Page 400 - IRSEM_Main Book

Section 6: Axle Counters - General

17.6.1 Axle Counter consists of track device (axle detector) mounted on the rails,
track side electronic equipment provided near the track and connected with
track device & evaluator. Evaluator monitors the counts of track device(s) to
give clear/occupied indication. Evaluator/track side electronic equipment may
be kept in relay room or site.

(a) Digital Axle Counters of approved type may be used in lieu of track circuits
to prove the clearance of a portion of track.

(b) Axle Counters may also be provided in lieu of conventional track circuits for
block working, viz. Intermediate Block Signalling, Automatic Signalling,
Block Working controlled by track circuits, etc.

(c) Digital Axle Counter (DAC) may be preferred on girder bridges in lieu of
DC track circuits.

17.6.2 Typical usage of Axle Counters is for following applications:

(a) Intermediate Block Stop Signalling.

(b) Automatic block signaling.

(c) Station Section having poor drainage, flood prone sections.

(d) Block Section Proving of Clearance (BPAC).

(e) Tracks having problem of rust.

(f) Tunnels and bridges as per site requirement.

17.6.3 Trolley Suppression

Axle counter shall not count standard 4 spoke wheels of push trolleys.

Note: In those sections where certain models of Motor/Light motor/Moped/Scooter
trolley in use which may not get detected shall be taken care of, by suitable
provisions in Station Working Rules, working Time tables and subsidiary Rules. Such
Trolleys shall be run as per GR 15.25 for working of Motor trolleys.

Section 7: Installation of Axle Counters

17.7.1 The installation of Axle Counters shall be done as per prescribed installation
guidelines of OEM and approved pre-commissioning checklist.

Chapter 17: Train Detection Track Circuits & Axle Counters Page 348 of 535