UNIT 1 EARTH MOVING EQUIPMENT’S

Construction layout, capacity, and applications of earthmovers like dumpers, front-

end loaders, bulldozers, backhoe loaders, scrappers, Bucket conveyors etc. Selection
criteria of prime mover for dumpers and front end loaders based on vehicle
performance characteristics.

DUMPERS

A dumper is a vehicle designed for

carrying bulk material, often on building
sites. Dumpers are distinguished
from dump trucks by configuration: a
dumper is usually an open 4-wheeled
vehicle with the load skip in front of the
driver, while a dump truck has its cab in
front of the load. The skip can tip to dump
the load; this is where the name "dumper"
comes from. They are normally diesel powered. A towing eye is fitted for secondary
use as a site tractor. Dumpers with rubber tracks are used in special circumstances
and provide a more even distribution of weight compared to tires. Continuous tracks
allow the operator to carry heavier payload on slick, snowy, or muddy surfaces, and
are popular in some countries.
Early dumpers had a payload of about a ton and were 2-wheel drive, driving
on the front axle and steered at the back wheels. The single cylinder diesel engine
(sometimes made by Lister) was started by hand cranking. The steering wheel turned
the back wheels, not front. Having neither electrics nor hydraulics there was not
much to go wrong. The skip was secured by a catch by the driver's feet. When the
catch is released, the skip tips under the weight of its contents at pivot points below,
and after being emptied is raised by hand.
Modern dumpers have payloads of up to 10 tones (11 short tons; 9.8 long tons)
and usually steer by articulating at the middle of the chassis (pivot steering). They
have multi-cylinder diesel engines, some turbocharged, electric start and hydraulics
for tipping and steering and are more expensive to make and operate. An A-frame
known as a ROPS (Roll-Over Protection) frame, may be fitted over the seat to protect
the driver if the dumper rolls over. Some dumpers have FOPS (Falling Object
Protection) as well. Lifting skips are available for discharging above ground level.
In the 1990s dumpers with swivel skips, which could be rotated to tip sideways,
became popular, especially for working in narrow sites such as road works. Dumpers
are the most common cause of accidents involving construction plant. These vehicles
are also called "dumper" in some mainland European languages.
High speed pneumatic wheeled trucks. Short chassis, Strong bodies, Loading,
hauling and dumping is done very fast as compared to other equipment, Suitable for
short hauls on rough roads, especially where a shuttle movement is required.

 The constructional features of Dumper is similar to that heady duty truck,

except a high strength container or trolley is mounted at back side of the Cabin
and Hydraulic assisted load raising and lowering facility is provided for
dumping material in the trolley.

 Some dumpers may have 2 hydraulic cylinders and the size of rear wheel and
number of rear axles may vary with load carrying capacity and mode of
operations.

 Suspension at front is of rigid elliptical type and at rear heavy duty leaf springs
are provided to absorb high impact loading under severe operating conditions.
  Container for dumper is specially constructed to withstand ill handlings.
Heavy duty air cleaner, filter, share proof mountings of all instruments, dust
proof electrical systems and cushion mountings for radiator may present in
some dump trucks.

 Dumpers play important role in dam construction, road making, mining etc.
for carrying materials and dumping at required place quickly and conveniently

FRONT END LOADERS

A loader (also known as:
bucket/ front end/ pay/ scoop/
skip/ wheel loader and or shovel)
is a type of tractor, usually
wheeled, sometimes on tracks,
that has a front mounted square
wide bucket connected to the end of two booms (arms) to scoop up loose material
from the ground, such as dirt, sand or gravel, and move it from one place to another
without pushing the material across the ground.
Often used in construction, primarily used to Load material (such as asphalt,
demolition debris, dirt, snow, feed, gravel, logs, raw minerals, recycled material,
rock, sand, and woodchips) into or onto another type of machinery (such as a dump
truck, conveyor belt, feed-hopper, or railcar).
1. Crawler loaders
2. Wheel loaders
a) Two-wheel drive
b) Four-wheel drive
c) Articulated type
d) Rigid frame type
 I. Two-wheel steer
II. All wheel steer

There are two types of loader arms, namely “lift arms” and “drop arms”. Lift
arms helps to raise and lower bucket. They are attached to bottom of bucket and
column. While droparms connected to top of bucket and hydraulic cylinder in the
column, and helps for tilting the bucket nearly 1000. Operations done by loaders
1. Loading: - scooping, lifting, turning and dumping
2. Hauling: - moving loose materials over short distances
3. Excavating
4. Clearing: - knock down temporary buildings and clear the debris
Types of Buckets for loaders are as follow,
 Standard,
 Rock,
 Side Dump,
 Grapple,
 Head Dump,
 Waste Handling,
 Coal, Sand and Gravel
BULLDOZERS

A bulldozer is a crawler
(continuous tracked tractor)
equipped with a substantial metal
plate (known as a blade) used to
push large quantities of soil, sand,
rubble, or other such material
during construction or conversion
work and typically equipped at the
rear with a claw-like device (known as a ripper) to loosen densely compacted
materials.
Bulldozers can be found on a wide range of sites, mines and quarries, military
bases, heavy industry factories, engineering projects and farms.
The term "bulldozer" is often used erroneously to mean any heavy equipment
(sometimes a loader and sometimes an excavator), but precisely, the term refers only
to a tractor (usually tracked) fitted with a dozer blade. They are machines designed
primarily for cutting and pushing materials over relatively short distances.
Bulldozers (dozers for short) are tractors equipped with a front pusher blade,
which can be raised or lowered by hydraulic control and is used for digging and
pushing.
The bulldozer's primary tools are the blade and the ripper. The bulldozer
blade is a heavy metal plate on the front of the tractor, used to push objects, and
shove sand, soil and debris. Dozer blades usually come in three varieties:
 A straight blade ("S blade") which is short and has no lateral curve and no side
wings and can be used for fine grading.
  A universal blade ("U blade") which is tall and very curved, and has large side
wings to carry more material.
 An "S-U" combination blade which is shorter, has less curvature, and smaller
side wings. This blade is typically used for pushing piles of large rocks, such
as at a quarry.
 Rake Blade Used in land clearing operation, they penetrate well into the soil
and remove vegetation, tree stumps, roots and rocks.Generally replaceable
arm is attached with rake.
 Clearing blade, This blade is chosen when land clearing operations are
primary important.
 V-Blade is used to shear trees, stumps and bushes at ground level. The two
cutting edges form a sharp V. The vegetation can be cut and pushed to the side
at a constant level.
 Land Fill Blade Specially designed to handle loose materials. The
guard/screen mounted on top of the blade offers good visibility and protects
radiator. The curved moldboard imparts rolling motion to the materials pushed
forward.
 Angle Blade or A-Blade It is superior to the straight blade in light trench
backfilling and some other jobs. Can be angled up to 25o left or right. It cannot
be pitched and effective in side-casting material. Wider by 1-2 feet than S-
blade.
Blades can be fitted straight across the frame, or at an angle, sometimes using
additional 'tilt cylinders' to vary the angle while moving. The bottom edge of the
blade can be sharpened, e.g. to cut tree stumps.
 Sometimes a bulldozer is used to push another piece of earth moving equipment
known as a "scraper". The towed Fresno Scraper, invented in 1883 by James
Porteous, was the first design to enable this to be done economically, removing the
soil from the cut and depositing it elsewhere on shallow ground (fill). Many dozer
blades have a reinforced center section with this purpose in mind, and are called
"bull blades".

In military use, dozer blades are fixed on combat engineering vehicles and can
optionally be fitted on other vehicles, such as artillery tractors such as the Type 73
or M8 Tractor. Dozer blades can also be mounted on main battle tanks, where it can
be used to clear antitank obstacles, mines, and dig improvised shelters. Combat
applications for dozer blades include clearing battlefield obstacles and preparing fire
positions.
Dozer Blade
 The blade is a massive structure that has a rectangular base and back. The
leading edge of the base is a flat blade or knife of tough, hard steel which
projects ahead of and below the rest of the blade.
 The front of the blade is called the moldboard
and is concave and sloped back. As this blade is
pushed into the ground, the knife cuts and breaks
up the dirt, which is then pushed up the curve of
the moldboard until it falls forward.
 Push arms should be attached to the blade
near its outside edges, as the greatest strains
normally occur at the corners. Push arms are
heavy, hollow beams extending from a hinged
connection with the tractor to the bottom of the
blade.
 Originally, dozers had arms that were
mounted on the outside of the track frames, but more recently they have inside
arms. Pitch Arms (Pitch Braces) are diagonal members between the push arms
and the blade top. They brace the blade against loads above the line of the
push arms, and may provide means for regulating its pitch and tilt.
 Lengthening both pitch arms will tip the blade forward, shortening them will
bring it back. Tipping forward will increase the suck of the edge and improve
penetration in hard soils.
 It will also increase the upward pressure against the blade of loosened material
coming up from the edge. Tipping the blade back reduces penetration, and
may prevent the edge from cutting down except under heavy pressure.
  Such a setting is good in cleaning loose material off a firm, level surface, or
in cutting off humps or knobs without regard to the whole surface. The
nuisance of mechanical adjustments of blade tilt is avoided by putting a two
way hydraulic ram in one of the pitch braces, or in one or both of the push
arm hinges, and controlling tilt by a valve at the operator’s station. This
permits rapid and effortless adjustment during operation.

Bull dozers are mainly used for the following operations

 For spreading the earth fill
 For opening up pilot roads through mountainous and rocky terrains.
 Clearing construction sites.
 Maintaining haul roads
 Clearing land from the trees and stumps
  back-filling trenches at construction sites by dragging the earth from one
place to another

RIPPERS
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). Usually, a single shank is preferred for heavy ripping. The ripper
shank is fitted with a replaceable tungsten steel alloy tip. Ripping rock breaks the
ground surface rock or pavement into small rubble easy to handle and transport,
which can then be removed so grading can take place. With agricultural ripping, a
farmer breaks up rocky or very hard earth (such as podzol hardpan), which is
otherwise unploughable, in order to farm it. For example, much of the best land in
 the California wine country consists
of old lava flows. The grower
shatters the lava with heavy
bulldozers so surface crops or trees
can be planted. A less common rear
attachment is a stump buster, which
is a single spike that protrudes
horizontally and can be raised to get
it (mostly) out of the way. A stump
buster is used to split a tree stump. A
bulldozer with a stump buster is used for land clearing operations, and probably has
a brush-rake blade.

BACKHOE LOADERS
A backhoe loader, also called a loader backhoe, is
a heavy equipment vehicle that consists of a tractor like unit
fitted with a loader-style shovel/bucket on the front and
a backhoe on the back. Due to its (relatively) small size and
versatility, backhoe loaders are very common in urban
engineering and small construction projects (such as building
a small house, fixing urban roads, etc.) as well as developing
countries. This type of machine is similar to and derived from
what is now known as a TLB (Tractor-Loader-Backhoe), which is to say, an
agricultural tractor fitted with a front loader and rear backhoe attachment.
A backhoe, also called a rear actor or back actor, is a piece of excavating
equipment or digger consisting of a digging bucket on the end of a two-part
articulated arm. They are typically mounted on the back of a tractor or front loader.
 The section of the arm
closest to the vehicle is known
as the boom, and the section
which carries the bucket is
known as the dipper or dipper
stick (the terms "boom" and
"dipper" having been used
previously on steam shovels).
The boom is attached to the
vehicle through a pivot known
as the kingpost, which allows the arm to slew left and right, usually through a total
of around 200 degrees. Modern backhoes are powered by hydraulics.
It is the most suitable machine for digging below the machine level, such as,
trenches, footings, basements etc. It can be efficiently used to dress or trim the
surface avoiding the use of manual effort for dressing the excavated the surface.

Backhoe loaders are very common and can be used for a wide variety of tasks:
construction, small demolitions, light transportation of building materials, powering
building equipment, digging holes/excavation, landscaping, breaking asphalt, and
paving roads. Often, the backhoe bucket can also be replaced with powered
attachments such as a breaker, grapple, auger, or a stump grinder.
Enhanced articulation of attachments can be achieved with intermediate attachments
such as the tilt rotator. Many backhoes feature quick coupler (quick-attach)
mounting systems and auxiliary hydraulic circuits for simplified attachment
mounting, increasing the machine's utilization on the job site. Some loader buckets
have a retractable bottom or "clamshell", enabling it to empty its load more quickly
and efficiently. Retractable-bottom loader buckets are also often used for grading
and scraping. The front assembly may be a removable attachment or permanently
mounted.

Their relatively small frame and precise control make backhoe-loaders very
useful and common in urban engineering projects such as construction and repairs
in areas too small for larger equipment. Their versatility and compact size makes
them one of the most popular urban construction vehicles.

SCRAPPERS
 It is a device to scrap the
ground & load it simultaneously,
transport it over required
distance. It can dig, load, haul and
discharge the material in
uniformly thick layers. In civil
engineering, a wheel tractor-scraper is a piece of heavy equipment used for
earthmoving.
 The rear part has a vertically moveable hopper (also known as the bowl)
with a sharp horizontal front edge. The hopper can be hydraulically lowered
and raised. When the hopper is lowered, the front edge cuts into the soil or
clay like a plane and fills the hopper.
 When the hopper is full, it is raised, and closed with a vertical blade (known
as the apron). The scraper can transport its load to the fill area where the
blade is raised, the back panel of the hopper, or the ejector, is hydraulically
 pushed forward
and the load
tumbles out. Then
the empty scraper
returns to the cut
site and repeats the
cycle.
 They are used for
site levelling, loading, hauling over distances varying between 150m-
900m. They may be towed, two-axle or three-axle type.
 Unique machine for digging and long-distance hauling of plough able
materials. self-operating machine, It is not dependent on other equipment.
Wheels of machine cause some compaction. The basic parts of scrapers are
the bowl, apron and tail gate or ejector.

There are 3 types of Scrappers

 Towed tractor-scraper
 Pusher-loaded or motorized
 Self-loading scraper

Pusher loaded is divided into Self-loading also divided into

 Single powered axle  Push-pull tandem powered

 Tandem powered axle  Elevating
 Augar scraper
Major Parts of Scrapers are as follow,
 Bowl - into which the material is loaded
 Cutting edge
 Apron - which control inflow and outflow to the bowl
 Tailgate/ejector - which pushed out the material during dumping
BUCKET CONVEYORS
A conveyor system is a
common piece of mechanical
handling equipment that moves
materials from one location to
another. Conveyors are especially
useful in applications involving the
transportation of heavy or bulky
materials. Conveyor systems allow
quick and efficient transportation for
a wide variety of materials, which make them very popular in the material handling
and packaging industries
 It has buckets in the shape of ‘V’ which are open at the top. They may be feeder
loaded or may drag in a vertical movement or along an incline.

 The length of these type of conveyors are generally limited to 25 m. (due to weight
of the conveyor and strength of the chains). This type of conveyer is mainly used
in coal handling where bucket elevators
carry the material vertically.

Normally Two Types of conveyors are in use

such as,
 Vertical Bucket Conveyor
 Sliding Bucket Conveyor