SUMMER TRAINING AT INDIAN RAILWAYS STUDY AND EXAMINATION OF VARIOUS

SHOPS

MECHANICAL WORKSHOP NORTH EASTERN RAILWAYS GORAKHPUR PRESENTED BY - Gaurav Kumar Singh ROLL NO. 1003240022

INTRODUCTION

This workshop is a public sector industry which is governed by the workshop manager who is appointed by the central government. He is responsible for every action in the workshop.

Initially the workshop was concerned with the maintenance of steam engines. Now the steam engines are outdated so the workshop has adopted a new line of action i.e. maintenance of railway wagons and some parts of diesel locomotives are also manufactured here such as break blocks, rear cover, front cover, nuts, face plates etc.

INTRODUCTION

The workshop is divided in a number of shops. Each shop does a specific job. All shops are separately managed by senior section engineers with the help of junior engineers in various sections of the shops.

Regular inspection is done in the workshop to examine the quality of raw materials and products manufactured.

HISTORY

Mechanical workshop, N.E Railway is a leading Industrial unit which has completed hundred years of glorious existence in eastern U.P.

This workshop was established in 1903 and was named as Bengal and Assam north west Railway LOCO and Carriage workshop.

Indian Railway after independence, this workshop became an important center for maintenance of passenger coaches, Hence a major investment plan was approved by railway board in 1952 .

Many new shop like furnishing ,wagon lifting ,paint saw mill came into existence during this period and repair shop in 21st century.

DIFFERENT SHOPS IN THE WORKSHOP

• BLACK SMITHY SHOP

• HEAT TREATMENT SHOP

• MACHINE SHOP

• SPRING SECTION

• WHEEL SHOP

• WELDING SHOP

• BREAKING SYSTEM

• PAINT SHOP

BLACK SMITHY SHOP

• This is the most important shop in the industry. This is concerned with manufacturing. The required shape and size is given to the work piece in this shop.

• The basic process is initially the material is heated to a specified temperature range and then by hand hammering as well as power hammering the required shape is given to the work piece.

• Forging is the main operation carried out in this shop.

• Various machines employed in this shop are

1. Oil furnace 2. Power hammer 3. Pearson cutting machine 4. Shearing and pressing die 5. Drop forging machine 6. Trimming press machine

Besides these machines other machines that are available in the shop are: 1. Hardness testing machine 2. Visual and magnetic crack detector 3. Radial drilling machine 4. Gang drilling machine 5. Surface grinding machine 6. Frame press The various divisions of smithy shop are: 1. Nut and bolt section 2. Spring section 3. Light and medium forging section 4. Heavy forging section 5. Drop forging section 6. General section

HEAT TREATMENT SHOP Heat treatment is done to get the desired properties in the work

piece. The basic process of heat treatment is of three steps:

1. Heating the job at predetermined temperature

2. Holding the job at that temperature for sometime

3. Cooling down the job in controlled environment.

The various heat treatment process that are performed in this shop are:

1. Annealing

2. Normalizing

3. Tempering

4. Hardening

5. Case hardening

6. Nitriding

7. Carburizing

8. Quenching (air , water , oil)

Various apparatus used to perform the above processes are: 1. Oil furnace 2. Hot ovens 3. Electric furnace 4. Oil quenching tank 5. Water quenching tank 6. Jib crane/EOT crane 7. Pyrometer Annealing Annealing consists of heating a metal to a specific temperature and then cooling at a rate that will produce a refined microstructure . The rate of cooling is generally slow. Annealing is most often used to soften a metal for cold working, to improve machinability, or to enhance properties like electrical conductivity. Normalizing Normalizing is a technique used to provide uniformity in grain size and composition throughout an alloy. The term is often used for ferrous alloys that have been austenitised and then cooled in open air.

Quenching Quenching is a process of cooling a metal at a rapid rate. This is most often done to produce a martensite transformation. In ferrous alloys, this will often produce a harder metal, while non-ferrous alloys will usually become softer than normal. Tempering Untempered martensitic steel, while very hard, is too brittle to be useful for most applications. A method for alleviating this problem is called tempering. Most applications require that quenched parts be tempered. Tempering consists of heating steel below the lower critical temperature, (often from 400 to 1105 ˚F or 205 to 595 ˚C, depending on the desired results), to impart some toughness.

MACHINE SHOP

In this section all kinds of machining operations are performed using different types of machines like lathe, milling, drilling, shaping etc.

A total of 48 machines are present in the machine shop to perform different kind of operations.

Besides this, there is some modern and automatic machinery is also present like –

• NC Machines (Numerically Controlled).

• CNC Machines (Computerized Numerically Controlled.

• DNC Machines (Direct Numerically Controlled).

NC Machine- The machining parameters are fed from the control panel by pushing buttons. The job is machined according to the parameters. There are NC boring and milling machines present in this shop.

CNC Machine- In this machine, all the data related to the machining is fed into a computer. All the machining processes required are defined in terms of programming. All the processes are then performed automatically by the machine. In this shop, there is one CNC Turret Lathe machine is present.

DNC Machine- This machine is controlled by installing a control room away from the machine. These machines are fully automated.

SPRING SECTION • In this the helical and leaf spring are prepared . For this purpose there

certain machine for testing, grading and repairing it.

• The test performed on helical and laminated springs are:

1.VISUAL AND MAGNETIC CRACK DETECTION:- In visual test with the help of magnifying lens and glass the spring is inspected if

Corroded Fail

Deep sear of mark Fail

Surface cracks Fail

In the magnetic testing a mixture of kerosene oil and magnetic red ink is sprayed on the spring and inspected for clinging of oil droplets.

If oil clings at some place it represents the presence of crack.

2. D’ BUCKLING:- Buckling is performed on the laminated spring. The leaves of the

spring are assembled and pressed. Now it is put on the buckling machine and axial and longitudinal forces are applied.

3. SPRING SCRAGGING:- After the buckling test , the spring should be put on scragging

machine and the camber should be measured. The spring should be pressed quickly and the camber should be measured 2 times.

In case of helical springs, the spring is kept on m/c and its free height is measured, then it is compressed under certain load and the compression is noted down. If the compression matches from the table provided for springs, it is passed.

Failure:- Over chamber, short chamber, leaf broken, gap between the leaves.

WHEEL SHOP

• In this shop repair works of wheel and axle is undertaken. As it is known that the wheel wears through out its life. When at work the profile and diameter of the wheel constantly changes.

• To improve its working and for safety reasons, it is repaired and given correct profile with proper diameter.

• The diameter of a new wheel is 915 mm.

• The minimum diameter of wheel after which it is discarded is 813 mm.

The shop consists of: 1.Axle journal testing lathe On this lathe , the diameter of the axle is brought to the correct diameter. The cutting tool used is a carbide tool. 2.Hydraulic wheel press with facility of mounting The wheel is pressed on the axle with the help of this machine. A calculated amount of pressure is applied and the wheel is pressed. 3.Axle turning lathe External and internal diameter is corrected by this lathe. Wheel is tightened on the rotating clutch. the stationary carbide tool cuts the wheel to correct diameter. 4.Vertical turning lathe

It is used for heavy machining of wheels.

WELDING SHOP • The joining of similar and dissimilar metal sheets is performed in this

shop. The welding is either performed by force or by heating.

• On this basis welding are of two types

Cold welding

Hot welding

Hot welding is mainly performed in this shop by ELECTRIC ARC WELDING and GAS WELDING process.

ELECTRIC ARC WELDING

In this process, an electric arc is established b/w the work piece and the electrode.

High temp. up to 4000 degree Celsius can be achieved.

Here the 2/3 of the heat is generated at the anode, so the w/p is attached to the anode.

Coated and non coated electrode are used according to need.

GAS WELDING This welding is performed from the heat generated by the combustion of oxygen

and acetylene. Depending upon the ratio of mixture of oxygen acetylene , the flames are classified

as FLAME RATIO OF OXYGEN AND ACETYLENE TEMP. ACHIEVED 1.Oxidizing > 1:1 3700 deg. Cel 2.Neutral = 1:1 3300 deg. Cel. 3.Carburizing < 1:1 2800 deg. Cel Mostly neutral flame is used for welding process. Oxidizing flame is used for cutting purpose.

BRAKING SYSTEM

Brakes have utmost importance in a moving body. Every moving body has brakes to control its speed or motion. Frictional force is utilized in process of application of brakes. Therefore, our braking system issues maximum development of frictional forces.

In the Indian railway two types of braking system are used in engines and all types of coaches. They are:

1. Vacuum brake system

2. Air brake system

VACUUM BRAKE SYSTEM

PRINCIPLE OF APPLICATION OF VACUUM BRAKES

• The vacuum brake system is controlled by a brake pipe connecting a brake valve in the driver’s cab with the braking equipment in every vehicle.

• The operation of the brake equipment on each vehicle depends on the condition of vacuum created in the pipe by an ejector or exhauster.

• The ejector using steam on a steam engine, or an exhauster, using electric power on other type of engine, removes atmospheric pressure from the brake pipe to create vacuum.

• With a full vacuum, the brake is released. With no vacuum, at normal atmospheric pressure in the brake pipe, the brake is fully applied.

VACUUM BRAKE SYSTEM

AIR BRAKE SYSTEM

• PRINCIPLE OF APPLICATION OF AIR BRAKE

• This system uses a reduction in air pressure in the train line to apply the brakes.

• When the engine operator applies the brake by operating the locomotive brake valve, the train line vents to atmosphere at a controlled rate, reducing the train line pressure and in turn triggering the triple valve on each car to feed air into its brake cylinder.

• Thus air brakes are applied by reducing train line pressure and released by increasing train line pressure.

AIR BRAKE SYSTEM

PAINT SHOP • The work of this shop is to paint the bogie. This is one of the

important part of the manufacturing process, mainly used in overhauling of board gauge coaches . It is mainly done for the purpose of preventing the coaches from corrosion and other defect.

TYPES OF PAINT

• Aluminum paint

• Anticorrosive paint

• Bituminous paint

• Cement paint

• Distemper

• Emulsion paint

• Enamel

• Graphite

• Oil paint

• Plastic paint

In this shop there are many sections are:-

Coach painting Trimming section Corrosion section Polish section

CONCLUSION

With the end of day 28, my training at MECHANICAL WORKSHOP NER also came to a completion. It was a huge learning curve for me, especially as being a raw hand, I got my first opportunity to see the practical side of things and learn various aspects of Indian Railways. For this I would like to express my gratitude to MR. SHISHIR DUTT(C.W.M.) for having allowed me to take my training at their company. I would also like to express my gratitude to the various Officers assigned to me during the training period.