Pilot Tube Microtunneling

Pilot Tube Microtunneling

Pilot Tube Microtunneling (PTMT) is a trenchless method to install new service lines and gravity flow sewer tunnels with pinpoint accuracy.  This method requires a multi-step sequence of accurately installing a pilot tube, followed by upsizing stages to the final product pipe diameter.

Step One

Pilot tubes are accurately installed from the launch shaft to the receiving shaft with tooling selected based on the ground conditions encountered.

Step Two

Small diameter cased augers are connected to the installed pilot tubes and advanced from the launch shaft.
Excavated material is removed by the augers and transferred to the launch shaft for removal.
As the cased augers advance, pilot tubes are thrust into the reception shaft where they are disassembled, cleaned, and placed into storage containers.

Step Three

If the product pipe matches the diameter of the temporary cased augers, the product pipe is connected to the last casing.  The pipe then thrusts out the temporary cased augers into the reception shaft for storage until the drive is complete.

If the product pipe is larger, a Powered Cutting Head (PCH) or Power Reaming Head (PRH) is used to increase the cut diameter to match the final product pipe.   Excavated soil is removed by reversing the direction of augers and transferring the excavated material to the reception shaft.