summer training report of internship at indian railway welding research institute (IRWRI) , diesel locomotive works (DLW) varanasi

1. Summer training report
On training at
IRWRI , DLW VARANASI

2. TRAINEE AT DLW VARANASI
HARSHIT MISHRA
MECHANICAL ENGINEERING
KIIT UNIVERSITY, BHUBANESWAR

3. 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.

4.  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.

5. some facts about diesel electric locomotive
 DLW’s annual production - 304
Cost of one loco - 12 to 14 crore (EMD)
8 crore (Alco)
Weight of one Loco - 121 Ton
 Fuel Consumption; At Full Load - 540 lt/hr.
Idle Load - 40 lt/hr.
 Max. Speed - 160 Km/hr.
 Dia of Wheel - 1092 mm
Wheel to Wheel Distance - 1596.5 mm
 Length of Under Frame - 19962 mm

6. 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.

7. Classification of locomotives
Locos, 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)

8.  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……..

9. 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.

10. 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 .

11. Advantages of SMAW
• 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
8/31/2014 Build the nation with welding capability 11

12. 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.

13. 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

14. 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.

15. 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.

16. FCAW Process Features
 Uses tubular wire with flux
inside
 Gas 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. 17
LASER CUTTING-UPTO 4MM

18. Laser cutting
 The 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

19.  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. 20
UNDER WATER PLASMA CUTTING UPTO 16 MM

21. Plasma cutting
 Plasma 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
.

22.  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

24. 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.

25.  . 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

26. 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.

27. 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.

28. 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.

29. THANKS