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Operation
Note: Determine the left and right sides of the machine
from the normal operating position.
Understanding Horizontal
Directional Drilling
Horizontal directional drilling is a process used for drilling a
horizontal bore through the soil and under obstructions such
as roads, buildings, bodies of water, etc. Once you drill the
bore, you pull back the utility lines or pipes through the bore
and connect them as needed. Because it does not require
very much disturbance of the surface, installation of utilities
using directional drilling preserves the environment and saves
both time and money over traditional installation methods
such as trenching.
When installing cabling or pipe using a directional drill, you
complete the following steps:
1. Gather site information.
Before operating in an area with high-voltage lines or
cables, contact a "One-Call System Directory" service.
In the USA, call 811 or your local utility company. If
you do not know your local utility company's phone
number, call the national number (USA and Canada
only) at 1-888-258-0808. Also, contact any utility
companies that are not participants of the "One-Call
System Directory" service. Please refer to
Near Utility Lines (page 6)
Before fully planning the bore, you must gather
information about the job site such as the location of
other utilities, obstacles at the site, and what regulations
and permits you will need to complete the job; refer to
Gathering Site Information (page
2. Plan the bore.
Before you can drill, you must first plan the bore path
based on the information you gathered. Refer to
Planning the Bore Path (page
3. Prepare the job site and the machine.
Before drilling, you prepare the job site with an entry
point, depth-gauge hole (optional), and an exit hole.
You also need to drive the unit to the site, set it up for
drilling, and connect it to a drilling-fluid mixer.
Note: When drilling, you connect the machine to a
drilling-fluid mixer that mixes water with bentonite
clay and other ingredients. The machine pumps this
mixture, referred to as drilling fluid or "Mud", through
the drill pipe and out the drill bit. The drilling fluid
lubricates the bit, helps to hold the bore open while
drilling, and mixes with the spoils, flushing them out
of the bore through the entry point.
Drilling
for more information.
32).
34).
Refer to
Preparing the Job Site and the Machine (page
39)
for instructions on preparing the job site and the
machine.
4. Drill the bore.
You drill the bore in three stages:
A. Entry
In the entry phase of the bore, you push the drill
bit and head into the ground at an angle of up to
16 degrees. After pushing in one or more pipes,
you begin drilling down and forward until you
reach the desired depth or depth-gauge hole (if
used).
B. Horizontal Reach
After reaching the desired depth, you push the
bit forward, steering the bit to a horizontal depth.
The drill bit emits a radio signal from the sonde
housing, which allows a crew member on the
surface to track the location and depth of the head
using the sonde receiver as you drill and steer it
along a planned route.
C. Exit
Once you have attained the planned horizontal
reach, you steer the head up at an angle similar
to your entry angle bringing the bit into the exit
hole or trench.
Refer to
Drilling the Bore (page
5. Backream the bore and pull back the cabling or
pipe.
After entering the exit hole, the end crew detaches the
drill bit and sonde housing from the drill pipe. In its
place, they attach a reaming bit and the end of the cable
or pipe to be pulled through the bore. The reaming
bit is designed to enlarge the bore as you pull it back.
As before, you pump drilling fluid through the pipe
to the reaming bit as you pull the cable or pipe back
through the bore to lubricate the reamer and allow
the cable or pipe to slide easily through the bore. You
continue pulling the pipe back until the reamer reaches
the depth-gauge hole or exits at the entry point. There
you remove the reamer and product from the drill pipe,
pulling the pipe the rest of the way back to the machine.
Refer to
Backreaming and Pullback (page 52)
instructions on backreaming and pulling cable or pipe.
6. Finish the bore and leave the job site.
After completing the operation, you need to disconnect
and clean the machine and load it on the trailer; refer
to
Finishing the Job (page
31
49).
for
54).
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