• A dragline excavator is a piece of heavy equipment used in civil
engineering and surface mining.
• Draglines are amongst the largest mobile equipment ever built
on land, and weigh in the vicinity of 2000 metric tonnes, though
specimens weighing up to 13,000 metric tonnes have also been
– Port construction
– Pile driving rigs
– Strip-mining operations to move overburden above coal
• A dragline bucket system consists of a large bucket
which is suspended from a boom
• Boom is a large truss-like structure with wire ropes.
• The bucket is manoeuvred by means of a number of
ropes and chains.
• The hoist rope, powered by large diesel or electric
motors, supports the bucket and hoist-coupler
assembly from the boom.
• The dragrope is used to draw the bucket assembly
horizontally. By skillful manoeuvre of the hoist and
the dragropes the bucket is controlled for various
TYPES OF DRAGLINE
• Crawler type
• Wheel mounted
• Truck mounted
• Buildings are constructed higher and deeper.
• Underground spaces are being used more briskly for
– underground shopping malls
– subway systems
– underground water supplies and sewer systems
– underground stockpile bases
– underground water reservoirs for emergency
– and many other purposes
• Important task is how to dig, hoist, and discharge a large
quantity of underground soil safely and economically.
• Underground workability at a greater depth of 70 meters
• Improved methods for construction underground work
and civil engineering underground work.
• Efficiency has improved by almost 20% as compared to
conventional methods using crane.
• Applicability to underground work at a great depth.
• A single machine unit can cover construction
• Easy operation as compared to crane.
• Capable of transporting whole machine without
• The ripper is the long claw-like device on the back of the bulldozer.
• Rippers can come as a single (single shank/giant ripper) or in groups of two
or more (multi shank rippers).
• The ripper shank is fitted with a replaceable tungsten steel alloy tip.
• Ripper lets the ground surface rock be broken into small rubble easy to
handle and transport, which can then be removed so grading can take
• Agricultural ripping lets rocky or very hard earth (such as podzol hardpan)
be broken up so otherwise unploughable land can be farmed.
• Hard earth can be ripped and broken up to allow planting of orchards where
trees could not otherwise grow.
• Trench excavation for underground utilities is
done in the following sequence:
1. A surveyor stakes the route of the trench and details
the depth of cut.
2. A bulldozer and motor grader are used to grub, clear,
and stabilize the surface.
3. An excavator or backhoe is used to scoop the dirt
from the trench and pile it parallel to the trench.
• Dense soils require use of a ditcher.