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CM $2113$ Fall $2024$

HW$6$: Equipment Power Performance

A fully loaded Caterpillar $775$F Off$-$Highway Truck must travel down a $4\%$ slope on loose sand and gravel surface to dump the dirt, and return empty through the same slope route. You obtain the following information from the manufacturer's data:

Empty Weight: $154,000$ lbs

Fully loaded weight: $294,000lb$

a$.$ What is the total rolling resistance $(1$b$)$ when traveling down the slope with fully loaded? We assume the tire penetration is known as $3\mathrm{.}5$ inches. Please use the equation that includes tire penetration for calculation.

b$.$ What is the total rolling resistance $($lb$)$ when returning up the slope with the empty vehicle? Please use the rolling assistance factor from the reference table below to solve this problem. For this problem, we assume the truck has high$-$pressure rubber tires, and use the average number of the factor range you find out.

c$.$ What is the total grade resistance $($lb$)$ for both traveling down the slope and returning up the slope?

d$.$ What is the total resistance $($lb$)$ for both traveling down the slope and returning up the slope?

e$.$ What is the total effective grade $(\%)$ for both traveling down the slope and returning up the slope?

TABLE $6\mathrm{.}1$ Representative rolling resistances for various types of wheols and crawler tracks versus various suraces'

$\backslash$table$[[$Type of surface,Steel tires, plain bearings,Crawler type track and wheal,Rubber tires, antifriction bearings$],[$lb $/$ton$,k\frac{g}{m}$ ton,Ib$/$ton$,k\frac{g}{m}$ ton,High pressure,Low preesura$],[$lbiton k$,k\frac{g}{m}$ ton,lb$/$ton kat,kgimton$],[$Smooth concrete,$40,20,55,27,35,18,45,23],[$Good asphat,$50-70,25-35,60-70,-30-35,40-65,20-33,50-60,25-30$