Electrical Safety in Railways
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Questions and Answers

The normal height of the contact wire for Broad Gauge is 6.00 meters at supports.

False (B)

The clearance for safety requires individuals to stay at least 2 meters away from live parts of the O.H.E.

True (A)

Caution Boards should be placed at a height of 4 meters above rail level on signal posts.

False (B)

The dotted outline in the diagrams is applicable for anchor spans.

<p>False (B)</p> Signup and view all the answers

In tunnels, the contact wire may be lowered to 4.58 meters for Broad Gauge.

<p>True (A)</p> Signup and view all the answers

It is advisable for personnel to avoid approaching within 1 meter of live conductors under normal conditions.

<p>False (B)</p> Signup and view all the answers

The diagrams consider the effects of wind on the displacement of wires.

<p>True (A)</p> Signup and view all the answers

Signal posts must always have protective iron screening if within 2 meters of a 25 KV live conductor.

<p>True (A)</p> Signup and view all the answers

The time delay for the relays releasing an interlocking should be between 0.6 to 0.8 minutes.

<p>False (B)</p> Signup and view all the answers

All external circuits in AC electrified areas must work with double cutting.

<p>True (A)</p> Signup and view all the answers

The maximum induced voltage from the traction system for signalling line circuits must not exceed 500 Volts under normal conditions.

<p>False (B)</p> Signup and view all the answers

The induced voltage in underground unscreened cable is considered to be 95 Volts/km on a single line under normal conditions.

<p>False (B)</p> Signup and view all the answers

All signals should be located on the right side of the track for which it refers.

<p>False (B)</p> Signup and view all the answers

The immunity of circuits terminated on relays/equipment must be at least 400 V AC.

<p>True (A)</p> Signup and view all the answers

The distance between a traction mast and a signal post should not be less than 30 meters.

<p>True (A)</p> Signup and view all the answers

It is permissible for a traction mast to be located less than 10 meters in advance of a signal post.

<p>False (B)</p> Signup and view all the answers

Signal posts must be sufficiently high to ensure visibility.

<p>True (A)</p> Signup and view all the answers

On tangent tracks, signals should be located outside the OHE structure.

<p>False (B)</p> Signup and view all the answers

The signal sighting committee is responsible for deciding the location of signals in obstructed areas.

<p>True (A)</p> Signup and view all the answers

No portion of a post or fittings of a color light signal can infringe the schedule of dimensions from the nearest track's center line.

<p>True (A)</p> Signup and view all the answers

OHE mast distances are irrelevant and can be placed arbitrarily according to Drg.No.22-D6.

<p>False (B)</p> Signup and view all the answers

The height of the center line of the red signal should be approximately 5.2 meters above rail level.

<p>False (B)</p> Signup and view all the answers

No OHE structures shall be provided in the same track space for at least 600 meters in front of the signals.

<p>False (B)</p> Signup and view all the answers

Portal drop arms can be located at least 600 meters before signals in track spaces where signals are present.

<p>False (B)</p> Signup and view all the answers

A special study is required if a portal drop arm is located in rear of the signal.

<p>True (A)</p> Signup and view all the answers

The visibility of the signal should only be checked during the day.

<p>False (B)</p> Signup and view all the answers

Signals without Junction Indicators between tracks do not require any distance restrictions for OHE structures.

<p>False (B)</p> Signup and view all the answers

The parameters for the location of portal drop arms are specified in a different section from where signals are discussed.

<p>False (B)</p> Signup and view all the answers

The drawing number Drg.No.22-D7 contains details regarding the setting distances of OHE masts for signals with Junction Indicators outside tracks.

<p>True (A)</p> Signup and view all the answers

The setting distance for Starter Signals of loop lines may be reduced under certain conditions.

<p>True (A)</p> Signup and view all the answers

The drop arms of portals should normally be located less than 600 m before a signal.

<p>False (B)</p> Signup and view all the answers

A colour light signal without a Route Indicator can be higher than 5.2 m above rail level.

<p>False (B)</p> Signup and view all the answers

Special studies must be conducted for drop arms near signals when necessary.

<p>True (A)</p> Signup and view all the answers

All overhead equipment should ideally be located less than 600 m before the signal.

<p>False (B)</p> Signup and view all the answers

No work can be done within a distance of two meters from the live parts of the O.H.E without a 'permit-to-work'.

<p>True (A)</p> Signup and view all the answers

The Engineering Inspector must apply for traffic and power blocks only after the work is completed.

<p>False (B)</p> Signup and view all the answers

A tree should be maintained at least 4 meters away from the nearest live conductor.

<p>True (A)</p> Signup and view all the answers

Authorized O.H.E staff are responsible for cutting or trimming trees near live conductors.

<p>True (A)</p> Signup and view all the answers

Fallen wires can be touched without turning off the power as long as they are earthed.

<p>False (B)</p> Signup and view all the answers

Staff on station roofs can use tools near live Overhead Equipment without any precautions.

<p>False (B)</p> Signup and view all the answers

In D.C. traction areas, prior notice must be given to the Traction Distribution Officer before excavation work.

<p>True (A)</p> Signup and view all the answers

The Gatekeeper must stop all road traffic immediately if wires drop at a level crossing.

<p>True (A)</p> Signup and view all the answers

In exceptional cases, signals may be located on the left side of the track.

<p>False (B)</p> Signup and view all the answers

The distance between the traction mast and signal post must not be less than 10 meters.

<p>False (B)</p> Signup and view all the answers

The signal sighting committee is essential for examining the site of signals on curved tracks or obstructed areas.

<p>True (A)</p> Signup and view all the answers

Signal posts should be located within the OHE structure on tangent tracks.

<p>False (B)</p> Signup and view all the answers

No color light signal can exceed the specified schedule of dimensions from the nearest track's center line.

<p>True (A)</p> Signup and view all the answers

OHE mast distances can be disregarded in favor of arbitrary placements.

<p>False (B)</p> Signup and view all the answers

The height of color light signals without Route Indicators can be up to 5.2 meters above rail level.

<p>True (A)</p> Signup and view all the answers

It is mandatory for a signal post to be sufficiently high to ensure visibility.

<p>True (A)</p> Signup and view all the answers

The minimum clearance required from the live conductor for a signal post or its fittings is 700 mm.

<p>True (A)</p> Signup and view all the answers

The approved checklist for works to be completed must be issued by the Chief Electrical Engineer.

<p>False (B)</p> Signup and view all the answers

Signals must be positioned so that no part is less than 2 meters away from any authoritative structure.

<p>False (B)</p> Signup and view all the answers

Insulated tools are mandatory for maintenance staff to work safely on electrical equipment.

<p>True (A)</p> Signup and view all the answers

All overhead track crossings must be converted into insulated cables and all associated overhead wires removed.

<p>True (A)</p> Signup and view all the answers

A clearance certificate from DOT for anti-theft energisation is mandatory for voltages above 2.2 KV.

<p>True (A)</p> Signup and view all the answers

The signal clearance diagrams are applicable for all types of electrified tracks without exception.

<p>False (B)</p> Signup and view all the answers

The drawing number 22-D1 provides the signal clearance diagram specifically for curved tracks.

<p>False (B)</p> Signup and view all the answers

Metal structures close to overhead equipment can have dangerous $50$ volts induced on them.

<p>False (B)</p> Signup and view all the answers

When unloading rails, they should form a continuous metallic mass of length less than $300$ meters.

<p>True (A)</p> Signup and view all the answers

Permanent Way staff must maintain a distance of $500$ meters from electrified trains.

<p>False (B)</p> Signup and view all the answers

In the case of a fire next to electrified equipment, immediate extinguishing efforts are required.

<p>False (B)</p> Signup and view all the answers

Electric shock victims can often be revived with prompt First Aid application.

<p>True (A)</p> Signup and view all the answers

It is safe for personnel to contact rails if they are $100$ meters away from an electrically hauled train.

<p>False (B)</p> Signup and view all the answers

Catch sidings can be energized when electric trains are standing in them if personnel are evacuated.

<p>False (B)</p> Signup and view all the answers

Permanent Way tools must be insulated to be used as approved by the Chief Engineer.

<p>True (A)</p> Signup and view all the answers

In AC traction areas, excavation work may proceed without notifying the concerned officers of the Electrical General Services.

<p>False (B)</p> Signup and view all the answers

Tiles and bricks are placed over cables in AC traction areas purely for aesthetic reasons.

<p>False (B)</p> Signup and view all the answers

The specified tolerances for the alignment of the track with respect to the contact wire allow for significant deviations.

<p>False (B)</p> Signup and view all the answers

Slewing or lifting of track outside agreed maintenance limits requires simultaneous alteration of the contact wire position.

<p>True (A)</p> Signup and view all the answers

All bonds removed by the Engineering Department must be replaced by an external contractor.

<p>False (B)</p> Signup and view all the answers

Cranes may be operated without a permit in emergency situations as long as safety precautions are taken.

<p>False (B)</p> Signup and view all the answers

The overhead equipment must be rendered 'dead' before inspecting the roofs and sides of a tunnel.

<p>True (A)</p> Signup and view all the answers

The contact wire's height above the track can be adjusted freely without notifying the traction staff.

<p>False (B)</p> Signup and view all the answers

A tree can be maintained within 4 meters from the nearest live conductor without any risks.

<p>False (B)</p> Signup and view all the answers

A 'permit-to-work' must be obtained before starting work within a distance of two meters from the live parts of the O.H.E.

<p>True (A)</p> Signup and view all the answers

Cutting or trimming trees adjacent to live conductors can be carried out by any staff member.

<p>False (B)</p> Signup and view all the answers

The Traction Power Controller issues a 'Permit-to-work' only after the work is completely finished.

<p>False (B)</p> Signup and view all the answers

Fallen wires can be safely touched if they are switched off and not earthed.

<p>False (B)</p> Signup and view all the answers

When working on station roofs near live Overhead Equipment, using measuring tools is strictly prohibited.

<p>True (A)</p> Signup and view all the answers

In D.C. traction areas, it is not necessary to inform the Traction Distribution Officer in advance for excavation work.

<p>False (B)</p> Signup and view all the answers

The Engineering Inspector must apply for traffic and power blocks significantly ahead of the scheduled work to ensure safety.

<p>True (A)</p> Signup and view all the answers

No aerial circuits are permitted in the electrified zone if they do not exceed a maximum induced voltage of 60 volts.

<p>False (B)</p> Signup and view all the answers

All luminous indicators must be connected to external circuits in AC electrified areas for proper functionality.

<p>False (B)</p> Signup and view all the answers

Polarized relays using permanent magnets may be safely used in any external circuit in 25 KV AC electrified areas.

<p>False (B)</p> Signup and view all the answers

Barring block-instrument circuits, earth-return circuits can be safely used in A.C. electrified territory.

<p>False (B)</p> Signup and view all the answers

The wiring in equipment located in cabins must be insulated from the ground using wires that meet approved specifications.

<p>True (A)</p> Signup and view all the answers

A separate battery or DC-DC converter must only be provided for external circuits according to the regulations.

<p>False (B)</p> Signup and view all the answers

The coils of equipment indicated such as telephone type relays can be used in external circuits if adequately filtered.

<p>False (B)</p> Signup and view all the answers

All batteries and wiring associated with electrical signaling equipment must be properly insulated to prevent induced voltage issues.

<p>True (A)</p> Signup and view all the answers

The time delay for relays releasing an interlocking should be between 0.6 to 0.8 seconds.

<p>True (A)</p> Signup and view all the answers

The maximum induced voltage from the traction system for signalling line circuits must not exceed 300 Volts under normal conditions.

<p>False (B)</p> Signup and view all the answers

The induced voltage in underground unscreened cable is considered to be 116 Volts/km on a single line under normal conditions.

<p>True (A)</p> Signup and view all the answers

All external circuits in AC electrified areas may work with single cutting.

<p>False (B)</p> Signup and view all the answers

When terminated on relays/equipment, their immunity shall not be less than 500 V AC.

<p>False (B)</p> Signup and view all the answers

The induced voltage in cable conductors is influenced by soil conductivity.

<p>True (A)</p> Signup and view all the answers

All signals in electrified areas can be of any type, not just colour light signals.

<p>False (B)</p> Signup and view all the answers

The Signal Sighting Committee is responsible for checking actual visibility of signals.

<p>True (A)</p> Signup and view all the answers

Special protective measures are not required if a portion of a signal post infringes the shaded area.

<p>False (B)</p> Signup and view all the answers

Return current through rails is a factor that influences the induced voltage.

<p>True (A)</p> Signup and view all the answers

Signal posts must not infringe the un-shaded portion of the standard moving dimensions diagram.

<p>True (A)</p> Signup and view all the answers

The separation between catenary and cable does not impact the induced voltage.

<p>False (B)</p> Signup and view all the answers

Masts, insulators, wires, and supports can totally obstruct the visibility of signals.

<p>False (B)</p> Signup and view all the answers

The maximum permissible length for a QNA1 relay on a single line is 2.1 km.

<p>True (A)</p> Signup and view all the answers

The maximum induced voltage for human safety is restricted to 600 V.

<p>False (B)</p> Signup and view all the answers

The maximum length for unscreened cable in a double track is 220 meters.

<p>True (A)</p> Signup and view all the answers

The AC immunity level for a K50 B1 relay is 130 volts.

<p>False (B)</p> Signup and view all the answers

A signal must be fed locally if located more than the prescribed distance from the signal control relays.

<p>True (A)</p> Signup and view all the answers

For a K50 relay, the maximum permissible length on a double line is 750 meters.

<p>False (B)</p> Signup and view all the answers

110 V 50 Hz type is the only type allowed for signal feed systems.

<p>False (B)</p> Signup and view all the answers

The maximum permitted length for direct feed of signal on single track is 180 meters.

<p>True (A)</p> Signup and view all the answers

The Train Controller must inform the staff about a break in the catenary/contact wire immediately.

<p>True (A)</p> Signup and view all the answers

An authorized representative of the Signal Department must verify and certify the functioning of the signalling equipment after a break.

<p>True (A)</p> Signup and view all the answers

All signalling equipment will continue to operate normally even if the block operations are suspended.

<p>False (B)</p> Signup and view all the answers

The existing signals must have a working clearance of at least 2 meters.

<p>True (A)</p> Signup and view all the answers

The guidelines for anti-theft charging must be disregarded in favor of other procedures.

<p>False (B)</p> Signup and view all the answers

No part of the signal post should be closer than 500 mm from the live conductor.

<p>False (B)</p> Signup and view all the answers

Immediate action is unnecessary if abnormal working is noticed in signalling equipment.

<p>False (B)</p> Signup and view all the answers

The clearance for safety requires individuals to stay at least 2.5 meters away from live parts of the O.H.E.

<p>False (B)</p> Signup and view all the answers

Maintenance staff are supplied with insulated tools for safety.

<p>True (A)</p> Signup and view all the answers

The replacement of existing DC track relays by AC immunized relays is necessary for 2.2 KV charging.

<p>True (A)</p> Signup and view all the answers

The distance between overhead wires and signals must be at least 1 meter.

<p>False (B)</p> Signup and view all the answers

A detailed test report is optional for the Signal Department's certification process.

<p>False (B)</p> Signup and view all the answers

All staff must be informed about any break in the Traction Overhead Lines by the quickest means possible.

<p>True (A)</p> Signup and view all the answers

A certificate of clearance from DOT is required for anti-theft energisation at 2.2 KV.

<p>True (A)</p> Signup and view all the answers

An approved checklist for works must be issued by the Principal Chief Signal and Telecom Engineer.

<p>True (A)</p> Signup and view all the answers

All overhead track crossings must be converted into cables and overhead wires should remain.

<p>False (B)</p> Signup and view all the answers

Continuity of return current path can be achieved by using mild steel straps or G.I. wire ropes when space is constrained.

<p>True (A)</p> Signup and view all the answers

Cross bonds are used to increase the resistance of the current in adjacent tracks.

<p>False (B)</p> Signup and view all the answers

Structure bonds connect all structures supporting overhead equipment to the earth for better grounding.

<p>True (A)</p> Signup and view all the answers

Failure of insulators or leakage of current does not affect the supply from the substation.

<p>False (B)</p> Signup and view all the answers

Precautions must be taken due to the proximity of a non-live conductor.

<p>False (B)</p> Signup and view all the answers

The return current in the rails can cause a potential difference between the rail and the surrounding mass of earth.

<p>True (A)</p> Signup and view all the answers

Removal or tampering of bonds can lead to safe working conditions.

<p>False (B)</p> Signup and view all the answers

Potential differences can occur between two ends of a fractured rail.

<p>True (A)</p> Signup and view all the answers

Flashcards

Catenary and Contact Wires

Parallel, insulated and un-insulated wires used in 25kV AC electrified areas.

Diagram Applicability

Dotted outlines in Drg. Nos. 22-D1, 22-D2, 22-D3 apply only to specific locations.

Excluded Locations

Anchor spans, turnouts, 3 meters from masts, loco sheds, inspection pits, along with feeder lines, and booster transformers are excluded from dotted outline diagrams.

Catenary Height

7.05 meters at its highest point are the normal standard height of the catenary.

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Contact Wire Height

5.60 meters at supports is the typical height for the contact wire.

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Low Clearance

Contact wire height may drop to 4.58 meters and catenary may be lowered in tunnels and under bridges for clearance.

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Electrical Safety Clearance

No one can come closer than 2 meters from the live parts of the overhead system (OHE).

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Protected Signal Posts

Posts close to live wires must have iron screens or caution boards to protect workers.

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Signal Location in RE Area

Signals in railway electrification areas (RE) are typically placed on the left side of the track, but right-side placement is permitted in exceptional cases.

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Visibility of Signals

To ensure signals are easily visible, overhead line equipment (OHE) masts are positioned appropriately, and signal posts are tall enough.

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Mast-Signal Distance

The distance between traction masts and signal posts must be at least 30 meters, with exceptions given for straight tracks, proper visibility and staggered positioning, and approval from railway authorities, in special cases. This distance can be reduced to 10 meters, when approved.

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Signal Height

Signal posts should be tall enough for good visibility.

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Signal Placement on Curved Tracks

Signal placement on curved tracks or areas with obstructions needs a special examination by a signal sighting committee to determine the safest location.

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Signal Post Dimensions

Signal posts and their components must not infringe on the permissible space limits (dimensions) from the center of the nearest track.

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Signals without Junction Indicators

For signals without junction indicators outside the tracks, the placement of OHE masts must adhere to specific drawings.

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OHE Mast Placement

OHE (Overhead Line Equipment) masts placement, especially in relation to signals, must adhere to design requirements on curves and obstruct-free straight stretches.

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Signal Height

The red signal's center line must be approximately 3.65 meters above rail level.

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Signal Height Limit (No Route Indicator)

No part of the signal without a route indicator can be higher than 5.2 meters above rail level.

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OHE Structures Placement (Signals between Tracks)

No OHE structures are allowed within 600 meters behind signals located between tracks.

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Portal Drop Arm Placement (Signals between Tracks)

Portal drop arms should not be located within at least 600 meters before the signal.

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Signal Mounting (Portal Drop Arm in rear of signal)

If an OHE portal drop arm is unavoidable near signals between tracks, offset mounting is required.

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Junction Indicator Location (Outside Tracks)

Signal settings of OHE masts (junction indicators outside tracks) shall comply with Diagram 22-D7.

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Signal Visibility Checks

Signal visibility must be checked by day and night after any OHE work, like mast erection or wiring.

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Visibility Issues Action

If visibility is inadequate, the relevant official must impose speed restrictions and take corrective actions.

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Slow-acting relays

Relays that release an interlocking slowly, preventing accidental release from short-duration voltage variations.

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Double cutting

External AC circuits in electrified areas must use double cutting in their operation.

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Maximum signalling line length

Signalling circuits must be limited to prevent induced voltage from the traction system from exceeding 400 Volts.

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Sectionalized power supply

Used when signalling line circuits leave enclosures in separate directions, to maintain induced voltage limits.

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Induced voltage in underground cable

The induced voltage in unscreened underground cables is 116 Volts/km for single line and 95 Volts/km for double line, under normal conditions.

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Signal Setting Distance

The distance between a signal and overhead equipment can be adjusted, as specified in drawings ETI/OHE/G/00112 Revision 'D' or latest.

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Signal Location Considerations

Signals should be positioned at least 600 meters from overhead equipment and drop arms to avoid conflicts; offsetting signals and drop arms may be necessary. Height and clearance must be checked.

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Signals with Route Indicators

Signals with route indicators require careful location to maintain sufficient clearance with live parts and pantograph sway zones.

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Signal Height Restrictions

Signals without route indicators should not be higher than 5.2m above rail level, maintaining minimum clearances for safe operations.

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Special Study Required

Cases where signals cannot be positioned at least 600 meters from interfering equipment require special analysis to ensure adequate clearance and safe operation.

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Overhead Equipment (OHE) Work Permit

A formal authorization required before any work within two meters of live OHE, necessary for safety procedures and isolating power and traffic.

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Live parts of OHE

Parts of overhead electric lines that are energized (carrying electricity).

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Safety Distance from OHE

Minimum distance (2 meters) required between workers and live OHE parts to prevent accidents.

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Earth Work in Traction Areas

Excavation near tracks requires advance notification (DC traction) to Traction staff, to prevent damaging underground cables.

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Tree Clearance from OHE

Trees and branches must be 4 meters from live conductors to prevent accidents, maintained by authorized OHE staff

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Fallen Wires

Fallen wires should only be touched after power is off, suitable earthing done to reduce hazardous electricity.

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Station Roofs Work

No tools or materials that could be wind-carried onto OHE are allowed during work on station roofs or signal gantries.

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Traffic Control on Level Crossings

If wires fall on a level crossing, the gatekeeper stops road traffic immediately.

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Signal Location (RE Area)

Signals in electrified railway areas (RE) are usually on the left side of the track, but can be on the right in special cases.

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Signal Visibility

Ensure signals are clearly visible by properly placing OHE masts and making the signal post tall enough.

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Mast-Signal Distance

The distance between traction masts and signal posts needs to be at least 30 meters, but can be reduced to 10 meters with approval if visibility isn't compromised.

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Signal Placement (Curves & Obstructions)

Signal locations on curves or areas with obstructions require independent review by a Signal Sighting Committee.

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Signal Post Dimensions

Signal posts and components cannot exceed the allowed space on the track.

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OHE Mast Placement (Signals without Indicators)

OHE mast placement for signals without junction indicators follows specific drawings.

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Signal Height Requirement

Signal posts have to be tall enough for clear visibility.

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Visibility Check After OHE Work

Daily and nightly visibility checks of signals are necessary after OHE (Overhead Line Equipment) tasks.

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Electrical Working Clearance

A minimum distance of 2 meters must be maintained between workers and live overhead equipment (OHE) for safety.

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Insulated Maintenance Tools

Maintenance workers must use insulated tools when working near live electrical conductors.

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Overhead Track Conversions

Converting overhead track crossings to cable-based systems and removing overhead wires.

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2.2 KV Anti-theft Energization Certificate

A required document verifying the safety of the 2.2 KV anti-theft energization setup.

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Signal Visibility in Electrified Area

Ensure signals are clearly visible in railway electrification areas, considering overhead line equipment placement.

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OHE Work Checklist

A checklist, approved by the relevant engineer, for completing the required tasks before charging overhead lines.

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Signal Clearance Diagrams (25kV)

Sets of diagrams defining safe distances around signals for 25 kV AC electrified tracks, accounting for curves and tangents.

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Signal Post Minimum Distance

The minimum distance of a signal post from live conductors is 700mm, to ensure safety.

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High-Rise OHE Clearances

Clearances for signals when running double-stack containers and three-tier cars, documented in Annexure 22-A3 and Drg. No. 22-D7.

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Aerial Circuits in Electrified Zones

Generally, aerial circuits should not remain within electrified areas. Parallelism and distance from electrified tracks must meet voltage restrictions.

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Earth-Return Circuits in AC Areas

Except for block instrument circuits, no other earth-return circuits are allowed in AC electrified areas, requiring special filters for block instruments.

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AC-Inducted Voltage Sensitive Equipment

Certain signalling equipment (e.g., luminous indicators, relays) are unsafe for use with AC induced voltages, requiring separate DC power.

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Battery Insulation in Equipment

All batteries and wiring within equipment enclosures (cabins, boxes) must be insulated from the ground to prevent short circuits.

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Separate AC/DC Power for Circuits

External and internal circuits should use separate batteries or DC-DC converters to control induced voltage exposure.

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Polarized Relays in AC Areas

Permanent magnet polarized relays are prohibited in external circuits, due to potential magnetic property loss.

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Cable Wiring Arrangement

Wires for individual circuits within a location or installation should, as far as possible, be bundled within the same cable to reduce disturbances and conflicts.

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Safety Distance from Live OHE

Workers must maintain a minimum distance of 2 meters from energized overhead equipment.

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Work Permit for OHE

Formal authorization required before any activity within 2 meters of live overhead equipment to prevent accidents and safely isolate power & traffic.

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Tree Clearance from OHE

Trees and branches must be at least 4 meters away from overhead electric conductors to prevent hazards.

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Fallen Wire Procedure

Fallen wires should only be touched after turning off power and performing safe earthing procedures.

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Station Roof Work Precautions

Tools and materials that could be windswept onto live overhead equipment cannot be used during operations involving station roofs and signal gantries.

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Level Crossing Wire Drop

Immediately stop all road traffic if overhead wires fall on or near a level crossing.

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Earth Work in Traction Areas (DC)

Prior notification is required for excavation work near tracks in DC traction areas to ensure that the relevant traction staff is on site to prevent damage to underground cables.

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Adjacent OHE Work

Engineering Inspector must seek authorization from proper authorities for work near overhead equipment to sanction traffic and power control measures.

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AC Traction Area Intimation

In areas with alternating current traction, inform Electrical General Services and S&T Department officials about cable locations due to electrical induction.

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Cable Markers

Traction department provides cable markers to indicate cable locations in AC and DC traction areas.

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Excavation in Traction Areas

If workmen find arranged tiles/bricks while excavating, report to higher officials. Further excavation requires authorized staff.

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Track Alignment Tolerances

Maintain specified track alignment tolerances (horizontal & vertical) with respect to contact wire alignment.

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Track Slewing/Lifting Limits

Slewing or lifting of tracks is restricted outside agreed limits unless the contact wire position is adjusted concurrently.

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Crane Operation Permit

Crane operation requires an authorized 'permit-to-work' and presence of overhead equipment staff for safety procedures.

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Tunnel Inspection & OHE

For tunnel roof/side inspections, rendering overhead equipment 'dead' is mandatory.

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Track Bonding Alterations

Engineering department staff must replace any removed bonds themselves and immediately notify the Assistant Electrical Engineer, and Traction in-charge.

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Sand-Sided Catching Siding

A siding section that is protected from electrical contact through grounding unless another train is connected via buffers or couplings.

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AC Traction Area Precautions

Additional safety measures needed in areas with alternating current traction, including potential buildup and rail unloading precautions.

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Induced Voltage (Metallic Bodies)

Dangerous voltage generated in metallic objects near overhead lines due to induction.

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Rail Unloading Caution

Rails must be unloaded, so that they don't touch to form a metallic mass longer than 300 meters.

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Fire in Electrified Area Response

For fires near electrified equipment, permanent way officials should report the fire to the station master without trying to extinguish it.

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Permanent Way Tools Safety

Using approved insulated and un-insulated permanent way tools, along with gloves, is essential in electrified areas.

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Electric Shock First Aid

Electric shock victims can often be revived with prompt first aid application.

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Staff Distance Requirements

Permanent way staff must maintain a safe distance (at least 250 meters) from trains' electrified components to prevent accidental contact during electrified train operation.

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Signal Clearance (25kV)

Safe distances around signals on 25 kV AC electrified tracks, considering curves and tangents. Specific diagrams exist for various track types.

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Signal Visibility

Ensuring signals are clearly visible, by appropriate location and height of the signal posts, considering OHE (Overhead Line Equipment) masts.

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Electrical Working Clearance

Minimum (2 meters) distance between workers and live OHE equipment for safety.

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Induced Voltage (Cables)

Voltage generated in conductors near electrified tracks, affecting signalling circuits. Measured based on parallelism and separation distances.

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OHE Work Permit

Formal authorization required before any work within 2 meters of live OHE, necessary for safety procedures.

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Signal Height Restrictions

Signals without route indicators should not be higher than 5.2m above rail level to keep clear of overhead systems.

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Visibility Check (After OHE Work)

Signal visibility from day and night are required after overhead line (OHE) work; e.g: mast erection or wiring.

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Mast-Signal Distance

Minimum distance between traction masts and signal posts (30 meters, reducible to 10 meters with approval).

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Slow-acting relays

Relays designed to release interlocking slowly, preventing accidental release due to short-duration voltage fluctuations.

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Double cutting

Using a double-cutting method in external AC circuits within electrified areas for safety.

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Maximum signalling line length

The longest allowable length for a signalling line circuit to prevent induced voltage from exceeding 400 Volts.

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Sectionalized power supply

A power supply system divided into sections to control induced voltage when signalling line circuits branch in different directions.

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Induced voltage in underground cable

The voltage induced in unscreened underground cables, which is 116 Volts/km on a single line and 95 Volts/km on a double line under normal conditions.

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Maximum DC Circuit Length (Line Relays)

The longest permissible distance for DC circuits on line relays with unscreened cables in electrified zones, determined by AC immunity levels, single and double-line configurations.

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Signal Feed Distance Limit

The maximum distance between signal control relays and the signal itself in electrified zones, preventing dangerously high induced voltages in the signal feed circuit, measured along the line of way.

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Maximum Permissible Length (Unscreened Cable)

The longest allowable distance of a direct signal feed using an 110V 50Hz system with unscreened cables on a single or double-track line.

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110 V 50 Hz Signal Feed System

A standard signal feed system that should be used or an approved equivalent in electrified areas, designed for signal control, maintaining proper operating voltages.

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Local Signal Feeding

A method of supplying power to a signal that's located beyond the maximum direct feed distance by installing controlling relays at that location.

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Remote Signal Feeding from Cabin

A method of providing signal power beyond the direct feed distance using controlling relays and cables.

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Separate Power Transformer

Power transformers that supply signal circuits exceeding the specified distance should be separate from those powering shorter circuits. This prevents issues associated with electrical interference.

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Maximum Permissible Induced Voltage

The maximum voltage that can be induced in a circuit, restricted to a safe value (400 V) for safety and taking a safety factor of 1.5 into consideration.

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Continuity Bonds

Metal connections between rails to ensure a continuous return path for current, preventing unsafe conditions.

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Cross Bonds

Connections between adjacent tracks to reduce electrical resistance and maintain safe current flow.

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Structure Bonds

Connections between structures supporting overhead equipment and the running rails for electrical safety.

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Live Conductor Proximity

Risk of direct contact with energized overhead equipment during work in electrified sections

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Return Current Potential

Potential differences that can arise between rails, earth, and other metallic parts due to return current.

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Safety Distance (OHE)

Minimum distance (2 meters) required between workers and live overhead equipment (OHE) parts

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Signal Location in RE Area

Signals in electrified railway areas are usually on the left side of the track, but can be on the right in special cases.

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Mast-Signal Distance

Minimum distance (30 meters, reducible to 10 meters with approval) between traction masts and signal posts.

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Catenary/Contact Wire Breakage

A broken catenary or contact wire (overhead electrical equipment) requires specific safety precautions for signal equipment operation.

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Train Controller Action

The Train Controller must immediately notify all signalling staff about a broken Traction Overhead Line (TOH).

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Signal Equipment Check

Signalling staff must verify if block and other signalling equipment are operating normally after a TOH break.

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Suspended Equipment

If any abnormal operation is found in the signalling system, its operation must be stopped immediately, following rules.

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Signal System Maintenance

Maintenance staff must immediately inspect all circuits and equipment, paying attention to external parts after receiving the intimation.

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Signal Department Certificate

An authorized Signal Department representative, no less than an SSE (Signal), must confirm the proper operation of the systems and submit a report to superiors.

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2.2 KV Anti-theft Charging

Anti-theft charging guidelines from Appendix VII of ACTM Vol-II Part II must be followed for S&T works.

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AC Immunized Relays

Existing DC track and line relays must be replaced with AC-immunized relays in S&T works before 2.2 KV charging.

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Electrical Working Clearance

Minimum 2-meter distance between workers and live overhead equipment (OHE).

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Insulated Tools

Maintenance staff must use insulated tools when working near energized conductors.

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Overhead Track Conversion

Changing overhead track crossings to cable-based systems and removing overhead wires.

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2.2 kV Anti-theft Certificate

Document confirming safety of 2.2 kV anti-theft energization system.

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Signal Visibility in RE Area

Ensuring signals are visible in electrified railway areas.

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OHE Work Checklist

Approved list of tasks before charging overhead lines.

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Signal Clearance Diagram

Drawing showing safe distances around signals for 25 kV AC traction.

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Signal Post Minimum Distance

Minimum distance of 700 mm between the signal post and the live conductors.

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