Page 51 - วิศวกรรมสาร ปีที่ 74 ฉบับที่ 4 ตุลาคม - ธันวาคม 2564

Axle Counters Track Circuits

contaminants. Lightly used
passenger vehicles on
infrequently used lines may
also fail to provide an
adequate shunt. To avoid
safety hazards, track circuits
in such problematic areas
need closer monitoring, often
special technical measures
are required as well
Type of rail Can operate with practically Rail characteristics
all widely used rail profiles (resistance and inductance)
should be taken into account
in the parametrisation of the
TC

Installation requirements After installation training, 5 Drilling of rail required as well
minutes for each sensor as installation of insulated rail
using Frauscher rail claw joints
Bonding Not longer required for ACs, TC bonding is essential to
leading to less maintenance ensure that any short circuit
and greater reliability due to or disconnection in the track
the elimination of a weak circuit is indicated as
component compared to TCs apparent presence of a train.
Bonding is a weak and
maintenance consuming TC
component
Maintenance requirements Low – remote calibration and Frequent and regular
diagnostics reduce need for maintenance schedule
regular maintenance on site required
Track maintenance Sensors can be easily Wiring prevents easy removal
precautions removed, repositioned and from rail. Can be damaged
placed back on track during track maintenance
Train passage frequence Once in two years Every few days required to
required prevent rusty rails which
would decrease electric
conductivity between wheel
and rail
Installation costs Low High
Life-cycle maintenance costs Low High

All things considered, axle counting solutions convince with several advantages. They play out
their strengths also as vital and fail-safe “quick fixes” to existing systems with problematic track
circuits.

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วิศวกรรมสาร ปีที่ 74 ฉบับที่ 4 ตุลาคม-ธันวาคม 2564