CommScope ConQuest Conduit Construction - Manual (Page 24)

4.6 Underground Installation Methods
Boring (Conventional Bores)
Conventional Boring Installation Method
Mechanical Boring Machines may be utilized to push an auger (jack and bore) to make an adequate
conduit passage. The auger diameter should be 1 inch (2.5 cm) larger diameter than the conduit being installed.
The equipment manufacturer should
support the operation instructions for this
equipment. In general practice, the set
up should be done so that the auger is
oriented in the direction of the receiving pit.
Pneumatically Driven Pistons (missiles) may be used as well. The missile diameter should be 1 inch (2.5 cm)
larger diameter than the conduit being installed. The equipment manufacturer should support the operation instructions
for this equipment. The operation of this equipment requires skills that can only be acquired through practice. Soil
conditions will determine the orientation of the missile when starting it. Some examples are:
In standard soil conditions, the missile will usually be
pointed down slightly to compensate for the natural tendency of it
to rise, as the soil above it offers less resistance to it than the soil
beneath it.
In sandy and wet soil conditions, the missile will usually
need to be pointed slightly up to compensate for the natural
tendency to sink, as the soil is unstable and offers little support
beneath it.
In extremely dense and hard soils, the missile will usually need to be pointed level since the soil is more uniform
in density above and below.
bore pit
missile