The good news is that despite some rocky going lately, the horizontal-directional-drill (HDD) business is still viable, although not in areas that once showed the greatest promise. A couple of years ago, it looked as if the telecommunications market would take just about all of the HDDs being produced. But with the decline of the big telecoms, that HDD business took a big dip.
Contractors who had staked their claim on the future of the telecom business lost out. Today, the market points to used HDDs, and that market is doing well. According to the 2003 Universe of Construction Equipment study conducted by Construction Equipment, the number of HDDs acquired new has decreased from 86 percent in 1999 to 67 percent in 2003.
But while the telecom segment of the market has diminished, other areas such as cable installation and utilities work remain viable. And the use of HDDs to install underground lines remains the best and most efficient way to go. The benefits of HDD installation stay unchanged. When it comes to underground installation in areas where ground surfaces can't be disturbed, the HDD remains the choice. When accuracy over longer distances is required, the nod goes to the HDD.
In this story, we'll be focusing on HDDs with a thrust/pullback of more than 20,000 pounds. This represents 38 percent of the total number of HDDs in operation, according to Construction Equipment's Universe Study. Of this number, 29 percent fall into the 20,000- to 50,000-pound category. The largest HDDs, running up to several hundred thousand pounds in thrust/pullback generally are owned, and often designed, by companies that specialize in work requiring these size machines.
A look at some of the newest HDDs shows that despite slack sales, manufacturers are not neglecting advancements in design and operation. For example, Vermeer's two newest machines, the D100×120 Navigator and the D200×300 Navigator, account for a number of important features. The D100×120, with 100,000 pounds of pullback, also has 12,000 ft.-lb. of rotational torque—a combination, says Vermeer, that results in easier, more efficient handling of larger products. In addition, the drill is designed to produce high mud flow. This is accomplished using a 200-gpm on-board pump for increased backreaming efficiency and powering downhole mud motors.
Where once HDDs were difficult to operate, refinements have greatly eased the job. Case in point: the operator's station on the D100×120. At the operator's station, an adjustable swivel, toggle switches with breakout system, fluid pump, radio and throttle switches are all within easy reach. Strategically placed between the operator and the bore path, drilling pressure gauges, a flow meter and a drilling fluid pump monitor the bore. Also featured is a Remote Lockout System, a two-way communication and control tool that allows workers to lock out the drill stem rotation, thrust and fluid flow along the bore path or at the exit site.
The larger D200×300, with 200,000 pounds of thrust/pullback, has many of the same features as the D100×120, but also has a two-man enclosed operator's station from where virtually all functions are controlled. It also has an attached crane to handle drill stem up to 32 feet long and upset diameters up to 10 inches.
Among the latest models in Ditch Witch's HDD line is the JT4020, which comes in two versions: Mach 1 and All Terrain. With 40,000 pounds of pullback, the unit is packed with electronics that handle many of the HDDs functions. A cruise-control feature maintains desired thrust, pullback and rotation speed. And a single-lever control allows for precise drilling and backreaming adjustments. In addition, the automated pipeloader consists of hydraulic pipe grippers, single pipe loading, hydraulic shuttle stop, and automated thread lubrication. A high drilling fluid flow is achieved with an on-board pump that enables productive drilling at extended distances. Normal flow rate can be operated simultaneously with thrust/pullback and rotation.
The JT4020 All-Terrain version is designed to take virtually all types of conditions, including the ability to drill through rock, cobblestone, broken rock, gravel, and soil/rock mixes. The system uses an outer pipe for steering and backreaming, and an inner pipe for mechanically powering the bit during the pilot bore. The HDD remains secure in all types of ground conditions, thanks to a hydraulic four-point anchor system. As with the Mach 1, the All Terrain has an adjustable drill frame that can be set up at normal drilling angles without raising the tracks off the ground.
Also available in a Mach 1 and an All Terrain version is the JT2720. It has an on-board processor that controls the ground drive and pipeloader, as well as all drilling functions. This processor also works to increase productivity with a diagnostics feature that automatically monitors and troubleshoots the system. Also included is the cruise-control feature found on the larger JT4020. The JT2720 has a pullback of 27,000 pounds and a thrust of 24,800 pounds.
TT Technologies' solution to drilling through rocky soils is the Grundodrill 15x c. In addition to the typical thrust and rotation applied to the drill, the Grundodrill also applies a percussive action. According to TT Technologies, this percussive action lets the 15x c take on jobs that usually are reserved for larger machines. With 33,000 pounds of thrust and pullback, the 15x c has an on-demand percussive force that provides the dynamic energy needed to steer in difficult and rocky soils.
Astec Industries, which purchased American Augers and also markets Case HDDs as well as three machines under the Astec name, offers a number of machines in a wide size range through its Astec Underground Group. Case's offering in the 20,000-pound-pullback-and-up range is the 6030 Turbo. The machine features Case's Duplex Drive System, a chain-drive system that Case says reduces load on key drive components by more than 50 percent compared to competitive HDDs. The system also provides smooth operation and fine controllability of the drill head. Maintenance demands are also reduced, because there are no cylinders. The system's components can be easily accessed for routine service and adjustment.
An optional Load Management and Control System controls thrust speed to manage engine load and automatically assists the operator to maintain maximum system performance. The 6030 Turbo has a two-speed thrust/pullback of 30,000 pounds.
Larger HDDs from American Augers range from the DD-6, with a thrust/pullback of 60,000 pounds, to the massive DD-Million Eighty, which develops 1.08 million pounds of thrust/pullback. This HDD is powered by two Cat engines, providing a total of 1,500 horsepower. This maxi-rig also served to introduce American's new control panel, now available on mid-range as well as maxi-rigs. The new low-profile panel gives the operator a better view of the drill stem as it is being put into the ground. In addition, the illuminated gauges for pressure, thrust, and pullback have been enlarged for easier viewing at the top of the new panel. The updated panel also includes new cabling and connectors throughout and more durable labeling. The operator's controls have friction-hold settings built in so that the operator can set desired levels for speed, rotation and thrust/pullback without having to physically hold them in position. As with previous models of this control panel, drilling-fluid-system controls, if used, may be integrated directly into the panel or attached afterward if desired.
Others with HDDs in the mid- to maxi-size range include StraightLine, Robbins and Barbco. StraightLine, which was one of the first companies to produce HDDs, has the model 2462, with 24,000 pounds thrust and pullback. The drill string has been lowered to the same plane as the pull down chains, providing more stable platform and transforming power more effectively into the ground. The Auto Drill feature allows the rotation/pullback speeds and mud flow to be precisely set for "hands-free" drilling.
Robbins, long known for its large tunneling equipment, now has the HDDs previously sold under the Contractors Manufacturing Services name. The new group is known as Robbins HDD. In the lineup are a number of machines ranging from the 3010TMSC with 32,800 pounds pullback up to the 55030TLMSC at 550,000 pounds pullback. The 3010TMSC can drill up to 1,200 feet in soft soil or rock. The fully self-contained unit has a rack-and-pinion carriage travel system with fast two-speed carriage travel. The maxi HDDs start with the 18030TMSC at 180,000 pounds pullback and range up to the 55030TLMSC.
Barbco offers three HDD models ranging up to 110,000 pounds pullback. This machine, the BD110-20SC, is powered by a 275-hp John Deere engine. The rod-loading system is available with an automatic rod loader or a crane with a rod handler. The operator's station is enclosed in a heated and air-conditioned cab.
|Basic Specifications: HDDs (Over 20,000 pounds of pullback)|
|Manufacturer/Model||Maximum Pullback (lbs.)||Maximum Thrust (lbs.)||Max. Rotational Torque (lb.-ft.)||Mounting||Gross Engine Power (hp)||Operating Weight (lbs.)|
|Specifications shown here are based on information provided by manufacturers and Spec Check and are given here for comparison only. Specifications are subject to change and manufacturers or their distributors should be contacted for the most current information.|
|JT2720 All Terrain||27,000||16,500||2,700||Track||125||19,850|
|JT2720 Mach 1||27,000||24,800||3,200||Track||125||20,320|
|JT4020 All Terrain||40,000||36,000||5,000||Track||185||22,380|
|JT4020 Mach 1||40,000||36,000||5,000||Track||185||27,500|
|JT7020 Mach 1||70,000||70,000||10,000||Track||261||42,600|
|Grundodrill 12 G||26,977||26,977||2,655||Track||86||—|
|Grundodrill 20 S||44,962||44,962||7,380||Track||160||—|