d. Solid rock below ground level. Where solid rock is encountered below the ground level, set
poles to the minimum depths shown in Table 1-4. Where solid rock is encountered within 6 inches of
the required depth of setting in firm ground, the pole may be set at this reduced depth; this will avoid
blasting provided the adjacent poles are set to the full standard depth.
Table 1-4. Minimum total depth of setting.
Methods of digging pole holes. Pole holes can be dug with hand tools, an earth boring machine,
a water jet, or dynamite.
a. Digging holes with hand tools. To dig holes with hand tools, use long-handled, straight
shovels and digging spoons, a gooseneck shovel, and digging bars. Keep the area around the hole clear
of earth removed from the hole. See Figure 1-1.
(1) Using the long-handled straight shovel or a digging bar, depending upon soil conditions,
loosen the dirt in the bottom of the hole. Use a digging spoon to remove the loose earth. Pry the
digging spoon against the side of the hole to gain leverage. Square of the bottom of the hole to the full
(2) Shift large rocks that cannot be removed by hand or with the digging spoon from side to
side, and drop them to the bottom of the hole. Backfill around these rocks and thoroughly tamp the soil.
Dig the hole deep enough to cover the rocks.