Introduction to construction equipments
Types of earth moving equipment
Classified into following types
Ø Production equipment
Ø Equipment used for digging and moving
Ø Service equipment
Ø Dozers and motor girders
1 Tractors
Tractors are machine which change the engine energy into tractive energy
These are primarily used for pull or push the loads
They are also used for different purposes by mounting many types of accessories
Types of tractor
Crawler type or track type
Rubber tired or wheel type
The tractor is multi purpose machine
Light models are used for agricultural or short haulage works
Heavy models are employed in earth moving works, cranes, shovels or special rigs
Wheeled types or employed in light but speedy jobs
Main constituents of tractor are engine ,clutch ,transmissonsystem,ground drive and
controls
Factors should be considered while selecting a tractor dozer
Size of the dozer for given job the type expected from the track to dozer
The type and condition of haul
road distance to be move
2 Bulldozers
Dozers are machine designed primarily for cutting and pushing the material over short
distance
They consist with a front mounted blade controlled by hydraulic cylinder to vary the depth of cut and rate of leveling depending on the material and application
a dozer is frame mounted unit with a blade, curved in its section, extending in front of the tractor
Bulldozer is most versatile and most important equipment on construction project
Basically its pushing unit but its widely used as multipurpose equipment and can perform large number of operations with minor changes
3 Scrapers
Scrapers are the devices to scrap the ground and load it simultaneously, transport it for the required distance and dump it and then spread it for the required area
The scrapers are designed to dig,load,haul,dump and spread
The scrapers are of three types
Ø towed type
Ø conventional type
Ø self loading or elevating scrapers
Towed type
The towed type scrapers are provided with either cable or hydraulic control It can be operated in extremely adverse condition
Conventional scrapers
These are generally manufactured from 10to 25cubicmetres
Self loading scrapers
These are twin engine scrapers
It can work completely independently of all other plants
It has the following parts
o Bowl
o Cutting edge o Apron
o Tail gate or ejector
Following or three major operations of scrapers
Loading or digging
Transporting
Unloading
