Horizontal Directional Drilling

“No Dig, It’s Boring”

HDD is one of the most versatile trenchless technologies used for the installation of many product lines, including service connections and pipes and cables under roads and reinforced concrete, various watercourses and water-logged terrain, environmentally sensitive areas, banks, hills, mounds, sites with Tree Protection Orders and Sites of Special Scientific Interest. In the simplest of terms, an HDD rig will ‘drill’ a guided pilot bore, from which the ‘hole in the ground’ can be enlarged if required to permit the installation of a larger sized pipe or cable, with a process known as reaming. Horizontal Directional Drilling, using surface and pit launch machines allows us to perform trenchless shots over 300+m, pulling pipe and ducts in excess of 710mm . Boring through soft rock and non-reinforced concrete, new connections can be made on grade, directly from the point of connection to any desired location. In suitable geological formations the bore is precisely guided within 5cm+/- accuracy, allowing us to follow bends in roads or avoid obstacles in order to hit targets. We can launch through any angle between 0-90 degrees vertically and at 360 degrees laterally on grade, below or between any known utilities or infrastructure. This technique is ideal for the installation of small to medium diameter single or multi pipes and ducts on a straight or curved alignment. It is used extensively by the gas, water, telecoms and electricity industries.

Advantages of Horizontal Directional Drilling

Quick, efficient and therefore cost effective. No disruption to the surface infrastructure or services. Unaffected by surface obstacles. Cost effective and time saving alternative to open cut methods when installing pipes amidst extensive underground infrastructure, or at significant depths. Relatively small overall footprint. Pipework and cables can be installed in either a straight or curved alignment to help avoid underground complications and services. HDD minimises the need for deep excavations. Can be used for gravity gradient installations, where the required grade and ground conditions allow. Reduced requirement for road closure notices / restricted working hours / premium rate working.

Surface Launch HDD

Installation rates: Can be in excess of 200 metres per day, dependent on required pipeline diameter and ground conditions.

Accuracy: +/- 50mm ground dependent

Depth: Up to 8 Metres

Pit Launched HDD

Used specifically for the trenchless installation of service lines in confined and congested working locations, where traditional open cut or unguided surface launched drilling is not suitable.

Working from small excavations, services up to 315mm in diameter can be installed over relatively short distances. Essentially, the plant and equipment is simply a scaled down version of a surface mounted Horizontal Directional Drilling (HDD) rig and adopts the same principles and processes.

The Pit Launch machine measures just 2100mm long by just 600mm wide, which keeps surface disturbance to an absolute minimum where excavation is required. This technique is particularly popular in urban areas where space is at a premium.

Distances: Bore lengths up to 100 metres.

Installation rates: Up to 100 metres per day, dependent on required diameter and ground conditions.

Accuracy: +/- 50mm ground dependent

Depth: Up to 8 Metres

Rock Drill HDD

This technique enables non-displacement boring into solid rock, gravels, cobbles and boulders. With diameters ranging upwards from 100mm available, this method is suitable for the installation of steel and polyethylene pipes.

We have the ability to deploy air hammers or mud-motors depending on the required bore length, hole diameter and strength of the formation the bore will be in.

Distances: Pipe lengths up to 300 metres.

Installation rates: Comparative to traditional open trenching, dependent on the required diameter and ground conditions.

Depth: Up to 8 Metres

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