Earth Hauling Equipment

The type of earth hauling equipment primarily depends upon the haulage distance. A rough guideline for selecting equipment based on haulage distance.

Guidelines for Selecting Equipment Based on Haulage Distance (in meters)

Type of Equipment	Range of Haulage Distance
Front-end loader track	Up to 80
Front-end loader (wheeled)	Up to 200
Bulldozers	Up to 80
Towed scrapers	100-300
Elevating self-loading scrapers	100-1000
Single engine scrapers (double pusher arrangement)	500-1500
Double engine motorized scrapers (push pull arrangement)	2000 and above
Tippers and dump trucks	800 and above

Mostly the excavated earth is hauled in heavy duty rubber-tyred tippers, lorries and rear-opening dump trucks. Over  long distance these vehicles vary in capacity from 5 m³ to 30 m³ dumpers. Tipping lorries are employed for transporting materials over level grounds whereas dumpers are used for moving large quantities of materials across rough areas. Generally, front-end loaders and excavation are used to load tippers and dumpers.

Haulage vehicle required = 1 + Cycle time per trip of vehicle / Load filling time of vehicle

Example

Construction of a military helipad at an altitude of 2400 m involves 80,000 m³ (loose) of area excavation in soft soil. This task is to be completed in 200 working hours. The company entrusted with the execution of the task has two dozers each with an output of 220 m³/h under job conditions. It also holds wheel loaders and 22 m³ dump trucks. One loader can load in trucks about 120 m³ of excavated soil per hour. The dump truck cycle time for disposal of excavated materials is 35 minutes. This includes 7 minutes of loading time by a loader team consisting of 2 loaders. Estimate the output of front-end loader for loading excavated soil heap into dump trucks and determine approximately the number of dozers, loaders and dumpers required to complete the task on time.

Solution

A.     Dozers required = Excavation quantity / (Output/h) x Working hour

                              = 80,000/(220x220) = say

B.     Loaders required = (Excavation/h by dozers) / (Loader output/h)

                                = (No. of dozers x dozer output/h) / (Loader output/h)

                                 = (2 x 220) / 120

                                 = 4 = 2 loader teams, each team consisting of 2 dozers.

C.    Dumpers required = 1 + Dumper cycle time/Loading time

For each loading team of 2 front end loaders

                                  = 1 + 35/7

                                  = 1 + 5 = 6

Total dumper required = 2 x 6 = 12