Trucks and Equipment

7/25/2019 Trucks and Equipment

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Trucks and Equipment

Trucks are hauling units

Trucks have high travel speeds when operating on suitable roads, provide relatively

low hauling costs.

Trucks provide a high degree of exibility permitting modications in the total

hauling capacity of a eet and adustments for changing haul distances.

!ost trucks may be operated over any haul road for which the surface is su"ciently rm

and smooth and on which the grades are not excessively steep.

#ome trucks now in use are designated as o$%highway trucks because their si&e and

total load are larger than that permitted on publics highways. These trucks are used for

hauling materials on large proect sites, where their si&e and costs are ustied.

Trucks may be classifed according to a number o actors including:

The si&e and type of engine% gasoline, diesel, butane and propane

The number of gears The kind of drive%two%wheel, four%wheel and six%wheel.

The number of wheels and axles and arrangement of driving wheels

The method of dumping the load%rear%clump, side%dump

The class of materials hauled ' earth, rock, core, ore

The capacity ' in tons or cubic yards

(ote) Distanceis the principal factor in selecting hauling units

Rear dump trucks are used when:

The material to be hauled is free%owing or has bulky components

The hauling unit must dump into restricted locations or over the edge of a bank or

ll.

!aximum maneuverability in the loading of dumping area is required.


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Bottom dump trucks are used when:

The materials to be hauled is free%owing

There are unrestricted loading and dump sites

Hauling Equipment these are speciali&ed trucks for hauling a eet of

equipment from one point to another.

*eneral +onstruction

!ilitary

#ervices


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Tiresare about - of a truck/s operating cost. 0verload a truck and you abuse the

tires.

Tires are designed for a wide range of applications.

The Terex Titan, the world/s largest truck at -1%ton was designed around the tires.

CAPACITY OF DUMP TRUC!

There are three methods of expressing the capacities of trucks and wagons)

2y the load which it will carry, expressed gravimetrically in tons

2y its struck volume 3cu yd4

2y its heaped volume 3cu yd4


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354!truc" Capacit#' is the volume of material which it will haul when it is lled level

to the top of the sides of the body.364Heape$ capacit#' is the volume of material, which it will haul when the load is

heaped above sides.

7t varies with the height and angle at which the material may extend

above the sides.

8et earth or sandy clay may be hauled with a slope of about 5)5

9ry sand or gravel may not permit a slope greater than )5

!truc" material measured straight across the top of the body.

PERFORMA%CE CAPA&I'ITIE! OF TRUC!

The productive capacity of a truck of wagon depends on)

si&e of its load

number of trips it can make in an hour.

The si&e of the load can be determined from the specications furnished by the

manufacturer.

The number of trips per hour will depend on the weight of the vehicle, the horsepower of

the engine, the haul distance and the condition of the haul road.


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&A'A%CI%( THE CAPA&I'ITIE! OF HAU'I%( U%IT! )ITH E*CA+ATOR !I,E

8hen loading with hoes, shovels, draglines or belt loaders, it is desirable to use haul

units whose capacities balance the output of the excavator

:actors which will a$ect the production rate and cost of handling earth)

;dvantages of using small trucks compared with large trucks

9isadvantages of using small trucks compared with large trucks

;dvantages of using large trucks compared with small trucks

9isadvantages of using large trucks compared with small trucks.

U!I%( !MA'' TRUC! COMPARED )ITH 'AR(E TRUC!

Advantages:

They are m-re .exi/lein maneuvering, which may be an advantage on short

hauls.

They have 0ig0er spee$s

There is less l-ss in pr-$ucti-nwhen one truck in a eet breaks down.

7t is easier t- /alancethe number of trucks with the output of the excavator,

which will reduce the time lost by the trucks or the excavator.

9isadvantages)

; small truck is m-re $i1cult 2-r t0e exca3at-r t- l-a$ -4ingto the small

target for depositing the bucket load.

M-re t-tal sp-tting time is l-stin positioning the trucks because of the larger

number required

M-re $ri3ers are require$ t- 0aula given output of material.

The greater num/er -2 truc"s increases t0e $anger -2 units /unc0ingat

the pit, along the haul road or at dump

The greater num/er -2 truc"s require$ ma# increase t0e t-tal in3estment

in hauling equipment, with more expensive maintenance and repairs, and more

parts to stock.

U!I%( 'AR(E TRUC! COMPARED )ITH !MA'' TRUC!5

Advantages:

Fe4er truc"s are require$, which may reduce the total investment in hauling

units and the cost of maintenance and repairs

Fe4er $ri3ers require$

The smaller number of trucks facilities synchroni&ing the equipment and re$uces

t0e $anger -2 /unc0ingby the trucks. This is especially true for long hauls.

There are 2e4er truc"s t- maintain an$ repairand fewer parts to stock.

The engines -r$inaril# use c0eaper 2uels, i.e. gasoline versus diesel, but this

must be based on fuel prices at the specic proect location.


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Disadvantages:

The c-st -2 truc" time at l-a$ing is greater, especially with small excavators

The 0ea3ier l-a$s ma# cause m-re $amageto the haul roads thus increasing

the cost of mechanical maintenance to the trucks and requiring more support

equipment for maintenance of the haul road.

7t is m-re $i1cult t- /alance t0e num/er -2 truc"s with the output of the

excavator. Repair parts ma# /e $i1cultto obtain

The largest si6es ma# n-t /e permitte$ t- 0aul -n 0ig04a#s7


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TRUC PRODUCTIO%

Step 1: BUCKET LOADS

The number of bucket loads required to ll the truck.

Bucket Loads= TruckCapacity

Loader Bucket Capacity

(ote) 2ucket loads must be an integer number. +heck weight limit against gravimetric

capacity of the haul unit.

Step : LOAD T!"E

Load time=Excavator cycle timeNo .of bucket loads

Step #: $AUL T!"E

Haul Time=Haul Distance( ft)88x Haul Sp eed

Step %: RETUR& T!"E

ReturnTime=Return Distance( ft)88x Haul Speed

Step ': DU"( T!"E

This will depend on the type of hauling unit.

Step ): TRUCK C*CLE T!"E

CycleTme=Load time+Haul Time+Dump Time+Return time

Step +: &U"BER O, TRUCKS RE-U!RED

Trucksre!uired= Truck cycle time

Loader cycle time

+1

Step +: &U"BER O, RE-U!RED TRUCKS

The match point typically does not coincide with an even number of trucks.

Step .: E,,!C!E&C*

Three critical factors to consider)


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&unc0ing

Operat-r ' longer hauling distances usually results in better operator e"ciency.

0perator e"ciency increases as haul distance increases to about

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Trucks and Equipment