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ft) of forward travel. If you steer more than this,
you will damage the drill pipes.
Boring the Horizontal Shaft
After creating the entry shaft, you gradually steer
the drill head up while pushing forward, following
the planned bore path. When you reach the desired
depth, level out the drill head and bore the horizontal
shaft, adding pipes as you go. While boring, pay close
attention to the information relayed back to you by
the crew member about the status and location of the
drill head to ensure that you are following the planned
path.
Important:
While drilling, watch the sonde
temperature. All sondes have a maximum
temperature above which they will be damaged.
Friction between the drill head and the soil
causes the temperature to raise. To reduce
the temperature, slow down, decrease forward
pressure, and increase the drilling fluid flow. If
the drill head is entering a soil type other than
what it is designed for, that can also raise the
temperature. Assess the situation and pull out the
drill head and change it if necessary.
If you run into an obstruction, do the following:
1.
Increase the flow of the drilling fluid for a few
seconds without drilling, then attempt to continue
drilling forward.
This may loosen the obstruction and allow you
to push past it.
2.
If the obstruction persists, try 1 or more of the
following options:
•
If the obstruction is in an area where you
can dig, stop the drill head with the Exit Side
Lockout and dig down to the obstruction to
identify it and remove it if possible.
•
Pull the drill head back 15 m (50 ft) or more
and steer the drill head to the side, marking
a new drill path around the obstacle.
Important:
more than 20 cm (8 inches) off center for
every 3 meters (10 ft) of forward travel. If
you steer more than this, you will damage
the drill pipes.
•
If the obstruction is actually a change in soil
types, such as a zone of rocky soil, pull the
drill head all the way back and change to a
drill bit appropriate for drilling through the
new soil type.
Do not steer the drill head
Exiting the Ground
As you approach the end of the bore, steer the drill
head to the exit point, keeping the steering limits in
mind as you do so. Before exiting the ground, ensure
that everyone is away from the exit point. As soon as
you break through, stop the drilling-fluid flow. Extend
the drill forward until the entire drill head is out of the
ground.
Backreaming and Pullback
After drilling the initial bore, you attach a reamer to
the pipe, which is then connected to a the product you
are installing. The reamer is designed to widen the
bore, pack the walls, and lubricate the passage of the
product into the bore.
The following reamers are available from your
Authorized Service Dealer in various sizes to meet
your needs and soil conditions:
•
Carbide step-wing cutter—Use this reamer in
sandy and medium clay soil conditions to mix the
drilling fluid with the soil, making a mixture that
flows easily around the product being pulled.
•
Cast cone packer—Use this reamer in soils that
pack easily, such as soft clay, peat, and loam, to
pack the sides of the bore, maintaining the bore
opening.
•
Fluted reamer—Use this reamer in hard clay and
rocky soils; it combines the features of the other
2 reamers.
Connecting the Reamer and
Product
WARNING
If the drill rotates or extends while you or
others are manually working on the drill bit or
pipe in front of the machine, the worker could
get caught in the bit or pipe causing serious
injury, amputation, or death.
• Enable the exit-side lockout on the
exit-side-lockout transmitter before
approaching the dill bit or pipe when
attached to the machine. This disables the
drill carriage and rotary gearbox.
• Do not wear loose clothing or jewelry when
working on a drill bit or pipe attached to
the machine. Tie long hair up and out of
the way.
1.
Using the exit-side-lockout transmitter, enable
the exit side lockout.
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