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The earth moving equipment can
be broadly divided into two groups
Excavating and earth moving equipment
Tractor is an engineering vehicle specially designed to
deliver a high tractive effort or torque at slow speeds
for the purpose of hauling a trailer or machinery used
These are multi purpose machines used mainly for
pulling and pushing the other equipments or heavy
They are also used for agricultural purposes.
Primary purpose is to pull or push loads,
Also used as mounts for many types of accessories
There are types and sizes to fit almost any job for
which they are usable.
FACTORS FOR SELECTION
1. The size required for a given job
2. The kind of job for which it will be used
3. The type of footing over which it will operate
4. The firmness of the haul road
5. The smoothness of the haul road
6. The slope of the haul road
7. The length of the haul road
8. Finally, the type of work it will do after this job is
TYPES OF TRACTORS
Usually rated by size or weight
The weight is important on many
projects because the maximum
tractive effort that a unit can provide
is limited to the product of weight
times the coefficient of traction for
the unit and the particular road
surface, regardless of the power
supplied by the engine.
Most manufacturers make crawler
tractors with some or all models.
Either two-wheel or four-wheel.
One of the primary advantages of a
wheel tractor compared with a
crawler tractor is the higher speed
that may exceed (50 km/hr).
In order to attain a higher speed a
wheel tractor must sacrifice pulling
Because of lower coefficient of
traction between rubber tires and
soil surfaces, the wheel tractor may
slip its wheels before developing its
rated pulling effort.
COMPARISON BETWEEN CRAWLER
TRACTOR AND WHEELED TRACTOR
More compact and powerful and
can handle heavier jobs
Cost of operation and
maintenance is high
Stick control for steering
Moves on rough roads only
Used for short distances
Requires skillful operation,
maintenance and repairs
Can handle only lighter jobs
Operation and maintenance cost
Wheel steering controlled
Moves on rough as well as good
Used for longer distance
Lesser skills required for
operation, maintenance and
The other related equipments are
scrapers have an important position in the earth moving
It is a unique machine for digging and long distance
It is a self-operating machine.
The wheels of the machine cause some compaction. The
ability of these machines to deposit the loads in uniformly
thick layers facilitates the succeeding spreading operations.
They are classified as Crawler -tractor- pulled and wheel-
tractor- pulled, depending on the type of tractor used to
The basic parts of scrapers are bowl, apron and tail gate
Commonly used in construction projects.
It is a heavy steel blade mounded on the front of the
The tractor can be of Crawler or Wheeled type.
The heavy blade attached to the tractor pushes the
materials from one place to another.
BASED ON POSITION OF BLADES
Bull dozers with blades perpendicular to the direction of
Angle dozers in which the blade is set an angle with the
direction of movement.
BASED ON MOUNTINGS
BASED ON THE CONTROL
For spreading the earth fill
For opening up pilot road through mountainous and
Clearing construction sites
Maintaining hawl roads
Clearing land from trees and stems
Backfilling trenches at constructions sites by earth
from one place to another.