Electrical Connections for Rail Jumper

Connection and Bonding

• Connections shall be firmly fitted to the web of the rail.
• Galvanized iron wires or cables may be used for short or long jumpers, respectively.
• The cross-section of galvanized iron wire shall not be less than 8 SWG, and cables shall not be smaller than 7/0.750 mm.
• Lead wires used for connecting feed sets to feed end boot leg/track lead Junction Box (JB) and track relay to relay end boot leg/track lead JB shall preferably be of copper conductor with a minimum cross-section of 2.5 sq.mm.

Bond Wires and Rope Wires

• Bond wires/rope wires shall be of an approved type, with duplicate wires installed close to the fish plate.
• Bond holes shall be drilled with a twist drill, and bonds driven in immediately.
• The resistance of rail and bonding per 1000 meters of track shall not exceed 0.5 ohms for track circuits longer than 700 meters.
• Rail bonding and connections to the relay and feed set shall be made according to approved drawings.

Types of Bonds in RE Area

• Rail Joint Bonds: Two 8 SWG bare galvanized steel wires or copper bonds/steel wires or flats secured by means of channel pins or welding/riveting.
• Rail bonds and Cross bonds: Installed by and remain the responsibility of the electrical department.
• Longitudinal bonding on a non-track circuited track adjacent to a track circuit shall be extended for a distance of 50 meters beyond the track circuit.
• The two rails of the non-track circuited track outside any track circuit or in between two track circuits shall be bonded together immediately after the block joints.

Maintenance

• The SSE/JE (Traction) and SSE/JE (Signal) of section shall arrange for physical inspection at six-month intervals to ensure conformity with approved Bonding Plan.
• In the event of faulty connection or bond being found, immediate remedial action will be taken to restore system integrity.

Stretcher Bars and Point Rodding Connections

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

Bond Wires/Rope Wires

• Bonds shall be inspected frequently and maintained in good condition.
• Bonds shall be painted with aluminum paint, where bond corrosion is excessive.
• 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.

Jumper Connections

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

Ballast

• Minimum ballast resistance of track should not be less than 2 ohms per km in station yards and 4 ohms per km in block sections.

Drainage

• Special attention shall be paid during the rains to track drainage.
• Defects, if any, shall be reported to the SSE/JE(P-Way).

Joint Inspection of Track

• The track circuited portion of the track shall be jointly inspected by SSE (Signal)/incharge and SSE(P-way)/incharge and jointly by Sectional SSE/JE (Signal) & SSE/JE (P-way) at least once in six months.

Hammer Driving and Rail Hole Alignment

• Hammer driving offish-bolt should be avoided to prevent damage to nylon bushes.
• Fish bolt can be easily inserted by hand pressure if the rail hole and fishplate holes are in proper position and alignment.

End-Post Trimming

• End-post should be trimmed and brought to the level of the rail table, especially when inserted between worn-out rails, before the first wheel of a train passes over it.

Insulated Block Joint and Detection Point

• The distance of 13 meters between the Insulated Block Joint or Detection Point and the starter signal can be reduced to 3 meters for signaled movements.
• The insulated Rail Block Joint or Device of Axle Counter or Joint Less Track Circuit should be fixed so that their boundary is within 0 to 3 meters in advance of the starter signal.

Point Track Circuits

• Insulation joint should not be in the stock rail joint but in the rail joint ahead of it wherever feasible.

Glued Joint Portions of Track

• Only 'J' type clip should be used in glued joint portions of track.

Track Indicators

• At track-circuited stations where track indicators are provided, the track indicators would show no light when the line is unoccupied.
• When the line is unoccupied, the track indicator light for the route shows yellow/white.
• When the track is occupied, a "RED" indication is shown on the panel diagram, irrespective of the route being set or not.
• At panel interlocked/route relay interlocked stations, the track indicators would show white/yellow light when the track is cleared after the intended movement is completed.
• At other stations, the indicator shall show yellow/white light when the line is unoccupied and RED when the line is occupied.

Axle Counter Resetting

• Preparatory reset arrangement should be provided, so that whenever the axle counter shows fault condition, the same can be reset by the on-duty Assistant Station Master/Station Master.
• The on-duty Assistant Station Master/Station Master should positively verify the clearance of the block section with the on-duty Assistant Station Master of the Train receiving station by exchanging private numbers and recording the same in the Train Signal Register.

Track Circuits and Axle Counters

• The maximum length of track circuit under different track parameter conditions shall not exceed the limits as given in the specified table.
• Limiting resistance of DC track circuits shall be adjustable and of an approved type.

Track Relays

• DC track relays of approved design should be used.
• In future installations, only plug-in type track relays (9 ohm) should be used, both in Non-RE and RE areas.
• Q series track relay must be used in conjunction with Q series slow to pick-up relay as a repeater relay.
• Excitation of DC Track Relay should be at minimum 125% of its rated pick-up voltage under minimum ballast resistance condition and normal working voltage of the supply.

Stretcher Bars and Point Rodding Connections

• Insulation for stretcher bars and point rodding should be periodically checked to ensure they are in sound condition.
• All defective insulation should be changed.

Bond Wires/Rope Wires

• Bonds should be inspected frequently and maintained in good condition.
• Bonds should be painted with aluminum paint where bond corrosions are excessive.
• 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.

Jumper Connections

• Jumper connections should be inspected frequently and maintained in good condition.
• Long jumper connections should be properly secured.

Ballast

• Minimum ballast resistance of track should not be less than 2 ohms per km in station yard and 4 ohms per km in the block section.

Drainage

• Special attention should be paid during the rains to track drainage.
• Defects, if any, should be reported to the SSE/JE(P-Way).
• All cases of defective valves of overhead water pipes in track-circuited area should be reported to the Inspector of works SSE/JE(Works).

Joint Inspection of Track

• The track-circuited portion of the track should be jointly inspected by SSE (Signal)/incharge and SSE(P-way)/incharge and jointly by Sectional SSE/JE (Signal) & SSE/JE (P-way) at least once in six months.

Power Supply and Cabling

• All lead connections to and from battery and DC-DC converter should have adequate current capacity to ensure that the voltage drop does not exceed 0.2 V.
• These connections at terminals should be secured properly and should preferably be made through lugs to give firm contact.
• Connections between battery, battery charger, and DC-DC converter should not be bunched with any other wires.
• These wires should preferably be laid at least 150 mm from any other bunch of wires.
• Positive and negative wires should be twin twisted to avoid interference pick up especially when the lead wires are long.

Communication Media

• The quad cable or PIJF Telecom Cable used with axle counters should be of approved type.
• The transmission loss, cross-talk measurements should be within limits specified for the axle counter to be installed.
• Optical Fibre Cable (OFC) may also be used for communication with suitable interfaces.
• All precautions prescribed for laying and installation of communication cables should be strictly followed.