Three components make up this critically important tool
On the job, it may look like a beefed-up metal detector and strike you as something of minimal importance to a horizontal directional drilling (HDD) operation. But an HDD locating system is a key component of a precise, effective and efficient HDD job.
Employing an HDD locator system, like the DCI® models commonly used with many Vermeer HDD systems, is part of a well-thought-out job. Bore planning — which includes accounting for the specific terrain in which you’ll be working and how you’ll sustain the necessary pitch to reach your goal — is one of the first steps to getting the job done right. Once you’ve planned out where you’ll be drilling and the pitch you must maintain to avoid any cross bores or other issues during operation, that’s when an HDD locator enters the equation, according to Vermeer HDD Customer Training Lead Tim Poyzer.
The DCI DigiTrak® Aurora® display like the Digitrak FalconF5® used with Vermeer HDD systems comprise three components:
- Transmitter. This is located in the drill head. Usually around 15 inches (38.1 cm) in length and with a diameter of 1-½ inches (3.81 cm), the transmitter collects and relays two major pieces of information during operation: data strength and signal strength. The two make up the clock position of the drill bit — the direction the bit is pointing — and its depth in the bore. Most transmitters can track signal strength up to 150 feet (45.7 m) into a bore. The DCI Falcon F5 transmitter, for example, can be programmed to hundreds of frequency combinations to help you accurately monitor and transmit the right data on every job.
- Receiver. This is the handheld unit that receives data from the transmitter in the drill head. The operator — sometimes referred to as the locator — on the surface holds the unit near where he or she anticipates the drill head will be located in the bore.
- Aurora display. This is the monitor on the HDD drill itself to which the receiver relays data it collects from the transmitter. It gives the drill operator the ability to see the location and orientation of the drill head as it relates to the job’s bore plan. This information enables the operator to make any adjustments to the pitch, direction or depth of the drill head to help it follow that plan.
Taken together, these components make up not just a way to stay informed about the drill head’s specific location, but also guidance to help the operator make the right decisions during operation to precisely follow the right bore path. DCI systems use Ball-in-the-Box™ guidance technology to locate not just the drill head, but its expected path based on pitch and position in the ground. The system creates a visual interface for the receiver operator, enabling them to guide the HDD operator’s adjustments to keep the drill head on the right bore path.
“When you look at a receiver screen, 3/4 of it is broken up into four squares in a crosshair. The center of the crosshair is a bird’s-eye view of the locator. A small box in the middle of the crosshairs visually represents the receiver, and I should always have a ‘ball’ on the screen. It could be in any of those four quadrants, and it indicates the direction the drill needs to travel to stay on the planned bore. If the ball is on the right side of the grid, I need to move right to get that ball in the middle of the box,” Poyzer said. “Before this technology, overhead locating was pretty complicated, but with this Ball-in-the-Box system, I know the direction I need to move to keep that ball in the center of the screen and keep me in the bore.”
As the receiver operator tracks the bore’s path by keeping the ball in the box, that data is relayed to the HDD operator, who’s monitoring progress on an Aurora display. The path is also typically marked on the ground’s surface; three locate points are marked with spray paint (usually for each rod) on the ground to provide an additional visual guide to help the HDD machine follow the pre-planned bore path. Once in the optimal location, the operator pulls a trigger on the receiver to mark the optimal central locate point and confirm the depth of the drill head.
“Once I’ve got that ball in the box, I’m going to use a can of paint and mark the line. We correlate these to the points on a plane. The front locate point is the nose of the plane. Then I’ll walk backward and I’ll watch the ball go away in the top, and when it enters through the bottom of the monitor, I’m at the tail of my plane. Once I have those points, I’m going to walk between them; a horizontal line will come up on the screen and I’ll stop when I get that line parallel or right over the top of my crosshairs. That line represents the wings or center of the plane. That is the best place to press the trigger,” Poyzer explained. “Pressing the trigger will tell me the depth of my drill head. If I don’t find that front and rear locate point all the time, I may be losing the ability to measure my depth. With this system, I can locate that line every time and just click the trigger and see my depth.”
This data is important to not only checking that the HDD operator is following the desired bore path, but also facilitates quick decisions to adjust the drill head’s pitch and angle to remain on that path. The DCI system shows operational data in real time, but it takes strong teamwork between drill and receiver operators to allow the system to do its job.
“The front locate point of one rod will basically start becoming the rear locate for the next rod, so you may not always have to mark both the front and rear lines. But especially for new operators, they want to be certain they understand the importance of front and rear locate points. It’s so important to an HDD operation,” Poyzer said. “It’s a best practice to locate all three using a locator like the DCI systems. It all starts with walking the bore path, creating a good bore plan and being proactive in collecting the right data through the length of the entire bore.”
Vermeer Corporation reserves the right to make changes in product engineering, design and specifications; add improvements; or discontinue manufacturing or distribution at any time without notice or obligation. Equipment shown is for illustrative purposes only and may display optional accessories or components specific to their global region.
Vermeer and the Vermeer logo are trademarks of Vermeer Manufacturing Company in the U.S. and/or other countries. DCI, DigiTrak, Aurora, FalconF5 and Ball-in-the-Box are trademarks of Digital Control Incorporated.