Compact Directional Drilling
May 1, 2006
The market for compact directional drills continues to expand. With a surge of last-mile projects, as well as street-to-home sewer, water and gas projects, compact directional drills are getting a lot of attention from a wide variety of contractors. Badger State Plumbing, Menomonee Falls, Wis., is a good example of a specialized underground contractor taking advantage of what the latest generation of compact directional drilling rigs has to offer.
Badger State Plumbing president Jeff Proell says, “Directional drilling offers our company a new level of capability and efficiency. It is a great tool for our service offering.”
Badger State Plumbing has been specializing in the installation and repair of water and sewer services, laterals and mains since 1965. In addition to directional drilling, the eight-person company also offers excavating, horizontal boring and pipe bursting services. For the recent installation of an 85-foot water service in the city of Milwaukee, Proell chose the Grundodrill 4X from trenchless equipment manufacturer TT Technologies, Aurora, Ill.
Compact CapabilitiesWith some compact drills offering as much as 9,800 pounds of thrust and pullback, the machines are able to accomplish a wide range of installation tasks. At Badger State Plumbing, the Grundodrill 4X is being used to install water mains and sewer laterals, as well as various services, up to 6 inches in diameter.
According to TT Technologies directional drilling specialist Bill Brennan, the use of compact directional drilling units has increased dramatically. He says, “I think a lot of it has to do with a change in perception about directional drilling. Big jobs, big crossings and large pipe diameters got a lot of attention during the early days of directional drilling. But eventually your local contractors started wondering, 'What about us? What can HDD do for us?' The development of compact, portable and powerful HDD rigs has answered the question and made the method accessible to a wide range of small and medium sized contractors.”
According to Proell, the unit's size and power makes it ideal for his territory. He explains, “Within the Milwaukee area, we can encounter any number of soil conditions. And when dealing with services and laterals, you're always running into tight working spaces. Having the power to overcome the tougher soils, while still being able to operate in tight working conditions is a huge advantage for us.”
Brennan notes, “These mini-drills work well in residential or commercial areas. They're lightweight. They can be transported on a trailer pulled by a pick-up truck, and require minimal crews to operate. The 4X's special steel track with bonded rubber pads offers excellent traction and durability while minimizing potential damage to concrete and turf, which is important in residential settings.
“Plus the units are very easy to operate. The computerized Smart Vice system simplifies the drilling process by automating the drill's vice cycling operations. The operator has single push-button control of the function. That helps improve efficiency and speeds up drill times. The vice also is self-centering, reducing wear and tear. The operator can return to manual control with the flip of a switch. The whole system is very user-friendly.”
Proell agrees, saying, “So far, our crews love it. We also use piercing tools and they work fine, but not having to pull the hose in by hand … the drill does all the work. Plus, the crews have been able to adjust to the machine quickly. We have a good deal of boring experience with other types of equipment, so it was just a matter of applying that knowledge to this method. We caught on pretty quickly.”
Drilling in BadgerlandMany of Proell's recent projects have been new installations for new construction. He concedes, however, that most of his future work with the compact HDD rigs will be dealing with deteriorating infrastructure. He says, “We recently installed a 160-foot sewer lateral for a new home on the south side of Milwaukee that came out right on the money. But most of the work down the road will be replacing old lines. We've got a big problem in the Milwaukee area with our copper lines. They call it aggressive water. We have copper lines ranging in age from 3 years to 15 years old that are completely rotting out.”
According to Proell, soil conditions can vary greatly in the Milwaukee area, but hard clay is predominant and can make any kind of underground work challenging. He says, “We're able to improve our efficiency dramatically with the compact directional drill. With the hard soils we have around here, other construction methods can take hours. But, when you add water and bentonite to that drill, there's no comparison. You can get done in a half hour what would take you all day with other tools.”
On the JobFor the recent water service installation project in Milwaukee, Badger State Plumbing was contracted to install an 85-foot, 11⁄4-inch copper water service. Proell explains, “The project was done for a development company. They were in the process of renovating one of their properties - a duplex with a parking garage. The new plan required that the water meter move from the front of the parking garage to a utility room at the rear of the building. Because of the state of the construction and the location of the project, an open trench application would have been extremely difficult and time-consuming. Compact directional drilling was the method of choice.”
The Badger crew also faced obstacles underground. According to Proell, when the existing structure was torn down and replaced by the duplex and parking garage, the old concrete footings were abandoned. In order to facilitate the new water service line, the Badger crew would have to drill through those footings. In addition, the crew faced rock-hard clay soils that made the project even more challenging.
Because of the tight working conditions, the crew decided to position the compact rig inside of the parking garage and drill out to the water main located on the edge of the street. The crew then dug a pit at the water main in the street to facilitate the pullback of the new 11⁄4-inch copper service. After locating existing utilities, the crew was ready to begin drilling. The 3-inch pilot bore was completed without difficulty despite having to overcome the abandoned concrete footings. No bentonite was required for the drilling operation. Once at the pit, the Badger State Plumbing crew attached a swivel to the drill head and made the connection to the new copper product pipe and began pullback. From start to finish, the entire project was completed within two hours.