This document discusses different types of excavators used in construction. It describes the history and development of excavators from the late 1700s/early 1800s. It outlines three main types of excavators - crawler excavators, wheel excavators, and shovel excavators. Crawler excavators are used in hilly areas due to their low ground pressure, while wheel excavators are used for plain ground operations. Shovel excavators include power shovel, backhoe, and front shovel excavators. The document provides details on the applications and operation of each type. It also discusses factors that affect shovel excavator production rates, such as bucket size, cycle times, fill factors, and operator efficiency.

1. EXCAVATORS
1 Submitted by:
Karthik V (MT15CTM006)
Faisal V A (MT15CTM004)

2. EXCAVATORS:
 An excavator has been defined as a power-driven
digging machine, usually mounted on crawler
tracks.
 The major types of excavators used in construction
include hydraulically powered excavators and the
members of the crane-shovel family.
 However, dozers and scrapers are also capable of
excavating soil and rock.
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3. HISTORY
1.FIRST APPEARED IN LATE 1700’S/EARLY 1800’S
2.IN 1990 HAD A LONG CONVENTIONAL COUNTER
WEIGHT ON REAR END

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5. CRAWLER EXCAVATOR
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.

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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.

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•POWER SHOVEL EXCAVATORS
•BACK HOE EXCAVATOR
•FRONT SHOVEL EXCAVATOR
THREE TYPES...

8. POWER SHOVEL EXCAVATOR
 Long-lasting and useful class of earth moving equipment
 Capable of excavating all types of earth except hard rock
 Size of power shovel varies from 0.375-1.05m3
 It may be crawler mounted or wheel mounted shovels
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Crawler mounted shovel:
Low speed
Effective in unstable soil
Wheel mounted shovel:
Higher speed
Effective only in firm ground

10. Power shovel efficiency depends on:
 Class of material
 Depth of cutting
 Angle of swing
 Job conditions
 Management conditions
 Size of hauling units
 Skill of the operator
 Physical condition of the shovel 10

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12. Applications:
 Suitable for close range work
 Capable of digging very hard materials & remove big
boulders
 Used in digging in gravel banks , clay pits , digging cuts
in road works , road-side berms etc.
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13. BACK HOE EXCAVATOR
 Also known as hoe , back shovel & pull shovel
 Used to excavate below the natural surface on which it rests
 Hoes used to excavate trenches , pits for basemants & grading works
 Used to establish natural slopes
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14.  In strom drain and utility work the hoe can perform the
trench excavation and can handle the pipe by eliminating
a second machine
 There are special buckets for everything from light sand
to hard rock digging
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15. Parts of a back hoe excavator
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17. IDEAL PRODUCTION:
 Size of bucket (Q)
 Cycle time(T)=Lt +St +Dt +Rt
 Fill factor(F) (Table 9.1)
 Efficiency Factor(E)
 Height & Swing Factor (Table 9.2)
 Volume Correction Vc
 Production (lcy/hr) =
3600sec/hr∗Q∗F∗E
T∗V 𝐶

18. Applications:
 Suitable for digging below the machine level
 Effectively used to dress or trim the surface avoiding the use of
manual effort for dressing the excavated surface
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19. FRONT SHOVEL EXCAVATOR
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Track system

20. FRONT EXCAVATOR
 Used predominately for hard digging above track level
and loading haul units
 Loading of shot rock will be a typical application
 Shovel is capable of developing a high break out force
 The material being excavated should be such that it will
stand with a fairly vertical face
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21. FRONT SHOVEL EXCAVATOR
 High excavation rate due to unique front shovel and side
tip operation
 Prolec laser system enables excavation to a more
accurate level – resulting in quicker excavation rates
while reducing the chance of over-digging
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22.  Improved track quality due to the excavation action
(pushing into spoil rather than pulling it back)
 Fewer machine controllers on site meaning less risk and
safer operations
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26. Factors afecting shovel excavators are:
 Class of material
 Height of cut
 Angle of swing
 Size of houling units
 Operator skill
 Physical conditions of the shovel
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27. CALCULATING SHOVEL PRODUCTION
 Four elements in the production cycle of a shovel
are:
 Load bucket
 Swing the load
 Dump load
 Return swing

28. IDEAL PRODUCTION:
 Size of bucket (Q)
 Cycle time(T)=Lt +St +Dt +Rt
 Fill factor(F) (Table 9.1)
 Efficiency Factor(E)
 Height & Swing Factor (Table 9.2)
 Production (lcy/hr) =
3600sec/hr∗Q∗F∗Height & swing factor ∗E
T(sec/cycle)

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