OHE Breakdown Management — Traction Distribution Notes

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Traction breakdowns fall into three broad categories: sub-station/switching station failures, remote control equipment and cable failures, and OHE feeder-line/transmission-line failures. Each has its own emergency infrastructure and reporting chain.

Emergency Stores & Breakdown Equipment

Each OHE depot/sub-depot keeps a stock of masts, conductors, insulators, and fittings specifically earmarked for breakdowns — to start with, enough material for 3 kilometres of single line is kept, revised over time based on experience.
OHE Inspection Cars, wiring trains, breakdown lorries, and all breakdown tools/tackles/straining screws/clamps/ladders must be kept ready for use at all times.

Central Repair Shop & Mobile Power Van

Traction transformer failure requiring core/winding lift is extremely rare, but each railway maintains a Central Repair Shop with a crane bay (rail-accessible), underground oil storage tanks (separate for old/new oil), a 2500 litre/hour electrically-driven oil purification plant, dielectric-strength oil testing, and a test-room for relay/instrument calibration.

Each railway maintaining traction transformers also provides a Mobile Power Van: a 100 kVA, 415V AC 50Hz 3-phase engine-generator set, a 2500 litre/hour oil purification plant, a small mobile workshop (drilling, grinding, power hacksaw, welding, oxy-acetylene cutting), and portable flood-lights — allowing in-situ oil purification without bringing the transformer to the Central Repair Shop, and providing site lighting for extensive OHE breakdowns.

Remote Control Breakdown — Manual Operation

When remote control fails (P&T cable fault, remote equipment fault, battery failure), SSE(RC) or TPC suspends remote operation and arranges manual switching by an authorised 'Operator' — someone trained, examined, and declared competent by ADEE(TrD), listed in a TPC-maintained register.

Real Operator Duties (Manual Switching Post)

Must maintain a log book of all operations carried out, in order, including interruptions, abnormal occurrences, and defects — signed by both relieving and relieved operators at every shift change.
Forbidden to leave the post unless relieved by an authorised person — no interchange of duties or variation of duty hours without TPC's prior permission.
Must always be accompanied by another person (e.g. a Khalasi) who can intelligently use the telephone — a real staffing requirement, not just a suggestion.

The 6 Real Types of OHE Breakdown

Uprooting of or damage to OHE masts (cyclone, derailments, etc.).
Entanglement of pantographs with the OHE.
Snapping of OHE conductors.
Flash-over or other damage to insulators.
Faults on account of stray wires, etc.
Theft of OHE conductors.

Reporting Chain & TPC's Decision-Making

Engine crew of ALL trains must keep a sharp lookout for OHE defects and report to the nearest station. Any breakdown is reported immediately to TPC (or, if unreachable, the nearest SM/CASM, who relays it onward). The reporter should give the fullest possible detail — nature, location, whether masts are uprooted, whether both lines of a double-track section are affected — and must stay near the phone in case TPC needs to call back.

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Exam Focus — TPC Doesn't Just Cut Power Blindly

TPC switches off power to affected lines immediately, but the response is proportionate: the faulty elementary section is identified and isolated as quickly as possible so power stays available elsewhere. Often, TPC can block the line for electric locos/EMUs only — allowing steam and diesel trains to keep moving — or even permit electric traction to coast through at restricted speed with pantograph lowered, if damage is only slight. This decision requires consultation with traffic officials, not a unilateral electrical call.

Protective Steps at Site

SM/Section Controller regulates traffic on affected lines, issues caution orders, and introduces single-line working if feasible.
Every railway servant who notices hanging OHE conductors must take immediate preventive steps to keep people away — treating them as LIVE — until an authorised OHE-section person arrives and makes the OHE dead and earthed.