Air Breaking System Report Diesel Training Centre, Tughlakabad, New Delhi

7/30/2019 Air Breaking System Report Diesel Training Centre, Tughlakabad, New Delhi

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DIESEL TRAINING CENTERTUGHLAKABAD, NEW DELHI PROJECT REPORT

Submitted by:-Suneel Kumar MeenaRamavatar MeenaIndian Institute of Technology Indore,M.P.

2012


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Acknowledgement

We would like to express our deepest gratitudetowards Mr.Omkant Sharma C.I.(DTC/Mechanical)and Mr. Vipin Kumar (Principal of Training school,Tughlakabad, New Delhi) for offering us theopportunity to work on a project and also all theSSE and the Workers of every section forcontinuously guiding us throughout the projectwork. Throughout the course of the project work,in this Internship, their advice and guidance gaveus the required motivation which ensured glitchfree completion of the project.

Mr. Omkant Sharma has been a guide to us in allsenses of the word and has been a constantsource of inspiration.

Mr. Omkant Sharma

SSE Mechanical (DTC Tughlakabad)


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INDEX

History of Indian RailwayIntroduction of Diesel Shed TKDTurbo supercharger SectionRunning/Mech. Goods and Mail SectionBogie SectionSpeedometer SectionYearly/Mech. Section

Fuel Injection Pump (FIP) SectionPit Wheel Lathe SectionCylinder Head SectionMetallurgical Lab & Zyglo Test SectionExpressor SectionCTA Cell SectionFuel Section

Control Room SectionProject Report On Air Braking SystemRefrences


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HISTORY OF INDIAN RAILWAY

Indian railway history

The plan to introduce a railway network, transformed the entireIndian history. This pioneering plan of action was first introduced in1832, but no measures were taken into consideration. In 1844, theprivate industrialists were permitted to initiate a railway system.Governor General of India, Lord Hardinge proposed this plan tointroduce the railway system. East India Company along with twoprivate companies initiated the establishment of rail system.

Origin of the Indian Railways

In 1851, 22nd December, the first rail came into being at Roorkee.After a year, got introduced first passenger rail service betweenThana, Mumbai and Bori Border. This railway track covered around34 kilometers distance. Since its inception, the Indian railway service


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never looked back. British Government advanced towards severalprivate investors to persuade them to enter the venture, with apromise to obtain 5% annual return initially. The railway network in1880 acquired a mileage of around 9,000 miles, working mostlythrough Calcutta, Madras and Bombay.

Development of the system

India, by 1895 had started industrializing its own engines. In a shortspan of time, various kingdoms started their independent railwaysystems. The network of railway system extended up to AndhraPradesh, Rajasthan and Assam. In the year 1901, a board of railwayswas formed, which worked underneath the supervision of Department of Commerce and Industry. The board comprised of railway manager, an agent and a Chairman respectively.

Railway gaining popularity

In 1907, many railway companies came under the control of thegovernment and started to draw efficient profits. Consequently, the

primary electronic locomotive materialized in the subsequent year.At the time of war, the conditions of railway became worse. Thegovernment in 1920 captured the Railway administration and linkagebetween the governmental revenues and railways funding gotdetached.


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INTRODUCTION TO DIESEL SHED

TUGHLAKABAD

Introduction:-


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About Diesel Shed Tughlakabad:-

At A Glance:-

Inception-----------------------------------------22 nd April, 1970

Present Holding --------------------------------154 Locos

Target ---------------------------------------------135 Locos

Accreditation-------------------------------------ISO-9001-2000 & ISO 14001

Covered Area of Shed--------------------------10, 858 sq. metre.

Total Area of Shed-------------------------------1, 10,000 sq. metre.

Staff Strength-------------------------------------sanction- 1357

-------------------------------------On roll- 1201

Berthing Capacity--------------------------------17 Locomotives


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The shed has a total berthing capacity for 17 locomotivesunder 4 covered bays. The main bays are:-

1. The subassemblies section.2. The heavy repair and bogie section(3 berths for heavy repairs & 2lifting points).3. Mail running repair bay(6 berths).4. Goods and out of course running repair bay(6 berths).

LOCOS AT TKD DIESEL SHED:- WDM2 - 2600 HP

WDP1 - 2300 HP WDP3A - 3100 HP WDM3A - 3100 HP WDM3C - 3300 HP

Schedule:- There are two types of Schedule:

1) Minor Schedule.

2) Major Schedule Minor Schedule :- The following types of Minorschedule are there:

1. T-1 SHEDULE AFTER 15 DAYS2. T-2 SHEDULE AFTER 30 DAYS3. T-1 SHEDULE AFTER 45 DAYS4. M-2 SHEDULE AFTER 60 DAYS

5. T-1 SHEDULE AFTER 75 DAYS6. T-2 SHEDULE AFTER 90 DAYS7. T-1 SHEDULE AFTER 105 DAYS8. M-4 SHEDULE AFTER 120 DAYS9. M-8 SHEDULE AFTER 135 DAYS

MAJOR SCHEDULES:

M-4 SCHEDULE.


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TURBO CHARGER SECTION

Introduction: -

A turbo charger is a forced induction device used to allow morepower to be produced for an engine of a given size.

Working Principle:-

The amount of power obtained from a cylinder in a diesel enginedepends on how much fuel can be burnt in it. The amount of fuelwhich can be burnt depends on the amount of air available in thecylinder. So, if you can get more air into the cylinder, more fuel willbe burnt and you will get more power out of your ignition. Turbocharging is used to increase the amount of air pushed into eachcylinder. The turbo charger is driven by exhaust gas from the engine.This gas drives a fan which, in turn, drives a small compressor whichpushes the additional air into the cylinder. Turbo charging gives a50% increase in engine power.

A turbocharger does not place a direct mechanical load on theengine. It is more efficient because it uses kinetic energy of theexhaust gas to drive the compressor.
http://en.wikipedia.org/wiki/Forced_inductionhttp://en.wikipedia.org/wiki/Forced_inductionhttp://en.wikipedia.org/wiki/Forced_inductionhttp://en.wikipedia.org/wiki/Forced_induction


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Fig:- Air inlet section of turbo charger

The main advantage of the turbo charger is that it gives more powerwith no increase in fuel costs because it uses exhaust drive power. itdoes need additional maintenance, however, so there are some typesof lower power locomotives which are built without it. The mainworking of this section is to maintain the supercharger. The differenttypes of supercharger used in TKD diesel shed are as follows :-

1. ALCO Turbocharger (Capacity of 1.2-1.5kg/cm2)------water cooled2. A.B.B Turbocharger (Capacity of 1.2-2.0 kg/cm2)-----water cooled3. G.E. Turbocharger (Capacity of 1.2-2.30 kg/cm2)------water cooled4. A.B.B TPR --------air cooled5. STANO SUJA (MEKA) Turbocharger ---------air cooled6. NAPIER Turbocharger -----water cooledThe difference between them is based on cooling system used &

power required. STANO SUJA & NAPIER are air-cooled and otherare water cooled.


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Working:-

The turbocharger is bolted to the exhaust manifold of the engine. Theexhaust from the cylinder spins the turbine, which works like a gasturbine engine. The turbine is connected by a shaft of the compressor,which is located between the air filter and the intake manifold. Thecompressor pressurizes the air going into the pistons. Hence theengine produces more power.

RUNNING/Mech./GOODS&MAIL SECTION


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BOGIE SECTION

Introduction:-

A bogie is a wheeled wagon or trolley. In mechanics terms , a bogie isa chassis or framework carrying wheels, attached to a vehicle. It canbe fixed in place, as on a cargo truck, mounted on a swivel, as on arailway carriage/car or locomotive, or sprung as in the suspension of acaterpillar tracked vehicle, or as an assembly in the landing gear of anaircraft.This is the part (called the bogie) carrying the wheels and traction

motors of the locomotive. A pair of train wheels is rigidly fixed to anaxle to form a wheel set. Normally, if two wheel sets are mounted in abogie it is known as BO-BO type, but if three wheel sets are mountedon truck, it is called as CO-CO type. Most bogies have rigid frames asshown below.

The key component include in Bogie are:The bogie frame : This can be of inside frame type where the main

frame and bearings are between the wheels, or (more commonly) of


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outside frame type where the main frame and bearings are outside thewheels.

Suspension to absorb shocks between the bogie frame andthe rail vehicle body : Common types are coil springs, or rubberairbags.

At least one wheel set, composed of an axle with a bearings andwheel at each end.

Axle box suspensions absorb shocks between the axle bearingsand the bogie frame. The axle box suspension usually consistsof a spring between the bogie frame and axle bearings to permitup-and-down movement, and sliders to prevent lateralmovement. A more modern design uses solid rubber springs.

Brake equipment : Two main types are used: brake shoes thatare pressed against the tread of the wheel, and disc brakes andpads. Etc.


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Bogie Function:-

A bogie in the UK, or a wheel truck, or simply truck in NorthAmerica, is a structure underneath a train to which axles (and, hence,wheels) are attached through bearings.

Bogies serve a number of purposes: Support of the rail vehicle body.

Stability on both straight and curved track. Ensuring ride comfort by absorbing vibration and minimizing

centrifugal forces when the train runs on curves at high speed. Minimizing generation of track irregularities and rail abrasion.

Note:- The connections of the bogie with the rail vehicle allow acertain degree of rotational movement around a vertical axis pivot(bolster), with side bearers preventing excessive movement. More

modern, bolster less bogie designs omit these features, instead takingadvantage of the sideways movement of the suspension to permitrotational movement.

Classification of Bogies:-Bogie is classified into the various types according to their

configuration in terms of the number of axles, and the design andstructure of the suspension. According to UIC classification two

types of bogies in Indian Railway are:


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Bo-Bo and Co-Co.

SPEEDOMETER SECTION


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Introduction:-

The electronic speedometer is intended to measure travelling speedand to record the status of selected locomotive engine parametersevery second. It comprises a central processing unit that performsthe basic functions, two monitors that are used for displaying themeasured speed values and entering locomotive driversidentification data and drive parameters and a speed transducer. Thespeedometer can be fitted into any railway traction vehicles. Themonitor is mounted on every drivers place in a locomotive. It isconnected to the CPU by a serial link. Monitor transmits a driver,locomotive and train identification data to the CPU and receives dataon travel speed, partial distance travelled , real time andspeedometer status from the CPU. A locomotive drivercommunicates with the speedometer using the monitor:-a keyboard

and alphanumeric displays are used for authorization purposes,travel speed values are monitored on analog and digital displays,whereas alphanumeric displays, LEDs , and a buzzer signal provideinformation on speedometer and vehicle status.

Working Mechanism:-

Speedometer is a closed loop system on which opt-electronic pulsegenerator is used to convert the speed of locomotive wheel into thecorresponding pulses. Pulses thus generated are then converted intothe corresponding steps for stepper motor. These steps then decidethe movement of stepper motor which rotates the pointer up to thedesired position. A feedback potentiometer is also used with pointer

that provides a signal corresponding to actual position of the pointer,


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which then compared with the step of stepper motor by measuringand control section. If any error is observed, it corrected by movingthe pointer to corresponding position. Presently a new version of

speed-time-distance recorder cum indicator unit TELPRO is used inthe most of the locomotive. Features and other technicalspecification of this speedometer are given below:

Salient features:-

Light weight and compact in size. Adequate journey data recording capacity. Both analog and digital displays for speed. Both internal and external memories for data storage.

Memory freeze facility. Step less wheel wear compensation. Dual sensor opto-electronic pulse generator for speed sensing. Over speed audio visual alarm. 7-digit odometer. User friendly Windows-based data extraction and analysissoftware.


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Graphical and tabular reports generation for easy analysing of recorded data.

Cumulative, Trip-wise, Train-wise, Drive-wise and Data-wise

report generation. Master-slave configuration.

Applications:-

Speed indication for driver. Administrative control of traction vehicle for trafficscheduling.

Vehicle trend analysis in case of derailment/accident. Analysis of drivers operational performance to providetraining, if required.

Fig: TELPRO speedometer connection

Technical Specifications:

The system requires a wide operating voltage of 50 V DC to 140 V DC.


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A. Operating conditions :

Conditions Values

Temperature -5C to +70C

Relative humidity 95% (max)

Accuracy of Master& Slave 1.0% of full scale deflection

B. Analogue indication:

Factors Values

Scale spread over 240

Illumination 12 equally spaced LEDS on dial circumference

Brightness control 0-100% in 10 steps

Dial size 120 mm

Dial colour White with black pointer & numerals

Max speed range 0-150, 0-160 & 0-180 Km/hr

C. Digital Indication:

Features Values

LCD Display 16 x2 character alphanumeric LCD with

black lit control

Time Display HH:MM:SS in 24 hours format

D. General:

Factors Values

Size 145 x215 x 160 mm (typical)


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Weight: Master &Slave 3.5 Kg (master) & 3.15Kg (slave)

Odometer 7 digit with 1 km resolution

Input speed sensing 2 inputs for opto-electronic pulse

generator 200 or 100 pulses/rev

YEARLY/MECHANICAL SECTION

Introduction:-

In this section, major schedule such as M-24, M-48 and M-72 arecarried out. Here, complete overhauling of the locomotive is doneand all the parts are sent to the respective section and new parts areinstalled after which load test is done to check proper working of theparts.

Work done:-

The work done under this section is as follows:

Repeating of all items of trip, quarterly and monthly schedule.


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Replacement of coalesce element of air dryer. Reconditioning, calibration and checking of timing of FIP is

done injector is overhauled.

RDP testing of radiator fan, greasing of bearing, checking of shaft and keyway. Examination of coupling and backlashchecking of gear unit is done.

Testing of all valves of vacuum/compressed air system, repair if necessary.

Examination of piston for cracks; renew bearing shell of connecting rod fitment, checking of connecting rod elongation.

Checking of crankshaft thrust and deflection. Lube oil system: Overhauling of pressure regulating valves, by

pass valve, lube oil filters and strainers is done. Fuel oil system: Overhauling of pressure regulating valves,

pressure relief valve, primary and secondary filters. Cooling water system: Draining of the cooling water from

system and cleaning with new water carrying 4 Kg of tri-phosphate is done. All water system gaskets are replaced.Water drain cock is sealed. Copper vent pipes are changed andwater hoses are renewed.

Bogie : Checking of frame links, spring, equalizing beamlocating roller pins for free movement, buffer height, equalizerbeam for cracks, rail guard distance is done. Refilling of centre

plate and loading pads is done. Axle Box: cleaning of axle-box housing is done. Wheels: inspection for fracture or flat spot. Wheel are turned

and gauged. Traction motor suspension bearings: cleaning of wick

assembly, checking of wear in motor nose suspension. Correctof felt wick lubricators is ensured.


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Examination while engine is running:-

Expressor orifice test is performed. Engine over speed tripassembly operation, LWS operation are checked.

Brake at all application positions is checked. Checking of fastand flexible coupling is done and the expressor is properlyaligned. Inspection of camshaft. Lubrication of hand brake leverand chain.

Speedometer: Overhaul, testing of speed recorder andindicator, pulse generator is done.

Fig: Schematic diagram of Yearly/Mech. process

Additional items for W DP1: - Overhauling and operation of TBUis done, centre pivot pin is checked and CPP bush housing linersare checked for wear, inspection of vibration dampers for oil

leakage and their operation. RDP test is done to check for


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cracks at critical location in the bogie frame. Checking of coilsprings for free height.

Additional items for W DP2: Checking for cracks bogie frame

and bolster. Checking of hydraulic dampers for oil leakage.Check coil spring for free height. Zyglo test of guide link bolts isperformed. Examination of taper roller bearing for theircondition and clearance is done. Check and change centre pivotliners. Checking of tightness of nuts on break head pin.Disassembly, cleaning, greasing, repairing, replacement of break cylinder parts Is done. Ultrasonic test of axles isperformed. Visual examination of suspension springs for crackand breakage. Checking of free and working height of spring.Inspection of bull gear for any visible damage is done and theteeth profile is checked. Test loco on load box as per RDSOstandards.

FUEL INJECTION PUMP SECTION


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Introduction:-

It is a constant stroke plunger type pump with variable qualityof fuel delivery to suit the demands of the engine. The fuel camcontrols the pumping stroke of the plunger. The length of thestroke of the plunger and the time of the stroke is dependenton the cam angle and cam profile, and the plunger springcontrols the return stroke of the plunger. The plunger movesinside the barrel, which has very close tolerances with theplunger. When the plunger reaches BDC (bottom dead centre),

spill ports in the barrel, which are connected to the fuel feedsystem, open up. Oil then fills up the empty space inside thebarrel. At the correct time in the diesel cycle, the fuel campushes the plunger forward, and the moving plunger covers thespill ports. Thus, the oil trapped in the barrel is forced outthrough the delivery valve to be injected into the combustionchamber through the injection nozzle. The plunger has twoidentical helical grooves or helix cut at the top edge with therelief slot of the control sleeve. When the rotation of theengine moves the cam shaft, the fuel cam moves the plunger tomake the upward stroke.

The engine stops because of no fuel injected and this isknown as NO FUEL position. When alignment of helix relief

with spill port is delayed, it results in a partly effective strokeand engine runs at low speed and power output is not themaximum.

When the helix is not in alignment with the spill portthroughout the stroke, this is known as FULL FUEL POSITION,because the entire stroke is effective.


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Fuel Injection Nozzle:-

The fuel injection nozzle or the fuel injector is fitted in thecylinder head with its tip projected inside the combustionchamber. It remains connected to the respective fuel injectionpump with a steel tube known as fuel high pressure line. Thefuel injection nozzle is of multi-hole needle valve typeoperating against spring tension. The needle valve closes the oilholes by blocking the oil holes due to spring pressure. Properangle on the valve and the valve seat, and perfect bearing

ensures proper closing of the valve.

Due to delivery stroke of the fuel injection pump, pressure of fuel oil in the fuel duct and the pressure chamber inside thenozzle increases. When the pressure of oil is higher than thevalve spring pressure, valve moves away from its seat, whichuncovers the small holes in the nozzle tip. High-pressure oil isthen injected into the combustion chamber through theseholes in a highly atomised form. Due to injection, hydraulicpressure drops, and the valve returns back to its seatterminating the fuel injection, termination of fuel injection mayalso be due to the bypassing of fuel injection through the helixin the fuel injection pump causing a sudden drop in the

pressure.Calibration of Fuel Injection Pumps:- Each fuel injection pump is subject to test and calibration afterrepair or overhaul to ensure that they deliver the same andstipulated amount of fuel at a particular rack position. Everypump must deliver regulated and equal quantity of fuel at thesame time so that the engine output is optimum and at the

same time running is smooth with minimum vibration.


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The calibration value of fuel injection pump as supplied by themakers is tabulated in the following table at 300 working strokes ,500 rpm, temp 100 to 120 F & pressure 40 psi

Table

Dia. Of element(mm) Rack(mm) Requiredvolume of fuel(cc)

15 mm 30 mm(full load)

9 mm(Id ling)

351cc+5/-10

34cc+1/-517 mm 28 mm(full load)

9 mm(Id ling)401cc+4/-1145cc+1/-5

Fuel Injection Nozzle Test:-

The fuel injection Nozzle are tested on a specially designed teststand, where the following tests are conducted:-1)Spray Pattern

Spray of fuel should take place through all the holesuniformly and properly atomized. While the atomization canbe seen through the glass jar, an impression taken on asheet of blotting paper at a distance of 1 -1.5 inch also givesa clear impression of the spray pattern.

2)Spray Pressure

The stipulated correct pressure at which the spray shouldtake place 3900-4050 psi for new and 3700-3800 psi forrecoondtioned nozzles. If the pressure is down to 3600 psithe nozzle needs replacement. The spray pressure isindicated in the gauge provided in the test machine. Shims


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are being used to increase or decrease the tension of nozzlespring whicch increases or decreases the spray pressure.

3)DribblingThere should be no loose drops of fuel coming out of thenozzles before or after the injections. The process of checking dribbling during testing is by having injectionsmanually done couple of times quickly and checks the Nozzletip whether leaky.

The reasons of nozzle dribbling are:-i) Improper pressure settingii) Dirt stuck up between the valve and the valve seatiii) Improper contact between the valve and the valve

seativ) Valve sticking inside the valve body.

1) Nozzle ChatterThe chattering sound is a sort of cracking noise created dueto free movement of the nozzle valve inside the valve body.If it is not proper then chances are that the valve is notmoving freely inside the nozzle.


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PIT WHEEL LATHE SECTION

Introduction:-

Various type of wear may occur on wheel tread and flange dueto wheel skidding and emergency breaking. Four types of wearmay occur as following:-1) Tread Wear2) Root Wear3) Skid Wear4) Flange Wear


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For maintain the required profile pit wheel lathe are used. Thislathe is installed in the pit so that wheel turning is withoutdisassembling the axle and lifting the loco and hence the name

Pit Wheel Lathe

Wheel Turning:-

Wheel turning on this lathe is done by rotating the wheels,both wheels of an axle are placed on the four rollers, two foreach wheel. Rollers rotate the wheel and a fixed turning tool isused for turning the wheel.

Different gages are used in this section to check the thread profile:-

1) Star Gage2) Root Wear Gage3) Flange Wear Gage4) J Gage

J-gage is used to calculate the app. Dia. of wheel

Dia. Of wheel = 962+ 2 x (j-gage reading) mm

For WAGON:-


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Types of wear which is maintained in this section areas follows:-1. Trade wear

2. Root wear3. Skid wear4. Flenge wearFor LOCO :-

Causes of Wheel Skidding:-i) On excessive brake cylinder pressure(more than 2.5

kg/cm 2) ii) Using dynamic braking at higher speedsiii) Continue working, when C-3-W Distributor valve P/G

handle is in wrong position.iv) Shunting at higher speedsv) When any of the axle gets locked during on the line.


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CYLINDER HEAD SECTION

Introduction:-

The cylinder head is held on to the cylinder liner by seven hold downstuds or bolts provided on the cylinder block. It is subjected to highshock stress and combustion temperature at the lower face, whichforms a part of combustion chamber. It is complicated casting where

cooling passages are cored for holding water for cooling the cylinderhead. In addition to this provision is made for providing passage of inlet air and exhaust gas. Further, space has been provided forholding fuel injection nozzles, valve guides and valve seat insertsalso.

Component of Cylinder Head:-

In cylinder heads valve seat inserts with lock rings are used asreplaceable wearing part. The inserts are made of satellite or weltite.To provide interference fit, inserts are frozen in ice and cylinder headis heated to bring about a temperature differential of 250F and theinsert is pushed into recess in cylinder head. The valve seat insertsare ground to an angle of 44.5 whereas the valve is ground to 45 to

ensure line contact (In the latest engines the inlet valves are ground


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at 30 and seats are ground at 29.5). Each cylinder has 2 exhaustand 2 inlet valves of 2.85 in dia. The valves have stem of alloy steeland valve head of austenitic stainless steel, butt-welded together

into a composite unit. The valve head material being austenitic steelhas high level of stretch resistance and is capable of hardening aboveRockwell-34 to resist deformation due to continuous poundingaction.

The valve guides are interference fit to the cylinder head with aninterference of 0.0008 to 0.0018. After attention to the cylinder

heads the same is hydraulically tested at 70 psi and 190F.

Features for Different type Locos:-

The fitment of cylinder heads is done in ALCO engines with a torquevalve of 550 Ft.lbs. The cylinder head is a metal-to-metal joint on tocylinder.

ALCO 251+ cylinder heads are the latest generation cylinder heads,used in updated engines, with the following features:-

Fire deck thickness reduced for better heat transmission. Water holding capacity increased by increasing number of

cores (14 instead of 11).

Middle deck modified by increasing no. of ribs (supports) toincrease its mechanical strength. The flying buttress fashion of middle deck improves the flow pattern of water stagnation atthe corner s inside cylinder head.

Use of frost core plugs instead of threaded plugs, arresttendency of leakage.

Make lighter by 8 kgs (Al spacer is used to make good the gapbetween rubber grommet and cylinder head).

Retaining rings of valve seat inserts eliminated.


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Benefits:-

Better heat dissipation. Failure reduced by reducing crack and eliminating sagging

of effect of fire deck area.

Check during overhauling:-

Ground the valve seat insert to 44.5/29.5, maintain runout of insert within 0.002 with respect to valve guidewhile grinding.

Grind the valves to 45/30 and ensure continuous hairline contact with valve guide by checking colour match.

Ensure no crack has developed to inserts after grinding,checked by dye penetration test.

Make pairing of springs and check proper draw on valvelocks and proper condition of groove and locks whileassembling of valves.

Lap the face joint to ensure leak proof joint with liner.

Blow by test:-

Blow by test is also conducted to check the sealing efficiency of the combustion chamber on a running engine, as per the followingprocedure:-

Run the engine to attain normal operating temperature(65)


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Stop running after attaining normal operatingtemperature.

Bring the piston of the corresponding cylinder at TDC in

compression stroke. Fit blow-by gadget removing decompression plug. Charge the combustion chamber with compressed air. Cut off air supply at 70 psi. Through stop cock and recordthe time , when it comes down to zero. 7 to 10 secs is OK.

METALLURGICAL LAB AND ZYGLO. TEST

Introduction:-

Metallurgical lab concern with the study of material composition andits properties. Specimens are checked for its desired composition. Inthis section various tests are conducted like hardness test,composition test, determination of % of carbon, swelling test etc.


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S.No. Compound Function1 Phosphorous Increase the fluidity property2 Graphite Increase machinability

3 Cementite Increase hardness4 Chromium Use for corrosion prevention5 Nickel Use for heat resistance6 Nitride rubber Oil resistance in touch of O ring 7 Neoprine Air resistance and oil resistance in fast

coupling in rubber block

8 Silicon Heat resistance and wear resistance (upto600C) use at top & bottom pore of liner

Swelling test:-

Swelling test is performed for rubber. Three type of oil solution areused for this purpose:

1. ASTM 12. ASTM 23. ASTM 3

Types of rubber:-

There are two types of rubber:

1. Natural rubber- this has very limited applications. It is used inwindows and has a life of 1 year.

2. Synthetic rubber- this is further subdivided into five types.I. VUNA-N (2 year life): used in oily and watery area.

II. Polychloroprene or Neoprene (2 year life): used in areassurrounding by oil and air.

III. SBR (3 year life)


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IV. Betel (3 year life): used in areas subjected to hightemperature such as piston.

V. Silicone (3 year life): used in areas subjected to high

temperature such as piston.

Experiment on rubber:-

When the fresh supply of rubber comes from the suppliers it istested to know its type. The test consist of two solutions, solution 1and solution 2, which are subjected to the vapours of the rubberunder test and then the colour change in solution is used fordetermination of the type of rubber. The various colour changes areas follows:

Violet-natural rubber Pink-nitrile Green- SBR

When no colour change is observed the vapour are passed throughsolution 2. The colour change in solution 2 is: Pink-neoprene.

Silicon produces white powder on burning. If there is no result onburning then the rubber is surely betel.

Zyglo Test:-

It is a NDT(non destructive testing) method that helps in locating andidentifying surface defects in order to screen out potential failure-producing defects.

FLUORESCENT PENETRATE DYE (water washable) is applied on theclean surface of component washed under pressure stream of waterto clean the surface. Dried in oven as a result of thus the Penetrateentered in cavity/crack ejects out after developing. Developer


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powder adheres with the ejected out Penetrate and glows under theUV light.

Important Components Tested are as following:-

1) Engine piston2) Air inlet/ exhaust valve3) Yoke4) L.W.S Float

EXPRESSOR SECTION

Introduction:-

In ALCO locos the exhauster and the compressor are combined intoone unit and it is known as EXPRESSOR. It creates 23 of vaccum in


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the train pipe and 140 psi air pressure in the reservoir for operatingthe brake system and use in the control system etc.

The expressor is located at the free end of the engine block anddriven through the extension shaft attached to the engine crankshaft. The two are coupled together by fast coupling (copperscoupling). Naturally the expressor crank shaft has eight speeds likethe engine crank shaft. There are two types of expressor are:6CD,4UC & 6CD,3UC. In 6CD,4UC expressor there are six cylinder andfour exhauster whereas 6CD,3UC contain six cylinder and three

exhauster.

Components of Expressor:-

1. Crank Case2. Crank shaft3. Four/Three exhauster cylinders with cylinder heads4. One/Two low pressure compressor cylinder with cylinder head.

5. One high pressure cylinder with cylinder head.6. Six pistons with connecting rods (including one/two LP, one HPand four/three exhausters.)7. Lube oil pump.

Working of Expressor:- The Expressor is driven through theextension shaft attached to the engine crankshaft. Expressor is a

combined unit of exhauster and compressor. The main function of exhauster unit is to create vacuum 2 2 in train pipe. Air from vacuumtrain pipe is drawn into the exhauster cylinders through the inletvalves during its suction stroke and that air is thrown out toatmosphere during compression stroke through discharge valves.

The main function of compressor unit is to create air pressure in

main reservoir of locomotive up to 10kg/cm2. Atmosphere air isdrown into the compressor LP cylinder through the open inlet valves


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during suction stroke and same air is discharged to HP cylinderthrough discharge and delivery pipe. The HP cylinder compresses theair at high pressure and discharges it in main reservoir of locomotivefor the use of brake system.

Models of Expressors used in Diesel Locos:-There are two models commonly used in Diesel Locos. They are asfollowing:-

1. 6CD-4UC

2. 6CD-3UC

In 6CD-4UC Expressor, there are six cylinders out of which the onehaving smaller diameter acts as HP and one LP and four exhausterswhile in 6CD-3UC, there are one HP, two LP and three exhausters.

In both models, the LP cylinder head and each exhaust cylinder headcontains two inlet and two discharge valves and the HP cylinder headcontains one/two inlet and discharge valves. The valves are such thatthey have liberal air flow passages to avoid flow restrictions and toprevent excessive heating and choking of valve ports with carbondeposits due thermal decomposition of lube oil. The retainer stud inboth the assemblies must project upward to avoid hitting the piston.The inlet valves of both LP and HP cylinders are equipped withunloaders which help to unload the compressor when the desired

pressure in the main air reservoir is reached. Similarly, thecompressor cylinders are loaded whenever there is a drop in airpressure.


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CTA (Chief Technical assistance) CELL

Introduction:-

The information for any movement is necessary to be given to thehead office. So there should be a body which can form a likebetween administration and the shed. This is done by C.T.A. (Chief Technical Assistance) cell .

Functioning:-The cell performs the following function:

Interaction between H.O and shed. To keep check of the technical view on the working in the

shed. To check the work quality according to the standards. To solves the problem s of the sheds different departments. To contact the concerned private agencies if there is some

problems in their services.

To maintain the standard criteria of I.S.O as they need the sixmonthly contracts . Failure analysis of diesel locos. Finding the causes of sub system failures and material failures. Formation of inquiry panels of Mechanical and Electrical

engineers and to help the special inquiry teams. Issues the preventive instructions to technical workers and

engineers. Preparation of full detailed failure reports of each loco and sub

systems, components after detailed analysis. The reports arethen sent to the Divisional HQ.

So, in this way C.T.A cell plays an important role of interactionbetween shed and administration.


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11. FUEL SECTION

Introduction:-

The section is concern with receiving, storage and refilling of dieseland lube oil. It has three large storage tanks and one undergroundtank for diesel storage (in tughlakabad diesel shed) which have acombined storage capacity of 10,60,000 liters. This stock is enough toend for 1516 days. The fuel is supplied by truck from IOC Panipatrefinery each truck diesel sample is treated in diesel lab and after it

in unloaded. Sample check is necessary to avoid water kerosenemixing diesel. Two fuel filling points are established near the controlroom. It also handles the Cardian compound, lube oil. Diesel is onlyfor loco use if the diesel samples are not according to the standard,the delivery of the fuel is rejected. Viscosity of lube oil should be100-1435 CST. Water mixing reduces the viscosity.


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Statement of diesel storage and received is made after every 10 daysand the report is send to the Division Headquarter. The record of each truck, wagons etc are included in it. The record of issued oil is

also sending to HQ after each 4 months. A survey is conducted byhigh level team about the storage, records etc. 0.1% of total storedfuel oil is given for handling losses by the HQ. The test reports of diesel include the type of diesel (high speed diesel- Euro-3 with0.035% S), reason for test, inspection lot no., store tank no. batch no.etc.

Before unloading following thing are checked:-1. The oil is tested by lube oil lab.2. The temperature at time of unloading and by multiplying by thetemp. With the Correction factor, the exact volume is calculated.3. The moisture in the oil is checked.

Following important factors are considered by the fuel

section:-

1. Fuel consumption rate of shed. (gross tone/kilometer, per unit tone/kilometer)2. Economic factor.3. Maintaining safety standard.4. Oil testing.5. Temp. correction factor.

6. Wastage allowed only 0.001%.7. Schedule ration.

For further records fuel trip cards are maintained by the driver in thislube oil change, fuel oil are filled by the driver & kept in record.These all records came in major schedule & send to major headoffice .


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The oil used are:-

HSD High speed diesel as fuel oil

RR-813 Engine block lube oil RR 407 Expressor oil T77 grade oil Governor, traction generator, wick lube Cadmium compound gear & pinion on axle, fast coupling.

CONTROL ROOM SECTION

Introduction:-It controls and regulates the complete movement, schedule, duty

of each loco of the shed. Division level communications andcontracts with each loco on the line are also handled by the controlroom. Full record of loco fleet, failures, duty, overdue and availabilityof locos are kept by the control room. It applies the outage target of

loco for the shed, as decided by the HQ. It decides the locomotivesmail and goods link that which loco will be deployed on which train.It operates 116 Mail and 11 Goods link from the shed locos. For o-ooutage total 127 should be on line.

The schedule of duty, trains and link is decided by the controlroom according to the type of trains. If the loco does not return onschedule time in the shed then the loco is termed as over due andcontrol room can use the loco of another shed if that is available.

The lube oil consumption is also calculated by the control room foreach loco:-

Lube Oil Consumption (LOC) = Lube oil consumed in liters/ totalkms travelled100

New and better operational loco have less LOC


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07 JUNE, 2012

Submitted by:Suneel Kumar Meena

Ramavatar Meena

INDIANINSTITUTE OFTECHNOLOGY

INDORE, M.P.

DIESEL TRAINING CENTER TUGHLAKABAD, NEW DELHI


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INTRODUCTION:-

An air brake is a conveyance braking system actuated by compressedair. Modern trains rely upon a fail preventive air brake system that isbased on a design patented by Georgr Westinghouse on March 5,1872. In the air brakes simplest form is called Straig ht Air System,compressed air pushes on a piston in a cylinder. The piston isconnected through mechanical linkage to brake shoes that can rubon the train.

BASICS:-

A moving train contains energy, known as kinetic energy, whichneeds to be removed from the train in order to cause it to stop. Thesimplest way of doing this is to convert the energy into heat. Theconversion is usually done by applying a contact material to therotating wheels or to discs attached to the axles. The materialcreates friction and converts the kinetic energy into heat. The

wheels slow down and eventually the train stops. The material usedfor braking is normally in the form of a block or pad.

The vast majority of the world's trains are equipped with brakingsystems which use compressed air as the force to push blocks on towheels or pads on to discs. These systems are known as "air brakes"or "pneumatic brakes". The compressed air is transmitted along thetrain through a "brake pipe". Changing the level of air pressure inthe pipe causes a change in the state of the brake on each vehicle. Itcan apply the brake, release it or hold it "on" after a partialapplication. The system is in widespread use throughout the world.


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THE PRINCIPAL PARTS OF AIR BRAKE SYSTEM:-

COMPRESSOR:-

The pump which draws air from atmosphere and compresses it foruse on the train. Its principal use is for the air brake system,although compressed air has a number of other uses on trains.

MAIN RESERVOIR:-

Storage tank for compressed air for braking and other pneumaticsystems.

DRIVERS BRAKE VALVE: -

The means by which the driver controls the brake. The brake valve

will have (at least) the following positions: "Release", "Running",


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"Lap" and "Application" and "Emergency". There may also be a "ShutDown" position, which locks the valve out of use.

The "Release" position connects the main reservoir to the brakepipe. This raises the air pressure in the brake pipe as quickly aspossible to get a rapid release after the driver gets the signal to startthe train.

In the "Running" position, the feed valve is selected. This allows aslow feed to be maintained into the brake pipe to counteract anysmall leaks or losses in the brake pipe, connections and hoses.

"Lap" is used to shut off the connection between the main reservoirand the brake pipe and to close off the connection to atmosphereafter a brake application has been made. It can only be used toprovide a partial application. A partial release is not possible with thecommon forms of air brake, particularly those used on US freighttrains.

"Application" closes off the connection from the main reservoir andopens the brake pipe to atmosphere. The brake pipe pressure isreduced as air escapes. The driver (and any observer in the know)can often hear the air escaping.

Most drivers brake valves were fitted with an "Emergency" position. Its operation is the same as the "Application" position, except that

the opening to atmosphere is larger to give a quicker application.

FEED VALVE:-

To ensure that brake pipe pressure remains at the required level, afeed valve is connected between the main reservoir and the brakepipe when the "Running" position is selected. This valve is set to aspecific operating pressure. Different railways use different


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pressures but they generally range between 65 and 90 psi (4.5 to 6.2bar).

EQUALISING RESERVOIR:-This is a small pilot reservoir used to help the driver select the rightpressure in the brake pipe when making an application. When anapplication is made, moving the brake valve handle to theapplication position does not discharge the brake pipe directly, it letsair out of the equalising reservoir. The equalising reservoir isconnected to a relay valve (called the "equalising discharge valve"and not shown in my diagram) which detects the drop in pressureand automatically lets air escape from the brake pipe until thepressure in the pipe is the same as that in the equalising reservoir.

The equalising reservoir overcomes the difficulties which can resultfrom a long brake pipe. A long pipe will mean that small changes inpressure selected by the driver to get a low rate of braking will notbe seen on his gauge until the change in pressure has stabilised alongthe whole train. The equalising reservoir and associated relay valveallows the driver to select a brake pipe pressure without having towait for the actual pressure to settle down along a long brake pipebefore he gets an accurate reading.

Brake Pipe:- The pipe running the length of the train, which transmits the

variations in pressure required to control the brake on each vehicle.It is connected between vehicles by flexible hoses, which can beuncoupled to allow vehicles to be separated. The use of the airsystem makes the brake "fail safe", i.e. loss of air in the brake pipewill cause the brake to apply. Brake pipe pressure loss can bethrough a number of causes as follows:

A controlled reduction of pressure by the driver


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A rapid reduction by the driver using the emergency positionon his brake valve

A rapid reduction by the conductor (guard) who has anemergency valve at his position

A rapid reduction by passengers (on some railways) using anemergency system to open a valve

A rapid reduction through a burst pipe or hose A rapid reduction when the hoses part as a result of the train

becoming parted or derailed.

ANGLE COCKS:-

At the ends of each vehicle, "angle cocks" are provided to allow theends of the brake pipe hoses to be sealed when the vehicle isuncoupled. The cocks prevent the air being lost from the brake pipe.

COUPLED HOSES:-

The brake pipe is carried between adjacent vehicles through flexiblehoses. The hoses can be sealed at the outer ends of the train byclosing the angle cocks.

BRAKE CYLINDER:-

Each vehicle has at least one brake cylinder. Sometimes two or moreare provided. The movement of the piston contained inside thecylinder operates the brakes through links called "rigging". Therigging applies the blocks to the wheels. Some modern systems usedisc brakes. The piston inside the brake cylinder moves inaccordance with the change in air pressure in the cylinder.

AUXILIARY RESERVOIR:-

The operation of the air brake on each vehicle relies on the

difference in pressure between one side of the triple valve piston


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and the other. In order to ensure there is always a source of airavailable to operate the brake, an "auxiliary reservoir" is connectedto one side of the piston by way of the triple valve. The flow of airinto and out of the auxiliary reservoir is controlled by the triple valve.

BRAKE BLOCK:-

This is the friction material which is pressed against the surface of the wheel tread by the upward movement of the brake cylinderpiston. Often made of cast iron or some composition material, brakeblocks are the main source of wear in the brake system and requireregular inspection to see that they are changed when required.

Many modern braking systems use air operated discbrakes. These operate to the same principles as thoseused on road vehicles.

BRAKE RIGGING:-

This is the system by which the movement of the brake cylinderpiston transmits pressure to the brake blocks on each wheel. Riggingcan often be complex, especially under a passenger car with twoblocks to each wheel, making a total of sixteen. Rigging requirescareful adjustment to ensure all the blocks operated from onecylinder provide an even rate of application to each wheel. If youchange one block, you have to check and adjust all the blocks on thataxle.

TRIPLE VALVE:-

The operation of the brake on each vehicle is controlled by the"triple valve", so called because it originally comprised three valves -a "slide valve", incorporating a "graduating valve" and a "regulatingvalve". It also has functions - to release the brake, to apply it and tohold it at the current level of application. The triple valve contains aslide valve which detects changes in the brake pipe pressure andrearranges the connections inside the valve accordingly. It either:


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recharges the auxiliary reservoir and opens the brake cylinderexhaust,

closes the brake cylinder exhaust and allows the auxiliaryreservoir air to feed into the brake cylinder

or holds the air pressures in the auxiliary reservoir and brakecylinder at the current level.

The triple valve is now usually replaced by a distributor - a moresophisticated version with built-in refinements like graduatedrelease .
http://www.railway-technical.com/air-brakes.shtml#Distributorshttp://www.railway-technical.com/air-brakes.shtml#Distributorshttp://www.railway-technical.com/air-brakes.shtml#Distributorshttp://www.railway-technical.com/air-brakes.shtml#Distributors


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TYPES OF VALVES USED IN AIR BRAKE SYSTEM:-

A-9 Automatic Brake Valve:-

The A-9 Automatic Brake Valve is a compact self lapping, pressuremaintaining Brake Valve which is capable of graduating theapplication or release of locomotive and train brakes. A-9 AutomaticBrake Valve has five positions: Release, minimum Reduction, FullService, Over Reduction and Emergency.

SA-9 Independent Brake Valve:-

SA-9 Independent Brake Valve is a compact self lapping, pressuremaintaining Brake Valve which is capable of graduating theapplication or release of Locomotive Air Brakes independent of Automatic Brake. The SA-9 Independent Brake Valve is also capableof releasing an automatic brake application on the Locomotivewithout affecting the train brake application. The SA-9 Brake Valvehas three positions: quick release, release and application.


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VA-1 Release Valve :-

The VA-1 Release Valve without choke is used as a remote controlledcut out cock. It is installed in the Vacuum Brake pipe line betweenthe VA-1B Control Valve and the Train Vacuum Brake pipe.

H-5 Relay Air Valve:-

The H-5 relay air valve is an air operated three way valve that

changes the air passage through it when the control air pressure isvented to atmosphere.


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HB-5 relay Air Valve:-

The HB-5 relay Air Valve is a pneumatic, double piloted, three wayvalves that changes the air passages through it when air pressure of a predetermined amount or more is in the control chamber.

HS-4 Control Air Valve:-

The HS-4 Control Air Valve delivers a regulated, uniform,predetermined air pressure, which usually serves to regulate theoperation of another device in the brake System.

F-1 Selector Valve:-


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The F-1 Selector Valve performs the function of commanding thebrake equipment on the locomotive to lead or trail position of theadjacent locomotive and ensures operation of brakes in the traillocomotives when initiated from the lead locomotive.

A-1 Differential Pilot Air Valve:-

The A-1 Differential Pilot Air Valve is designed to activate a numberof pneumatic devices for a predetermined length of time eventhough it's control air supply is maintained for a considerably longperiod.

C2W Relay Air Valve:-

The C2W Relay Air Valve is a diaphragm cooperated self lapping valvehaving higher capacity which is used as a remote controlledpneumatic device to relay a large quantity of main air reservoirpressure to the operating system for brake application.


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MU-2B valve:-

The MU-2B Valve is a manually operated, two position and multi-ported valve arranged with a pipe bracket and is normally used forlocomotive brake equipment for multiple unit service betweenlocomotives equipped with similar system in conjunction with F-1Selector Valve.

VA-1B Control Valve:-

The VA-1B Control Valve proportions the amount of vacuum in thevacuum brake pipe to the air pressure in the compressed air brake

pipe on the locomotive and acts as a pilot valve to operate the trainvacuum brake, thus securing an application simultaneously with, andin proportion to the locomotive air brake application.


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D-1 Emergency Brake Valve:-

The D-1 Emergency Brake Valve is a manually operated device whichprovides a means of initiating an emergency brake application.

J-1 Safety Valve:-

The J-1 Safety Valve installed vertically in the main reservoir systemvents pressure at a predetermined setting to atmosphere in order toprevent excessive main reservoir pressure build-up.

D-1 Automatic Drain Valve:-


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The D-1 Automatic Drain Valve automatically discharges precipitatedmoisture from reservoir with each operating cycle of the controldevice. The drain valve may be installed on main reservoir with asump.

D-24 B Feed Valve:-

The D-24 B Feed Valve is a large capacity highly sensitive relay valvewhich is designed to direct the flow of air under pressure to variousdevices in air brake equipment arrangement at a predeterminedpressure.

Duplex Check Valve:-

Piston type duplex check valves are generally used in RailwayCompressed Air Brake systems to prevent excessive use of auxiliaryequipment from depleting the main compressed air supply to thedetriment of the brake equipment.


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24-A Double Check valve:-

The 24-A Double Check Valve is used to permit a device to becontrolled by either of two other devices.

PANEL BRAKE SYSTEM:-

The Tri-Plate Panel Mounted Brake System is mainly made out of Aluminium alloy plates specially machined and then sandwiched.These are used for compact assembly of brake valves thus saving thespace as well as reduction of large number of pneumatic fittings. Thisis modular in concept as well as maintenance friendly.

Vacuum Console Panel is a compact unit housing the Vacuum Valvesas well as the Filters and also a small panel comprising of other


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associated Valves related to Vacuum Brake System in theLocomotive. This eliminates dispersed fitment of Vacuum Valves inthe Locomotive Brake System thus eliminating leakages as well assaving of space in the Locomotive.

8" x 8" UAH Brake Cylinder:-

UAH Brake Cylinder is used for Locomotive Brake application. Itdevelops forces due to outward movement of Piston due to airpressure. The Brake Cylinder includes a Piston and Push Rod so

designed that when it is connected to suitable brake rigging it willprovide brake force through the rigging. This can be supplied in 9"and 10" dia. version depending on customer's requirement.

AB Test Rack:-


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This is a composite test rack where all the WABCO Brake Valves canbe tested by using separate test plates for individual Brake Valves.

Tread Brake Unit type BF2S:-

Tread Brake Unit type BF2S as per SAB-WABCO design is a verycompact device integrating entire brake actuating mechanism forRailway vehicles comprising of Brake Cylinder, Levers formagnification of Braking efforts, Slack Adjuster to keep Cylinderstroke constant irrespective of Brake Shoe Wear and Brake ShoeHolder with twin Brake Blocks.

C3W Distributor Valve as per SAB WABCO Design:-

C3W Distributor Valve is a graduated release UIC approvedDistributor Valve for application in the Coach Brake System used forinitiating the brake application. These valves are supplied in

Aluminium version as well as Cast Iron version as far as Body, Topcovers and Bottom Covers are concerned.


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THE WORKING OF 28 LAV-1 BRAKE SYSTEM

The compressor in the locomotive produces the air supplied to thesystem. It is stored in the main reservoir. Regulated pressure of 6kg/cm 2 flows to the feed pipe through the feed valve and 5 kg/cm 2

pressure by drivers brake valve to the brake pipe. The feed pipethrough check valve charges air reservoir via isolating cock and alsoby brake pipe through distributor valve. The brake pipe pressurecontrols the distributor valves of all the coaches/wagons which inturn control the flow of compressed air from Air reservoir to brake

cylinder in application and from brake cylinder to atmosphere inrelease.

During application, the driver in the loco lowers the BP pressure. Thisbrake pipe pressure reduction causes opening of brake cylinder inletpassage and simultaneously closing of brake cylinder outlet passageof the distributor valve. In this situation, auxiliary reservoir suppliesair to brake cylinder. At application time, pressure in the brake

cylinder and other brake characteristics are controlled by distributorvalve.

During release, the BP pressure is raised to 5kg/cm 2 . This brake pipepressure causes closing of brake cylinder inlet passage andsimultaneously opening of brake cylinder outlet passage of thedistributor valve.

The distributor valve connects brake cylinder to atmosphere. Thebrake cylinder pressure can be raised or lowered in steps.

In case of application by alarm chain pulling, the passengeremergency alarm signal device(PEASD) is operated which in turnactuates passenger valve(PEV) causing exhaust of BP pressurethrough a choke of 4mm. Opening of guard emergency brake valve

also makes emergency brake application.


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There are two case of braking, when loco move (SA 9) and when theentire train move(A 9). Consequently there are two valves in thedriver cabin viz SA-9 & A-9. Braking operation of above case is shownin chart below.


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Layout Block Diagram:-


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COMPARISION OF VARIOUS BRAKE SYSTEM:-

Comparison of Air Brake & Vacuum Brake

Parameter Air Brake Vacuum BrakePrinciple of working The compressed air is

used for obtaining brakeapplication. The brakepipe and feed pipe run

throughout the length of the coach. Brake pipe

and feed pipe on

consecutive coaches inthe train are coupled to

one another by means of respective hose

couplings to form acontinuous air passagefrom the locomotive to

the rear end of the train.The compressed air issupplied to the brake

pipe and feed pipe fromthe locomotive. The

magnitude of brakingforce increases in stepswith the correspondingreduction in brake pipepressure and vice-versa

The vacuum brakesystem derives its brake

force from theatmospheric pressure

acting on the lower sideof the piston in the

vacuum brake cylinder

while a vacuum ismaintained above thepiston. The train piperuns throughout the

length of the coach andconnected with

consecutive coaches byhose coupling. The

vacuum is created in thetrain pipe and the

vacuum cylinder by theejector or exhauster

mounted on thelocomotive

Pressure Effective cylinderpressure = 3.8kg/cm 2 Feed pipe - 6kg/cm 2 Brake pipe - 5kg/cm 2

Effective pressure onpiston - 0.kg/cm 2

Nominal vacuum ontrain pipe - 510mm

Pipe Diameter Feed pipe - & 25 BoreBrake pipe - & 25 Bore

Train pipe - & 50 Bore


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Components of air brake and vacuum brakesystems

Air Brakes Vacuum Brakes

Brake pipe and feed pipe (twin pipesystem for coaching stock, singlepipe system for goods stock).

Train pipe -- single pipe

Air brake cylinder - 355mm dia Vacuum brake cylinder- 24" type 'F'Distributor ValvePassenger Emergency Alarm SignalDevice

Alarm chain apparatus

Passenger Emergency Valve Clappet Valve

Guard's Emergency Valve Guard's Van ValveSlack Adjuster Slack AdjusterDirect Admission Valve

Hose coupling for brake pipe andfeed pipe

Hose coupling for train pipe

Auxiliary reservoir 100 l capacity Vacuum reservoir 320 l capacityCut off Angle cockCheck valve with chokeDirt collector

Advantages of air brakes over vacuum brakesParameters Air Brakes Vacuum Brakes

Emergency brakingdistance (4500 t leveltrack, 65 kmph)

632m 1097m

Brake power fading No fading At least by 20%Weight of equipmentper wagon (approx.)

275kg 700kg

Pressure Gradient No appreciable difference in airpressure between locomotiveand brake van up to 2000m.

Steep reduction invacuum in trainslonger than 600m.

Preparation time indeparture yards (45BOX or 58 BOXN)

Less than 40 minutes. Up to 4 hours.

Safety on down

gradients

Very safe Needs additional

precautionsOverall reliability Very good Satisfactory


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Comparison of single-pipe and twin-pipe systems

Single-pipe System

Twin-pipe System


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Parameters Single Pipe Twin PipePrinciple of operation

The operation is same asthat of the twin pipesystem except that the

auxiliary reservoir ischarged through the D.V.instead of feed pipe, sincethere is no feed pipe insingle pipe system.

The Brake pipe is charged to5kg/cm 2 by the driver's brakevalve. The auxiliary reservoir is

charged by the feed pipe at6kg/cm 2 through a check valveand choke. The brake cylinder isconnected to the atmospherethrough a hole in the D.V. whenbrakes are under fully releasedcondition. To apply brakes, thedriver moves automatic brakevalve handle either in steps for agraduated application or in onestroke to the extreme positionfor emergency application. Bythis movement the brake pipepressure is reduced and thepressure differenced is sensedby the D.V. against the referencepressure locked in the control

reservoir. Air from the auxiliaryreservoir enter the brakecylinder and the brakes areapplied.At the time of releasethe air in the brake cylinder isvented progressively dependingupon the increase in the brakepipe pressure. When the brakepipe pressure reaches

4.8kg/cm2

the brake cylinder iscompletely exhausted andbrakes are fully released.

Chargingauxiliaryreservoir

Discontinued during brakeapplication

Uninterrupted

B.C. and A.R.pressureequalisation

Occurs during prolongedbrake application

Does not occur


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Release of brakes(reduction inbrake cylinder

pressure)

Proportionate to build upof A.R pressure

Auxiliary reservoir iscontinuously charged throughfeed pipe

Leakage inbrake cylinderduringapplication

During emergencyapplication, feed forauxiliary reservoir frombrake pipe is discontinued.Leakages in brake cylinderwill therefore reducebraking force sinceauxiliary reservoir may notbe able to equalise theleakages.

Auxiliary reservoir iscontinuously charged throughfeed pipe and hence leakages inbrake cylinder can be equalisedeven during emergencyapplication ensuring full brakeforce.

Colour Brake pipe - GreenFeed pipe White

Pressure Brake pipe - 5kg/cm 2 Brake pipe - 5kg/cm 2 Feed pipe- 6kg/cm 2

Comparison of conventional and bogie-mounted airbrakes

Parameters Conventional AirBrakes

Bogie-mounted Air Brakes

Bogie cylinder mountinglocation

Underframe Bogie frame

No. of air brake cylinders/ coach

2 4

Size of cylinder 14" 8"

Slack adjuster External Integral with the air brakecylinder

Brake block Conventional High friction 'K' typecomposite block


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FUNCTION OF AIR COMPRESSOR

Introduction:-An air compressor is a device that converts power (usually from anelectric motor, a diesel engine or a gasoline engine) into kineticenergy by compressing and pressurizing air, which, on command, canbe released in quick bursts. There are numerous methods of aircompression, divided into either positive-displacement or negative-displacement types.

Types of AIR COMPRESSOR:-


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According to the design and principle of operation

1. Reciprocating compressor2. Rotary compressor

According to the number of stages

1. Single stage compressor2. Multi stage compressor

According to the pressure limits

1. Low pressure compressors

2. Medium pressure compressors3. High pressure compressors4. Super high pressure compressors

According to the capacity

1. Low capacity compressors2. Medium capacity compressors3. High capacity compressors

According to the method of cooling

1. Air cooled compressor2. Water cooled compressor

Function of AIR COMPRESSOR:-To supply high-pressure clean air to fill gas cylinders

To supply moderate-pressure clean air to a submerged surfacesupplied diver

To supply moderate-pressure clean air for driving some office and

school building pneumatic HVAC control system valves


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To supply a large amount of moderate-pressure air topower pneumatic tools

To produce large volumes of moderate-pressure air formacroscopic industrial processes.

The function of the air compressor is to build up and maintain airpressure required to operate air brakes and air-powered accessories.

All compressors run continuously while the engine is running, but

air compression is controlled and limited by a governor whichloads or unloads the compressor. In the loaded stage, air ispumped into reservoirs. In the unloaded stage (with two cylindercompressors), the compressor pumps air back and forth between thetwo cylinders without supplying the reservoirs.

BRAKE BINDING: ITS CAUSES & EFFECTS

Introduction:-

Brake binding is defined as the situation when the brake block is in contact withthe wheel tread though the A-9 valve position is in released position.

The severity of the brake binding depends on the force exerted by the brakeblocks on the wheel tread.

MAJOR CAUSES FOR BRAKEBINDING:-

1) Defects in LOCOMOTIVE 2) Defects in Train Handling 3) Defects in Distributor Valve


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4) Defects in Break Cylinder 5) Defects in Dirt Collector 6) Defects in Sab Brake Regulator

7) Defects in Brake Gear

SOLUTIONS FOR AVOIDING BRAKE BINDING:-

Check for fluctuation in BP pressure Check for moisture/oil / dirt content incompressed air. Close the brake pipe cut out cock, place MU- 2B valve in Trailposition.

Keep both i ndependent and automatic driver s brake valve inrelease position.

Recharge the system with A-9 automatic brake handle in releaseposition.

Make a 0.6-kg/cm 2 reduction in brake pipe.

Close cut out cock. Move MU-2B control valve in trail position. Overhaul / Repair distributor valve with Intermediate flange as asingle unit.

Check the valve is free from rubber buldging or deboned for valveplate in KE type or valve (37) in C 3 W type.

Check for breathing passage. This is ascertained by: Avoid greasingof Trunk during assembly.

Clean annular space between Trunk and Front cover. Condition of outlet passage. This is ascertained by cleaning Dirtcollector in every schedule.

Check that the barrel has no dent. Confirm that Traction sleeve passes smoothly inside the entire lengthbarrel during assembly.

Adjust end pull rod hole and maintain length of pull rod such thatthe Equalising levers be in near vertical in brake applied position.


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TO STUDY BENEFITS OF PANEL MOUNTED AIR BRAKESYSTEM AND THEIR FAILURES.

Introduction:-

Insight of panel mounted on a loco following are:-

The tri plate panel mounted brake system is mainly made of aluminium alloy plates specially machined and then sandwiched.These are used for compact assembly of brake valves thus savingspace as well as reduction of large number of pneumatic fittings. Thisis modular in concept as well as maintenance friendly.

Vacuum Console Panel is a compact unit, housing the vacuum valvesas well as the filters and also a small panel comprising of all otherassociated valves related to vacuum brake system in locomotive. Thiseliminates dispersed fitment of vacuum valves in locomotive brakesystem thus eliminating leakages as well as saving of space in thelocomotive.

Benefits of Panel Mounted Air Brake System:-

8) It provides compact city to the system thus reducingspace utilized by the braking system on the locomotives.

9) It reduces large number of pneumatic fittings.10) This is maintenance friendly for the technician.11) It also reduces leakage as it does not require any

compactness for the fitting of vacuum and pneumaticvalves.


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12) By using this, it becomes very easy to identify thetrouble in running condition.

13) It is very reliable and works satisfactorily.

Reasons of Failures in Various Locos:-

1) Air dryer outlet pipe flange joint O-ring was worked outdue to allen bolt loosening.

2) R-1 reducing valve gauge pipe union was leaking due tovibration as gauge screw worked out.

3) MR safety valve was blowing due to choking of hornstrainer.

4) S/H Control stand A-9 movement was restricted by AFIgauge due to excess length.

5) Loco was detached at NDLS due to air leakage fromright side control stand A-9 Valve but no leakage wasobserved during joint inspection.

6) Right side control stand A-9 valve was stuck up due toingress of dust in double check valve assembly.

PERFORMANCE PARAMETRES:-

1. Year of Establishment : Diesel Shed, Tuglakabad was established

in the year 1970 with a planned holding of 80 locomotives andinitial holding of 26 WDM2 locomotives .

2. ISO Certification Year9001 : ISO-9001:2000 certification from ISO certification body

Florida, U.S.A through Quality Services International/JaipurJuly, 2003, as per the required Quality Standards

14001 : ISO-14001 certification on 13.10.03 through Indian Register

Quality Systems.18001 : OHSAS-18001compliant by M/s. Kvalitet Veritas Quality


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Assurance on 30 May06.

3. No. of Officers : 07

4. No. of Supervisors : 126

5. %age of Staff housed in Railway Quarters : 26%

6. Power Consumption : 2431830 unit/2008-09

2350674 unit/ 2009/10

7. Water Consumption : 718900 ltrs/days

8. Educational Profile of Staff :

Upto 8 th >8th 10th pass 10-12 th ITI Graduate8.38% 13.8% 14% 12.16% 40.10% 11.56%

9. Age Profile of Staff:


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Refrences:-

Google

Stone India Limited IRFCA Wikipedia Tughlakabad Library Scribd webcache.googleusercontent.com/search?q=cache:LoBZYF5FPHwJ:www.123seminarsonly.com/

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Air Breaking System Report Diesel Training Centre, Tughlakabad, New Delhi

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