Boring vs. Drilling: What to Know
Jack and bore and directional drilling are trenchless techniques used to install underground utilities such as pipelines, cables and conduits. These technologies circumvent the need for disruptive excavation and, by minimizing surface disruption and reducing environmental impact, have helped revolutionize underground utility installation and repair.
Both jack and bore and directional drilling are invaluable techniques in trenchless technology, each with their own strengths and limitations. The choice between the two depends on the specific requirements of the project, such as distance and soil condition.
The Jack and Bore Method
The Jack and bore underground utility installation method involves installing a pipe or other utility casing horizontally under the ground from a launch pit to a receiving pit. The term "jack" refers to pushing the pipe into place, while "bore" refers to the digging – often done a with large auger – that creates the tunnel. This method is also known in the industry as horizontal auger boring or auger boring.
Why Contractors Choose Jack and Bore
Contractors choose the jack and bore installation method for its high level of accuracy, especially in stable soils. But it can still perform well in rocky terrain. The equipment and jack and bore process are relatively straightforward, making it a reliable choice for projects where conditions are well understood. However, the method is best suited for short to medium distances ranging from 50 to 300 feet. Longer distances would require multiple setups, increasing cost and time. Additionally, the need for launch and receiving pits means that some surface excavation is necessary, which could be a drawback in highly developed areas or sensitive environments.
The Directional Drilling Method
Directional drilling, also referred to as directional boring, allows for the installation of pipes or cables at varying depths and angles. In comparison, the jack and bore method only allows for horizontal installation. In directional drilling, operators drill a hole, known as a pilot hole, to create the underground cavity. Once the pilot hole is completed, it’s enlarged using a reamer, and the utility pipe is pulled through the enlarged hole with a directional drilling rig.
Like jack and bore, direction drilling is a trenchless solution for situations where open trenching would be disruptive, such as when utilities must cross highways, railways, or bodies of water. However, because directional drilling allows for installation at varying angles and depths, this method is often used over long distances and in areas where utilities must maneuver challenging terrain.
Why Contractors Rely on Directional Drilling
Contractors choose directional drilling when utilities must be installed for a long distance or at multiple angles. The ability to steer the drill allows for complex paths, making it possible to navigate around underground obstacles such as existing utilities or natural barriers. This method can be used for deep installations, often reaching several hundred feet. Unlike jack and bore, directional drilling requires only small entry and exit points, significantly reducing surface disruption. This is beneficial in environmentally sensitive areas or urban settings.
Jack and Bore vs. Directional Drilling
Here's a quick overview for deciding which method is best when different factors are a concern:
- Distance – Directional drilling excels in projects requiring long-distance installations. Jack and bore is more suited for shorter distances.
- Precision – Both methods offer precision. Jack and bore is typically favored for projects where precise alignment is critical and directional drilling is chosen when utilities must navigate challenging terrain and complex paths.
- Surface disruption – Directional drilling causes minimal surface disruption, as it requires small, less complex pits, making it preferable in urban areas or environmentally sensitive sites. Jack and bore requires some surface excavation due to the need for larger pits.
- Soil conditions – Jack and bore can handle a wider range of soil conditions, including rocky terrain, whereas directional drilling may struggle in certain soils.
Utilize Trenchless Technology and Minimize Disruptions
When traditional trenching is out of the question, jack and bore and directional drilling can save the day.
By understanding the nuances of each trenchless utility installation method, engineers and project managers can select the most appropriate technique to ensure a successful, efficient and cost-effective installation.
At Castle Contracting, our experienced underground utility installation teams help project owners determine the best trenchless technology for their site. Contact Castle today to learn more about our trenching and utility installation services.
