Planning The Bore Path - Toro 2226 Operator's Manual

Planning the Bore Path

Before setting up the job site, you need to plan the bore path, including the following:
1. Bore entry
2. Beginning of bore-at-depth point
3. Bore depth
•
Bore entry
This is the location where you setup the machine
and the drill bit enters the ground. Depending
on conditions, this will typically be set back
9 to 15 m (30 to 50 ft) from the beginning of
the-bore-at-depth point.
•
Beginning of bore-at-depth point
This is the point where you want the utility line
or pipe to end after installation is complete. It is
typically the point at which the bore levels out
and begins to bore horizontally. This may be the
same as the entry point, or you may dig a separate
depth-gauge hole at this point
•
Bore depth
This the depth at which you want to install the
utility line or pipe.
•
Obstacles in the path
You will need to steer around or under obstacles.
It is important to know where these obstacles will
be before starting so that you can plan where to
begin steering prior to reaching the obstacle.
•
End of bore-at-depth point
This is the point where you want the utility line or
pipe to begin after installation is complete. Often
this will also be the bore exit.
•
Bore exit
This is the location where the drill head will exit
the ground and the point at which you will pull the
utility lines or pipe into the bore. If this point will
be at the surface instead of at installation depth,
Figure 40
(Figure 40).
39
4. Obstacle
5. End of bore-at-depth point and bore exit
you will need to determine the distance from the
end-of-bore-at-depth location needed for steering
the drill to the surface, typically 9 to 15 m (30 to 50
ft) from the end-of-the-bore-at-depth point.
Determining the Bore Entry Point
One of the more challenging aspects of planning the
bore path is to determine the entry point of the bore.
You need to take the following traits into account when
determining the location of the entry point:
•
Bore depth
This the depth at which you want to install the utility
line or pipe. This machine is designed primarily for
installations between 1 and 3 m (3.5 to 10 ft).
•
Pipe and material flexibility
The 3 m (10 ft) pipes used on this machine can
flex to an 8% pitch over the length of the pipe;
this equates to a bend of no more than 20 cm (8
inches) off of a straight path
Important:
If you steer the pipe to bend
sharper than 20 cm (8 inches) per pipe, you
may damage the pipes and their connections.
You must also make steering changes
gradually over the entire length of each pipe.
If you steer the whole 20 cm (8 inches) in
only 25 to 50 cm (1 to 2 ft) of travel, you can
permanently damage the pipes.
g218955
(Figure 41).