The document discusses dragline operation in surface coal mining. It describes how draglines are well-suited for mining flat, thick coal seams with uniform overburden depth. Planning is important to maximize dragline efficiency through proper equipment mixes and cut sequencing. Common methods for extracting cuts include advance benching and extended benches. Blasting can aid dragline extraction by breaking up hard rock. Overall, draglines provide a low-cost method of overburden removal when geological conditions allow for their effective use.

1. 1

2. 2
DRAGLINE: Application.
Further, the choice of stripping unit is influenced
primarily by the system of mining, which is itself
influenced by surface topography, nature and shape of
coal seam, production requirement, nature and depth of
overburden as well as reclamation considerations. The
factors influencing most of the designers to go in for the
deployment of Dragline are due to
 The flexibility of its operation.
 Greater digging depths (compared to a shovel of comparable
cost).
 Greater range which can be well used for multi-seam working.
 It safeguards against spoil pile slides.
 Lowest maintenance Cost per cubic metre.
 High percentage of coal recovery.
 Its cheaper operational cost and
 Low ground pressure (less than 1kg/cm2) exerted makes it

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FORMULA FOR CALCULATING
THE HEIGHT OF THE BENCH.
t + tan x ( R - W / 4 )
H = ----------------------------
S + tanx / tan y
H= Height of the OB Bench.
t= Thickness of the Seam.
x= Angle of repose OB.
y= Angle of High wall.
S= Swell factor ( 1.25).
R= Effective of Dragline.
W= Width of the cut.

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DRAGLINE OPERATION AT
OPENCAST PROJECT - I ;R.G
10 20 30 40 50 60 70 80 90
60

5. 5
DRAGLINE: Application.
A BORE HOLE SECTION
SHOWING THE INTERBURDENS

6. 6
OPENCAST MINING WITH
WALKING DRAGLINE.
W - 2000
WALKING
DRAGLINE

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SALIENT FEATURES
OF DRAGLINE
1. Make : Ramson & Rapier
2. Boom Length : 95.6 Mtrs.
3. Digging radius : 88 Mtrs.
4. Dumping Height : 39.6 Mtrs.
5. Bucket Capacity : 24 M³
6. Base Dia : 16 Mtrs
7.Shoe Length/Width : 17 Mtrs./2.8 Mtrs.
8. Movement of Machine / Step :2.2 Mtrs
9. WT. Of Machine : 2000 Tonnes
10. Total HP :3500 HP ( Swing motors:3 No.s ;
Hoist motors :2 No.s ;
Drag motors :2No.s ; )
11. Annual Target : 4.00 M. M³
12. Material Handled since inception : 67.29 M. M³ ( up to FEB-03 )

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Use of Draglline:
There are lot of controversies over the actual
and best use of Dragline. Some experts say that the
excavating capacity of traditional equipment for pre-
stripping, should far exceed the excavating capacity
of Dragline. Usually Dragline machine, being the
last equipment to be used immediately above the
bottom most coal seam, has got limited scope of
enhancement on production, even by increase in the
strength of conventional equipment. Initial
development for deployment of Dragline has to be
carried out by shovel-dumper combination and they
are to be continued to be used for pre-stripping or
removal of upper thin seams if any.

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Use of Draglline:
The other opinion emphasises and banks more
on the operational cost of Dragline, the excavation
cost with Dragline being minimum, tendency is
always to fully use Dragline and therefore would
prefer more excavation capacity in the form of more
number of Draglines. To accommodate more
number of Draglines, these experts like to either the
property in a suitable way for unit work or combine
two to three seams working with multiple Draglines
or by having tandem application with wider cuts etc.
Even though multiple seam operation is being
effected by single Dragline, it may be remembered
that, any mode of operation above the level of
Dragline tub is inefficient. Mines have already come
up with production reaching 10 million tonnes with
as many as four Draglines of different sizes.

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The advantages offset the
minimal disadvantages like
1) Requirement of bench preparation and
2) Higher capital cost
3) It's limitation to work only bottom most seams.
Advantages:
The greatest advantage of Dragline machine is that,
its cost of overburden removal is the cheapest within its
limitations. Though the machine is huge and requires
special and stringent maintenance, it's operating cost per
cubic metre works out cheaper than any other method.
As earlier said, the machine also has its limitations and is
ideally suited for flat thick seams with extensive property
on strike direction and with uniform thickness of
overburden. The presence of geological disturbances,
multi direction dipping seams or steep seams complicate
its field of operation.

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Planning of Dragline
Operation:
Once the choice of the machine is made, its
successful operation depends a lot on careful and efficient
planning. Planning takes into account, apart from the best
working of the machine, the correct and systematic
deployment of other traditional equipment for pre
stripping etc. Aspects which require close attention, at the
planning stage itself include:
 Selection of proper machinery mix for allowing the
Dragline, to have uninterrupted work.
 Initial planning of Dragline cuts and the sequence of
operation.
 System for proper evacuation of the coal from the
cuts.

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Planning of Dragline
Operation:
Drainage, to conduct water away
from coal extraction area and to
prevent ponding. I.e., De-watering
arrangements.
Study of actual operational time of
Dragline.
Study of bank overburden removal
and rehandling operations and to
minimise rehandling.
Fragmentation and blasting aspects
to avoid hard digging conditions.

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WORKING WITH DRAGLINE
: Steps & Methods
DRAGLINE CUTS PLAN
H
A
U
L
R
O
A
D
CUT-60
CUT-61
CUT-63
CUT-65 CUT-64
CUT-66
CUT-67
CUT-62
BLOCK-A
BLOCK-B
COAL EXCAVATION

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WORKING WITH DRAGLINE :
Steps & Methods
For any dragline operation two
most important dimensions are
operating radius and the dumping
height, which describe the physical
stacking capability of a particular
machine, the operating radius is
dependant on the positioning of the
machine from the crest and decides
the point of discharge/dumping. In
other words, reach factor decides the
exact place of dumping and can be
obtained from the following
relationship.
Operating radius = Positioning +
Reach factor.
H
T
OR

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WORKING WITH DRAGLINE :
Steps & Methods
For any dragline operation two
most important dimensions are
operating radius and the dumping
height, which describe the physical
stacking capability of a particular
machine, the operating radius is
dependant on the positioning of the
machine from the crest and decides
the point of discharge/dumping. In
other words, reach factor decides the
exact place of dumping and can be
obtained from the following
relationship.
Operating radius = Positioning +
Reach factor.
H
T
OR

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WORKING WITH DRAGLINE :
Steps & Methods
General Working Methods of Dragline:
In open pit mining with single
Dragline, the strip/cuts method is adopted
generally. Where the area is divided into
long strips/cuts. The entire quarry area is
divides into a number of cuts as given in
the working plan. Usually the width of the
cuts is constant throughout except for the
boxcut.

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WORKING WITH DRAGLINE
: Steps & Methods
GENERAL CROSS SECTION

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WORKING WITH DRAGLINE :
Steps & Methods
The extraction of cuts with Dragline can be done with
various methods like Advance benching. Simple side casting.
Extended bench etc., depending upon the geological conditions
and the depth of the over overburden, but an initial boxcut is an
essential requirement.
Boxcut can be developed with the help of shovel-dumper
combination or Dragline itself. Boxcut derives its name due to
its shape and overburden removed from the cut is carried away
to the regular dumps. Usually boxcut is located such that the
overburden removed from the boxcut is not rehandled, except
under exceptional conditions and therefore better done by
shovel-dumper combination.

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BLASTING - AN AID TO
DRAGLINE WORKING:

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BLASTING - AN AID TO
DRAGLINE WORKING:

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BLASTING - AN AID TO
DRAGLINE WORKING:

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BLASTING - AN AID TO
DRAGLINE WORKING:

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WORKING WITH DRAGLINE :
Steps & Methods
PLAN OF
BOX CUT
SECTION
VIEW OF
BOX CUT

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Advantages of bench extended Method.
 Dagline has more room maneuver resulting in faster
cycle times and safer operations.
 Scheduling easier as each slice takes longer complete.
 Higher production can be concentrated in a cut width
along strike length.
 The extended bench offers a much safer position for
Dragline to work from taken the original high wall.
 Coal recovery is more.
 Reduces the contamination of coal as it is easy to clean
out the coal edge.
Disadvantages are only to schedule.

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DRAGLINE WORKING:

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CONCLUSIONS:
CONCLUSIONS: Related to Surveyors
1. We must know the existing technology or
methodology in our company thoroughly.
2. Management has to conduct special training
programs to related technologies of particular
projects.
3. To show the better performance their
involvement to relevant works.
4. To involve in deep discussions about the any
good achievement or any problem faced, a
record maintains necessary for future
reference.
5. Update the knowledge of their system of
works, using electronic optical instruments
i.e.,"Total station" and the data processing
using the computer system related to survey.