In the land down under, more and more underground utilities are being placed down under by horizontal directional drilling (HDD).

Infrastructure Constructions Pt. Ltd., Sydney, Australia, specializes in the installation of duct and cable for telecommunications and power and pipe for water and sewer systems.

“At least half of the work we complete these days is constructed using HDD,” says Peter Brown, business development manager, Infrastructure Constructions. “We own and operate four Ditch Witch® directional drilling machines, and it is rare that there is a day when one is not out on a job, and that's usually only when it is being serviced.”

Infrastructure Constructions® Ditch Witch equipment includes two 17,000-pound pullback JT1720 models, one 27,000-pound pullback JT2720 All Terrain, and one 40,000-pound pullback JT4020 unit, Ditch Witch 750 electronic trackers, and FM13 fluid mixing equipment.

Brown says the company is primary contractor for most projects.

Recent HDD projects include installation of 240 meters (approximately 787 feet) of 125-mm (5 inch) diameter HDPE pipe through solid rock for a low pressure sewer system and installation of multiple conduits for upgrading of an electrical distribution system.

Explains Brown: “The sewer installation was for Sydney Water, and we used the JT4020 with a mud motor and fluid recirculation system. This was a difficult installation due to several factors, beginning with the rock. The route was beside a major arterial road which snaked through a valley, and we had to keep within very narrow tolerances and maintain a negative fall. HDD was used because trenching would have caused major traffic disruptions.”

The electrical project was for Integral Energy, in the Kellyville area (Sydney’s northwest) and included multiple bores totaling approximately 2760 m (9055 feet). The JT4020 and JT2720 All Terrain and JT1720 equipment all were used on the project.

“Construction,” says Brown, “occurred mainly among residential properties, many with well-manicured lawns and stencil-crete driveways, so only minimal restoration was required. For that reason HDD completed 2690 of the 2760 m of conduit installed. Product varied from single-140-mm (51/2-inch) conduit to bundles of as many as eight-63-mm (21/2-inch) ducts. To install eight conduits would require a fairly large open trench. With HDD, only minimal reinstatement of entry and exit pits was necessary.”

Established in 1998, Infrastructure Constructions employs about 40 people and also uses subcontractors when appropriate. The company performs a wide range of utility construction, including trenching and non-destructive excavation, termination and testing of fiber-optic and copper cable, construction of manholes, technical advisory services, and project planning and management.

Brown says the company believes demand for underground construction services will increase over the next few years due to population growth and modernization of current underground infrastructure.

“Infrastructure Constructions is always striving to find more productive and cost effective ways of using HDD to benefit the customer,” Brown says. “Over the last 12 months, we have successfully completed a number of projects using HDD where trenchless technology originally wasn’t even considered.”