The document provides an overview of dragline components, functions, and types, highlighting its main purpose of excavating earth and loading it for transportation or disposal. It details the operation procedure, various types such as crawler, wheel, and truck mounted draglines, and their applications in construction and mining. Advantages include operation from firm ground and trench excavation, while the disadvantage is lower output compared to power shovels.

1. DRAGLINE
Components of a dragline.
Prepared by
VIKAS K. VERMA
B.E. Civil - 46

2. Dragline
 The basic character of the machine is dragging the bucket
against the material to be dug.
 A dragline is used to excavate the earth and load it into
hauling units such as trucks or tractor pulled wagons or to
deposit it into dams/ embankments or spoil banks near the pit
from which it is excavated.
 Primarily, the function of a dragline are as that of a power
shovel but in some projects, a dragline has distinct advantages
compared with power shovel because of its long light boom.

3. Procedure of Dragline
 Excavation is started by swinging the empty bucket to the
digging position, at the same time slacking off drag and hoist
cables.
 Then the bucket is pulled towards the machine while digging
depth is regulated by means of the tension maintained in the
hoist cable.
 When the bucket is filled, the operator takes in on the hoist
line while playing out the drag cable.
 Hoisting, Swinging and Dumping of the loaded bucket follow
in that order, then the cycle is repeated.

4. Types of dragline and Particulars of
components
 Crawler mounted dragline
 Wheel mounted dragline
 Truck mounted dragline
Particulars of components Range
Boom length 15m to 24m
Capacity in Kg 5400 to 2700
Boom angle in degree 20 to 45
Dumping radius in meter 12 to 26
Dumping height in meter 3 to 13
Maximum digging depth in
meter
12 to 6
Bucket quantity 0.38 m^3 to 3.25 m^3

5. Application of dragline
 Bulk pit excavation.
 Digging canal or a Ditch or near a pit.
 Excavation in mines.
 Road excavation.
 Underwater excavation.
 Useful in soft and medium hard soil.

6. Advantages of dragline
 A dragline usually does not have to go into a pit or hole
for excavating the earth. It may operate on natural firm
ground.
 When the excavated earth is to be deposited on nearby
banks or dams, then dragline is enough to dispose of
earth in one operation.
 A dragline is excellent for excavating trenches without
shoring.
• Its output is lower than power shovel.
Disadvantages of dragline