Ditch Witch JT922 - Manual (Page 88)

JT922 Operator’s Manual
Conduct a Bore - 87
Assemble Backream String
CMW
Assemble Backream String
Sometimes it is necessary to enlarge the pilot hole to accommodate larger product. As a general rule, the
final hole should be 1.5 times larger than the diameter of the product being installed. The number of
passes needed depends on soil conditions. Do not try to increase hole size too much in one pass. Several
passes using successively larger reamers will save wear on machine.
Moving tools will kill or injure. Shut off drill string power when anyone can
be struck by moving or thrown tools. Never use pipe wrenches on drill string.
Jobsite hazards could cause death or serious injury. Use
correct equipment and work methods. Use and maintain proper safety
equipment.
NOTICE: Continue to use strike system during backreaming.
Turning shaft will kill you or crush arm or leg. Stay away.
NOTICE:
• Maintain two-way communication with tracker operator.
• Begin backream only when tracker operator has communicated that everyone is clear of the
exposed backream string or has disabled thrust and rotation hydraulics using tracker control.
• Do not allow anyone to stand to the side of the exposed drill string. Drill string and backreamer can
move sideways suddenly if rotated while away from the exit hole.