Powerful crawler equipment with a blade is called a bulldozer. Even though any heavy engineering vehicle is known by the term bulldozer, practically the term refers only to a tractor with dozer blade.
Earlier tractors were used to plough the fields and the first bulldozer was adapted from this tractor. During the First World War a bulldozer was used as an armoured tank because of its versatility in grounds which were soft.
A big thick metal plate is fixed on the front of the bulldozers for use in earthmoving jobs, raising dams and digging canals. As the tractor advances, the blade in front removes layers of soil. To move coal in the coalmines, to move large boulders or cut tree stumps various specialized blades are used. Earlier, the driver used to sit on top of the bulldozers, which lacked a cabin. When powered down bulldozers were introduced in the 1930′s it became the excavation equipment preferred by contractors.
When equipment was needed to execute large-scale earth works, several bigger models were manufactured by various engineering firms. These machines were noisy, large and powerful and that’s where it got its name bulldozer.
More powerful engines, better tracks, more reliable drive tracks, raised cabins and instead of the usual cable operations, hydraulic arms were some of the important improvements included in the bulldozer development. More precise blade manipulation was made possible by hydraulic systems. To loosen soils which were rocky, or for pavement bread-up, a ripper claw was also added to bulldozers.
Throughout the world, these durable and tough machines are used by construction units of the military, they are also the preferred equipment for civil construction. Some of the other uses of bulldozers include demolition of enemy structures and clearing mines.
The tracks on the bulldozers give good hold on ground and easy mobility over rough terrain. In order to prevent it sinking in muddy or sandy ground, the wide tracks help the distribution of the weight of the bulldozer over large area. The torque divider in the bulldozer converts its power into ability to drag.