Keep The Bore Path On The Straight And Narrow

A New Auger Boring Steering System Helps Georgia Contractor Stay On Course
October 2011, Vol. 66 No. 10

Alignment, grade critical
The ON Target system from McLaughlin allows contractors to adjust the lateral direction of the steering head along with the vertical movement. The ability to make lateral corrections allows operators to make adjustments in any direction: up and down, left and right, resulting in more accurate cutting paths, something that is especially useful for longer, more difficult on-grade bores.

As Moore explains, the grade and lateral movement of the ON Target steering head is controlled by hydraulic actuated panels that open and close to keep the head on the intended course. A control station features a hydraulic power pack to control the movement of the steering head, and a built-in water level helps monitor grade throughout the bore. Two halogen lights in the control station indicate lateral steering head alignment.

“This is a significant upgrade from the traditional manual knuckle that has been the industry standard,” Moore says. “When this knuckle was exposed to challenging soil conditions there was a tendency for the steering head to resist, resulting in inadvertent downward movement away from the desired path. By using a hydraulic control system, we’ve been able to remove that unknown movement factor from the bore.”

Putting ON Target to the test
Lewis put McLaughlin’s ON Target steering to the test on a recent water line expansion project just outside of Savannah, GA. The task was to install a 36-inch casing for a 24-inch water main (configured in 40-foot segments) beneath two interstate highways at the northeast corner of the I-95 and I-16 interchange. The challenges were several, including the length of the two bores (400 feet and 440 feet respectively), the soil conditions (unpredictable variations of sand and gumbo) and lastly, the depth required to complete the bores.

The two installations were among 30 bores that L&L Utilities was subcontracted to complete for an 80,000-foot water line expansion project by the project’s general contractor, Lee Contracting, based in Heartyville, SC. After reviewing the project details and analyzing the soil profiles, Lewis knew they would be facing some difficult challenges.