A bulldozer is acrawler(caterpillar tracked tractor), equipped with a substantial metal plate (known as ablade), used to push large quantities of soil, sand, rubble, etc, during construction work. The term "bulldozer" is often used to mean any heavy engineering vehicle(frequently loaders and in particular track loaders), but precisely, the term refers only to a tractor (usually tracked) fitted with a dozer blade. That is the meaning used here.Sometimes a bulldozer is used to push another piece of earthmoving equipment known as a "scraper". The towed Fresno Scraper, invented in 1883 by James Porteous, was the first design to enable this to be done economically, removing the soil from the cut and depositing it elsewhere on shallow ground (fill). Many dozer blades have a reinforced center section with this purpose in mind, and are called "bull blades."
