Construction equipments By T.Ravi Prakash

construction equipment 1
By,
T.Ravi prakash
Assistant Professor
Kongu Engineering
College,Perundurai

CONTENT
 Introduction
 Factors behind the selection of construction
equipments
 Types of construction equipments
 Selection criteria for various construction equipment
 Plant and equipment acquisition

Introduction
construction equipment
3
 In the case of huge construction projects;
 Proper use of the appropriate equipment contributes to
economy, quality, safety, speed and timely completion of a
project.
 Equipment are use for highway projects, irrigation,
buildings, power projects etc.
 15-30% of total project cost has been accounted towards
equipment and machinery.

Introduction
 Good project management in construction must vigorously
pursue the efficient utilization of labor, material and
equipment.
 The use of new equipment and innovative methods has
made possible wholesale changes in construction
technologies in recent decades.
 The selection of the appropriate type and size of
construction equipment often affects the required amount
of time and effort and thus the job-site productivity of a
project.
 It is therefore important for site managers and construction
planners to be familiar with the characteristics of the major
types of equipment most commonly used in construction.

Advantages of utilizing the construction
equipments
5
 Increase the rate of output through work progress with the
best effective and efficient methods.
 Reduce the overall construction costs especially for large
contracts.
 Carry out activities which cannot be done manually or to do
them more economically and much faster.
 Eliminate the heavy manual work by human thus reducing
fatigue and eliminates various other hazards and health issues.
 Maintain the planned rate of production where there is a
shortage of skilled or unskilled labor.
 Maintain the high quality standards often required by present
day design and specifications (technical standards).

FACTORS AFFECTING SELECTION OF
CONSTRUCTION EQUIPMENT
 USE OF EQUIPMENT AVAILABLE WITH THE ORGANIZATION
 SUITABILITY FOR JOB CONDITION WITH SPECIAL REFERENCE TO
CLIMATIC AND OPERATING CONDITIONS
 UNIFORMITY OF TYPE
 SIZE OF EQUIPMENT
 USE OF STANDARD EQUIPMENT
 COUNTRY OF ORIGIN
 UNIT COST OF PRODUCTION
 AVAILABILITY OF SPARE PARTS AND SELECTION OF
MANUFACTURERS
 SUITABILITY OF LOCAL LABOUR FOR OPERATION
6

FACTORS BEHIND THE SELECTION OF
CONSTRUCTION EQUIPMENTS
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 Economic Considerations
 Company-Specific
 Site-Specific
 Equipment-Specific
 Client And Project-Specific
 Manufacturer-Specific
 Labour Consideration

Economic Considerations
The economic considerations such as owning
costs, operating labour costs and operating fuel
costs of equipment are most important in selection
of equipment.
Besides, the resale value, the replacement costs
of existing equipment, and the salvage value
associated with the equipment are also important.

Company-Specific
The selection of equipment by a company
maybe governed by its policy on 'owning' or
'renting’.
While emphasis on 'owning' may result in
purchase of equipment keeping in mind the future
requirement of projects, the emphasis on 'renting'
may lead to putting too much focus on short-term
benefits.

Site-Specific
Site conditions-both ground conditions as
well as climatic conditions-may affect the
equipment-selection decision.
For example, the soil and profile of a site may
dictate whether to go for a crawler-mounted
equipment or a wheel-mounted equipment. If
there is a power line at or in the vicinity of site,
one may go for a fixed-base kind of equipment
rather than a mobile kind of equipment.

Equipment-Specific
Construction equipments come with high
price tags. While it may be tempting to go for the
equipment with low initial price, it is preferable
to opt for standard equipments.
Such equipments are manufactured in large
numbers by the manufacturers, and their spare
parts are easily available, which would ensure
minimum downtime. Besides, they can also fetch
good salvage money at the time of their disposal.

Client And Project-Specific
The owner/client in a certain project may
have certain preferences that are not in line with
the construction company's preferred policies as
far as equipment procurement is concerned.
The schedule, quality and safety
requirements demanded of a particular project
may in some cases force the company to yield to
the demands of the client.

manufacturer-Specific
A construction company may prefer to buy
equipment from the same manufacturer again
and again, and that too from a specific dealer.
This may be to bring in uniformity in the
equipment fleet possessed by the company or
because the company is familiar with the working
style of the manufacturer and the dealer.

Labour Consideration
Shortage of manpower in some situations may
lead to a decision in favour of procuring equipment
that is highly automated.
Further, the selection of equipment may be
governed by the availability or non-availability of
trained manpower.

Operations involved in construction of any
project
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 Excavation
 Digging of large quantities of earth
 Moving them to distances which are sometimes fairly long
 Placement
 Compacting
 Leveling
 Dozing
 Grading
 Hauling

Classification of Construction Equipment
16
1. Earth-moving equipment
2. Hauling equipment
3. Hoisting equipment
4. Conveying equipment
5. Aggregate and concrete production equipment
6. Pile-driving equipment
7. Tunneling and rock drilling equipment
8. Pumping and dewatering equipment

Excavator
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 Excavator is the machine used for construction activities.
 Excavator is the machine that can excavate the soil of
various types forcefully and then using hydraulic system a
hydraulic force is generated and utilizing this force bucket
is pull back towards the machine. They are primarily used
for digging, demolition, forestry work, grading,
landscaping, heavy lifting, and brush cutting.
 Excavators are heavy construction equipment consisting
of a boom, stick, bucket and cab on a rotating platform
(known as the "house").
 Excavator comes in numerous sizes depending on bucket
size, length of boom, length of arm, and operation speed

Excavators are used in many ways:
18
 Digging of trenches, holes, foundations
 Material handling
 Brush cutting with hydraulic attachments
 Forestry work
 Demolition
 General grading/landscaping
 Heavy lift, e.g. lifting and placing of pipes
 Mining, especially, but not only open-pit mining
 River dredging
 Driving piles, in conjunction with a pile driver

CRAWLEREXCAVATOR
Crawler excavator runs on two endless tracks (chain wheel
system). These types of excavators are used in hilly areas where
risks of sliding of machinery are on the verge. Crawler type
excavator has low ground pressure because of spreading of load
on large area. Therefore, it is also used where soil support is
weak.
WHEEL EXCAVATOR
Wheel excavator runs on wheels and are used for excavation
and loading of dump trucks and most of the time it is only
used for plain ground operations. Because of wheel, it is not
suitable for hilly areas due to low grip value to the ground.

VARIOUS KIND OF EXCAVATORS
1.Compact Excavators
2.Crawler Excavators
3.Dragline Excavators
4.Long Reach Excavators
5.A Suction Excavators

1.COMPACTEXCAVATOR
They are wheeled machines weighing at least 0.7 tones. The
movement of compact lifters is enhanced by hydraulic fluid powered
by hydraulic cylinders. The compact excavators consist of a work group,
under carriage and house. The house is used for slewing while the
undercarriage is a major support to the workgroup and house. The
work group consists of a boom, arm and bucket

2.CRAWLER EXCAVATORS
This are the main excavators on the market. They are build to
release heavy work such as mining. They are usually very big and
very large and they always come with very high horsepower. This
is one of the most well-known type of excavator in the world

3.DARGLINE EXCAVATOR
(1) LIFTING CRANES
lifting cranes contain units that are easily dismembered and
ferried by trailers. The small cranes are used for civil engineering
tasks such as road, pond and port construction.
(2) HEAVY DUTY BUILT IN SITE
The larger build on site equipment is used mainly in the mining
of tar and sand. The dragline has a boom and bucket. The bucket
of the dragline is moved with the aid of ropes powered by a
motor.

4.LONG REACH EXCAVATOR
It is an excavator with a long arm. The length of the arm is
suited for destruction activities. It is able to reach the top of
buildings and methodically crumple the structures.

5.A SUCTION EXCAVATOR
It is also known as a vacuum excavator. This equipment
lifts and clears debris on land through its suction pipe.
The suction pipe measures a foot in width. It consists of
a nozzle with handles used to control the machine. The
suction pipe has teeth used to cut the earth during
excavation. An air lance water jet is used to loosen the
earth before sucking it out. Suction excavation is used
for safely identifying and removing underground
elements.

EXCAVATORATTACHMENTS
BACK HOE BUCKET
LOADER BUCKET

MULTI GRAPPLE
BOTTOM DUMP BUCKET

USES OF EXCAVATORS
Usage
Excavators are used in many ways:
Digging of trenches, holes, foundation
Material handling
Brush cutting with hydraulic attachments
Forestry work
forestry mulching
demolition
General grading/landscaping
Mining, especially, but not only open-pit mining
River Dredging
Driving piles, in conjunction with a pile driver
Drilling shafts for footings and rock drilling

SELECTION CRITERIA FOR EARTHWORK
EQUIPMENTS
The selection of earthmoving equipment is mainly
dependent on the following factors:
 Quantities of material to be moved
 The available time to complete the work the job conditions
 Height of the excavation
 The prevailing soil types, the swell and compaction factors,
etc.
 The job conditions include factors such as availability of
loading and dumping area, accessibility of site, traffic flows
and weather conditions at site.
 Disposal of the excavated material
 Distance of excavation site to hauling units

In order to plan the number of Earthwork
Equipment needed, the planner first determines
the following:
 The suitable class of equipment for earthwork-for
example, if the soil to be excavated is loose and marshy,
and bulk excavation is involved In the project, one may
opt for a dragline.
 The appropriate model of equipment based on
different characteristics such as payload of bucket and
speeds required. For example, draglines come in different
capacities ranging from 0.38 cum to 3.06 cum;
scrapers in capacities ranging from 8 cum to 50 cum and
so on.
 The number of equipment needed for the project to
carry out the given quantity.
 The number of associated equipment required to
support the main equipment

Types of EARTH EXCAVATION
EQUIPMENTS
1. POWER SHOVEL
2. BACK HOE
3. DRAG LINE
4. CLAM SHELL
Construction Equipments
32

POWER SHOVEL
 LONG-LASTING.
 EXCAVATEALL TYPES OF EARTH EXCEPT HARD ROCK
TYPES:
 WHEEL MOUNTED (HIGH SPEED - FIRM GROUND)
 CRAWLER MOUNTED (LOW SPEED - UNSTABLE SOIL)
BASIC PARTS:
* TRACK SYSTEM * CABIN
* CABLES * RACK & STICK
* BOOM FOOT PIN * SADDLE BLOCK
* BOOM POINT SHEAVE * BUCKET ( Size = .375 m3 to 5 m3)
33

OPERATION:
CABLE CONTROLLED & IT MAKES OUTWARD STROKES WHILE DIGGING.
APPLICATIONS:
CLOSE RANGE OF WORK.
VERY HARD MATERIALS, BIG SIZED BOULDERS.
DIGGING IN GRAVEL BANKS, CLAY PITS, CUTS IN ROAD WORKS, ROAD
SIDE BERMS Etc.,
FACTORS CONTROLLING OUTPUT:
* CLASS OF MATERIAL * DEPTH OF CUTTING
* ANGLE OF SWING * SKILL OF OPERATOR
* SIZE OF HAULING UNITS * JOB CONDITION
POWER SHOVEL
34

POWER SHOVEL
36

POWER SHOVEL
37

POWER SHOVEL
38

Old  new
39

BACK HOE
• ALSO TERMED AS HOE, BACK SHOVEL AND PULL SHOVEL.
• USED TO EXCAVATE BELOW THE SURFACE OF EQUIPMENT - IT CAVES INTO THE
GROUND.
BASIC PARTS:
* BOOM * JACK BOOM
* BOOM FOOT DRUM * BOOM SHEAVE
* STICK, BUCKET * BUCKET SHEAVE
OPERATION:
• SIMILAR TO SHOVEL EXCEPT IT MAKES INWARD STROKES WHILE DIGGING.
APPLICATION:
• DIGGING BELOW MACHINE LEVEL LIKE TRENCHES, FOOTINGS, BASEMENTS.
• TO TRIM THE SURFACE (DRESSING).
40

Back hoe
41
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.
 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 boom is generally attached to the vehicle through a
pivot known as the king-post, which allows the arm to slew
left and right, usually through a total of around 200
degrees.

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 It is hinged in three places, making it resemble an
arm: a shoulder joint attached to the tractor, an
elbow sticking up in the air, and a wrist, where a
relatively narrow bucket is attached. The bucket is
extended away from the tractor, lowered, and filled
by dragging toward the tractor -- then raised and
moved to the side before being dumped. Extending
and raising a backhoe reduces overall stability, so
before the backhoe is used outriggers are extended
for safety.

Back hoe
43

BACK HOE
45

BACK HOE
46

Application
47
 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.

Drag line
48
 The drag line is so name because of its prominent
operation of dragging the bucket against the
material to be dug.
 Unlike the shovel, it has a long light crane boom
and the bucket is loosely attached to the boom
through cables.
 Because of this construction, a dragline can dig and
dump over larger distances than a shovel can do.
 Drag lines are useful for digging below its track
level and handling softer materials.

Crawler mounted
- Low travel speed, soft ground,
large projects
Wheel mounted
- high travel speed, firm ground
& scattered job
Truck mounted
- high travel speed, firm ground
& scattered jobs
Walking draglines

DRAG LINE
BASIC PARTS:
* BOOM * HOIST CABLE
* DRAG CABLE * HOIST CHAIN
* DRAG CHAIN * BUCKET
APPLICATIONS:
o Dragging softer material and below its track level
o It is very useful for excavating trenches when the sides are permitted to
establish their angle of repose without shoring.
o It has long reaches.
o Excavation for canals and depositing on the embankment without
hauling units.
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FACTORS CONTROLLING OUTPUT:
• TYPE OF MATERIAL
• DEPTH OF CUTTING
• SIZE AND TYPE OF BUCKETS
• SKILL OF OPERATOR
• SIZE OF HAULING UNITS & METHOD
• ANGLE OF SWING
• LENGTH OF CRANE BOOM
• JOB CONDITION
DRAG LINE
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Output = dragline capacity × C × F
where C = cycles/hr
F = correcting factor
Advantages Disadvantages
 Can work from the ground
surface while shovel has to
be taken into the pit.
 Hauling equipments need
not to go in the pit.
 Excavated material
disposed in one operation.
 High range than shovel.
 Less digging force.
 As the boom length
increases the bucket size
must be decreased.
 Output is less than shovel.

DRAG LINE
55

DRAG LINE
56

Clam shell
57
 This is so named due to resemblance of its bucket to a clam
which is like a shell-fish with hinged double shell.
 The front end is essentially a crane boom with a specially
designed bucket loosely attached at the end through cables as in a
drag line.
 There are hydraulic clamshell buckets that are mounted on the
stick of hydraulic hoes.
 The capacity of a clam shell bucket is usually given in cubic
meters.
 The basic parts of clam shell bucket are the closing line, hoist
line, sheaves, brackets, tagline, shell and hinge.

Application
58
• Used for handling loose material such as crushed stone, sand,
gravel, coal etc.
• Main feature is vertical lifting of material from one location to
another.
• The two jaws of a clamshell bucket clamp together when the
bucket is lifted by the closing line.
• Mainly used for removing material from coffer dam, sewer main
holes, sheet-lined trenches, well foundations etc.

Clam shell
60

CLAM SHELL
61

CLAM SHELL
62

COMPARISON BETWEEN DIFFERENT TYPES OF
EQUIPMENT
S.No. Items of comparison
Power
shovel
Back hoe Drag line Clam shell
1
Excavation in hard soil or
rock
Good Good Not good Poor
2
Excavation in wet soil or
mud
Poor Poor
Moderately
good
Moderately
good
3
Distance betweenfooting
and digging
Small Small Long Long
4 Loading efficiency Very good Good
Moderately
good
Precise but
slow
5 Footing required Close to work Close to pit
Fairly away
from pit
Fairly away
from pit
6 Digging level
Digs at or
above footing
level
Digs below
footing level
Digs below
footing level
Digs at or
below footing
level
7 Cycle time Short
Shortly more
than power
shovel
More than
power shovel
More than the
other
equipmentConstruction Equipments
63

EARTH MOVING EQUIPMENTS
1. TRACTORS
2. SCRAPERS
3. BULL DOZERS
4. MOTOR GRADERS
5. FRONT END LOADERS
64

TRACTORS
65
Multi-purpose machines used mainly for pulling and
pushing the other equipment.
Tractors may be classified as
a)Crawler type tractor- Used to move bull dozers, scrapers.
The crawler has a chain by which these tractors can be
very effective even in the case of loose or muddy soils. The
speed of this type dose not exceed 12 kmph normally.
b)Wheel type tractor- The engine is mounted on four
wheels. The main advantage is higher speed, sometimes
exceeding 50 kmph it is used for long-distance hauling and
good roads.

Applications
 CLEARING& EXCAVATING MACHINERY
 HAULING & CONVEYING MACHINERY
66

TRACTOR
67

CRAWLER TRACTOR
68

WHEEL TRACTOR
69

COMPARISON BETWEEN CRAWLER
AND WHEELED TRACTORS
70
Crawler type Wheeled type
1. Slow speed 1. Greater speed
2. More compact and powerful and can
handle heavier jobs
2. Con handle only lighter jobs
3. costly 3. cheaper
4. Cost of operation and maintenance is
high
4. Operational and maintenance cost is
less
5. Stick control for steering 5. Wheel steering control
6. Moves on rough roads only 6. Moves on rough as well as good
roads
7. Used for short distances 7.Used for longer distances
8. Requires skillful operation,
maintenance and repairs
8. Lesser skills required for operations,
maintenance and repairs

SCRAPERS
• Used to load and haul a wide variety of materials
• Economical over wide range of haul lengths and haul conditions
• Self loading – not dependent on other equipment
• Not as efficient as exclusively designed machines
• Off highway and <1 mile scraper is better than trucks
• Ability to deposit loads in layers of uniform thickness
• It cannot be used on rocky ground either as this causes excessive
wear. It takes between 30 seconds or one minute for the scraper to
load itself
• The bowl capacity ranges from 5 cum to 20 cum and takes nearly
halfto one minute for loading.
• It’s blade cuts a thin slice of a earth usually between 100 mm to
250mm thick over a distance of nearly 30 m
71

CONSTRUCTION
Parts : Bowl, Apron and Ejector
Bowl:
Loading and carrying component
Has a cutting edge that extends horizontally across front bottom edge
Lowered for loading, raised during travel
Apron:
Front wall of the bowl, independent of bowl
Raised during loading and dumping, lowered during haulage – to avoid
spillage
Ejector:
Rear vertical wall, gets activated and moves forward, helps positive
discharge of material

STANDARD USAGE
Loading and transporting earth over short distances (i.e. >2miles)
Unfortunately it cannot be used to transport materials over long
distances because of heating of the tires
www.terex.com/main.php?obj=prod&action=VIEW&id=21&nav=prod&cid=e3959eefdc65adcc4e0e616b833694b1

CAPACITY:
• HEAPED CAPACITY OF THE BOWL.
OPERATION:
• While digging cutting edge enters the ground by lowering the bowl,
the front apron is raised
• Edge is raised, apron is lowed while hauling.
• While dumping ejector is used.
 Either self-propelled or towed, it consists of a wagon with a gate
having a bladed bottom. The blade scrapes up earth as
the wagon pushes forward and forces the excavated material into
the wagon. When the wagon is filled, the gate is closed, and the
material is carried to the place of disposal. The scraper is the
dominant tool in highway construction.
SCRAPERS
74

TYPES
Based on method of loading & number of axles
1. Pusher Loaded ( Conventional )
a) Single powered axle
b) Tandem powered axles
2. Self Loading
a) Push – pull, tandem powered axles
b) Elevating type
c) Auger type
• Crawler tractor pulled
• Wheel tractor pulled
• Towed Scraper
• Open and Coal Bowl Scraper
• Elevating Scraper

PUSHER LOADED
High speeds on
favorable haul
roads
35 mph (50 km/hr)
when fully loaded
Lack of high
tractive effort reqd
for loading
Necessary to
supplement with
help loading

SELF LOADING - PUSH
– PULL TYPE
Tandem powered axle scrappers having a
cushioned push block & bail mounted at front
A hook on the rear above the usual back push
block
These features enable one another during loading
Trailing scrapper pushes the lead scrapper as it
loads
lead scrapper pulls the lead scrapper to assist in
loading
Each can individually work with a pusher

SELF LOADING – ELEVATING TYPE
Self contained loading & hauling
Loading mechanism: Chain
mounted elevator – mounted
vertically on front of bowl
Disadvantages: Weight of
elevator assembly – dead wt
during haul cycle
Applications:
utility work, dressing up behind
high production spreads,
shifting material during high
grading operations

AUGER TYPE
Can self load in difficult conditions
Ex: Laminated rock, granular materials, frozen material
Has independent hydrostatic system located at centre of the
bowl
Types – Single and Tandem powered
Dis:
• Non – load wt is added during haul (wt of
mechanism)
• More costly to own and operate

VOLUME OF SCRAPER
Struck or Heaped capacity
of the bowl (Cubic yard)
Struck capacity: Volume
that a scraper would hold
if the top of the material
was struck off even at the
top of the bowl
Heaped capacity: struck
capacity plus a heaped
load at a 2:1 angle on top
up to a point in the centre
(1/3 more than struck)
SAE – 1:1

SAFETY PROCEDURES
AND PRACTICES
Never operate a scraper at speeds that are unsafe, especially
with full pans
Always wear a safety belt. Uneven terrains may cause a
scraper to tilt
Be sure that communication between ground employees is
clear and evident
Proper maintenance and daily checks ensure safe operating
conditions
Source: Integrated Publishing: http://www.tpub.com/content/engine/14081/css/14081_267.htm

SAFETY PROCEDURES
AND PRACTICES
Be sure that proper brakes and ropes are all in working order
Only trained employeesshould operate and work near
scrapers
Do not operate scrapers on unsafe slopes

SCRAPERS
87

SCRAPERS
88

SCRAPERS
89

SCRAPERS
90

scraper
91

BULL DOZERS
• VERSATILE EQUIPMENT-ESSENTIALLYA HEAVY STEEL BLADE
MOUNTED ON THE FRONT OF TRACTOR.
CLASSIFICATION BASED ON:
POSITION OF BLADES - PERPENDICULAR BLADES TO THE
DIRECTION OF MOVEMENT
- BLADES AT AN ANGLE
MOUNTING - WHEEL MOUNTED
- CRAWLER MOUNTED
CONTROL - CABLE CONTROL
- HYDRAULIC CONTROL
92

CONSTRUCTION:
 CONSIST OF HEAVY BLADE WITH CONCAVE PROFILE.
 BLADE IS ATTACHED TO THE BODY WITH TWOARMS, A
SUPPORTINGFRAME & HELD BY TWO PUSH ARMS
APPLICATION:
 SPREADING EARTH FILL
 CLEARING, OPENING UP PILOT ROADS
 BACK FILLING TRENCHES
 CLEARINGCONSTRUCTION SITES
BULL DOZERS
93

Bull dozer
94

Crawler Dozers
 It is equipped with special clearing blades which are
excellent machine for loud clearing.
 Heavy ripping of rock is accomplished by crawler
dozers with use of rippers which are mounted rear of
dozers.

CRAWLER BULL DOZERS
96

TYRE MOUNTED BULL DOZERS
98

Front Casting mounted bulldozers

ANGLED BULL DOZERS
100

TYPES OF BULL DOZERS BLADE
101

Factors affect output of machinery
a. Efficiency of operator
b. Nature of soil
c. Topography of area
d. Type of equipment
e. Weather

What is tilt ?
 In some machines either end of the blade can be
raised or lowered in the vertical plane of the blade
called Tilt.
 The movement takes place within the vertical plane
of the blade.
 Tilting enables the concentration of dozer driving
power on a limited portion of the length of the blade.

What is pitch?
 The top of the blade can pitched forward or
backward varying the angle of attack of the cutting
edge. it is known as pitch.
 This is pivotal movement about the point of
connection between the dozer and blade.
 When top of blade pitch forward, the bottom edge
moves back. This increase the angle of cutting edge
attack.

What is angling?
 Blades which are mounted on a C frame can be
turned from the direction of travel. It is known as
angling.
 This features are not applicable for all blades.
 Turning the blade in such a way that it is not
perpendicular to the direction of the travel of the
dozer is known as angling.
 Angling causes the pushed material to roll off the
traveling end of trailing end of blade.
 This process of rolling material off one end of the
blade is known as side casting.

Applications
108
Bull dozers are mainly used for the following operations
1. For spreading the earth fill
2. For opening up pilot roads through mountainous and rocky
terrains.
3. Clearing construction sites.
4. Maintaining haul roads
5. Clearing land from the trees and stumps
6. back-filling trenches at construction sites by dragging the
earth from one place to another

Advantages of Crawler mounted dozer
 It delivers greater attractive effort especially when
operating soft grounds as loose or muddy soil.
 Capacity to travel over muddy surface.
 Work on different type of soil.
 Ability to travel on rough surface, which may reduce
the cost of maintaining the hauling roads.

Advantages of Crawler mounted dozer
 Greater flotation due to the lower pressure under the
track.
 Good for short distance jobs.
 Greater use in different type of jobs.
 Can push large blade loads.
 Speed is slow about 8 to 16 kmph.

Advantages of Wheel mounted dozer
 Provide higher travel speed from 13 to 42 kmph on
the job or from one job to another job.
 Eliminates the necessity of hauling equipment
required to transport the dozer to the job.
 Greater output, especially when considerable travel
is necessary.
 Less fatigue to operator.

Advantages of Wheel mounted dozer
 It is good for long distance.
 It can travel on paved highways without damaging
the surface.
 It is best for handling loose soil.
 It can push moderate blade load.

A grader, also commonly referred to as
a road grader, a blade, a maintainer, or
a motor grader, is a construction machine
with a long blade used to create a flat
surface. Typical models have three axles
with the engine and cab situated above
the rear axles at one end of the vehicle
and a third axle at the front end of the
vehicle, with the blade in between. Some
construction personnel refer to the entire
machine as "the blade."
In civil engineering, the grader's purpose
is to "finish grade" (refine, set precisely)
the "rough grading" performed by heavy
equipment or engineering vehicles such
as scrapers and bull dozers

MOTOR GRADERS
o they may be either towed or motorised.
o usually self propulsive.
CONSTRUCTION:
• The grader typically consist of three axles, with the engine and
cab situated top, the rear axles at one end of the vehicle and a
third axle at the front end of the vehicle, with the blade in
between.
• Front of the grader frame is supported on a pair of front wheels &
rear on tandem wheels.
• Curved blade is supported on the circle and be turned through
360 degree.
• Blade has replaceble edges.
• Cutting Depth - 2-4CMS.
114

SPEED:
 LIGHT DUTY - 6-10 KM/HR.
 HEAVY DUTY - 2-3 KM/HR.
 NORMAL DUTY - 4-6 KM/HR.
USES:
* GRAVEL ROAD REPAIRING * ROAD SHOULDER RESHAPING
* BANK CUTTING * DITCH FILLING
* BASE COURSE SPREADING * MATERIAL MIXING
* SNOW, LAND CLEARANCE * FROZEN TOP SOIL, ASPHALT
BREAKING
MOTOR GRADERS
115

MOTOR GRADERS
116

MOTOR GRADERS
117

FRONT LOADERS
• Also known as a front end loader, bucket loader, scoop
loader, or shovel,
• The front loader is a type of tractor that is normally
wheeled and uses a wide square tilting bucket on the end
of movable arms to lift and move material around.
• The loader assembly may be a removable attachment or
permanentlymounted on the vehicle. Often times, the
bucket can be replaced with other devices or tools, such
as forks or a hydraulicallyoperated bucket.
118

FRONT LOADERS
• Larger style front loaders, such as the Caterpillar 950G or
the Volvo L120E, normally have only a front bucket and
are known as front loaders, where the small front loaders
are often times equipped with a small backhoe as well and
called backhoe loaders or loader backhoes
• Loaders are primarily used for loading materials into
trucks, laying pipe, clearing rubble, and also digging.
Loaders aren’t the most efficient machines for digging, as
they can’t dig very deep below the level of their wheels,
like the backhoe can.
• front loaders are used to transport building materials such
as pipe, bricks, metal bars, and digging tools. Front
loaders are also very useful for snow removal as well, as
you can use their bucket or as a snow plow.
119

FRONT LOADERS
120

RIPPER
The ripper is the long claw-like device on the back of the
bulldozer. Rippers can comesingly (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 replaceabletungsten steel alloy
tip.
Ripping rock lets the ground surface rock be broken into
small rubble easy to handle and transport, which can then be
removed so grading can take place
With heavy bulldozers the lava is shattered, allowing
agriculture.Also, hard earth can be ripped and decompacted
to allow planting of orchards where trees could not otherwise
grow.
121

CONTENTS
 Introduction to Cost of Owning and
Operating Construction Equipment
 Ownership cost
 Operating cost
 Effect of Depreciation & tax on
selection of alternatives
 Equipment life & Replacement
Alternatives
 Conclusion

INTRODUCTION
The Plant, equipment and tools used in
construction operations are priced in the following
three categories
1. Small tools and consumables
2. Equipment usually shared by a number of work
activities
3. Equipment used for specific tasks
Total equipment cost comprises two
separate components
 Ownership cost
 Operating cost

OWNERSHIP COST
Ownership costs are fixed costs. Almost all of these
costs are annual in nature and include:
 Initial Cost
 Depreciation
 Investment Cost
 Insurance Tax and Storage Cost

INITIAL COST
On an average, initial cost makes up
about 25% of the total cost invested during the
equipment’s useful life. This cost is incurred for
getting equipment into contractor’s yard, or
construction site, and having the equipment ready
for operation. Many kinds of ownership and
operating costs are calculated using initial cost as
a basis, and normally this cost can be calculated
accurately. Initial cost consists of the following
items:
• Price at Factory + extra equipment + sales tax
• Cost of shipping
• Cost of assembly and erection

DEPRECIATION
The decline in market value of a piece of
equipment due to age, wear, deterioration and
obsolescence. Depreciation can result from:
• Physical deterioration occurring from wear and tear of the machine
• Economic decline or obsolescence occurring over the passage of
time
In the appraisal of depreciation, some
factors are explicit while other factors have to be
estimated. Generally the asset costs are known
which include:
• Initial cost
• Useful life
• Salvage value

DEPRECIATION
How ever, there is always some
uncertainty about the exact length of the useful
life of the asset and about the precise amount of
salvage value, which will be realized when the
asset is disposed. The Depreciation methods are
• Straight line method
• Sum of year digit method
• Sinking fund method
• Declining balance method

STRAIGHTLINE METHOD
It is the simplest to understand as it makes the
basis assumption that the equipment will lose the
same amount of value in every year of its useful
life until it reaches its salvage value. The
depreciation in a given year can be expressed by
the following equation
Dn = (C – S) / N
Where Dn = Depreciation in year n
C = The initial cost
S = The salvage value
N = The useful life (years)

SUM OF YEAR DIGITMETHOD
It tries to model depreciation that actual market
value of a piece of equipment after 1year is less
than the amount predicted by SL method. Thus
more annual depreciation in the early years of a
machine’s life and less in its later years. The
depreciation in a given year can be expressed by
the following equation
Dn = (year n digit) * (C – S) / ∑N
year n digit = The reverse order

DECLININGBALANCEMETHOD
The depreciation for a given year is calculated
on the basis of the undepreciated balance
(instantaneous book value), rather than the
original cost. Further the method does not take
into account any salvage value of the asset. The
factor can be determined using simple interest
formula and also special tables developed for the
purpose.
Dn = (M/N) * BVn-1 BVn = BVn-1 - Dn
M = constant (Generally 2)
BVn-1 = Opening book value at year n

SINKINGFUND METHOD
The method works in terms of a “sinking fund
factor”, which is determined on the basis of the
initial and salvage values of the asset, the service
life and rate of (compound) interest. The factor can
be determined using simple interest formula and
also special tables developed for the purpose.
Dn = (C – S ) * f
f = sinking fund factor

INVESTMENT COST
Investment (or interest) cost
represents the annual cost (converted into an
hourly cost) of capital invested in a machine. If
borrowed funds are utilized for purchasing a
piece of equipment, the investment cost is
simply the interest charged on these funds. If it
is purchased with company assets, an interest
rate that is equal to the rate of return on
company investment should be charged.

INSURANCETAX AND STORAGE COSTS
Insurance cost represents the cost
incurred due to fire, theft, accident and liability
insurance for the equipment.
Tax cost represents the cost of
property tax and licenses for the equipment.
Storage cost includes the cost of
rent and maintenance for equipment storage
yards, the wages of guards and employees
involved in moving equipment in and out of
storage, and associated direct overhead.

TOTAL OWNERSHIP COST
The total equipment ownership cost
is calculated as the sum of depreciation,
investment cost, insurance cost, tax and
storage cost.
This should expressed as an hourly
cost and used for estimating and for charging
equipment cost to projects, it does not include
job overhead or profit. Therefore if the
equipment is to be rented to others, profit
should include to obtain an hourly rental rate.

OPERATINGCOST
Ownership costs are also called “variable” cost.
Because they depend on several factors such as the number of
operating hours, the types of equipment used, and the location
and working condition of the operation.
 Maintenance & Repair cost
 Tire cost
 Consumable cost
 Mobilization & Demobilization cost
 Equipment Operator cost
 Special Items cost

THE EFFECT OF DEPRECIATIONAND TAX
ON SELECTIONOF ALTERNATIVES
The effect of depreciation and taxes is key
factor on selection of alternative equipments.

EQUIPMENTLIFE AND
REPLACEMENTALTERNATIVES
Once a piece of equipment is
purchased and used, it eventually begins to
wear out and suffers mechanical problems. At
some point, it reaches the end of its useful life
and must be replaced. The Equipment
replacement decision involves determining
when it is no longer economically feasible to
repair.
 Equipment Life
 Replacement alternatives

EQUIPMENTLIFE
Construction equipment life can be defined in three
ways.
Physical life:
Age at which the machine worn out and can no longer reliably
produce.
 Profit life:
The life over which the equipment can earn a profit.
 Economic life:
Time period that maximizes the profit over the equipment life.

REPLACEMENTALTERNATIVES
The owners have to take
replacement decision in correct time to avoid
losses. As there are many factors involved,
adopting the most appropriate method is also
important. In determining the optimum
replacement timing some analysis minimum
cost, maximum profit and payback period are
to be consider.

CONCLUSION
The selection of the appropriate
type and size of construction equipment and
its operation, maintenance affects the required
amount of time and effort and thus the job-site
productivity of a project.
It is therefore important for site
managers and construction planners to be
familiar with the characteristics of the major
types of equipment most commonly used in
construction.

Construction equipments By T.Ravi Prakash

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