The minimum strength requirement with D class weld for bogie structure is 52 kg/mm². This ensures structural integrity and safety under dynamic loading conditions.

Bogie is capable to permit the coach body to negotiate curve of 175 m radius at maximum speed potential of 40 kmph and 1 in 8½ turn out in either direction at 30 kmph.

Fluorescent tubes of 18 watts are used for general lighting, vestibule, toilet, pantry, and emergency working at 110 Volts AC/DC with inverter and polycarbonate diffusers.

The seats feature sleeplessly inclinable backrest with 17 degrees in upright position and 37 degrees in rest position. This allows smooth and continuous adjustment for passenger comfort.

The width between the arm rests is 420 mm in chair car and 500 mm in Executive class. The seat cushion height above floor level is 450 mm for both.

Non-AC LHB Hot Buffet Coach (EOG) with code LWCBNAC has 05 emergency windows, which is higher than the standard 04 emergency windows in most other coach types.

Non-AC luggage cum Guard Van (SG) with code LGSLRL has luggage capacity of 6.0 tonnes along with 30+6/4 berths. It has 03 lavatories and 03 emergency windows.

Non-AC Second class Three Tier (SG) coach has code LWGSCN with 78 Berths and tare weight of 39.60 tons. It also has 01 TTE berth as per specifications.

FIRST AC + AC TWO TIER composite coach has code LFCWAC with 10+28 passengers capacity (10 in First AC and 28 in AC Two Tier) and weight of 42.50 tons.

AC FIRST CLASS SLEEPER (SG) has the code LWGACW with 24 berths and weight of 47.50 tons. AC TWO TIER CLASS SLEEPER (SG) is LWGACC, and AC THREE TIER is LWGACCN.

The Generator cum Luggage & Brake Van (LWLRRM) has a weight of 53.00 tons with 5 berths (4 crew + 1 guard). This is one of the heavier LHB coach types due to the generator equipment.

Non-AC LHB Hot Buffet (EOG) has the code LWCBNAC with 15 berths and tare weight of 40.38 tons as per the important parameters table.

The Anubhuti Coach is similar to AC Executive Chair Car with advanced infotainment facilities. Like the Executive Chair Car, it has 56 passengers capacity (as per the AC Chair Car/First Class LFCZAC with 56 seats).

The High Capacity Double Decker AC Chair Car (EOG) has a maximum width over body of 3050 mm, which is narrower than the standard LHB coach width of 3240 mm.

The High Capacity Double Decker AC Chair Car (EOG) has a height of 4366 mm from rail level, which is higher than the standard LHB coach height of 4250 mm due to its double-decker configuration.

The length over CBC (Centre Buffer Coupler) is 24000 mm, while the length over body is 23540 mm. The difference accounts for the coupler projection.

The height of compartment floor from rail level under tare condition is 1320 mm. This provides appropriate platform interface height for passenger boarding.

The maximum distance between inner wheels is 12345 mm. This is an important dimensional parameter affecting the coach's stability and track interaction.

The window opening dimension in LHB coaches is 1480 x 760 mm, providing spacious and modern appearance to the coaches.

The wheel base of LHB coaches is 2560 mm. This is the distance between the front and rear axles of a bogie.

The minimum height from rail level is 91 mm. This is an important clearance parameter to ensure safe operation over track infrastructure.

The maximum CBC drop under gross load and worn conditions is 75 mm. The maximum height of centre line of side CBC above rail level for empty vehicle is 1105 mm, and minimum for loaded vehicle is 1030 mm.

The distance between centre pivots in LHB coaches is 14900 mm. This is the distance between the bogie pivot centers which affects the coach's ability to negotiate curves.

The coding system indicates suspension type: no suffix for coil spring, "A" for 120 KN Air spring, and "AA" for 160 KN Air spring. For example: LWLRRM (coil) → LWLRRMA (120 KN) → LWLRRMAA (160 KN).

LTLW (L) will always be counted from Passenger Emergency Relay valve fitment side. For power cars, it is counted from Guard compartment End looking towards generator cabin side.

Maximum Moving Dimension of LHB Coaches should be within "Diagram 1D (EDO/T-2202) of Schedule of Dimension BG (Revised 2004)" as per Railway Board letter No. 2019/CEDO/SD/IRSOD/O/ACS-27 dated 17.07.2019.

The couplers have adequate strength for satisfactory hauling of a train of 26 coaches at 110 kmph and satisfactory hauling of a train of 18 coaches at 160 kmph.

LHB coaches have been provided with tight lock centre buffer couplers instead of screw coupling. Couplers are AAR-H type and have anti-climbing features because of vertical interlocking.

Longitudinal traction efforts and braking powers follow the path: BODY → TRACTION CENTRE → TRACTION RODS → TRACTION LEVER → BOGIE FRAME → CONTROL ARM → AXLES.

Vertical forces follow the path: BODY → SECONDARY SPRINGS → BOGIE FRAME → PRIMARY SPRINGS/BALL JOINT CONTROL ARM → AXLES.

The body-bogie connection can cater for acceleration up to 0.5g in lateral and longitudinal direction. Beyond that value, a bracket comes into action between bogie bolster and coach body as a safety measure.

The body-bogie connection consists of disc spring, hemispherical ball, swinging link pin, link pin, etc. This connection is capable to cater for the acceleration value up to 0.5g in lateral and longitudinal direction.

The traction and braking force between bogie and body is transferred through a rocker device located at the center of the bogie approximately in the plane of axle.

A torsion bar having two forks is provided between bogie frame transverse beam with the help of two links to resist rolling motion of coach. This improves stability while negotiating curves.

One axle bearing on each bogie is fitted with a current return device. One bearing on each axle is fitted with sensors for detecting speed, and the remaining one bearing is without any attachment on each bogie.

Yaw damper for all types of LHB coaches fitted with FIAT Bogie has capacity of 11000 N and color RAL 7012 (Basalt Grey). Yaw dampers control the rotational movement of the bogie relative to the coach body.

Primary vertical dampers for all LHB coaches fitted with FIAT bogie have capacity of 2500 N and color RAL 7012 (Basalt Grey). Secondary vertical dampers for AC coaches are light green, while for Non-AC they are brown red.

Each FIAT bogie uses 4 primary vertical dampers, 2 secondary vertical dampers, one secondary lateral damper, and 2 yaw dampers. These are hydraulic shock absorbers to damp accelerations caused by track irregularities.

The IR-DRDO Small Bio-Digester Tank is used for LHB coaches. It is made of stainless steel with 06 partition walls inside the tank and two inbuilt C-Type mounting systems.

The bio-digester tank contains poly grass mats for protection of bacteria inside the walls. There is also stronger bonding of Colonized rubber mats with vertical walls.

The bio-digester tank is installed at a height of 270 mm from rail level. The tank dimensions are 515 mm height, 766 mm width, and 1040 mm length.

The bio-digester tank includes a ball valve with handle for operation during emergency for making toilet direct discharge in case of choking. This ensures that toilets remain functional even if the bio-digester system gets clogged.

The IR-DRDO Small Bio-Digester Tank has empty tank weight of 120 kg and full tank weight of 425 kg. The working volume is 332 litres with total volume of 410 litres.

Currently pressurized flushing system and bio vacuum toilets are being provided in LHB type coaches. These systems are more hygienic and environmentally friendly compared to traditional direct discharge toilets.

Flooring panels are lightweight, strong, warp resistant and also resistant to vibration/impact forces. These boards are specially treated for fire resistance. These are also resistant to moisture, cigarette burns, staining, ageing, etc.

The luggage racks are made from aluminum extrusion lengths and tempered safety glass. It can withstand distributed load of 1000 N (100 kgs) per meter length and pointed load of 850 N (85 Kgs) as per UIC 566.

Emergency window is similar to the fixed unit. A handle is connected to the rubber profile to open the glass unit of the emergency window. The breakage of glass unit while opening is prevented by a restraining chain.

The sealed unit consists of outer 8.4mm laminated glass and inner 4mm tempered safety glass with 6mm air gap with Krypton/Argon gas filling. Glasses are held by an aluminum extrusion frame with rubber profile.

Roof structure, side wall, and end wall are made of ferritic stainless steel. The floor sheet is corrugated austenitic stainless steel, while IRSM-41 CORTEN steel is used for underframe and other parts.

LHB coach can accommodate 72 passengers as compared to 64 in conventional AC III Tier Coach, thus giving better pay-to-tare ratio. This means more passengers can be carried without proportionally increasing the weight of the coach.

Indian Railways entered into a supply and technology transfer contract with M/s. ALSTOM LHB/Germany to initially supply 24 coaches consisting of 19 AC chair cars, 2 AC Executive Class Chair cars, and 3 Generator cum Brake vans.

ICF coaches had several limitations including limited speed potential, heavy corrosion problems, poor riding comfort, and wear and tear of undergear components. These limitations prompted Indian Railways to adopt LHB technology from ALSTOM LHB/Germany.