Railway Electrification
Railway Electrifications – Indian Railways
Overview
Railway electrification is the backbone of IR’s energy-efficiency drive. 100% electrification is targeted by Dec-2023 (achieved 98.3% by Mar-2024). Work started in 1925 with 1.5 kV DC on Harbour line (Mumbai); today 83%+ of BG route-km runs on 25 kV/50 Hz single-phase AC.
Key Facts & Figures
| Fact | Detail |
|---|---|
| 1st electrified section | Mumbai Victoria Terminus – Kurla (Harbour line), 1925 |
| Present system | 25 kV / 50 Hz AC, single-phase, overhead catenary |
| Current-collection device | Pantograph (maximum 2 per loco) |
| Standard height of contact wire (BG) | 5.45 m above rail level (min 4.57 m) |
| Standard tension length | 1000 m ± 200 m |
| Catenary wire material | Cadmium-copper / High-strength copper / Al-Alloy |
| Return circuit for traction | Running rails & buried traction earth wire |
| Traction substation spacing | 50–80 km (ideally 72 km) |
| Power block duration for OHE maintenance | 4 h (00:00–04:00 hrs) |
| OHE span (normal) | 72 m (max permissible 81 m) |
| Regulating organization | CORE (Central Organization for Railway Electrification) – HQ Allahabad |
| CORE formed | 1971 |
| States with 100% BG electrification | Odisha, Andhra Pradesh, Telangana, Chhattisgarh, Jharkhand (as on 31-03-24) |
| Energy-neutral plan | 100% electrification + 30 GW solar target by 2030 |
| Energy-consumption norm | ≈ 6.5 kWh per 1000 GTKM for electric loco |
| Savings vs diesel | 33% energy + 25% maintenance cost |
| Record electrification in FY 23-24 | 6,565 RKM |
| Total electrified RKM (Mar-24) | 65,000 RKM out of 66,000 RKM BG network |
Important Points (Quick Revision)
- Only 25 kV AC system is adopted for all fresh electrification since 1957.
- DC sections (1.5 kV) around Mumbai converted to 25 kV AC in 2016–17.
- CORE is one of the six Production Units of Indian Railways.
- Rail-wheel return is bonded every 250 m to reduce rail potential.
- Neutral Section (dead zone) length: 41 m (5 insulators) on straight track.
- OHE is fed via 132/220 kV utility grid → 25 kV via 21.6 MVA traction transformer.
- Auto-transformer system (2 × 25 kV) used only in high-density routes (e.g., Bina–Katni).
- Electric locos have regenerative braking – energy fed back to grid (saves 15–30%).
- Wind speed limit for OHE maintenance: 40 kmph (gust 50 kmph).
- Web-creep in contact wire limited to 150 mm per 1000 m tension length.
- Minimum clearances: 4.29 m for goods-platform, 5.3 m for foot-over-bridge soffit.
- SCADA (Supervisory Control & Data Acquisition) controls all traction substations remotely.
- Railway declared 100% electrified on 31-12-23 except 1,100 km under gauge-conversion.
- All electric locos are fitted with HOG (Head-On-Generation) to power coaches (saves 4 crore L diesel/yr).
- Next target: 100% Head-On-Generation coaches & 3-phase IGBT propulsion.
Frequently Asked in Exams
- Full form & HQ of CORE.
- Voltage and frequency of OHE.
- Standard height of contact wire.
- Purpose of neutral section & its length.
- Energy savings due to regenerative braking.
BETA
