Decko is recognized as East Africa’s industry-leader in Horizontal Directional Drilling (HDD), providing solutions for all our client’s horizontal directional drilling needs.
Boasting capabilities to complete crossings of up to 10-inch pipe with continuous lengths of over sixty feet. Whether the crossing is in soft soils or the hardest rock, a sensitive water body, crossing a major highway we manage each project with the proper equipment and planning to get the job done.
Our clients in East Africa include; Ericsson, Safaricom, Huawei, MTN, KIWASCO to name a few and we have successfully completed over 50kms of HDD and counting.
Continuously investing in new technologies and staying abreast of the latest techniques, Decko has remained on the leading edge of the HDD industry. Whether utilizing the intersect method, guiding the bore with gyroscopic technology or completing water-to-water crossings, we strive to bring the best the industry has to offer.
- Auger Boring, Pipe Ramming & Tunneling
- Guided Boring
The Guided Boring method installs small diameter pipes with grade and alignment precision. The pipe installation involves a three-step process where launch and reception shafts are strategically located to minimize surface disruption.
A pilot tube is then drilled at the precise grade and alignment as specified in contracts. Thirdly the pilot tube is used as a guide to install the casing at desired diameter.
GBMs are used in conjunction with a theodolite guidance system to provide accurate pipe installation. Our GBM is extremely versatile and our customers continually surprise us with new applications. For installation from 4" OD and larger in displaceable soil.
- Horizontal Augering
Horizontal Augering equipment is utilized for larger pipe diameters of 16-inch pipe and larger. In unison with our disc cutter heads, Horizontal Augering is also used for boring through solid rock for pipe diameters of 24 inches and more.
Our Horizontal Augering machines are frequently employed in cleaning out casings and culverts where dirt or other obstructions are restricting or blocking flow.
- Pneumatic pipe ramming
Pipe Ramming is used in a wide variety of soil types including gravel, cobble or sand. A pneumatic hammer is attached to the back of the product pipe and driven in any direction from horizontal to vertical through material.
The material is cleaned out of the pipe using one of several methods, determined by material content. Pipe Ramming methods are used for pipe diameters of 12 inches and larger and are also used for vertical installations such as large diameter piling or conductor barrels for drilling applications.
- Downhole hammers
Downhole hammers are utilized to install casing into any ground formation form till to the hardest rock. Combination of air and pneumatic compression in front of augering flights to remove spoils.
- Tunnel Boring / Pipe Jacking
Tunnel Boring and Pipejacking Systems are used to hydraulically install underground pipelines within strict alignment and grade tolerances for installation of pipe up to 168" OD range. Wheel machines are equipped with various cutter heads and sand shelves. A closed face attachment is available for boring in unstable ground conditions.
System contains a hydraulic power unit, skid base sections and a thrust yoke to evenly distribute the jacking forces to the pipe string. This versatile system easily adapts to any jacking pipe in any pipe joint length and a wide range of pipe diameters.
- Horizontal Directional Boring
Decko horizontal directional boring machines are the most versatile and powerful setup available. With a pullback force of 235,000 lbs and a thrust of 118,000 lbs We have the ability to thrust through adverse conditions including shale and sandstone and ream back through with plugs up to 20 inches in diameter and in excess of 30 meters in length. The equipment's tracking system utilizes the latest technology with accuracy in depth of five centimeters and accuracy in grade of 0.5 percent.
- Pipe Bursting
Pipe bursting can be used to replace pipe of equal or greater size without using open trench methods. Pipe bursting is accomplished by pulling a bursting device through the existing pipe.
This device, by virtue of its size or its radial expansion ability (depending on the type), shatters or splits the old pipe and forces the fragments or the old pipe wall into the surrounding soil.
The new pipe is typically attached to the bursting device and is thereby pulled into place as the device advances. Pipe bursting methods can be used to replace old pipe made of clay tile, concrete, cast iron, pvc, steel, or similar materials.
- Tunnel Boring Machines (TBMs)
TBMs are used to excavate tunnels with a circular cross section through a variety of soil and rock strata. They can bore through hard rock, sand, and almost anything in between. Tunnel diameters can range from a metre and exceed 15 metres.
- Microtunneling Boring Machines (MTBMs)
A method used to construct small diameter tunnels. The small diameter requires the equipment to be operated remotely. The operator is given constant feedback about the machine's location, orientation and hydraulic devices via a computer console.
The operator can control the MTBM and the jacking frame from the safety of the control room.
- Pressurised Tunnel Bore Machines (PTBs)
A method of tunnel construction in which allows the pressure at the face of the TBM to remain balanced with the use of slurry or air pressure. This allows unstable ground conditions (ground water, unconsolidated formations) to be tunneled.
- Tunnel Lubrication Systems
Bentonite and polymer mud products are injected into the annulus between the product line and the geological formation to reduce friction forces.
- Shotcrete Equipment
Shotcrete is concrete conveyed through a hose and pneumatically projected at high velocity onto a surface, as a construction technique. Shotcrete undergoes placement and compaction at the same time due to the force with which it is projected from the nozzle. It can be impacted onto any type or shape of surface, including vertical or overhead areas. Deckouses shotcrete during the construction of our entry and exit shafts.
- Tunnel Grouting Systems
Grouting systems are used to fill voids between the geological formation and installed product line or between product lines, one inside of the other. There are several reasons for grouting which include but are not limited to adding structural integrity and heat dissipation.
- Horizontal Directional Geotechnical (HDG) Services
With a vision of finding a better way of reducing costs and of predicting project durations; Decko has developed a unique geotechnical process (patent pending). This process can determine the soil conditions of any given project while simultaneously completing the pilot hole phase. This process, known as Horizontal Directional Geotechnical (HDG), allows the owner to reduce project costs by shifting the pilot hole phase into the planning and feasibility phase of a project.
Decko has geologists analyzing received samples and data to determine the specific conditions. We use this data and the information collected during the investigation, along with real-time drilling performance, to make adjustments to the pilot hole path.
The contractor will then be able to assess the data and select the proper downhole equipment to complete the reaming and pull phases. The HDG process can be completed with a smaller rig and labor force than would typically be used during the pilot hole phase, further reducing cost.
Included in this service is the ability to recover rock cores from the bore hole which allows the contractor to procure the exact type of reamer needed for their specific project.