Pilot Tube Machine

Guided Pilot System uses a laser to monitor line and grade

pilot tube steels

Receiving side of a pilot tube installation

Pilot Tube Method-Microtunneling

Pilot Tube Microtunneling is a hybrid version of multiple trenchless methods. The three main components consist of installation of a pilot tube on line and grade and then install of steel casing by pipe-jacking and removal of spoils by auger excavation. This method is highly accurate in softer soils and lengths up to 400 linear feet.

Installation Considerations:

• Overhead Power Lines – Generally auger boring requires the use of an excavator in order to dig the pit and extract spoils from the pit.

• Soil Conditions – Ground conditions are a very important aspect when choosing a cutting head. Pilot tubes can only be used in displace-able or softer soils. This method can not be used in rock situations.

• Lubrication – Occasionally soil conditions require the use of a bentonite mud mixture in order to reduce the skin friction between the casing pipe and the material that surrounds it.

• Grade Control – This aspect becomes critical when tunneling around existing structures. Grade is also crucial when installing certain utilities such as gravity sewer systems. In these situations Aaron Enterprises would use a steering head that would allow us to maneuver both horizontally and vertically.

• Ground Water Conditions – After the excavation of a launching pit, crews often find themselves below the water table. A well point can be installed in order to control the influx of water.

• Visible Restraints of Setup Area – Different job site constraints may require special attention during mobilization and pit excavation. Restraints at the job location are an important consideration when using the auger boring method.