The dozer, commonly called a bulldozer, is acrawler tractor on which a dozer blade has beenmounted (fig. 11- 1). Dozers are usually rated by size andpower. The pull developed at the drawbar is expressedin pounds or as drawbar horsepower. The drawbar pullis greatest in the lowest transmission gear range.Although the specifications for dozers may vary among different manufacturers, the maximum speeds areseldom in excess of 8 mph.
The dozer is equipped with a diesel engine and issupported on the ground by a track assembly. The trackassembly provides all-type-terrain versatility due to thelow ground bearing pressure at the track. This lowerground bearing pressure, varying from 6 to 9 pounds persquare inch, has a distinct flotation advantage overrubber-tired equipment ground bearing pressure thatvaries from 25 to 35 pounds per square inch. Dozers arecapable of operating efficient y in muck or water as deepas the height of the track for short periods of time. Whenthe dozer is properly waterproofed, it can operate infairly deep water.