Page 514 - Moving the Earth_ The Workbook of Excavation

PIT OPERATION

10.20 THE WORK

When digging a windrow ending in a wall or property line, as in (C), the shovel should be started
at that end and worked in, to minimize working soil over the end and losing it.
Draglines and backhoe shovels can be worked from one side of the pile, as in Fig. 10.17(A), or
preferably from the smoothed-off top, as in (B). The top of the pile is particularly suitable for
backhoes, as in (C), as they load more rapidly and easily if higher than the trucks. These rigs clean
up the edges without extra work but can strip closer if aided by a dozer.
Any shovel cutting to a grade will occasionally go below it so that fill will be dug. The mis-
take is immediately shown by the color of the bottom. The bucket should be dumped off to the
side to be wasted, or on the pile, to break up and mix the slice of fill. Subsoil may be deliberately
dug and mixed in this manner if the topsoil is rich and the price is low or the buyer indifferent.

Loading from the Field. Topsoil is often loaded directly from the field, with no systematic pre-
liminary piling. The efficiency of the operation depends on the depth of the soil, the machinery
used, and the output required.
Best results will be attained in deep soils, using the shovel excavator or backhoe, as increase in
depth reduces the proportion of time spent in trimming the bottom and in moving into the digging.
Unless the soil is very hard or rocky, the front-end loader gives good results, particularly as
vegetation does not have to be disked ahead of it. Front loaders dig easily, but may roll up big
masses of sod. Almost any loading machine can be used unless the soil is shallow or rocky.

FIGURE 10.17 Loading topsoil with dragline or backhoe.