1. L&T MHI TURBINE GENERATORS PRIVATE LTD.
HAZIRA, SURAT.
SUMMER INTERNSHIP
BY PARTH K. GANDHI
DURATION: 16TH JUNE TO 16TH JULY, 2014

2. INDUCTION
 The Production Shop is divided into six sub-divisions along with a Main Store.
 The six sub-divisions are four Machine Shops and two Fabrication Shops, being
listed from T1 to T4 and T5 to T6 respectively.
 Also there is High Speed Balancing Test Setup, Blade Manufacturing Shop, Coil
shop, Turbine and Generator Assembly.
 The various machines present in the production shop are capable of executing a
wide range of machining processes and have varying dimensional capabilities.
There is a collection of some of the best machines available across the world, such
as Pama, Skoda, Waldrich Coburg, Shweiss etc.

3.  The Machine Shops have various machines for performing operations like turning,
boring and milling.
 The machines in the Machine Shops include Gantry Plano-Miller(Biggest Machine
in INDIA), an Electric Discharge Machine (EDM), Vertical and Horizontal Turning
Lathes, Vertical Turret Center, Horizontal Boring Machines, Rotor-Slotter Machine, a
Side-Entry Groove Machine, and Radial Drilling Machines etc.
 The Vertical Turret Centre is the machine in T4 shop where both, turning and milling,
can be done.
 In Fabrication shop, operations like welding, cutting, heat treatment, shot blasting,
bending and packing are performed.
 Major equipment in the Fabrication shop includes Heat Treatment Furnace, 20T
Welding Positioner, Rolling Machine, Hydraulic Press, Plate Bending Machine,
Packing Machine and Shot Blasting Booth.

4. INDUCTION TO ALL MACHINES OF T3
SHOP
After the induction of all shops, I was allocated to T3 shop where I studied all
machines which are:
 VERTICAL TURNING LATHE
 HORIZONTAL BORING MACHINE
 ELECTRO DISCHARGE MACHINE
 PLANNO MILLER FOR MILLING OPERATION
 DEBURRING AND CLEANING SECTION
 MARKING TABLE

5. Project: Time Study and Evaluation of Machining
Process
 MENTOR: MR CHETAN PATIL (HEAD T3 SHOP)
 DEPARTMENT:MACHINE SHOP, T3 IN PRODUCTION SHOP
 MACHINE: VERTICAL PRECISION MILLING MACHINE, PM202
 ASSOCIATE ENGINEERS: MR ANKUSH JAGGI & MR DEVAL DIXIT
 OBJECT: HP PEDESTAL LOWER HALF

6. STEAM TURBINE
BEARING
PEDESTAL

7.  A steam turbine is a mechanical device that converts the heat energy of steam to
mechanical energy. This mechanical energy, in the form of rotary motion of the
turbine is particularly suited to drive an electrical generator.
 In large power stations, the steam turbine is divided into three distinct power
stages, the first being high pressure (HP), the second Intermediate pressure (IP)
and the third low pressure(LP). Separate cylinders for IP and HP stage can be
used or both the turbines can be housed in one casing and called HIP turbine.
 Bearing pedestals are provided for supporting this turbine rotors at the two ends
which enable them to rotate freely.

8. BEARING PEDESTAL
Bearing Pedestal performs the following functions: -
 It supports the rotor via journal bearing & maintaining gland clearances & also inter-stage
clearances.
 It houses the lubricating & jacking oil supply piping & bearing oil drain pipe work.
 Encloses various instrumentation connections. E.g. bearing temperature, speed measurement,
differential expansion, electricity, vibration pick-up, etc.
 It covers the rotor coupling.
 Oil guard rings provided at the two ends of pedestals prevents the leakage of oil & vapors.

9. PROJECT OBJECTIVE
 To study all production parameters like drawing study, process planning
sheet, route card, preventive and predictive maintenance sheet as well
as tooling sheet.
 To analyze the all machining processes and their respective timings with
standard timings given by MHI.
 To note the wastage or leisure timings done on shop floor.
 To enhance the efficiency of machine with possible adequate solutions
for current industrial problems.

10. METHODOLOGY
 First of all I studied the PPS of HP PEDESTAL LOWER HALF and note the basic
standard timing for completion of object.
 Then the analysis of drawing, that exactly what it is and how the machining
operations are done on it, in what order, with what tolerances and which
operation are difficult to process.
 Then I observed the whole process done by operators on HP PEDESTAL
LOWER HALF step by step and calculate amount of actual time required by
them to complete the component.
 Then we match the actual time with planned time and we found that the actual
time was more than the planned time but not by a larger quantity except for
two cases which are:
1. Roughing of Bottom Face.
2. Machining of Oil Groove.

11. COMPARISON FOR LAST 3 PROJECTS
308.5
286
239
0
50
100
150
200
250
300
350
MH3 SR1 SR2
SMH VS ACTUAL TIME
SMH =194.55
Y-AXIS: 1 UNIT = 1 HOURS

12. CASE STUDY
 ROUGHING OF BOTTOM FACE:
Planned time (By SMH) – 4 hours 18 minutes
Theoretical program time – 5 hours 4 minutes
Actual time – 11 hours 46 minutes

13. Problem Causes Corrective Action Extra Time
Taken
2 extra passes had to be
taken
Depth of cut chosen was 2mm less than the
planned value because machining limits.
An extra 2 hours 32 minutes of machining
had to be done to compensate.
2 hours 32
minutes
Use of extension head Extension head installed could not operate at
the desired cutting depth.
-
2 extra passes had to be
taken
Extra material of 5mm was present after
fabrication process.
An extra 2 hours 32 minutes of machining
had to be done to compensate.
2 hours 32
minutes
Insert wear out Inserts have to be replaced after every 1-2
passes. This replacement takes time.
Include an estimate of the time taken for
this in the planning or select working
ranges in which this would not happen.
Insert change For a tool with 16 inserts, up to 20 minutes
per pass was used in replacing worn out
inserts.
This time should be considered while
calculating the approximate machining
time.
1 hour 20
minutes
Offset had to be taken
again
For every tool and insert change, the offset
had to be taken again.
Extra time was taken to take the offset
again.
40 minutes
Development of chips
and coolant
accumulation
Anytime material removal is done, metal chips
are developed and have to be cleared.
Cleaning both takes approx. 5 minutes per
pass.
No corrective action possible. Necessary
action to ensure correct finish and
preventing the destruction/wear out of the
inserts or cutting tools.
40 minutes
Different cutting speeds,
feeds and depth of cut
Values prescribed in the PPS are difficult to
match for reasons such as machine capability
limits, material stress limits and the possibility
of insert and tool wear out.
The timings mentioned in the PPS are as
per theoretical calculations and the actual
parameters and timings are different.

14.  Machining of oil groove:
 Planned time (by SMH) – 2 hours 6 minutes
 Theoretical program time – 2 hours 34 minutes
 Actual time – 4 hours
Problems Causes Corrective Action Extra Time
Taken
Drilling done to generate
slot
Drilling had to be done to set the starting
point for further machining.
Extra time taken to drill the 6 holes
should be added to the PPS as it is a part
of machining time.
30 minutes
Time taken for setup Setting of the drilling tool and taking offset
for the same took up extra time.
Can be added to the PPS as setup time
for this operation.
10 minutes
Development of chips and
coolant accumulation
Anytime material removal is done, metal
chips are developed and have to be cleared.
Cleaning both takes approx. 5 minutes per
pass.
No corrective action possible. Necessary
action to ensure correct finish and
preventing the destruction/wear out of
the inserts or cutting tools.
40 minutes
Different cutting speeds,
feeds and depth of cut
Values prescribed in the PPS are difficult to
match for reasons such as machine capability
limits, material stress limits and the
possibility of insert and tool wear out.
The timings mentioned in the PPS are as
per theoretical calculations and the
actual parameters and timings are
different.

15. WHAT I LEARNT FROM MY TRAINING?
 I got to know about different type of tools and inserts used for different
processes. I also study the nomenclature and geometry of tools as well as
inserts which are used for machining.
 I came to know the basic process from operator by understanding loading
condition, speed override, feed override, spindle override, rpm, reference
machining, maximum rotation diameter, coolant condition, chip conveyor
arrangement, jigs and fixtures, tooling parts, dial gauge for levelling and
centering, measuring devices, inserts, jaws, blocks and clamps etc.
 I got to know about the magnetic chuck used for clamping the component
while it’s being machined.
 I also learned how to calculate the approximate time taken by the machine to
complete a specific process.

16.  Here also I understood the Industrial Management terms like wise EHS
(Environmental Health And Safety), 5 S, TBT (Tool Box Talk), HJS (Horizontal
Joint Surface), Route card, NCR (Non Conformance Report), PPS (Process
Planning Sheet), Tooling List, Preventive and Predictive Maintenance Check
Sheet etc.
 I also got to know about different process terms like spot facing, back spot
facing, weld edge and dry run.
 Also, I learnt the use of the Go-NoGo Gauge from my project mentor, who also
taught me how to use the same while checking the threading performed
internally in holes and bores on the machined surface.
 I also learned to analyze the programs made for the different operations and
how to interpret the various process parameters like depth of cut, cutting
speed, feed given etc.

17. OBSERVATION
 Clogging of chips around the tool and the component that is
machined makes it difficult to do the process properly.
 Excess use of coolant. It should be used within permissible limits as
sometimes coolants goes in part of component where it is not
required.
 Many times tools of the machine are taken by other machine
operators or by other shop which sometimes stops the machining
of component which increases actual time of machining.
 Leakage of air is observed in many machine and may be leading
to losses. Also there is misuse of compressed air in the purposes
where it is not required.

18.  At many instances, the operators ran the various operations at speeds lesser
than the prescribed values, resulting in the need for multiple passes and
therefore, more time than what is listed in the Standard Man Hours for the
operation.
 Usually operators stops working during the last half hour of their shift and
would spend the time idle. This time can be used up for other purposes or at
the very least another pass can be completed in the idle time.
 There is always a possibility of extra material being present on the component,
which was also the case with the HP Pedestal, which had 5mm of extra material
which took extra time to remove.

19. SUGGESTIONS
 For removing the chips during machining the workers used to remove it
by a steel rod which is dangerous and may also affect the surface finish of
the component. For that there should be CHIP BREAKERS fitted with tool
point, which will break the chips in discontinuous fashion, resulting in less
clogging of chips around the component and between the job and the
cutting edge of the tool.
 A set no. of tools should be present at every machine for all basic
purposes.

20.  The usage of coolant should be regulated in a way to extend the usable life of the
coolant. In many cases, multiple tubes or faucets delivering the coolant were switched
on, some of which weren’t even aimed at the surface being machined, thereby causing
major wastage of the coolant, which cannot be circulated permanently and has to be
replaced after set periods of time. This can be implemented by properly observing and
supervising the usage of coolant at the time of operation and then instructing the
operators as to the proper use.
 Leveling and Centering operation take almost half time of the whole machining
operation, so it must be reduced anyway by proper skilled operators or by proper
accurate clamping arrangement ex. Magnetic chuck.

21. THANK YOU