A bulldozer is a crawler (continuoustracked tractor) equipped with a substantialmetal plate (known as a blade) used to pushlarge quantities of soil, sand, rubble, or othersuch material during construction or conversionwork and typically equipped at the rear with aclaw-like device (known as a ripper) to loosendensely compacted materials.

A bulldozer is a crawler (Continuous trackedtractor) used to push large quantities of soil,sand, rubble, during construction work.

• The term “bulldozer” is often used to mean any heavy equipment (sometimes a loader and sometimes an excavator), but precisely, the term refers only to a tractor fitted with a dozer blade.

The bulldozer's primary tools arethe blade and the ripper.

Dozers, tractors equipped with a blade are standard equipmentfor excavating.

The first bulldozers were adapted from Holt farm tractors

that were used to plough fields. The versatility of the

bulldozers in soft ground for logging and road building led

directly to their becoming the armored tank in World War I.

In 1923, a young farmernamed James Cummings anda draftsman named J. EarlMcLeod made the firstdesigns for a bulldozer. Areplica is on display at thecity park in Morrowville,Kansas where the two builtthe first bulldozer.

Bulldozers can be found on a wide range ofsites, mines and quarries, military bases, heavyindustry factories, engineering projects and farms.

The tracks give them excellent ground holdingcapability and mobility through very rough terrain.Wide tracks help distribute the bulldozer's weightover a large area (decreasing ground pressure), thuspreventing it from sinkingin sandy or muddy ground. Extra wide tracks areknown as swamp tracks or LGP (low groundpressure) tracks. Bulldozers have transmissionsystems designed to take advantage of the tracksystem and provide excellent tractive force.

Most often, bulldozers are large and powerful tracked heavy equipment. The tracks give them excellent ground hold and mobility through very rough terrain.

Wide tracks help distribute the bulldozer's weight over a large area thus preventing it from sinking in sandy or muddy ground.

The bulldozer's primary tools are the blade and the ripper.

Bulldozer Sketch

The bulldozer blade is a heavy metal plate on the front of the tractor, used to push objects, and shove 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.

2. A universal blade ("U blade") which is tall and very curved, and has large side wings to carry more material.

3. 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.

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

Ripping rock lets the ground surface rock be broken into small rubble easy to handle and transport, which can then be removed so grading can take place.

Agricultural ripping lets rocky or very hard earth be broken up so otherwise unploughable

land can be farmed.

For example, much of the best land in the California wine country consists of old lava flows. With heavy bulldozers the lava is shattered, allowing agriculture.

Also, hard earth can be ripped and broken up to allow planting of orchards where trees could not otherwise grow.

Moisture Content –1. Moisture falls below the optimum moisture content value, particles will adhere to each other and more – effect – it make it diffcult to break material out of its natural state.

2. If moisture content increases above the optimum, material becomes heavy and will have a negative effect on dozeingperformance.

Particle size -1. Specific size of material has a direct bearing on the ability of dozer blade to penetrate and loosen materials. Large particles resist penetration more than smaller ones, requires more dozing power.

2. Sharp-edged particles exert more force against the curl movement of blade. Material consisting of irregularly and sharp-edged particles is more difficult to doze than material composed of round-edged particles.

Voids – 1. More force is required to break up the tightly bonded

materials. Also such materials is generally heavy, making additional demands on the available horse power of the dozer.

In military use, dozer blades are fixed on combat engineering vehicles and can optionally be fitted on other vehicles, such as artillery tractors like the Type 73 or M8 Tractor.

Dozer blades can also be mounted on Main battle tanks, where it can be used to clear antitank obstacles, mines, and dig improvised shelters.

Combat applications for dozer blades include clearing battlefield obstacles and preparing fire positions.

Bulldozers are large and heavy vehicles making them a good choice for demolition and clearing sites.

Caterpillar tracks give bulldozers a distinct advantage allowing them to be surprisingly maneuverable for their extreme weight.

The tracks are also quite wide which helps to distribute their heavy weight preventing them from sinking in sandy or muddy ground.

Bulldozers are renowned for holding their ground which gives them phenomenal strength for pushing and dragging obstructions in their path.

Some models of tanks can even tow up to 70 tons of weight and are used for moving written off vehicles and military purposes as well as in construction and demolition projects.

Bulldozers are often used in road building, construction, mining, forestry, land clearing, infrastructure development, and any other projects requiring highly mobile, powerful, and stable earth-moving equipment.

The bottom edge of the blade can be sharpened, e.g. to cut tree stumps.

Loads – Fully heaped blade Engine Speed – Full rpm / full capacity Travel – 1 to 8 km/hr,

haul distance- 60 to 90m etc. Spreading – Time being wasted? Mechanical – All adjustment to power unit

maintained General – Right machine for job?

Right operator?Right procedure?Machine proper maintained?