Table of Contents
Advertisement
The following example illustrates the process given an installation using the maximum entry pitch of the
machine (26%) on level ground:
1. 26% pitch
2. 76 cm (30 inches)
3. 142 cm (56 inches)
•
You insert the first 3 m (10 ft) of drill bit/pipe into
the ground with no steering. The end of the drill bit
is 76 cm (30 inches) deep
•
You begin steering up for the next 3 m (10 ft),
pushing the pipes in at the maximum pitch change
of 8%. This results in a change of pitch from 26%
at the beginning of the 3 m (10 ft) to 18% at the
end of the 3 m (10 ft) for an average pitch of 22%.
Given that, the drill head lowers another 66 cm (26
inches) and is now 142 cm (56 inches) deep.
•
Continuing steering up for the next 3 m (10 ft) at
an 8% pitch change, your pitch changes from 18%
to 10% for an average pitch of 14%. Given that,
the drill head lowers another 43 cm (17 inches)
and is now 185 cm (73 inches) deep.
•
Continuing steering up for the next 3 m (10 ft) at
an 8% pitch change, your pitch changes from 10%
to 2% for an average pitch of 6%. Given that, the
drill head lowers another 18 cm (7 inches) and is
now 203 cm (80 inches) deep.
•
Leveling the drill head from 2% to 0% takes less
than 1.5 m (5 ft) more for a final depth of 208 cm
(82 inches). Reaching this final point took 4 and
a half, 3 m (10 ft) pipes. So for this example your
entry point should be 14.7 m (45 ft) back from the
beginning-at-depth point of your installation.
Figure 44
4. 185 cm (73 inches)
5. 203 cm (80 inches)
6. 208 cm (82 inches)
(Figure
44).
7. 14.7 m (45 ft)
42
g218954
Advertisement
Table of Contents
