POWER SHOVELS: Function: excavate earth and load it into tractor pulled wagons, trucks or belt conveyors capable of excavating all types of earth except rock

1. Prepared by
Prof. Ashish Makwana
Civil Engineering Dept. - MEFGI
Prof. Ashish Makwana 1

2. PRESENTATION
OUTLINE…
POWER SHOVEL
– Basic parts and
operation
– Types of power shovel
– Output (production) of
a shovel
– Production cycle of a
shovel
DRAGLINES
– The operation of a
dragline
– Applications
– Types of draglines
– Advantages and
disadvantages of a
dragline
Prof. Ashish Makwana 2

3. PRESENTATION
OUTLINE…
HOES
– Operations of a
backhoe
– Applications
– Selection of hoe
– Advantages and
disadvantages
CLAM SHELLS
– The equipment
– Bucket
– Calm shell operation
– Effective use of calm
shell
– Applications
Prof. Ashish Makwana 3

4. PRESENTATION
OUTLINE…
TRENCHING MACHINES
– Applications
– Types of Trenching machines
– Points to be kept in mind in selecting equipment for
trenches
Prof. Ashish Makwana 4

5. POWER SHOVELS
 POWER SHOVELS:
• Function: excavate earth and load it into tractor pulled
wagons, trucks or belt conveyors
• capable of excavating all types of earth except rock
Prof. Ashish Makwana 5

6. POWER SHOVELS (CONTINUED..)
Power Shovel
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7. POWER SHOVELS (CONTINUED..)
 TYPES OF POWER SHOVEL:
• Crawler mounted Power Shovel
– Mounted on crawler
– Low travel speed
– Operated on soft ground
• Wheel mounted Power Shovel
– Truck mounted
– High speed
– Suitable for Hard ground
Prof. Ashish Makwana 7

8. POWER SHOVELS (CONTINUED..)
 OUTPUT (PRODUCTION) OF A SHOVEL:
• Class of material
• Height of cut
• Angle of swing
• Operator’s skill
• Management conditions
• Job condition
• Size of hauling units
• Physical condition of the shovel
• Haul unit exchange
• Clean up of loading area
Prof. Ashish Makwana 8

9. POWER SHOVELS (CONTINUED..)
 PRODUCTION CYCLE OF A SHOVEL:
• Load bucket
• Swing with load
• Dump load
• Return swing
Typical cycle element times for 3 to 5 cubic yard size
shovels:
1. Load bucket 7 to 9 sec
2. Swing with load 4 to 6 sec
3. Dump load 2 to 4 sec
4. Return swing 4 to 5 sec
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10. DRAGLINE
Prof. Ashish Makwana 10

11. DRAGLINES
Prof. Ashish Makwana 11

12. DRAGLINES (CONTINUED..)
 DRAGLINE:
• Function: dig and dump over larger distances compare
to shovel
• Useful for digging below its track level and handling
softer materials
• Dragline- Crawler mounted, wheel mounted or truck
mounted type
Prof. Ashish Makwana 12

13. DRAGLINESProf. Ashish Makwana 13

14. DRAGLINES (CONTINUED..)
 APPLICATION OF DRAGLINE:
• Most suitable for digging softer material and below its
track level
• Very useful for excavating trenches
• Possible for load material for long reaches
• Mostly used in the excavation for canals and depositing
on the embankment without hauling units
Prof. Ashish Makwana 14

15. DRAGLINES (CONTINUED..)
 FACTORS AFFECTING THE OUTPUT OF A
DRAGLINE:
• Size and type of bucket
• Length of crane boom
• Type of material
• Angle of swing
• Depth of cut
• Working conditions and maintenance of the machine
• Size of hauling unit and method
• Skill of operator
Prof. Ashish Makwana 15

16. DRAGLINES (CONTINUED..)
 TYPES OF DRAGLINES:
• Crawler mounted draglines
– Law travel speed
– Suitable for soft ground and large projects
• Wheel mounted draglines
– High travel speed
– Suitable for firm ground and scattered jobs
• Truck mounted draglines
– High travel speed
– Suitable for firm ground and scattered jobs
Prof. Ashish Makwana 16

17. DRAGLINES (CONTINUED..)
 ADVANTAGES OF DRAGLINE:
• Can work on a natural ground
• Disposed off in one operation
• Most convenient equipment for excavating ditch, trench
or canal containing water
• More range of working
 DISADVANTAGES OF DRAGLINE:
• Less digging force as compared to power shovel
• Size of the bucket decreased for increase the length of
the boom
• Less output of a dragline compare to shovel of the same
capacity
Prof. Ashish Makwana 17

18. HOES
Prof. Ashish Makwana 18

19. HOES (CONTINUED..)
 HOES:
• Termed as hoe, back shovel and pull shovel
• Function: excavate below the natural surface on which it
rests
• Used to trenches, pits for basements
 APPLICATION:
• Most suitable machine for digging below the machine
level, such as trenches, footings, basements etc.
• Efficiently used to dress / trim the surface avoiding the
use of manual effort for dressing the excavated surface
Prof. Ashish Makwana 19

20. HOES (CONTINUED..)
 SELECTION OF HOE:
• Maximum excavation depth required
• Maximum working radius required for digging and
dumping
• Maximum dumping height required
• Hoisting capability required
Prof. Ashish Makwana 20

21. HOES (CONTINUED..)
 ADVANTAGES OF HOE:
• Exert greater tooth pressure due to direct pull on the
dipper
• Operating on close range works due to their rigidity
• Superior to trenching machines, especially in digging
utility trenches
 DISADVANTAGES OF HOE:
• Not as efficient as a power shovel
• Slower in working especially when dumping into hauling
units
• Extra weight of the boom lifted in each cycle
• Material liable to fall off, while hoisting
Prof. Ashish Makwana 21

22. CLAM SHELLS
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23. CLAM SHELLS (CONTINUED..)
 CLAM SHELL:
• Machine name- derived from the shape of its bucket
• Shape of bucket- designed based on shell fish with a
hinged double shell
• Bottom bucket designed with sharp edge
Prof. Ashish Makwana 23

24. CLAM SHELLS (CONTINUED..)
 BUCKET:
• Selection of the bucket of a clam shell depends largely
on the requirement of the job
• Consists of two shells which are hinged at the top and
provided sharp edge at the lower end
• Available in various sizes. i.e. heavy duty types for
digging (hard soils), medium weight for general purpose
work, light weight type for handling the light materials
• Heavy bucket with sharp cutting edge - useful for digging
hard soils
• Light bucket with plane edges - useful for handling light
materials & also useful for lifting heavy rock pieces
Prof. Ashish Makwana 24

25. CLAM SHELLS (CONTINUED..)
 CAPACITY:
• Capacity of clam shell bucket – unit cubic yards (1 cubic
yard = 0.765 cum.)
 EFFECTIVE USE OF CLAM SHELL:
• Placed on level ground
• Bucket – sharp teeth and in good condition
• Equal distance of unit form digging and dumping places
• Teeth of the bucket removed while working in soft
materials
Prof. Ashish Makwana 25

26. CLAM SHELLS (CONTINUED..)
 FACTORS AFFECTING OPERATIONS:
• Height of the lift
• Difficulty of loading the bucket
• Angle of swing
• Method of disposing the load
• Experience of the operator
Prof. Ashish Makwana 26

27. CLAM SHELLS (CONTINUED..)
 APPLICATIONS OF CLAM SHELLS:
• Commonly used for handling loose material such as
crushed stone, sand, gravel, coal etc.
• Vertical lifting of material from one location to another
• Digging / dumping in a vertical plane – below or above
ground level
• Digging trenches
• Charging the materials in a stock pile
• Removing materials from cofferdams, sewer manholes,
well foundations, etc.
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28. Trenching Machines
Prof. Ashish Makwana 28

29. TRENCHING MACHINE (CONTINUED..)
 TRENCHING MACHINE:
 Applications:
• Useful for excavating trenches for the following:
– Water, oil and gas-pipe lines
– Sewers
– Drainage ditches
– Telephone cables
• Positive control of depth of trenches
• Fast digging
• Control of width of trenches
• Reduce cost of ‘Hand Finishing’
Prof. Ashish Makwana 29

30. TRENCHING MACHINE (CONTINUED..)
 TYPES OF TRENCHING MACHINES
1. Wheel Type Trenching Machines:
• Excavating part of a machine – consists of a power
driven wheel
 Characteristics:
• Cut trench width upto 30 cm to 150 cm
• Maximum cutting depth – 2.5 m to 3.0 m
• Digging speed – 30 m or more to suit any job conditions
Prof. Ashish Makwana 30

31. TRENCHING MACHINE (CONTINUED..)
 TYPES OF TRENCHING MACHINES
2. Ladder Type Trenching Machines:
• Excavating part of a machine – consists of two endless
chains
• Conveyor belt disposes off the excavated soil
 Characteristics:
• Cut maximum trench widths upto 360 cm.
• Maximum cutting depth – 9.0 to 10.0 m
• Digging speed – 30 m. or more for various jobs
• Ladder type trenching machine – not useful in case of
rock digging or area where large amount of water gets
accumulated
Prof. Ashish Makwana 31

32. TRENCHING MACHINE (CONTINUED..)
 TYPES OF TRENCHING MACHINES
3. Vertical Boom Type Trenching Machines:
• Modification of ladder type machine
• Available in 7 different boom sizes which allow trench
width from 40 to 7 cm.
Prof. Ashish Makwana 32

33. TRENCHING MACHINE (CONTINUED..)
 POINTS TO BE KEPT IN MIND IN SELECTING
EQUIPMENT FOR TRENCHES:
• Type of soil
• Depth of cutting
• Width of trench
• Job conditions
• Amount of work
• Ground water table
• Climatic conditions
• Obstruction like roads,
buildings, pipes etc.
• Width of right of way for
disposal of earth
• Type of Equipment
• Topography of the area
• Shoring, if required
Prof. Ashish Makwana 33

34. COMPARISON BETWEEN DIFFERENT TYPE OF EXCAVATING
EQUIPMENT
S
N
ITEM 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
Modera-
tely Good
Modera-
tely
Good
3.
Distance
between footing
and digging
Small Small Long Long
4.
Loading
Efficiency
Very
Good
Good
Modera-
tely Good
Precise
but slow
Prof. Ashish Makwana 34

35. COMPARISON BETWEEN DIFFERENT TYPE OF EXCAVATING
EQUIPMENT (continued..)
S
N
ITEM OF
COMPARISON
POWER
SHOVEL
BACK
HOE
DRAG
LINE
CLAM
SHELL
5.
Footing
required
Close to
work
Close
to pit
Fairly
away from
pit
Fairly
away from
pit
6. Digging level
Digs at or
above
Digs
below
footing
level
Digs
below
footing
level
Digs at or
below
footing
level
7. Cycle time Short
Slightly
more
than
shovel
More than
the power
shovel
More than
the other
equipment
Prof. Ashish Makwana 35

36. Prof. Ashish Makwana 36