LAVIN KATIYAR

1113331094

ECE-VIIA

OUTLINE

Introduction

Components

Working

Do’s & Don’t

Other technology

Present era of technology

Conclusion

INTRODUCTION

Track circuit is simple electrical device used to detect the

Presence/Absence of train on the rails.

Track circuit is the one of the primary input for a signal

interlocking plant.

The signal cannot be green while there is another train on

track segment ahead.

COMPONENTS

Battery.

Track Relay.

Adjustable resistance.

Insulated rail joints.

Cond.Battery

Gravity cells are used .

Relay

A relay is electrically operated switch.

The Relay switch connections are usually labelledcommon ,normally closed, normally open.

Cond. Adjustable Resistance

TRc - Track Lead Resistance at feed end

TRr - Track lead Resistance at Relay end

RT - Regulating Resistance

Rr - Rail Resistance (Rail joint Resistance)

RB - Ballast Resistance

TSR - Train Shunt Resistance

Insulated rail joints.

Track circuit required insulated rail joint for isolating

it the adjacent track circuit.

Cond.

Nylon IRJ

Glued IRJ

Track circuit bonding

Rail bond need to be provided on track circuit have

point turnout them.

Cond.

WORKING

The portion of the Track which is to be Track circuited,

is first provided with wooden or RCC sleepers and then

the rails are insulated from the rest of the Track by the

provision of Insulated rail joints.

At one end of the Track circuit feed is connected and at

other end track relay is connected.

When the track portion is not occupied by trains, the

fed is available for track relay and the relay is in

energized condition.

Cond.When a train occupies the track circuit portion, the axel & wheels

shunt the track much of the circuit current is passed through the

wheels due to less resistive path and very less current is available

for track relay, which is not sufficient enough to pick up the relay.

Cond.

DEAD SECTION

Those section of the track circuit in which occupation by a vehicle cannot be detected.

Curved track.

Cross.

Bridge .

DO’S & DON’T

Top up distilled water if the electrolyte level is low in batteries.

Change the relay which is due to for overhauling.

Replace the damaged and corroded bonding wires.

Do not Tilt the relay.

Do not Test the track circuit by shunting with a wire only.

Track circuit does not get shunted properly by vehicles.

Its working length is dependent on immunity of track relay.

OTHER TECHNOLOGY

AC Track circuit.

Audio Frequency Track circuit.

Axle Counter.

Cond.

PRESENT ERA

Indian Railways is installing a state-of-art technology

along train tracks to detect of faults and defective parts in

coaches, wagons and locomotives.

The new system, which uses high-speed infrared and

digital cameras, will replace physical examination of the

wagons by railway staff.

The project, which will be run as trial project will be

installed at 10 locations at an estimated cost of 73 crore

rupees in the first phase.

CONCLUTION

DC Track circuit are the simplest , least costly andmost reliable type of track circuit.

Now a days for signalling purposes , trains aremonitored automatically by means of TRACKCIRCUIT.

Track circuit play important role in stop accidents,traffic .