This document discusses the semi-mechanization of coal mining in India using Side Discharge Loaders (SDLs) and Load Haul Dumpers (LHDs). It provides background on the introduction of mechanization in coal mining in India. SDLs and LHDs have become important tools for intermediate technology in coal mining. The document describes the operations, capacities, advantages and safety features of SDLs and LHDs. It also discusses best practices, operating problems and the code of practice for operators.

1. SEMI-MECHANISATION BY SDLs & LHDs
I. Satyanarayana,
M.Tech,MBA,MCA
Dy. Manager, Project Planning, SCCL,
isnindian@gmail.com,
visit at
www.slideshare.net/isnindian
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2. PRESENTATION
ON
SEMI-MECHANISATION BY
SDLs & LHDs
I. Satyanarayana, M.Tech,MBA,MCA
Dy. Manager
Project Planning
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3. CHRONOLOGY OF INTRODUCTION OF UG
MECHANISATION IN SCCL
1956 – Coal Cutting and Coal ploughing
1962 – Gathering arm loaders and Shuttle Cars
1976 – SDLs (GDK No. 9 Incline)
1979 – Roadheaders
1980 – LHDs (GDK No. 9 Incline)
1983 – Longwall Technology
1989 – Blasting Gallery Technology
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4. INTRODUCTION
• In order to keep away with the arduous labor of
loading coal manually, to avoid exposure of
persons at face and improve productivity efforts
are made to introduction of intermediate
technology and continuous mining systems.
• as a result, in India SDLs & LHDs have taken
foot forward in intermediate technology.
contd…
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5. INTRODUCTION
• The Board and pillar method has been
predominantly adopted in SCCL and in India for
the extraction of coal seams due to shallow depth
and good roof conditions.
• Although every effort is made to introduce LW
method of mining, it is not likely to replace the
entire board and pillar method
contd…
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6. STATUS OF SDLs AS ON 24.01.2011
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7. STATUS OF LHDs AS ON 24.01.2011
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8. Cycle of Operations
•Drilling
•Blasting
•Supporting
•Coal loading (SDLs & LHDs)
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9. OPERATION OF LHDs and SDLs
Method of working
The method of development and depillaring with LHDs/SDLs
was similar to Conventional development of forming rectangular
OR square pillars as per Regulation 99 of Coal Mines
Regulations, 1957 and subsequent extraction of pillars by
splitting and judiciously reducing it.
Coal Preparation
Coal preparation for LHD/SDL was done by conventional
drilling and blasting.
Transportation
The coal carried by LHD/SDL from the face was discharged on to the
pony belt conveyor, which was maintained as near to the face as
possible, even though LHD/SDLISN cope with about 100m lead.
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10. LOAD HAUL DUMPERS (LHDs)
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11. Details of LHD
• an electro-hydraulic powered underground mining equipment
• used to collect the coal, haul upto the discharge point of
hopper/chain conveyor/belt conveyor located within 100 m from
the coal face and to dump on it.
• 50 HP (811 Model) Motor and 100 HP (912E Mode) Motor
•Three forward and three reverse speeds.
• The working pressure of hydraulic system is 2200 PSI and
discharge 16 GPM.
• The hydraulic tank capacity is 210 ltrs.
• Oil is cooled by a radiator and fan run by hydraulic motor.
• The power to the machine is fed by a trailing cable 16 m2
handled by a cable reeler, which can accommodate 100 m length.
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13. LHD mechanization – where the gradient is 1 in 6 & flatter
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14. Load Haul Dumpers
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15. LHD
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16. LOAD HAUL DUMPER IN BLASTING
GALLERY METHOD
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17. Capacity and Speed
6.15m3
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18. Advantages of LHDs
(a) Indigenous and : To save foreign exchange and to
availability of spares reduce breakdown hours.
(b) Robustness : To withstand difficult conditions.
(c ) Compactness : To work in restricted underground
space.
(d) Reliability and : To enable to resist difficult conditions.
susceptibility
(e) Adaptability : For easy maintenance.
(f) Portability : Easy to move from place to place.
(g) Safety : Proper guides and covers. Elect.
Protective devices.
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19. SAFETY FEATURES of LHDs
1. HEAD LIGHTS
2. OPERATOR’S CANOPY
3. DUMP VALVE
4. PARKING BRAKES & SERVICE BRAKES
5. GONG BELL
6. AUDIO VISUAL ALARM
7. EMERGENCY STOP BUTTON
8. DEAD MAN SWITCH
9. FLOAT (OIL LEVEL) SWITCH
10. TEMPERATURE SWITCH
11. CABLE OVERRIDING SWITCH
12. PILOT CORE PROTECTION
13. PUSH BUTTON STATION
14. BRAKE ACCUMULATORS
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15. FIRE EXTINGUISHERS

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21. Details of LHD ..Contd
•The temperature of hydraulic oil is kept well below 65o C.
Cycle Time for LHD 811 Model
1. Available time per shift - 390 minutes
2. Time for trip - 5.7 minutes
3. Number of trips per shift for LHD - 65
4. Output per shift for LHD - 72 tonnes
5. OMS - 3.375 tonnes
6. Output per drill - 60 tonnes
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22. BEST PRACTICES ..Contd
Keeping LHD path clean, dry and flat
Smooth and uniform discharge by LHD on the belt conveyor
Categorisation of Spares & ensuring availability of fast
moving parts in underground stores.
Providing appropriate tools for technicians
Avoiding acute angles
Preshift extention/retreating and maintenance of conveyor belts
Preshift maintenance of LHDs
Easily shiftable tail end assembly
Replacing/overhauling Transmission and axles of LHDs (biannual
Providing drill machine in each face and spare Gate End
Panels for LHDs
Cable Vulcanising
Tyre and tube repairing and inflation
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23. METHOD OF DEPILLARING
GOAF
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24. Manpower requirement for Depillaring district with 5 LHDs
Sl. SHIFT
Designation Gen. Shift Total
No I II III
1. Under Managers 1 1 1 1 4
2. Asst. Engineers 1 NIL NIL NIL 1
3. Overman 1 1 1 1 4
4. Mining Sardars 1 1 1 1 4
5. Electrical Supervisors 1 Nil NIL NIL 1
6. Shotfirers NIL 6 6 6 18
7. Coal cutters NIL 24 24 24 72
8. Support Mazdoors 15 15 15 15 60
9. LHD Operators NIL 5 5 5 15
10. Conveyor Operators NIL 7 7 7 21
11. Fitters + Helpers 6 4 4 4 18
12. Electricians + Helpers 2 2 2 2 8
13. Conveyor shifting gang 6 NIL NIL NIL 6
14. Water Spraying 3 NIL NIL NIL 3
15. Ventilation (Mazdoors) 4 NIL NIL NIL 4
16. Tyndals 9 NIL NIL NIL 9
17. Gen. Mazdoors 25 15 15 15 60
18. Cable Vulcanizer 2 NIL NIL NIL 2
total 77 ISN 81 81 81 320

25. SIDE DISCHARGE LOADERS
(SDLs)
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26. SDL mechanization – where the gradient is 1 in 4 & flatter
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27. Side Discharge Loaders
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28. SIDE DISCHARGE LOADER
IN SEMI MECHANISATION
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29. SIDE DISCHARGE LOADER
IN SEMI MECHANISATION
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30. COMPARISON BETWEEN SEMI-MECH & HANDSECTION
3 SDLs HS (2 Drills)
Output (LTPA) 1.62 0.9
Men on Roll(Nos) 181 281
OMS (at dist. Level) (T) 2 1.2
Cost of Production (Rs./T) 1859 4032
Profit over HS (Rs./T) 2227 --
Initial investment on
P&M (Rs.Lakhs) 180 57
*Output from SDL depends on its availability & utilisation
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33. SAFETY FEATURES of SDLs
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34. UNIVERSAL DRILL MACHINE
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38. CODE OF PRACTICE FOR SDL OPERATOR
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39. CODE OF PRACTICE FOR SDL OPERATOR
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40. CODE OF PRACTICE FOR SDL OPERATOR
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45. Code of Practice for Overman:
He should inspect the route of LHD/SDL marching prior
to marching and take the following precautions:
Ensure no obstruction in the way of marching. Check the
presence of W-straps, bolts, chock timber, old pipes and
other material that damage to the LHD/SDL and result to
other breakdowns.
Take necessary precautions to prevent dislodgment of
vertical supports, if any, due to moving trailing cable.
Ensure that the persons engaged have taken all necessary
precautions.
Take necessary precautions while crossing track line, pipe
line etc. And also avoid rubbing of trailing cable against
hard surfaces and to pillar corners.
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46. OPERATING PROBLEMS
• Non-availability of machine
• Poor utilization of machine
• Lack of Coal preparation
• Delay in supporting
• Delay in machine tramming
• Delay in tub supply or backup transport services
(crusher, belts, bunkers etc.,)
• Idle time due to shift change hours
• Lack of spares availability
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Contd…….

47. OPERATING PROBLEMS
• Lack of on-hand trained crew
• Lack of midlife overhaul of machinery
• Lack of maintenance of machinery
• Poor working environment
• Timely not positioning of supervisors
• Poor placement of orders
• Unsatisfactory incentive schemes
• Untrained mechanized district crew right from
supervisor to workmen.
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50. RECOMMENDATIONS
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51. PERFORMANCE SUMMARY
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52. Approved norms of SCCL for monitoring
UGMM equipment performance
Bucket
Standard Standard Production
Equipment capacity
availability utilization (TPA/TPD)
in Cu m
SDL 1.1 91% 58% 54000/180
LHD 811 1.5 91% 57% 60000/200
LHD 912 2.7 91% 57% 100000/333
BG LHD 2.7 91% 57% 100000/333
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53. INPUTS FOR IMPROVING
PRODUCTION
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54. 1. Improvement of availability and utilization of machinery
– Idle time due to shift change hours can be reduced by
implementing overlapping 4 shifts.
– Proper maintenance of machinery i.e., strict scheduled
maintenance should be followed.
– By making availability of coal at max. no of working faces.
– Reducing flitting distance of machine.
– Timely availability of spares by follow up with firms and
placement of RC & departmental contracts.
– By introducing sufficient number of mechanized roof bolting
machines with rated power pack/ air compressors.
– Deployment of trained efficient supporting crew, technicians and
operating personnel.
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55. 2. Working of full shifts.
– Implementation of staggered shifts
– Positioning of supervisors in time.
– By improving good environmental conditions such are
ventilation, supporting, drainage and house keeping.
– Keep availability of material for supporting , ducting
and spares.
– Efficient back up services like pumping, work-shops,
coal evacuation system, bunkers etc.,
– Proper incentive schemes.
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– Treating people with due regard.

56. 3. Other recommendations
– Introduction of high capacity and cable less LHD’s
– Good communication system at all levels.
– Intensive monitoring at all levels.
– Increasing length of cable by reducing diameter of cable
or increasing drum diameter.
– Mechanization of face drilling.
– Introduction of multi job concept like ‘operator cum
mechanic’, ‘coal cutter cum support men’
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57. 3. Other recommendations
– Introduction of equipment maintenance by OEM.
– Design of suitable training module.
– Out sourcing of non-core activities
– Adjusting general shift man power in production and
retaining only in statutory requirement.
– Explore the workings at suitable gradient.
– Avoiding water and slurry condition by proper
maintenance of drainage system
– Selection of educated and young persons as operation
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crew.

58. CONCLUSION
Availability of coal faces & more yield per blast
Maintain less lead (30m)
Continuous Loading
Extensions/Retreats & Pre-shift maintenance etc
Increase machine utilization
Better working conditions
Good discipline, higher morale and well planned actions
Training
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