Ditch Witch JT30AT - Manual (Page 123)

Conduct a Bore - 123
JT30 /JT30 All Terrain Operator’s Manual
Backream
CMW
Assemble Backream String
1. Select backreaming devices. See “Backreamers” on page 148.
2. Determine fluid rate requirements and install appropriate nozzles to provide sufficient flow. See
“Backream Fluid Requirements” on page 149 and “Nozzles” on page 146.
3. Attach backreamer to beacon housing if tracking backream.
4. Install beacon, following beacon instructions for:
• battery replacement
• beacon positioning
5. Install beacon housing lid. See page 147.
6. Follow beacon instructions to check beacon operation.
7. Follow tracker instructions to calibrate beacon.
8. If in AT mode, install inner spindle spacer
(shown) onto end of lead pipe.
9. Use quick wrenches to attach transition
sub to drill pipe string.
10. Use quick wrenches to attach backreamer/
beacon housing assembly to transition
sub.
11. Attach additional pullback devices or
product to end of backreamer/beacon
housing assembly.
Begin Backream
1. After backream assembly is attached to
pipe, tracker operator should:
• leave pit and stand away from the exposed drill string.
• if using tracker control, turn on tracker to enable drilling unit thrust/pullback and rotation.
• if not using tracker control, communicate to drill operator that backream string is clear.
2. Turn on drill fluid and pressurize drill pipe. Verify that jets are open.
3. Without rotating, slowly pull back until reamer contacts bore hole opening. Do not lodge reamer in
hole.
4. Begin slow rotation and pullback.
5. Increase drilling fluid flow and rotation as the backream string enters the ground.
6. If tracking backream, tracker operator may continue tracking when the backream string is no longer
visible.