Braking System Intro:
    Basic Requirements for Brake System:
    • Controlled braking
    • Braking control to loco pilots and guard.
    • Passenger communication system in coach.
    • EBD (Emergency Braking Distance) within the limit.
    • Fail-safe i.e. automatic braking when train parts.
    • Brake inexhaustibility.
    • Less fading of brake power during the long run.
    • Easy maintainability.
    • Reliability
    • Multiple operation
    Major Components:
    • Common pipe bracket (CPB)
    • Distributor valve (DV)
    • Control reservoir (CR)
    • Auxiliary reservoir (AR)
    • Brake cylinder (BC)
    • Brake pipe & feed pipe


    Common Pipe Bracket (CPB):
    • Mounted on the underframe of a vehicle.
    • Facilitates fitment of any make of DV.
    • The DV along with the intermediate piece (sandwich) and the CR mounted on it’s two opposite faces.
    • Facilitates easy removal of DV without disturbing the pipe connections.
    Distributor Valve:
    The function of DV:
    • – Charges the system to regime pressure:
    •   * During normal/running condition.
    • – Helps in all types of brake application:
    •     * Graduated, full service as well as emergency type.
    • – Helps in brake release:
    •     * Graduated as well as manual.
    • – Controls the brake application & release time:
    •      * As per service conditions.
    • - Limits max. designed BC pressure
    • – Accelerates propagation of initial reduction of BP pressure throughout the length of the train
    •  - By arranging local vent of BP pressure inside the DV till BC pressure maintained at 0.8 Kg/cm2.
    • – Protects overcharging of CR up to some extent:
    •  * When the BP is overcharged after full-service application for quick brake release.
    • – Facilitates to isolate the system if required, and
    • - The complete system can be evaluated manually.
    Three Working Stages:
    • – Charging stage
    • * Brake pipe(BP) charged with 5 Kg/cm2 air pressure.
    • – Application stage
    • * BP pressure dropped for brake application.
    • – Releasing stage
    •  * BP pressure again raised for brake release
    Single Pipe vs Twin Pipe System:
    Modes of Brake Application:

    Reduction in B.P.Pressure:

    Minimum Brake Application0.5 to 0.8 Kg/cm2Service Brake Application0.8 to 1.0Kg/cm2Full Service Brake Application1.0 to 1.5Kg/cm2Emergency Brake ApplicationBrake pipe pressure fully exhausted

    Brake Riggings (Brake Gear) :
    ICF Coach:
    1. Conventional BC fitted (Underframe Mounted)
    2. BMBC fitted (Bogie Mounted)
    LHB Coach:
    1. Axle mounted disc brake
    2. Some other examples:
    3. Brake applying on wheel disc or wheel trade.
    1. Conventional BC fitted with
    2. ELB device or
    3. Load Sensing Device (LSD)
    4. BMBC fitted wagons with
    Load Sensing Device (LSD):
    1. Automatic BC Pressure Modification Device (APM)
    2. Developments in the wagon:
    3. U/frame mounted to bogie mounted system.
    4. Fitment of automatic load empty device.
    5. Load Sensing Device (LSD) in U/f mounted system.
    6. Automatic Pressure (BC) Modification (APM) Device in bogie mounted system.
    Developments in coach:
    1. U/frame mounted to bogie mounted system.
    2. Axle mounted disc brake system in LHB coach.
    3. WSP (Wheel Slide Protection) fitted.
    4. EP brake system in DEMU coach

    Salient Features:
    Almost no brake rigging.

    1. Microprocessor based WSP.
    2. Wheel turning frequency reduced.
    3. Centralised control for the complete coach.
    4. Use of Emergency Brake Accelerator for sharp emergency application in the complete train set.
    Brake Container Consists of :
    1. Brake control panel
    2. Reservoirs
    3. One 125L for brake application only (Protected by check valve)
    4. One 75L for toilets as well as brake
    5. One Control reservoir 6L for DV
    6. Weight -350 kg (with all equipment)
    7. Brake Container Consists of:
    Brake control panel:
    1. One 125L for brake application only (Protected by check valve)
    2. One 75L for toilets as well as brake
    3. One Control reservoir 6L for DV
    4. Weight -350 kg (with all equipment)
    Brake control panel Consists of:
    1. Test fittings (To Check FP, BP, CR & BC Pressure)
    2. Isolating cocks for F P, Toilet, Bogie-1, and Bogie-2.
    3. Filters for BP and FP
    4. Distributor valve
    5. Pressure switch (to operate WSP)
    6. Check valve
    Brake Components on Axle :
    1. Friction ring
    2. Clamping ring
    3. Hub
    4. Spring washer
    5. Hexagon Nut
    6. Hex-head bolt
    7. Anti-twist stud
    8. Screw plug
    9. Sealing ring
    Brake Disc consists of :
    1. A gray cast iron friction ring(a) with integral
    2. Crosswise cooling ribs
    3. Carry off the heat.
    4. Hub (c)
    Brake Equipment on the pipeline:
    Emergency Brake accelerator:
    1. Actuates on any rapid pressure reduction in BP, equivalent to an emergency application.
    2. Allows the BP to vent locally via a large orifice.
    Introduction of Bogie Mounted Brake System (BMBS):

    Bogie mounted brake system has been introduced for the freight stock in Indian Railways to reduce maintenance and tare weight of the stock. In BMBS, brake cylinder is the system with automatic two-stage braking mounted parallel to the brake beams and transfers forces through the bell cranks. BMBS is designed for single pipe/twin pipe graduated release air brake braking.

    The advantage over conventional system:
    • Two numbers 10” Dia. Brake cylinder with inbuilt double acting slack adjuster provided to adjust slack up to 500 mm and maintain a constant stroke.
    • All cylinders are equipped with an automatic piston stroke indicator.
    • Improved Brake efficiency of the system and high rigging ratio.
    • Less system weight.
    • Reliable, safe and easy maintained.
    • Uniform wheel loading, uniform brake block, and wheel wear.
    • Easy to retrofit and no modification required in existing bogie for retro fitment.
    • Integrated handbrake arrangement with SS handbrake.
    Main components of BMBS for one Wagon:
    • 10 inch Brake Cylinder without handbrake 1No
    • 10 inch Brake Cylinder with handbrake 1No
    • Primary Beam one for each bogie 2Nos
    • Secondary brake beam one for each bogie 2Nos
    • Lever L.H. one for each bogie 2Nos
    • Lever R.H. one for each bogie 2Nos
    • Push Rod two for each bogie 4Nos
    • Brake head four for each bogie 8Nos
    • Brake head pin four for each bogie 8Nos
    • K-type Brake block four for each bogie 8Nos
    • Brake block key four for each bogie 8Nos
    • Key retainer four for each bogie 8Nos
    • Set of pins, cotter, and washer etc. 2Nos
    • Isolating cocks with vent for cylinder 2Nos
    Automatic Pressure Modification Device (APM):

    The load-sensing device protects the wheels by reducing empty-stock braking forces that can result in costly wheel skidding, especially under adverse weather or track conditions. The device is a body mounted valve to sense loaded or empty conditions and provides a visual indicator of brake cylinder pressure. This valve is designed to optimize trouble-free performance on any application.

    Working Principle of APM:

    The wagons are provided with two-stage Automatic Brake Cylinder Pressure Modification Device (APM) to cater for higher brake power in loaded condition instead of the conventional manual empty load device.

    In this, brake cylinder pressure of 2.2 Kg/cm2 is obtained in an empty condition and 3.8 Kg/cm2 is obtained in the loaded condition. APM is interposed between the underframe and side frame of the bogie.

    The mechanism gets actuated at a pre-determined change overweight and changes the pressure going to the brake cylinder from 2.2. Kg/cm2 to 3.8 Kg/cm2 and vice –versa.

    Operating Instructions:


    • Before starting the train, move the brake valve handle (A-9) to release position.
    • Wait for 3 minutes to release the brakes for single pipe brake system. If train brakes have not been released fully, it may result in brake binding and excessive force on coupler
    • Ensure that air flow indicator white needle coincide with fixed red needle and light and buzzer are not giving any indication.


    • Do not move train if the air flow indicator light is glowing, the buzzer is giving sound and its white needle has not coincided with a red needle.
    • Do not start train after stopping the train at least for 3 minutes in case of single pipe air brake system.
    • Do not move train unless the brakes on the entire train are released fully.
    • Do not operate D-1 emergency brake valve in case of train parting.
    • Do not move train unless specified pressure is achieved.