1. ROLE OF SIGNALLING IN RAILWAYS1
ROLE OF SIGNALLING IN RAILWAYS
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.

2. Key Lock Inter locking 2
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.

3. Mechanical Signaling 3
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.

4. Electrical Signaling 4 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.

5. Route Relay Interlocking5
Individual operation is
avoided.
Final function is achieved
though pre-defined
automatic operation .

6. IBS / Automatic signaling6
IBS / Automatic signaling
IB / Automatic Signaling enhances the section capacity
Automatic signals are self controlled and avoids human operations

7. Electronic Interlocking7
Operation is done through computer or Panel
Microprocessor based interlocking system
Interlocking is achieved through Software.

8. Modern signaling 8
TPWS: Automatic train protection and prevents collision.
Avoids SPAD cases.
Transmits advance information to the Driver & controls the engine.

9. Advanced Signaling 9
ATC-Automatic Train Control., CTC –Centralized Traffic Control, Moving Block and Radio Block.