A signal is a device to communicate to Loco Pilot to go ahead or stop.

Signalling system facilitates the safe and efficient movement of trains on the railway.

1ROLE OF SIGNALLING IN RAILWAYS

Key Lock Inter locking

The human

element :

• Setting of the point and locking is entirely manual through key and lock system.

• Signals controlled by levers situated at the signals.

2

Mechanical Signaling

Operation of Points and Signals from a fixed location with group of levers through rigid connection (Rod / Wire)

System is interlocked mechanically by grouping the levers.

3

Electrical Signaling

Panel Interlocking

• Signals controlled by Operation from a Panel through cables by electrical means.

• Each function to be operated individually

• Interlocking is achieved through relays.

4

Route Relay Interlocking

Individual operation is avoided.

Final function is achieved

though pre-defined automatic operation

.

5

IBS / Automatic signaling

IB / Automatic Signaling enhances the section capacity

Automatic signals are self controlled and avoids human operations

6

Electronic Interlocking

Operation is done through computer or Panel

Microprocessor based interlocking system

Interlocking is achieved through Software.

7

Modern signalingTPWS: Automatic

train protection and prevents collision.

Avoids SPAD cases.Transmits advance

information to the Driver & controls the engine.

8

Advanced Signaling

ATC-Automatic Train Control., CTC –Centralized Traffic Control, Moving Block and Radio Block.

9