Testing Equipment – Railway General Knowledge

1. Introduction

Railway testing equipment ensures safety, reliability and efficiency of rolling stock, track, signalling and electrical systems. Indian Railways (IR) follows RDSO/ICF/BIS/UIC/EN/ISO standards. Testing is done at three levels:

• Type (Design) Tests – on prototype
• Routine (Acceptance) Tests – on every unit
• Periodic (In-service) Tests – during maintenance

2. Classification of Railway Testing Equipment

3. Key Equipment in Detail

3.1 Ultrasonic Flaw Detector (USFD) – Track

• Purpose: Detect internal rail flaws (transverse, horizontal, bolt-hole).
• Technique: 0° & 70° probes, 4 MHz frequency, pulse-echo method.
• Spec: RDSO M&C/NDT/10/2004; sensitivity ≥ 2 mm FBH (Flat Bottom Hole).
• Recent: Indigenous “Rail-Saver” MK-IV (DRDO-IR) supplied 2023; GPS & cloud upload.

3.2 Track Recording Car (TRC)

• Measures geometry parameters: gauge (±0.5 mm), twist (base 3.6 m), alignment (±1 mm/10 m), top (±1 mm/10 m), cant deficiency.
• Speed: 160 kmph max (BG); 200 kmph on DFC (Wagon-TRC converted 2022).
• Sensors: Laser chord, accelerometer, gyroscope.
• Output: 3D track-geometry plot; alerts via T-369 software to track-machines.

3.3 Oscillograph Metro Coach (OMS)

• Introduced: 1962 Kolkata Metro; upgraded 2019 with MEMS-based 3-axis accelerometers.
• Use: Ride-index (RI) ≤ 2.75 (excellent) as per ISO 2631.

3.4 Wheel Impact Load Detector (WILD)

• Location: 88 installations (as on 1.4.2024) – 32 on DFC.
• Principle: Strain-gauge on rail web; measures vertical wheel-load > 90 kN (alarm) & > 110 kN (detain).
• Integration: RF-ID tag reading; auto SMS to ROH depot.

3.5 universal Testing Machine (UTM)

• Capacity: 1000 kN (electro-mechanical) at RDSO Lucknow.
• Tests: Tensile (UTS), Yield (0.2 % proof), % elongation, Bend (120°).
• Materials: IRS M-41 steel (350 MPa YS), IRS M-44 (540 MPa).

3.6 Spring Testing Machine

• Load range: 0–200 kN; deflection 0–150 mm.
• Acceptance criteria: Load loss ≤ 5 % after 3×10⁶ cycles (UIC 822).

3.7 Insulation & Hi-pot Tester

• OHE: 90 kV DC hi-pot for 1 min (new insulator string).
• Rolling stock: 4 kV AC, 1 min between windings & body (IRS S-23).

3.8 Earth Resistance Tester (Megger)

• Specification: ≤ 1 Ω for major stations, ≤ 2 Ω for minor stations (IS 3043).
• Method: Fall-of-potential (62 % rule).

3.9 Axle Counter Tester

• Count check: 0–9999; simulated wheel pass at 2 kHz.
• Safety: SIL-4 as per CENELEC 50129.

4. Historical Milestones

• 1926: First USFD trial on GIPR by Krautkramer.
• 1958: RDSO designs indigenous “Type-2” USFD; production at ICF.
• 1962: OMS commissioned for Kolkata Metro.
• 1987: TRC-1 built by BEML on YDM-4 under-frame; max 80 kmph.
• 1999: WILD prototype at Jhansi-North cabin.
• 2009: RDSO introduces digital USFD with A-scan & B-scan.
• 2014: TRC upgraded to 160 kmph with inertial referencing system (IRS).
• 2020: “Rail-Drishti” web-portal launched – live USFD & TRC data.
• 2023: First self-propelled 200 kmph TRC (SP-TRC-200) flagged off by MR.

5. Current Status & Recent Updates (2023-24)

• Mission 3000 T-18: 3000 km of track to be tested daily by TRC-18 coaches by 2025.
• AI-based USFD: Pilot on WCR; automatic classification of flaw severity.
• BEML order: 15 new USFD sets with Phased-Array (PAUT) capability (Feb 2024).
• DFCCIL: Deploying 24 WILD + 12 TRC for 3400 rkm DFC.
• Make-in-India: 85 % of testing equipment now procured through domestic vendors (RailTel, Medha, DEC).
• Green initiative: Battery-powered TRC-cum-RE (regenerative) saves 12 % traction energy.

6. Important Facts & Figures (Memory Bytes)

• RDSO: Established 1957, Lucknow; nodal agency for testing standards.
• Frequency used in USFD: 4 MHz (BG), 2 MHz (MG).
• Calibration block: V-2 (IS 6908) for rail; step wedge 1–10 mm.
• Record: Longest rail flaw – 450 mm transverse crack detected on 12-03-2022, ER.
• Penalty clause: Supplier pays 2 % extra if 1 % wagons fail static brake-test.
• Life of rail: 1000 GMT (Gross Million Tonnes) before scheduled USFD.
• Brake-power dyno: Absorbs 3000 kW (WAP-7 loco) at 120 kmph.
• Digital TRC sampling: 0.25 m (every) at 160 kmph → 640 Hz.
• Rail temperature expansion: 1 °C rise → 1.15 mm per 30 m rail → tested in climate chamber −10 °C to 70 °C.

7. 15+ MCQs with Answers

**Keep revising these facts and MCQs – 2-3 questions are assured every year in RRB technical categories.