A bulldozer is a tractor with a front-mounted blade used to level land and push materials over short distances. There are two main types - crawler dozers, which have tracks and can operate on soft ground, and wheel dozers, which have higher travel speeds but can't access muddy areas. Bulldozers are classified based on their blade type and mounting. The primary tools of a bulldozer are the blade, used for pushing and grading materials, and the ripper, which is a claw on the back used to tear hard ground and weak rocks.

1. Bulldozer

2. WHAT IS BULLDOZER
 Machines designed preliminary for cutting &
pushing material relatively short distance.
 Consist of a tractor with a front mounted blade
controlled by hydraulic cylinders use for different
cut for different depth & leveling as per condition of
land.
 The bulldozer's primary tools are the blade and
the ripper.

4. PURPOSE OF BULLDOZER
 Clear site of work
 Leveling of land
 Prepare roads on hilly areas as well as hard ground
 Excavate the material and haul in between 100
meters distance.
 Spreading earth
 Backfilling trenches
 Maintaining haul roads

6. CLASSIFICATION OF BULLDOZERS:
 It may either cable controlled or hydraulic
controlled.
 Depending upon mountings bulldozers classified as
I. crawler tractor mounted bulldozers
II. Wheel tractor mounted bulldozers

7. CRAWLER DOZERS
 It is equipped with special clearing blades which are
excellent machine for large clearing.
 Heavy ripping of rock is accomplished by crawler
dozers with use of rippers which are mounted rear
of dozers.

8. CRAWLER MOUNTED BULLDOZERS

9. WHEEL TRACTOR MOUNTED BULLDOZERS

10. 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.

11. 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.

12. 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.

13. 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.

14. CLASSIFICATION OF BULLDOZERS:
 Depending on nature of blade:
I. Front casting dozer
II. Angle dozer
 In case of front casting dozer blade is fixed
perpendicular to the direction of travel.
 In case of Angle dozer the moldboard pivots
about it's center point to cast materials left or
right as the blade is fixed at an angle with the
direction of travel.

15. FRONT CASTING DOZER

16. ANGLE DOZER

17. COMPARISON :
 In case of front casting dozer it moves earth in the
forward direction.
 In case of Angle dozer it moves earth one side in
the forward direction.
 Due to this different types of blades it can
converted in two types.

18. SIZE & OUTPUT OF BULLDOZER
 Size of bulldozer indicated by the dimensions of
blade & its output depends upon its operating
condition.
 Each blade has a capacity of hauling a particular
type of earth & knowing the number of turns a
bulldozer can be estimated.
 Output of all the earth moving machinery depends
on given factors.

19. FACTORS AFFECT OUTPUT OF MACHINERY
a. Efficiency of operator
b. Nature of soil
c. Topography of area
d. Type of equipment
e. Weather

20. UTILITY OF A BULLDOZER
 By suitable attachments to the bulldozer, it can be
utilized to remove trees,rocks,boulders etc.
 In order to increase output two bulldozers working
side by side with their blades in contact , can be
used.
 It can be used on wet ground and all types of
weather conditions.

21.  The bulldozer blade is a heavy metal plate on the front of
the tractor, used to push objects like sand, soil and debris.
 Three Types:
1. A straight blade ("S blade") which is short and has no
lateral curve and no side wings and can be used for fine
grading.
 They are not well suited to handling granular materials
since these materials spill off the ends during long
pushes.
BULLDOZER BLADE

22. 2. A universal blade ("U blade") which is tall and very
curved, and has large side wings to carry more
material.
 These blades are designed to push large quantities
of granular materials over long distances. They are
best suited for loose loads; coal, woodchips, and
overburden, which are evenly distributed across the
face of the moldboard.

23.  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.
 Built much like a Straight Blade but with a deeper profile
and closed ends to help keep granular materials in front
for long pushes. Semi-U Blades can be built with good
abrasion resistance for materials like gravel, and with
puncture resistance for handling large angular pieces of
rock.

24. BLADE ADJUSTMENT: 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.

26. 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.

28. 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.

29.  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
RIPPER
• The rippers are used to tear and
split hard ground, Weak rocks or
old pavements and bases.
• The heavy ripping can be done with
crawler tractor, because of the
power and tractive force available
from such machine
• For weak rock, cost of ripping half
of the cost of drilling, blasting and
hauling with truck.