1. INTRODUCTION TO LHB COACHES

1.1 Background

• Earlier Indian Railways mainly used ICF design coaches.

• Limitations of ICF coaches:

  • Limited speed potential

  • Heavy corrosion

  • Poor riding comfort

  • High undergear wear

To overcome these, Indian Railways collaborated with Alstom (LHB, Germany) for technology transfer.

• First LHB coaches commissioned in 2001.

• Bogies supplied by FIAT (Eurofima design).

2. ADVANTAGES OF LHB COACHES

2.1 Higher Carrying Capacity

• 2 meters longer than ICF coaches.

• Example:

  • AC 3-tier:

    • LHB → 72 passengers

    • ICF → 64 passengers

• Better Pay to Tare ratio

2.2 Lower Weight

• About 10% lighter than ICF.

• Reduces haulage cost.

2.3 Corrosion Resistance

• Extensive use of:

  • Stainless steel

  • CORTEN steel (IRSM-41)

2.4 Low Maintenance

• Major subsystem replacement only after 1 million km.

2.5 Safety Features

• Fire retardant furnishing

• Emergency openable windows

• Vertically interlocked Centre Buffer Coupler (CBC)

2.6 Passenger Comfort

• Better ride index

• FRP interior panels

• No visible screws

• Ergonomic seats

• Individual reading lights

3. IMPORTANT PARAMETERS OF LHB COACHES

3.1 General Dimensions

4. TYPES OF LHB COACHES

4.1 AC Coaches

4.2 Non-AC Coaches

5. BODY STRUCTURE

5.1 Car Body Shell

• Stainless steel construction

• Roof: Beaded sheet

• Floor: Corrugated austenitic stainless steel

• Side walls: Ferritic stainless steel

• Underframe: IRSM-41 CORTEN steel

5.2 Interior

• Modular construction

• Integrated lighting

• FRP panels

• Better aesthetics

6. HEAT AND SOUND INSULATION

• PU spray insulation

• Resonaflex mats

• Noise level inside coach: ≤ 60 dB

• Rubber-metal components in bogie

7. WINDOWS

Three types:

1. Fixed sealed window

   • 8.4 mm laminated outer glass

   • 4 mm inner tempered glass

   • 6 mm air gap (Argon/Krypton filled)

2. Emergency window

   • 4 per coach

   • Provided with handle and restraining chain

3. Hopper window

   • For lavatories

8. SEATS (Chair Cars)

• II AC Chair Car: 78 seats

• Executive Chair Car: 56 seats

• Seat cushion height: 450 mm

• Reclining:

  • Upright: 17°

  • Rest position: 37°

• Includes:

  • Foldable table

  • Bottle holder

  • Footrest

  • Magazine net

9. PASSENGER EMERGENCY ALARM

• Earlier: 5 per coach

• Now:

  • 2 in chair car

  • Provided in every bay for sleeper coaches

10. COACH LIGHTING

• Operates at 110V AC/DC

• Polycarbonate diffusers

11. FIAT BOGIE (EUROFIMA DESIGN)

11.1 Features

• Two-axle bogie

• Two-stage suspension:

  • Primary (helical springs)

  • Secondary (coil/air springs)

• Y-shaped frame

• Designed for:

  • 160 kmph

  • Upgradable to 200 kmph

11.2 Curve Negotiation

• 175 m radius curve at 40 kmph

• 1 in 8½ turnout at 30 kmph

11.3 Dampers Used

11.4 Axle Bearings

• Cartridge Taper Roller Bearings (CTRB)

• Pre-lubricated

• Maintenance-free

• One bearing per axle fitted with speed sensor

11.5 Anti-Roll Bar

• Torsion bar with forks

• Reduces rolling motion

11.6 Rocker Device

• Transfers traction & braking forces

12. FORCE TRANSMISSION

Vertical:

Body → Secondary Springs → Bogie Frame → Primary Springs → Axle

Lateral:

Body → Secondary Springs → Bogie Frame → Control Arm → Axle

Longitudinal:

Body → Traction Centre → Rods → Bogie Frame → Axle

13. CENTRE BUFFER COUPLER (CBC)

• Replaces screw coupling

• AAR-H type

• Anti-climbing feature

• Capable of:

  • 26 coaches @ 110 kmph

  • 18 coaches @ 160 kmph

• Allows angular misalignment

• Automatic locking

14. LAVATORIES

Types:

• Pressurized flushing

• Bio-vacuum toilets

Features:

• Wash basin

• Soap dispenser

• Shaver socket (110/220V)

• Flush button

• Hand grip

15. IR-DRDO BIO-DIGESTER TANK

Developed by Defence Research and Development Organisation

Dimensions:

• 1040 × 766 × 515 mm

• Total volume: 410 litres

• Working volume: 332 litres

• Empty weight: 120 kg

• Full weight: 425 kg

• Height from rail: 270 mm

Components:

• Stainless steel tank

• 6 partition walls

• Poly grass mats

• Ball valve for emergency discharge

• Colonized rubber mats

16. BIO-VACUUM TOILET SYSTEM

• Uses vacuum suction

• Minimal water usage

• Integrated with bio-digester

• Automatic bowl cleaning

17. OTHER ELECTRICAL EQUIPMENT

• Pantry equipment

• Soup warmer

• Hot case

• Refrigeration unit

18. MAXIMUM MOVING DIMENSION

Must comply with:

• Diagram 1D (EDO/T-2202)

• Schedule of Dimensions BG (Revised 2004)

• Railway Board Letter (17.07.2019)

IMPORTANT EXAM POINTS (VERY IMPORTANT)

1. Speed potential: 160 kmph (upgradable to 200)

2. Ride index: 2.5 at 160 kmph

3. Max axle load: 16.25 tonnes

4. Length over CBC: 24000 mm

5. FIAT bogie: 2-stage suspension

6. Noise level inside coach: ≤ 60 dB

7. CBC is anti-climbing type

8. LHB coach is 10% lighter than ICF

9. Emergency windows: 4 per coach

10. Bio-digester tank working volume: 332 litres