development of main headings and gate roads with the use of road heading and bolter miners has paramount importance for effective production from a Longwall mine

1. ROAD HEADERS & Bolter Miner
By
U. Siva Sankar,
Deputy Manager
Adriyala Longwall Project

2. • Roadheaders were first developed for mechanized excavation
of coal in the early 50s.
• Roadheaders offer a unique capability and flexibility for the
excavation of soft to medium strength rock formations, hence
widely used in under ground coal mining.
• Advantages:
– Improved productivity.
– Improved safety.
– Reduced ground support.
– Less manpower requirement.
– Reduced costs.

3.  Road header is excavating equipment consisting
of a boom-mounted cutting head, a loading
device usually involving a conveyor, and a
crawler travelling track to move the entire
machine forward into the coal face.
 Road header is exclusively used for drivage of
gate roadways in Longwall panel.
ROAD HEADER

4.  Depending on cutting head, Roadheader are two types.
• Borer type-Transversal - rotates parallel to the cutter
boom axis-DOSCO
• Ripper type-Longitudinal - rotates perpendicular to
boom axis – AM-50
 It can work gradient flatter than 18 deg/ 1 in 3.

5. Neil et. al (1994) refer road headers as small size up to 30 t, midsize between 30 to
70 t and large size between 70 to120 t.
Classification of Boom Type road Header:
Cutting Action of heads:
 Milling type or Borer Type (axial head), and
 Ripping Type (Transverse head)
Fig: Cutting action of road headers
a. Ripping type, b. milling type

6. Road Headers introduced in SCCL:
• ALPINE MINER AM-50
• EBZ -200
• DOSCO with onboard twin bolters
• WIRTH T 1.14 with onboard twin bolters

7. ALPINE MINER
AM-50
Overall length of machine 7.50m
Height of machine 1.64m
Width over machine gathering apron 1.91m
Machine weight (estimated basic machine) 24T
maximum working gradient 18°
Total power 166 kW

8. DOSCO- LH1400 MODEL
Overall length of machine 11.18m
Height of machine (canopy) 2.25m
Width over machine gathering apron 3.56m
Machine weight (estimated basic machine) 63T
maximum working gradient 18°
Total power 362 kW

9. WIRTH
Overall length of machine 10.29m
Height of machine 2.57m
Width 3.6m
Machine weight 65T
maximum working gradient 18°
Total power 360 kW

11. Working Section Layout of Road header
Heavy Section for gate
belt conveyorBridge belt conveyor
Road header
Air duct
Side bolts
Side bolts
Track line wit h endless haulage for material
transport

13. COMPARISON OF TECHNICAL SPECIFICATIONS OF DOSCO LH1400,
WIRTH T1.14 AND AM-50
TECHNICAL DATA T1.14 WIRTH MINER DOSCO LH1400 AM-50
Overall length of
machine
10.29 m 11.18 m 7.5 m
Height of machine 2.57m 2.250m 1.645 m
Width 3.6m 3.56m 2.5m
Machine weight 65 tonne 63 tonne 24 tonne
Maximum cutting
height
4.817m 4.5m 4.0 m
Maximum cutting
width
6.7m 7.02m 4.8 m
Maximum cutting
depth
260mm 330mm 100mm
Ground clearance 250mm 257mm 180mm
Max. gradient 18 degrees 18 degrees 18 degrees
Total installed power 360KW 362 KW 166KW
Total cooling water
requirement
25 l/min 40 l/min at31 bar 30 l/min

14. COMPARISON OF TECHNICAL SPECIFICATIONS OF DOSCO
LH1400, WIRTH T1.14 AND AM-50
UNDER CARRIAGE DETAILS
TECHNICAL DATA T1.14 WIRTH MINER DOSCO LH1400 AM-50
Crawler track
width
600mm 550mm 370mm
Track length 2900mm 3711mm
Tramming speed 0-18m/min 2.28m/min&9.6m/min 5m/min
Floor pressure 0.18Mpa 0.15Mpa 0.13Mpa
Track tensioning
arrangement
Track should be
tensioned manually
with grease pump
Tracks are
automatically tensioned
whenever tracks are
operated
Tracks are
tensioned with
grease pump
CUTTER BOOM
Cutter motor
size
180KW 250KW 100KW
Axial thrust 200kN 542kN
Speed 35.69 rpm 53 rpm 88.7 rpm
Cooling media Water water water

15. COMPARISON OF TECHNICAL SPECIFICATIONS OF DOSCO LH1400,
WIRTH T1.14 AND AM-50
TECHNICAL DATA T1.14 WIRTH
MINER
DOSCO LH1400 AM-50
LOADING ARRANGEMENT
Apron width 4.232m 3.560m 2.5m
Power 2x21KW hydraulic
motors
Hydraulic motors Conveyor chain
Star wheels speed 24rpm 33.4rpm Gathering arms
CHAIN CONVEYOR
Type of conveyor Twin outboard Twin outboard Single Chain
Conveyor width 740mm 694mm 370mm
power 2x25KW hydraulic 2x33.7KW hydraulic 2X11KW Electric
Conveyor chain
speed
1.15m/s 1.02m/s 0.9m/s

16. COMPARISON OF TECHNICAL SPECIFICATIONS OF DOSCO LH1400,
WIRTH T1.14 AND AM-50
TECHNICAL DATA T1.14 WIRTH MINER DOSCO LH1400 AM-50
HYDRAULICS
Hydraulic fluid HFDU 68 HFDU 68 Mineral oil or FRHF
of the HSC Group (Water-
Glycol)
Power pack motor size 180KW 112KW 11KW
No of pumps 3 2 1
Type of pumps 2 variable displacement
axial piston pumps of 275
l/min and 1 vane pump of
79l/min
1 variable displacement pump of 148
l/min and 1 four section gear pump of
486 l/min
Axial thrust pump of 40
lpm
Return line filters 2 of 10 micron filters 1 of 6 micron filters 10 micron filters
Hydraulic tank capacity 800ltrs 900ltrs 260 ltrs
Standard hose fittings Threaded (37 degree JIC)
hose fittings
Staple lock fittings Staple lock fittings
Normal working pressure 250bar 140 bar 200 bar
Parking brakes Spring applied hydraulically
released brakes
Spring applied hydraulically released
brakes
Nil
Cooling Hydraulic oil temperature
is controlled
through an heat exchanger
Oil temperature is controlled with
baffles mounted
on the tank
Close or open circuit Water
cooling

17. TECHNICAL DATA T1.14 WIRTH MINER DOSCO LH1400 AM-50
HYDRAULIC TANK SAFETY FEATURES
Oil level indicators Visual level indicators Visual level indicators Visual level indicators
Thermostatic cutoff 3 position combined oil level
and temperature sensor
Thermostatic cutoff sensor, low fluid
level cutoff sensor
Nil
Pressure switch Pressure switch Pressure switch
Hydraulic system All functions main valve
bank are controlled by
solenoids ,only bolters are
operated
manually
All functions on the main valve bank are
controlled by pilot operated circuit at 30
bar
All functions on the main
valve bank are controlled by
manual operating levers
All valve segments with
spools use proximity switch
to monitor the position of
the spool and ensure correct
operation
-- --
LUBRICATION SYSTEM
All 43 grease points are
lubricated with hand grease
gun individually
For lubricating the machine is fitted
with centralized lubricating system
(WANDERLEAD) at four points on the
machine, which is powered via a
diverter valve, from the machine
hydraulic system.
Manual Greasing
COMPARISON OF TECHNICAL SPECIFICATIONS OF DOSCO LH1400,
WIRTH T1.14 AND AM-50

18. COMPARISON OF TECHNICAL SPECIFICATIONS OF DOSCO LH1400, WIRTH
T1.14 AND AM-50
TECHNICAL DATA T1.14 WIRTH MINER DOSCO LH1400 AM-50
ELECTRICAL
Supply voltage 1100 V/50 Hz/3ph 1100 V/50 Hz/3ph 550 V
Total power 360KW 362KW 166KW
Power junction box PK-2003 main enclosure with
FLP features
KM52/300/AW24 ENCLOSURE KEYEE300A
Display monitor 160mm display monitor with
fault finding software ----------------------- -----------------------
HEAD LIGHTS 5 OPERATED AT 24V/35W
WITH 2 AREA LIGHT FOR
ROOF BOLTING
5 OPERATED AT 24V/70W 2 OPERATED AT 24V
EMERGENCY STOPS 4NO’S 2 ON EACH SIDE 6 NOS 3 ON EACH SIDE 1No at Control panel
BOLTER SPECIFICATIONS
type 2XDHMS TYPE ABE deployed
with 2 telescopic platforms
(HYDRAMATIC)
SERIES 4200 1850 ROOF BOLTER
-----------------------
Drill Feed Two Stage Two Stage
Operation Operation of the road header
shall be carried out by
PEMPEK OBELIX RADIO
CONTROL SYSTEM, MACHINE
CAN BE OPRATEDUPTO 50 M
AWAY FROM THE MACHINE
All operations are carried out with pilot
operated joy sticks mounted on the
machine.
All operations are carried out
with operating levers
Hydraulic oil filling Oil to be filled with hand
operated oil filling pump
Oil to be filled with hydraulic power
operated oil filling pump
Oil to be filled with hand
operated oil filling pump

19. Bolter Miner (BM)

20. Bolter Miner Overview
Model 12ED30
Machine operation Sumping type miner
Cutter head Wide head machine – extendable/retractable drums
Cutting width - extended 5,500mm (5.5 meters)
Maximum cutting height 4,500mm (4.5 meters)
Coal gathering Plow type machine
Bolting rigs: Roof Four roof bolters
Bolting rigs: Rib Two rib bolters
Roof support Four temporary roof supports
Machine stabilization Front and rear stabilizing jacks
Machine length 13,175mm (13.175 meters)
Machine weight 120,400kg (120.4 ton)
Control system Joy Faceboss
Dust suppression Water sprays and dust collection system

22. 12ED30 overview
Plow with
extendable/retractable wings
Extendable/retractable cutter
head
Bolting rigs and temporary roof
support cylinders

23. 12ED30 overview
Dust collection
system
Main electrical
enclosure
Bolting rigs and TRS
cylinders

24. 12ED30 overview
Rear stabilizing
jacks
Front stabilizing
jacks

25. Typical Twin Entry Sequence

26. Typical Twin Entry Sequence – Step 1

27. Typical Twin Entry Sequence – Step 2

28. Tailgate Options
X - Slit X - Slit
Tailgate roadway thirls into X-slit, which is
across (or part way across) junction.
Will have un-even roof across junction and
will have ‘triangle’ step at both sides of
junction.
Depending on roadway position, may have
un-even floor to grade out.
Tailgate roadway thirls at side of X-slit, roof
will be level in junction.
May have to cut out side of roadway to
complete thirling.
Floor will be level.
X-slit driven measure needs to be accurate.

29. Typical Twin Entry Sequence – Step 3

30. Typical Twin Entry Sequence – Step 4

31. Typical Twin Entry Sequence - Step 5

32. Typical Twin Entry Sequence – Step 6

33. Typical Twin Entry Sequence – Step 7

34. Typical Twin Entry Sequence – Step 8

35. Bolter Miner Vs Road header
BM RH
Gallery Shape Rectangular Square/rectangualr/other stable
shape
Cutting and bolting sequence Full face at one time Partial face
Cutting across roof and floor layers Cutting along roof layers
Cutting and bolting simultaneous Cutting and bolting not
simultaneous
Roof and sides stability Less More
Progress Can be up to 750m / month Can be up to 350m / month
Coal loading outby Shuttle cars/ flexible conveyor train Bridge belt conveyor
mobility More, can drive two parallel
drivages
Can drive crosscut galleries also
Less, can drive single drivage only
Can not drive crosscut galleries
Coal dilution more less