Govt. Exams
Entrance Exams
The maximum speed limit for narrow gauge trains in India is typically 80 km/h due to track specifications.
Railway crossings include level crossings, grade separations, and diagonal crossings. Overhead crossing is not a standard railway crossing type.
IRSS refers to Integrated Railway Signal System used in modern Indian Railways for safe train operations.
Percentage increase = (100-80)/80 × 100 = 20/80 × 100 = 25%
# OHE in Railway Terminology
OHE is a fundamental acronym used in railway electrification systems to describe the infrastructure that supplies power to electric trains.
Step 1: Understand the Context
In railway systems, particularly those using electric traction, infrastructure components are essential for delivering electrical power to moving trains. The abbreviation OHE refers to the complete system of cables, supports, and equipment mounted above the track.
Step 2: Analyze Each Option
- (A) Overhead Equipment — Comprehensive term covering all electrical apparatus mounted above the rail line (correct)
- (B) Overhead Electrical — While related to electrical systems, this phrasing is less precise and not standard railway terminology
- (C) Overhead Expressway — Incorrect; railways use "expressway" in different contexts, not for power infrastructure
- (D) Overhead Extension — Incorrect; "extension" does not describe the functional purpose of this system
Step 3: Standard Railway Definition
OHE (Overhead Equipment) includes pantographs, contact wires, catenary cables, and support structures that form the electrified infrastructure. This is the official terminology used by railway authorities like Indian Railways (RRB/NTPC standards).
Answer: (A) Overhead Equipment — OHE is the standard railway engineering term for all electrical and mechanical equipment installed above the track to supply power to electric trains.
Howrah Station in Kolkata has the maximum number of platforms (23 platforms) among Indian railway stations.
Sidings are branch tracks where trains can be parked, waiting, or loaded/unloaded without blocking main lines.
# Indian Railways Braking System
The primary braking system used in Indian Railways is the Air Braking System (Westinghouse type), which uses compressed air to apply and release brakes across multiple coaches simultaneously.
## Step 1: Understanding Braking System Types
Indian Railways operates over 68,000 km of track with thousands of coaches. The braking system must be:
- Reliable across long trains
- Quick-acting for emergency situations
- Fail-safe (brakes apply automatically if pressure drops)
## Step 2: Why Air Braking System (Westinghouse)?
The Westinghouse air braking system is preferred because:
- Uses compressed air supplied from the locomotive's compressor
- Operates through a triple-valve mechanism on each coach
- Provides fail-safe operation: if air supply breaks, brakes automatically engage
- Allows independent control of locomotive and train brakes
## Step 3: Comparison with Other Systems
| System | Advantages | Disadvantages |
|--------|-----------|---------------|
| Air (Westinghouse) | Fail-safe, long trains, quick | Complex |
| Vacuum | Simpler, older | Slower, unreliable |
| Hydraulic | Compact | Limited range, not fail-safe |
| Electromagnetic | Fast | Requires electricity, expensive |
## Step 4: Indian Railways Standard
Indian Railways adopted the Westinghouse air braking system as the standard because it is:
- Suitable for heavy freight and passenger trains
- Effective on long-distance routes
- Cost-effective for large-scale operations
- Industry-proven technology
Answer: Air braking system (Westinghouse) (Option B)
Railway buffers (couplers) absorb and dissipate shock energy, protecting coaches from damage during coupling/decoupling.
As of 2024, there are 18 railway zones in Indian Railways after recent reorganization.
