Page 69 - วิศวกรรมสาร ปีที่ 74 ฉบับที่ 1 มกราคม - เมษายน 2564 : Thailand Engineering Journal

Deposits on the Track

Systems that depend on the conductivity of
the rail and the track bed often reach their
limits given diverse influencing factors.
Damp leaves, large amounts of snow and
other conductive materials from the
industrial sector can, like flooding, lead to
false occupancy messages.
The introduction of road salt can also cause
a short circuit in the track circuit without an
axle. Conversely, rust and other deposits
can cause trains to be erroneously not
detected in individual sections if the rail's
conductivity is no longer given.
Inductive wheel sensors are not affected by
deposits on the track.
Inductive wheel sensors are not affected by these factors in their functionality. Even when covered
with different materials, they reliably detect trains thanks to their solid base technology. Even
deposits and rust formation on the rail itself have no influence.

Mechanical Impacts

Mechanical stresses on the track include substantial impacts or vibrations caused by wheel flats,
defective rail joints or even rail breaks. The resulting challenges affect both the components of
inductive wheel sensors and components of track circuits.

Depending on the functional principle, track circuits use different types of insulated rail joints to
separate individual track sections. However, these joints also form neuralgic points.
Displacements in the area of the rail joint, lead to the fact that track vehicles trigger shocks. It can
lead to breakouts in the area of insulated rail joints – the electrical separation of the affected track
sections is no longer given.

These mechanical impacts can also affect inductive wheel sensors that are mounted in the track.
Frauscher combines already known solutions with field-based know-how and comprehensive
laboratory tests when developing their sensors further accordingly. For example, the behaviour
of various housing and potting compound materials at varying temperatures was investigated
using suitable methods. Unique solutions have been developed to increase the mechanical
strength at neuralgic joints. Also, in the area of rail claws, experience and tests play a fundamental
role with regard to stability. Using optimised materials, fatigue fractures in the bolt are and the
loosening of mechanical clamping parts can be avoided even under extreme mechanical
influences.

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วิิศวิกรรมสาร ปีีที่่� 74 ฉบัับัที่่� 1 มกราคม-ม่นาคม 2564