CHAPTER 11DOZERS AND ROLLERSThe dozer, technically known as a crawler tractor,is used as follows: as a prime mover for pushing orpulling loads, as a power unit for winch operations, oras a dozer for earthwork operations and demolitionwork. Rollers are compaction equipment used toachieve mechanical compaction of earthwork materialsrequired by project specifications.A variety of makes and models of dozers and rollersare used by the Navy and the Naval Construction Force(NCF). Each operator is responsible for reading theoperator’s manual to obtain detailed information abouteach make and model. This chapter covers the generalcharacteristics and basic principles of dozer and rolleroperations.DOZERSThe 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 amongdifferent 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.CAUTIONWhen working in water that is deep enoughto reach the radiator, be sure to disconnect thefan belt. If the fan blades hit the water whileunder power, the y could bend or break off,possibly causing damage to the radiator.Additionally, exercise extreme caution toensure the engine does not overheat when thefan or water pump belts are disconnected.Figure 11-1.—Dozer.11-1
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