Ditch Witch JT40, Operator'S Manual

Page: 98 / 253

JT40/JT40 All Terrain Operator’s Manual
Prepare - 97
Plan Bore Path
Minimum Depth
Because you must bend pipe gradually, entry pitch and
bend limits determine how deep the pipe will be when
it becomes horizontal. This is called the
minimum
depth .
• To reduce minimum depth (D1), reduce entry
pitch. This also decreases setback.
• To increase minimum depth (D2), increase
entry pitch. This also increases setback.
Bore Path Calculator
Entry pitch, setback, and minimum depth work together with bend limits to determine the bore path. To find
the setback (B) and entry pitch (A) that will take you to the desired minimum depth (D), use the chart
below.
JT40 Power Pipe
®
HD
Minimum depth (D) Entry pitch (A) Setback (B) Depth to begin steering (S)
4’ 4” (1.32 m) 18% / 10.0° 37’ 3” (11.35 m) 2’ 2” (0.66 m)
5’ 5” (1.65 m) 21% / 11.6° 41’ 2” (12.55 m) 2’ 6” (0.76 m)
6’ 8” (2.03 m) 23% / 13.2° 45’ 1” (13.74 m) 2’ 9” (0.84 m)
7’ 11” (2.41 m) 26% / 14.8° 49’ 0” (14.94 m) 3’ 1” (0.94 m)
9’ 5” (2.87 m) 29% / 16.4° 52’ 10” (16.10 m) 3’ 5” (1.04 m)
10’ 11” (3.33 m) 32% / 18.0° 56’ 7” (17.25 m) 3’ 9” (1.14 m)
IMPORTANT: Numbers in table based on 146’ (44.5 m) minimum bend radius and beacon housing,
EZ-Connect connector, transition sub, and 1/3 of first drill pipe (L, totaling 12’ 1” [3.68 m]) in the ground
before steering.