Page 174 - Moving the Earth_ The Workbook of Excavation

BASEMENTS

4.14 THE WORK

FIGURE 4.13 Basement digging with a backhoe.

has dug as much of the south wall as it can from its position, it reaches to the center of the west
line and digs a trench back from there. The triangle included in these ditches is dug in layers to
bottom grade, which may be found by a measuring stick, and as near to straight down from the
west line as possible.
The shovel is then backed up a few feet to position (B). It can now cut the west end of the ditch to
be almost vertical, because of the more extended position of the bucket. The south wall ditch is then
extended as near the shovel as possible, and material between it and the center cut down in layers to
the bottom. The center-line will be irregular.
The spoil pile will tend to build up too sharply at the edge of the hole unless pushed back. This
pushing may be done by regulating the outward swing of the bucket during the dump, so that it
strikes the pile at a spot where its momentum will push a considerable quantity of dirt outward,
without stopping its own motion. Knocking dirt back should be started early, before the pile gets
high. The hoist clutch must be engaged during this operation. The quantity of dirt that can be put
in a pile is greatly increased in this way.
Digging is continued in the same manner, with careful attention to a clean, level bottom until
the east end is reached. The backhoe can probably cut this to a nearly vertical wall immediately
in front of it, but will leave a ragged edge, as (C) farther north. The backhoe is then turned and