Summer training report On training at

IRWRI , DLW VARANASI

TRAINEE AT DLW VARANASI

HARSHIT MISHRA

MECHANICAL ENGINEERING

KIIT UNIVERSITY, BHUBANESWAR

Introduction DLW, was founded by Late Railway Minister Mr. Lal Bahadur Shastri on 23

April 1956. It is spread in 300 acres area at Varanasi.

It is a production unit owned by Indian railways , for which it manufactures diesel–electric locomotives and its spares parts.

To meet the increased transportation needs of the Indian railways it was established in collaboration with ALCO( American Locomotive Company), USA in 1961.

DLW rolled out its first locomotive three years later, on January 3, 1964. It manufactures locomotives.

Got its first ISO certification in 1997 and ISO-9001 and ISO-14001 in

December 2002.

With technology transfer agreement from manufacturers such as GM-EMD, DLW today produces advance locomotives having output range from 2600 to 4000 hp.

At present the latest locomotive produced by DLW; i.e. WDG 5 has capacity upto 5000 HP & trying to make it 5500 HP.

It has supplied locomotives to other countries such as Sri Lanka, Bangladesh, Malaysia, Tanzania and Vietnam etc.

DLW is supplying locos to PSU’s & Industries Like NTPC, COAL, INDOGULF etc.

some facts about diesel electric locomotive

DLW’s annual production - 304Cost of one loco - 12 to 14 crore (EMD)

8 crore (Alco)Weight of one Loco - 121 TonFuel Consumption; At Full Load - 540 lt/hr.

Idle Load - 40 lt/hr.Max. Speed - 160 Km/hr.Dia of Wheel - 1092 mmWheel to Wheel Distance - 1596.5 mm Length of Under Frame - 19962 mm

Diesel electric locomotive In a diesel-electric locomotive, the diesel engine drives an electrical generator or

alternator whose output provides power to the traction motors. There is no mechanical connection between the engine and the wheels.

Classification of locomotivesLocos, except the older steam ones, have classification codes that identify them. This code is of the form WDG5A “ [ gauge ][ power ][load ][ series ][ sub type ]”

The first letter (gauge) W- Indian broad gauge

Y- meter gauge

Z- narrow gauge(2.5 ft)

N- narrow gauge (2 ft) The second letter (motive power) D- Diesel

C- DC electric (can run under DC traction only)

A- AC electric (can run under AC traction only)

CA- Both DC and AC (can run under both AC and DC tractions)

B- Battery electric locomotive (rare)

The third letter (load type) G-goods P-passenger M-mixed traffic ; both goods and passenger S-Used for shunting U-Electric multiple units (E.M.U.) R-Railcars

THE fourth letter (series) The series digit identifies the horsepower range of the

locomotive. Example for the series letter ‘3’ means that the locomotive has

power over 3000 hp but less than 4000 hp.

The fifth letter (subtype) an optional letter or number that indicates some smaller

variations in the basic model. For ex: ‘A’ for 100 hp, ‘B’ for 200 hp and so on……..

WELDING Welding is a process which produces joining of

materials by heating them to suitable temperatures with or without the application of pressure and with or without the use of filler material.

Welding is used for making permanent joints.

It is used in the manufacturing of automobile bodies, aircraft frames, railway wagons, machine frames, structural works, tanks, furniture, boilers, general repair work and ship building.

What is SMAW?

It is a welding process which joins metals by heating the metals to their melting point with an electric arc set up between the end of a coated metal electrode and the work piece.

Molten metal droplets and the molten weld are shielded from the atmosphere by the gases produced from the decomposition of the flux coating .

• Equipment used is simple, inexpensive.

• Electrode provides and regulates its own Flux.

• This process has excellent suitability for outdoor use lower sensitivity to wind and even for use under water.

• All position capability

04/12/2023 Build the nation with welding 11

Advantages of SMAW

SAW Process Principles

SAW is a welding process which joins metals by heating the metals to their melting point with an electric arc or arcs set up between a bare metal electrode and the job.

The arc, the end of electrode and molten pool remains completely hidden and are invisible being submerged under a blanket of granular flux.

The continuously fed bare metal electrode melts and acts as filler rod.

SAW Features• High Productivity,

high amperages may be used

• Easy to de-slag • High Quality• Deep penetration• Excellent

mechanical properties• Environment

friendly• Very little fume• No radiation• Easy operation

GMAW Gas Metal Arc Welding is a

welding process which joins metals by heating the metals to their melting point with an electric arc, produced between continuous consumable electrode wire and the metal being welded.

Wire is fed continuously and automatically from a spool through the welding gun

Shielding gases include inert gases such as argon and helium for copper and aluminum welding, and active gases such as CO2 for steel welding

Bare electrode wire plus shielding gases eliminate slag on weld bead. No need for manual grinding and cleaning of slag.

Applications:• Used for C, Si, Cu, Ni, Ti etc.• For welding tool steels and dies.• For the manufacture of refrigerator parts.

Gas Metal Arc ( MIG ) Welding

Uses continuous wire 0.6 – 2.0 mm as electrode

Gas shielded, inert or active gas

Manual, automatic or semi-automatic process

High productivity

If the wire feed speed is increased more current is drawn to burn it off .

Increasing the current increases the arc energy and therefore the heat input. This in turn increases fusion and penetration, wire deposition rate and travel speed.

FCAW Process FeaturesUses tubular wire with flux

insideGas shielded (FCAW-G) or

self shielded (FCAW-S)

The flux produces a protective slag and/or gas cover

High productivity process with low spatter. Smooth arc with CO2. Argon mixtures give superior performance

Problem of high fumes which need to be extracted in enclosed areas

17

LASER CUTTING-UPTO 4MM

Laser cuttingThe most common laser application in the

mechanical industry is laser cutting using a high power laser. Laser cutting is best suited to high precision cutting of thin pieces.The cut quality is so high that the pieces can be used directly, or sent for further processing without the need for post-cut finishing. Laser cutting is extensively used, especially by mechanical engineering companies that serve the automotive industry

A laser can also cut many other materials besides metals – such as plastics, wood etc. When cutting metals, the cutting gas is usually oxygen or nitrogen. The laser beam is focused through a lens on the material to be cut, which melts. In order to blow away the molten material, the cutting gas is fed through a concentric nozzle

The application determines which of the gases, oxygen or nitrogen, is better suited for the task.

Sensitive materials, such as titanium and zirconium, must be protected against oxygen and nitrogen, i.e. air. These materials are cut using high purity argon

20

UNDER WATER PLASMA CUTTING UPTO 16 MM

Plasma cuttingPlasma cutting was a method developed in

the 1950s for cutting metals that could not be cut by oxyfuel cutting. Such materials include stainless steel, aluminium and copper.Subsequently, the method has also been used for the cutting and precision cutting of mild and low-alloyed steel.

Plasma is a state of matter in which the gas is ionised. This means that it consists of positive ions and electrons, causing the media to be electrically conductive. Plasma is very energy-rich. Plasma melts materials locally, the molten material being removed from the cut by means of a gas jet .

Plasma cutting is a melt-cutting method, where the energy of the hot plasma arc is used for blowing away molten material

Water jet cutting Water jet is the method consisting of cutting

the material (or a water jet can relate to cleaning it) by the use of thin water jets under high pressure with added abrasive slurry used to cut the target material by means of erosion

Typical water jet cutting machines have a working space from few square feet to hundreds of square feet. In this moment the high pressure water pumps are available from 276 MPa up to 689 MPa

Oxyfuel cutting Oxyfuel cutting can be used for cutting mild

and low-alloyed steel, up to thicknesses of just over 1,000 mm. The cut quality also depends on the surface of the work piece, and can be affected by different types of shop primer. Use of several burners for straight cutting, phase cutting and joint preparation is an example of the cutting process’s versatility. The process is also easy to mechanise.

The use of fuel gases together with oxygen can give rise to dangerous situations, if the user lacks adequate knowledge of how gases, equipment and the necessary protective equipment must be used.

. When cutting, the purity of the oxygen is of huge importance to the cutting speed. The purer the gas, the higher the cutting speed and the better the productivity and cut quality.

. The choice of fuel gas affects cut quality and the time used for preheating. When choosing a fuel gas, the thickness of the material must also be considered.

. It is not the heating flame itself that does the actual cutting but an oxygen jet, which burns the material during heat formation and transports the combustion products (slag) away from the cut

MODIFICATIONS THAT MAY BE DONE in flame cutting:IN OXY FUEL CUTTING 1: By using odorised oxygen By using odourised oxygen we can minimize

the risk of fire and explosion which is always associated with fuel gases. the odor provides a timely warning in case of gas/fuel leakage .

2: modification of nozzle size by changing the size , geometry of nozzle

without compromising with surface finish and tolerance we may design customized nozzle for each type of material which will improve cut quality.

For example : curtain nozzle This type of nozzle has a special oxygen

channel which protects the cutting oxygen jet from impurities, making higher cutting speeds possible.

LASER CUTTING 1) preheating of material by preheating the material we can

increase the depth of cut by laser cutting without

compromising with the quality of cutting.

PLASMA CUTTING 1) by changing the plasma gas i.e

using different plasma gas for different materials.

2)customizing the water jet pressure for different materials to be cut for a better quality cut.

THANKS