signal Overlap from BSLB (Block Section Limit Board) or the outer most Facing Point, as the case may be (i.e 180 + 120 = 300 m in MACLS).
(ii) If there is rising gradient in between or there is no emergency crossover for criss-cross movement cutting across the main line, then this shall not be applicable.
Signal overlap SEM 7.1.9. -120 meter- Adequate Distance ahead starter signals only if we are lowering Home Signal to receive a train.
Where a sand hump of approved design,or under approved special instructions a derailing switch ,has been provided for the line on which a train is to be received,they shall be deemed to be efficient substitute for the adequate distance.
IB signal overlap -400 meter
No Block overlap in Automatic Block system.Only signal overlap
Automatic signalling possible in singal line but it is rare.
Adequate distance- distance to ensure safety
Block overlap and signal overlap are two types of Adequate distance
Fouling mark -
Fouling means the marks at which the infringement of two fixed standard Dimensions Fouling Block occurs,where two lines crosses or join each other.
It shall be placed at a location,where centre to centre distance :-
Minimum 4265 mm ( for existing line)
Minimum 5300 mm ( for New construction)
Glued joint should be placed more than 3m distance from Fouling mark to avoid side collision because in guard compartment the distance between wheel and last part of vehicle is around 3m.
POST--48
Validity of CST sanction is six months .Required when we are doing any changes in existing interlocking.e.g commissioning of BPAC
Validity of CRS and PCE sanction are same (01 year).
PCE sanction is required only for closing the LC gate.Earlier it was with CRS, now delegated to PCE.
ESP,SIP,SWRD,PD and SWR required to be attached with PCE sanction.
Type of block working in any section approved by CRS.
CRS sanction is must when do any change in interlocking,e.g.any new line is opened. Validity of CRS sanction is 01 year. CRS permission is required in following cases.
a) Additions/extensions or alterations to the existing block, Signalling and interlocking installations
b) Change in Block, Signalling and Interlocking installations.
c) New stations temporary or permanent.
d) Interlocking of level crossings, catch siding and slip sidings etc.
e) For any kind of clubbing of Signal CRS Sanction is required.
CST Sanction
CST Sanction required in following works
1) Provision of Telephone at already Manned level crossings.
2) Provision of electrical & mechanical lifting barrier including emergency interlocking arrangement at already Interlocked Level Crossings gates.
3) Interlocking of existing LC Gates within already existing Interlocked station yard by existing signals in the same or shifted location.
4) Provision of all categories of track circuits, axle counters including dual detection.
5) Replacement/ Modification of signalling assets without any change in the yard layout or signal interlocking scheme either in station or mid section LC Gates.
6) Replacement of Block instrument by any other type of instrument or provision of BPAC or Track circuiting using existing block equipment.
7) Replacement of block instrument without any change in the system of block working.
8) Providing electronic interlocking/panel interlocking/RRI in non passenger line section.
9) Changing from control panel to control terminal/ VDU in EI.
PCSTE sanction is not required for RE alone commissioning.
Application to CRS/ CSTE for sanction of work
1) For divisional level works applications for CRS shall be made by Sr.DSTE.
2) For Joint works or work by Railway 'PSU, the application for CRS sanction shall be signed by DRM.
3) When the work is executed by an Construction Organisation, the application shall be signed by Dy CSTE for Signalling works.For joint works, the application shall be signed by JAG officers of concerned departments executing the work.
In overhauling of Interlocking frame in Mechanical signalling, the caution order of speed restriction of 30 kmph will be imposed.
PCOM Sanction
For new work, installation of signals on RHS,Requires the sanction of PCOM. (Red Arrow mark with white background is required on Signal)
For Calling on under Starter Signal,PCOM Sanction is required.
POST--49
Approved special instructions- Special instructions Approved or prescribed by CRS.
Track feed battery charger - 10 Years
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