The document discusses the evolution of signaling systems in India from mechanical interlocking to modern technologies such as microprocessor-based and solid-state interlocking systems. It highlights the shift from manual to automated signaling equipment, improvements in telecommunications, and the introduction of advanced devices like digital axle counters and integrated power supply systems. The focus on upgrading maintenance practices and the increasing need for skilled technical staff to manage and operate these advanced systems are emphasized.

1. JUSTIFICATION Change of Cadre of Maintainers of S&T Department

2. When Interlocking first was first introduced in India during 1879 it was first Indirect type using Mechanical Key. This was followed by Direct Type Interlocking with Lever Frame which are actually mechanical logical gates . They were vary robust and a typical way side station will consist of these gates weighing approximately 5 tons of steel. Development of electrical Relay and Power Supply has evolved a relay based Interlocking over the years. With the advent of fail safe technique ‘ microprocessor’ were used for Interlocking application and has proved as a substitute to Relay Interlocking with added benefit . Thus the purely Mechanical Signaling of 50’s slowly made way to Power Signaling followed by Route Relay Interlocking and Panel Interlocking . Latest Solid State Interlocking with Data loggers and other advance Techniques.

3. The technical up gradation in the Signaling System is not limited to a particular section and are more rapid within these 10 to 15 years. The Evaluation of the sealed maintenance free Batteries (VRLA) are replacing Lead Acid Cells.Introduction of Integrated Power Supply (IPS), Uninterrupted Power Supply (UPS) with the help of VRLA Batt., supports Signaling Systems to face power Supply Crises vary effectively. On the Telecommunication front it saw the emergence of Electronic Exchanges from the manual types.T43 Trunk board giving way to EPBAX. Overhead alignment of Optic fiber System . 17 Impulses way station equipment to vary powerful Solid State Control Communication Equipment . From simple walkie talkie sets to mobile communication and analogue microwave by Digital Microwave equipment .

4. Interlocking Signals Points Track Circuits Block Instruments Modern Signaling Equipments. The Basic and Fundamental Part of the Signaling Systems

5. INTERLOCKING EARLY 50’S DIRECT TYPE INTERLOCKING ( LEAVER FRAME ,LOGIC GATES-ROBUST AND CONTAINS MINIMUM OF 3 TONES OF STEEL ) ELECTRO MECHANICAL INTERLOCKINGS LEAVER LOCK, CKT. CONTROLLER, REVERCERS AT PRESENT` Purely Electrical Interlocking RRI, PI NEXT FUTURE SOLID STATE INTERLOCKING

6. NOW AND FUTURE 1N 50’S IN 90’S Up gradation In Signal SEMAPHORE ARM SIGNALING , DOUBLE WIRE MECHANISM, REVERSERS, MECH.CRANKS COLOUR LIGHT SIGNALING, DOUBLE FILAMENT LAMPS ON & OFF ECR ADJUSTMENT DOUBLE FILAMENT LAMP WITH MECR RELAY, LED SIGNALS

7. Up gradation In Signal As pure Mechanical Signaling of 50’s changes to Power Signaling (Semaphore Arm Signal changes to Colour Light Signals) Now old SL-21,SL-18 CLS lamps are replaced by SL-35 , with Introduction of MECR relay to pre-warned the fusing of Lamp Further These lamps are going to be replaced by pre focused LED Units. These overcome the drawbacks in poor focusing of Signal Aspect and double lance arrangement. Introduction of Second Distance to compensate Driver’s confidence for increase in train speed

8. Up gradation In Track Circuit TREDLES AND LOCKBARS FOR TRAIN DETECTION DC TRACK CIRCUITS WITH SHEL TYPE RELAYS. SIEMEN’S SINGLE RAIL, DOUBLE RAIL AC 3PHASE POWER SUPPLY TRACK CKT AFTC, DIGITAL AXLE COUNTERS PAST NOW

9. Up gradation In Track Circuits Fundamental Concept being changed by AFTC and Axle Counter. Previous important factor of T. Ckt ‘Insulation Joint’ are not required DC Shelf type relay, Siemen’s 3 phase motor type track relay giving way to Electronic Circuit Boards. Electrical Feed Set, Relay Set (Transformers, Resistances )being replaced by Electronic Frequency Generators, Receivers, Modulators, D-Modulators, Amplifier and Filter Circuits.

10. POINT MECHANISM MECHANICAL POINTS ELECTRO-MECHNICAL POINT MACHINE ELECTRICALLY OPERATED POINT MACHINE LIVER CONTROLLED CABLE OPERATED POINTS PUSH BUTTON CONTROLLED CABLE OPERATED POINTS RODING OPERATED POINTS

11. Up gradation In Point Machine Wooden Sleeper Turn Out being replaced by Robust MBC Turn Outs Old Switches are replaced by Thick Web Switches for increase the speed of Trains. For Operate these Switches High Thrust Motors being introduced. Special Devise(SSD) being Introduced By Eng. Dept. for helping operation of point Motor. No of Cable Conductors and fuse capacity being increased to carry high currents. New sealing agent are in use for waterproofing of motors. Earth leakage meter now monitoring health of conductors

12. Up gradation In Block Inst. Norma Double Line Block Instruments being replaced with a Block Operating Panel , associated Relay and axle counter at stations at either End of the Block Station on Double Line. Operating Panel are used for operating Line Clear and Cancellation. Axle Counter are used for Auto verification of Section. By using Microprocessor based equipment- ‘ Multiplexer’ it has been possible to design ckt using only 2 PET quads

13. Modern Signaling Equipments Auxiliary Warning System Integrated Power Supply System(IPS) Un Interrupted Power Supply(UPS) . Digital Axle Counter. Audio Frequency Track Circuits. Solid State Interlocking. Train Management /Describer System

14. WHY MODERN SIGNALLING EQUIPMENTS (Source: Accident enquired into by CRS 93-94 to 97-98 Collision account the 1/4 th of the accident. The Driver will become the first casualty in any accidents,Hence he will never will dream of making an accident. 3% 51% 45% 1% Damage 11% 38% 4% 4% No Injured 17% 54% 19% 10% No. Killed 13% 27% 50% 10% No.of Accident MISC COLLISION DERAILMEENT LC GATES

15. Various railway Enquiry / safety committees have realized That There is an urgent need of an aid to warn the driver and Protect the traveling public in case of driver violating the Rules. They have recommended for the provision of AWS/ATS/ATP. Kazoo Committee:1962. Rancho Committee:1968. Skirl Committee:1979. Frostbit Accident Report:1995. Justice Venkatachala Committee:1996

16. Data logger Evaluator Connections of Relay Contacts and Interface Cards Assembly

17. A TYPICAL P.I. RELAY ROOM OF WAY SIDE STATION(NERAL,C.R. MUM. DIV.)

18. IN RELAY ROOM S&T SAFF HAS TO KEEP CONSTANT VIGIL OF THOUSANDS OF RELAY CONTACT FOR THE SAFE PASSAGE OF TRAIN

19. FIRE ALARM SYSTEM K- BOARD, CONNECTIONS BETWEEN INDOOR AND OUTDOOR SIG. EQUIPMENTS

20. POWER SUPPLY ROOM AND POWER SUPPLY EQUIPMENT TO BE LOOK AFTER BY SIGNAL TECHNITIAN

21. EVALUATOR UNIT OF S.E.L. AXLE COUNTER, MONITORS ENTRY & EXIST OF TRAIN BY COUNTING THE AXLE OF THE TRAIN,WHICH IN TURN MONITORED BY SIGNAL TECHNITIAN FOR ITS HEALTHY WORKING FOR SAFETY OF TRAFFIC

22. MEASERING EQUIPT. AND DIFF. RELAYS PHASE ANGLE METER EARTH LEAKAGE METER TRACK RELAY TIMER RELAY AFTC EVALUATOR

23. SPECIAL SPANNER FOR HANDELLING DELICATE EQUIPMENT FITTING SUCH AS AXLE COUNTER TRACK DIVICES DIGITAL MULTIMETER

24. FUSE RACK AND DIFFERENT SUPPLY BUSBAR 110V AC OR DC, 24 V AC OR DC OR FLASHING

25. A WHOLE TRAIN MAY DIVERT FROM ONE RAILWAY TRACK TO ANOTHR BY JUST OPERATION OF TWO POINT BUTTONS FROM PANEL ONLY

26. DUEL BANK BATT. CHARGER WITH MAINT FREE BATT. BANKS . BUT REQUIRE FREQUENT ADDITION OF DISTILLED WATER FOR PROPER FUNCTIONIG. THIS IS DONE REGULARLY BY SIGNAL TECHNITIAN

27. IMPORTED DIGITAL AXLE COUNTER (ALKATEL)

28. ADJUSTMENT OF AXLE COUNTER REQUIRE TECHNICAL & INTELECTUAL ATTENTION RATHER THAN PHYSICAL STRAIN.

29. TESTING KIT TRACK DIVICE. RECEIVER TRANMETER TEST WHEEL

30. SIGNALLING TECHNITIAN HAS TO SPENT FIVE TO EIGHT HOURS OF DUTY IN HIS SECTION IN ALL SEASON DAILY WITH TAKING CARE OF HIMSELF AND HIS STAFF SAFETY ALONE

31. ROUTINE MAINTANANCE EQUIPMENTS POINT MOTOR, POINT RODDINGS AND FITTINGS THEIR SETTING AND LUBRICATION

32. ROUTINE MAINTANANCE EQUIPMENTS SIGNALS, TRACK SIDE JUNCTION BOXES LOCATIONS AND FITTINGS

34. These all up gradation in signaling system may reduce the Physical strain of the S&T Staff but increases requirement of high level of technical mind set up. Special Instruments are required to note and record different parameters of devices. The requirement in delicate fittings increases rather than heavy Work. Demand for physical skill for connecting different Electrical component such as Transformer wiring, R/Room Wiring may reduced. But! It increases demand for high level intellectual ability to interface with the Electronics and Micro- Processor Circuitry. Require quick disision making mind to Analyze the Outputs and diagnosis the failure of equipments . S & T Staff which has so far proved its relevance to the changing needs of the time and technology are now again on the anvil to prove its ability to face the change in technology.

35. For the New Era it should have cleared picture of attribute of An Idle employee of an S&T Dept. who can make positive Contribution to growth of the Railway in the years to come So that this will effectively serve a reference standard to which All S&T staff are going to mould in new format . Though it will be difficult to steel possible to make a realistic guess and visualize of confidence we can then adopt such a frame work as the long term master goal to be achieved in the future the frame work can be improved and redefined as we pass through Era.