Page 326 - IRSEM_Main Book

13.2.4 ETCS level-1: Train Protection & Warning System (TPWS)

(a) Train Protection and Warning System assures higher level of safety during
train operation. It allows safe movement of trains under its supervision. It
enables automatic train protection and prevents collision, like situation. It
facilitates to run the train at maximum permitted speed by providing the
indication to the driver 500 meters in advance of signal and higher average
speed of train. The Entire system provides assistance to the Driver and
can be called as an aid to the Driver.

(b) TPWS basically consists of:

(i) Cab Equipment

(ii) Trackside Equipment

(c) Cab Equipment/On-Board Equipment

It consists of the following units:

(i) On-Board Computer (OBC)

(ii) Balise Transmission Module (BTM)

(iii) BTM Antenna

(iv) Simplified Driver Machine Interface (SDMI)
(v) Wheel Sensors

(vi) Brake Interface

(vii) Health indication Panel cum Emergency Brake (EB) counter

(viii) Audio Buzzer unit

(ix) Isolation switch

(d) Trackside Equipment

It consists of the following:
(i) Line Side Electronic unit (LEU)

(ii) Euro Balise consists of

 Fixed Balise
 Controlled Balise

(e) Sequence of Operation
(i) LEU picks up the Signal Aspect with its ECR input.

(ii) Aspect information passed on to the Balise.

(iii) BTM Antenna picks up telegram from Balise.

(iv) BTM decodes the data and sends to OBC.

Chapter 13: ATP, ETCS, IRATP (TCAS) & TMS Page 280 of 535