Horizontal directional drilling (HDD) is a trenchless technology that allows for services such as pipelines, sewer pipes, optic fibre lines, and powerlines to be installed below the surface without the need to dig a trench. This is particularly beneficial to environmentally sensitive areas, like forests and rivers. HDD projects are also perfect for urban areas, which are typically congested and tight with a lot of people and traffic. 

What is the HDD pipe installation process?


We’ll be quick here, but we think it’s important to know the process before describing the benefits of HDD. The HDD process is fairly complicated, but can be summed up in a three-step process. 

  1. To begin with, a pilot bore is drilled at an angle into the ground. Using a guiding system the drillers steer the drill head through the ground material until it reaches its destination. Once there, the drill head sticks out of the ground. 
  2. The next step is the reaming process, which requires a reamer to drill a larger diameter hole. This cleans out the hole and makes it larger, making it easier for the pipe to be fed through. 
  3. Lastly, the pipe is attached to the drill string at the exit location, and the drilling rig pulls it back through the ground until it’s correctly in position for whatever service needs to be there.  


Using HDD in an open environment vs an urban environment


There isn’t so much of a difference between horizontal directional drilling in an urban environment compared to an open environment. The job is still the same, a trenchless method of pipeline installation made by boring a hole through the ground. 

The difference is in the working space. If the surrounding area is open there is more room and space for larger drilling rigs. Whereas, in an urban environment, the working space is a lot more restricted, due to surrounding buildings, walkways, roads, etc. This means that drillers have to employ smaller drilling equipment, such as a smaller drilling rig, and shorter drill string lengths. It still all functions the same way, but makes the drilling process more fiddly and slower.

What are the benefits of HDD in an urban environment?


Directional boring is a great method for installing underground pipes and services, as it doesn’t affect the area above. HDD pipe installation projects are used for digging under transportation routes, such as roads and railways. Traditional pipeline installation requires a trench to be dug, which can severely disrupt and damage a road, causing delays and longer construction times.

Smaller footprint

As mentioned before, HDD pipe installations take up a small surface area, meaning that congested places such as roads and pathways, won’t have to deal with a large construction site.

Less reinstatement

When trenching for service and pipe installation, workers have to reinstate the hole. Meaning they have to refill the trench and compact it down, as well as repair the damage done to the road and pathway they were working on. The problem is that compacted fill settles when it rains and gets driven over, resulting in a shallow trench. This is especially bad for roads, as it can cause potholes.   

With horizontal directional drilling, the bore path is entirely underground meaning that once the pipe is installed the material on the surface won’t settle down and make a shallow trench. 

Faster installation time

Even with the smaller drilling equipment, directional boring is faster for installing pipe material. Trenching requires the surface area to be broken up and dug away, which needs to be done with machinery through roads and pathways. Then the pipeline needs to be installed and the trench filled in. Next, any roads or paths need to be repaired and fixed by workers who know how. This requires many people and plenty of time to get done. 

HDD projects typically require fewer workers, and the installation time is almost instant once the borehole is finished. HDD technology saves time and money, all while causing less disruption on the surface. 

Something to consider when using HDD 


Before starting an HDD project, it is crucial to do service locating. Any jobs that are below ground have to be located, especially in an urban environment. It is potentially dangerous and expensive to break any existing underground pipes and services. So, before work begins a locator needs to identify and mark out exactly where everything is. In some cases, potholing is done to locate the services. This isn’t an issue exclusive to horizontal drilling, as even trenching requires the same locating work. 

Explore our range of HDD equipment


Vermeer Equipment of WA & NT is a market leader in providing the best HDD equipment. If you’re after a horizontal directional drill with a small footprint, we have the VERMEER D8X12, which is a rideable rig that can fit in small locations like alleyways or the edge of the road. This is just one of the many horizontal drills we offer at Vermeer Equipment of WA & NT. Explore our full range in store or online, and for any queries call us on (08) 9479 4994

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