Horizontal Directional Drilling (HDD) has revolutionized the underground utility installation industry. Today, HDD is a recognized and often preferred method for installing all types of underground utilities such as water, sewer, gas, electric, and telephone. HDD is also well-suited for installing environmental remediation wells.
HDD is a process by which it is possible to install utilities underground with minimal disruption to the ground surface. This is accomplished by making a pilot bore into the ground at an angle and then leveling out at a specified depth. Once the proper depth has been reached, it is then possible to advance the pilot bore horizontally to a destination point where the drill is redirected so it exits the ground.
Directional drilling machines (also referred to as drill rigs, boring machines, or drills) are available in many sizes. Regardless of the size, they all have three main functions: rotation, forward thrust, and pullback. The industry-wide standard for rating the size of a machine is the total pounds of pullback capability. However, more emphasis is being placed on the rotational torque rating of machines. Directional drilling machines can also be split into two other categories: self-contained or remote units.
A self-contained unit refers to a machine that has the power unit, drill pipe, and rack on board. A remote unit consists of a power unit that is attached permanently to a truck bed, trailer, or is skid-mounted and has hydraulic hoses running to the drill rack. Self-contained machines are quite popular because of the reduced setup time and because the extra weight helps to hold the machine in place. However, the reduced weight of remote units coupled with a smaller physical footprint makes them a good choice for residential areas or areas with limited access for machine placement. Regardless of the size or style of the machine, they all have the same basic nomenclature. As you can see, the difference between the two styles is only in the configuration of the units.
Horizontal Directional Drill
Directional boring, commonly called horizontal directional drilling or HDD, is a steerable trenchless method of installing underground pipe, conduit, or cable in a shallow arc along a prescribed bore path by using a surface-launched drilling rig, with minimal impact on the surrounding area. Directional boring is used when trenching or excavating is not practical. It is suitable for a variety of soil conditions and jobs including road, landscape and river crossings.
Digital Locating System
The Digital Locating System is used during horizontal directional drilling operations to locate and track a transmitter installed in the drill head. You can use your existing System remote, MFD(Multi-Function Display) remote, or FSD (F Series Display) remote to view the transmitter data at the drill rig. The system consists of a handheld receiver, a transmitter, a battery charger system, and two rechargeable nickel-metal hydride (NiMH) battery packs used for powering the receiver.
Locating is streamlined using the receiver’s graphic display and menu system. The real-time graphics guide you in positioning a target in a box on the display window to help locate the transmitter.
Overview of Digital Locating System
The Digital Locating system provides the best in affordable horizontal directional drilling locating. Advanced technology and intuitive, icon-driven menus provide a level of productivity unmatched in the industry. In addition to the basic locating features of directional tracking and depth, the SE includes the advanced features of predicted depth, off-track locating when direct walkover is impossible, and left/right remote steering to navigate the drill head easily even when obstacles prevent walkover tracking. Roll offset allows the transmitter’s 12 clock positions to be electronically compensated to match that of the drill head. An update meter on the SE shows the data transfer rate, which clearly shows when you are in an area of interference or reaching the range limit of the transmitter.
Directional boring is used for installing infrastructure such as telecommunications and power cable conduits, water lines, sewer lines, gas lines, oil lines, product pipelines, and environmental remediation casings. It is used for crossing waterways, roadways, shore approaches, congested areas, environmentally sensitive areas, and areas where other methods are costlier or not possible. It is used instead of other techniques to provide less traffic disruption, lower cost, deeper and/or longer installation, no access pit, shorter completion times, directional capabilities, and environmental safety.
The technique has extensive use in urban areas for developing subsurface utilities as it helps in avoiding extensive open cut trenches. The use requires that the operator have complete information about existing utilities so that he can plan the alignment to avoid damaging those utilities. Since uncontrolled drilling can lead to damage, different agencies/government authorities owning the urban right-of-way or the utilities have rules for safe work execution. For standardization of the techniques, different trenchless technology promoting organizations have developed guidelines for this technique.
RTLS are generally used in indoor and/or confined areas, such as buildings, and do not provide global coverage like GPS. RTLS tags are affixed to mobile items to be tracked or managed. RTLS reference points, which can be either transmitters or receivers, are spaced throughout a building (or similar area of interest) to provide the desired tag coverage. In most cases, the more RTLS reference points that are installed, the better the location accuracy, until the technology limitations are reached.
A number of disparate system designs are all referred to as “real-time locating systems”, but there are two primary system design elements: