Page 390 - IRSEM_Main Book

(d) Fish bolts shall be kept tight. Nuts shall be tightened several times during
the first two weeks after installation/replacement, until all components of
an insulated rail joint are firmly set.

(e) A metal flow is seen often at the rail-table at the joints. Such metal flow of
metal forms a lip and creates sharp burrs at the rail ends. Projections
formed at the rail ends shall be chiseled without damaging the end post so
that these do not bridge the rail expansion gap and cause a short circuit.

(f) Brake block dust, which may accumulate on the head and sides of the end
post and top surfaces of the fish-plates, shall be brushed off frequently so
that the possibility of electrical conductivity being established between the
rail ends is eliminated.

(g) Opening & fixing of fish plates of Nylon insulation joint for installation/
replacement of joint shall not be done by S&T staff (as it is the responsibility
of Engineering Department).

(h) Special type pandrol clips ('J' type) shall be provided at Nylon insulation
joints/glued joint to avoid touching of pandrol clip with the fish plate.

(i) Periodic coating by insulating varnish/epoxy over the nylon-insulated
joint/glued joint to avoid shorting due to brake dust shall be done.

A faulty insulated joint may be detected by taking the voltage readings across
the track relay terminals and noting if this reading changes when the adjacent
track circuit feed is shunted or disconnected. Any change in the voltage
reading will indicate a faulty insulated joint.

17.3.4 Stretcher Bars and Point Rodding Connections

Insulation for stretcher bars and point rodding shall be periodically checked to
see that they are in sound condition. All defective insulation shall be changed.

17.3.5 Bond Wires/Rope Wires

(a) Bonds shall be inspected frequently and maintained in good condition.

(b) Bonds shall be painted with aluminum paint, where bond corrosions are
excessive.

(c) Voltage reading may be taken at every 15 rail lengths or less as required
by special track circuits, to determine if the variation in voltage is gradual
throughout the track circuit. If any unusual variations are found between
any two readings, defective bonding may be detected by taking readings
every rail length in that section or by inspection of each bond.

17.3.6 Jumper Connections: Jumper connections shall be inspected frequently and
maintained in good condition. Long jumper connections shall be properly
secured.

Chapter 17: Train Detection Track Circuits & Axle Counters Page 338 of 535