Equipment:StraightLine HDD® RockEye Air Hammer 5.0 on a Vermeer® D50x100, with a Sullair® 1150cfm x 350psi air compressor.
The Challenge: DBU Construction, Inc. was awarded a challenging 500′ bore near Louden, NH. Ground conditions included sand, gravel and granite, including multiple rock beds, as well as large granite boulders. The bore path was to cross the Soucook River, with a 30′ drop in grade, and back up again, on the opposite side of the tributary. Multiple unsuccessful shots had been attempted prior to DBU arriving on the scene, and owner Adam Towne, knew just who to call to make quick work of others losses. Mr. Towne left the conventional tooling behind, and called StraightLine® HDD, which deployed Lead Field Engineer, Ron Becker, and a RockEye 5.0 Air Hammer System.
Previous attempts had proven unsuccessful due to the inability to clear the rock shelves on either side of the river, as well as the inability to steer through the virtual mine field of granite boulders, incased by gravel and sand. Control over conventional drill heads had proven to be impossible over the 500′ bore path and the StraightLine® engineers spent considerable time, studying the ground conditions, prior to beginning drilling operations. Due to the severe sand content present in between the boulders, this bore required precise drilling technique and fluid management in order to be successful.
Outcome: In 9 short hours the hammer was steered up on the other side of the river on target. The combination of the appropriate drilling fluids and air made this shot possible. DBU Driller, Jeff Guay, demonstrated exceptional skill and patience while steering through the mid to large size boulders, encased in the loose sand and gravel. “I’ve run other hammers in the past, and the StraightLine® hammer is flawless- almost dummy proof. And it came out with no wear, which is unbelievable, really, for being in sand and granite. It’s a very efficient and a very tough tool,” stated Guay.