Category Archives: Horizontal Directional Drilling

Zinc Ribbon Installation Projects

MATCOR provides a full range of AC Mitigation capabilities including AC Modeling and Design engineering services, supply of our proprietary Mitigator® engineered AC grounding system, and an entire construction services organization capable of a wide range of AC Mitigation installation services. Two current projects highlight our construction service capabilities with regards to AC Mitigation. The first project involves several miles of zinc ribbon installation for an AC mitigation system in a congested suburban and urban environment using horizontal directional drilling (HDD) equipment. The second application is in a highly rocky environment in West Texas that requires the use of specialized rock trenching technology for zinc ribbon installation.

Zinc Ribbon Installation Using HDD in a Congested Environment

Zinc Ribbon Installation - HDD
Figure 1 – Zinc ribbon being installed through HDD bore hole

This project in northwestern Ohio involved the zinc ribbon installation over several miles using one of MATCOR’s in-house horizontal directional drilling crews. The project required horizontal directional drilling to minimize surface disturbances due to the congested area.

With any typical AC Mitigation installation there are numerous precautions that must be taken to assure a safe installation. This starts with a thorough pre-construction safety review to develop the project site-specific health and safety plan. Each crew member participates in a daily safety meeting to review the day’s planned activities and address all safety concerns in advance of performing any work. Each crew member is required to have the appropriate operator qualifications and site-specific safety training as identified by MATCOR and the pipeline owner.

HDD Bore for Zinc Ribbon Installation
Figure 2 – HDD bore in process

Prior to any other construction activities, the first task is to perform a thorough line locating including potholing (excavation of the top of the pipe). This is to physically assure that the location of the pipeline(s) being mitigated is accurately marked to avoid any risks associated with construction activities in close proximity to the pipeline.

Once the pipeline has been physically located and properly flagged, each individual bore must be planned. The route of the bore is assessed prior to boring activities commencing. The bore planning includes:

  • Identifying entry and exit points
  • How the bore is to be tracked
  • Special precautions that might be needed to maintain the bore during the ribbon installations
  • How the cuttings will be captured, stored and removed
Texas AC Mitigation Installation
Figure 3 – Zinc Ribbon Bore – AC Mitigation design detail – note rail line to the South

As with any construction project, logistics and project management are key to the successful execution of the project. Working in conjunction with the owner and their designated project inspector to assure that the work is performed safely and in accordance with the AC Mitigation design requirements. For the project in Ohio, some additional complications included difficult weather conditions and working in close proximity to a railroad which requires additional permitting and coordination with the railroad. In some locations, traffic control was also required during the installation work.

Rocky Conditions in West Texas

Rock Trenching | AC Mitigation Installation
Figure 4 – Rock trenching in a difficult West Texas environment

Another project that MATCOR is currently completing involves the installation of approximately 15 miles of zinc ribbon in West Texas. The original installation plan called for the use of a cable plow to install the zinc ribbon mitigation wire; however, for large stretches of the installation, the rocky conditions forced MATCOR to switch from the planned cable plow to a high-powered rock trencher to cut through the difficult rocky terrain. This project illustrates the importance of using the right equipment to overcome difficult installation challenges. In some cases, being able to adapt to adverse conditions requires a change in construction methodologies and for this project, MATCOR’s ability to react and make equipment changes allowed the project to proceed on schedule with minimal customer impact.

This project also requires the use of HDD for one specific mitigation segment, as the pipeline traverses a cotton field which includes a buried drip irrigation system. The use of HDD is required to prevent any damage to the drip irrigation system during the AC Mitigation zinc ribbon installation. Coordinating the installation schedule around the cotton crop cultivation added another logistical challenge to the project.

Whatever your AC Mitigation challenge might be, MATCOR’s construction teams are able to work with our clients and their project needs to assure a safe and cost-effective installation project.


Have questions about zinc ribbon installation, or need a quote for AC mitigation materials or services? Contact us at the link below.

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Selecting the Correct Linear Anode for Horizontal Directional Drilling (HDD) Installation

As the world’s leading manufacturer of linear anodes, and the only manufacturer of a linear anode specifically designed for use with horizontal directional drilling installations, we thought it would be appropriate to discuss various anode options for HDD installation.

Can any linear anode be used in conjunction with horizontal directional drilling?

An engineer’s favorite answer to any question is “It depends” and this is certainly the case with HDD installations. The important thing to note is that when attempting to pull a linear anode through a bore hole, there is a chance that the pulling forces on the anode will exceed the strength of the anode and cause the anode to break. Even if the anode does not break completely, stretching of the anode can weaken or damage the internal header cable or anode to cable connections.

There are a lot of variables that can impact the success of any linear anode HDD installation. The short answer is yes, with the right bore hole, any linear anode can be pulled successfully. Conversely, with the wrong bore hole, any linear anode can be pulled apart during installation.

What are the key factors to consider when planning an HDD linear anode installation?

The key factors include a site geotechnical investigation, terrain and route mapping, and bore planning.

Site Geotechnical Investigation

Any discussion about HDD installation planning starts with a site geotechnical investigation. Obtaining a geotechnical survey or as much geological information about the respective jobsite is very important. A great amount of record information is available through sources including:

  • United States Geological Society (USGS)
  • National Geological Map Database
  • Publications of the US Army Corps of Engineers
  • Earth Explorer
  • The National Soil Survey Center (NSSC) a division of the US Department of Agriculture
  • State Departments of Transportation
  • Highway Administrations
  • Original construction records

In addition to record information, site-specific investigations (soil bores and soil sampling) by trained geologists and geotechnical service companies can provide valuable detailed data on the planned bore area geology.  The geotechnical analysis should identify several relevant items including:

  • Soil identification along the bore route to locate rock, rock inclusions, gravely soils, loose deposits, discontinuities and hardpan
  • Soil strength and stability characteristics
  • Groundwater

Local drillers with experience in the identified area can often provide valuable insight based on similar projects in the same area.

Terrain and HDD Route Mapping

Collecting accurate topographical information of the bore route is another critical component in the planning phase.  Terrain and HDD mapping includes determining HDD bore hole entrance and exit locations, identifying and mapping elevation profile changes, ensuring that other utilities are appropriately identified and avoided, assessing the need for traffic control, evaluating any environmental considerations or limitations that might impact the use of drilling muds and hole conditioners.

Bore Planning Software

Several commercial bore planning software tools are available to assist in the planning phase.  These programs utilize the soil and geotechnical data combined with the terrain and route mapping information to provide a graphic visualization of the job helping the driller more accurately “see” and perform the job from start to finish.  These software tools help the contractor select the appropriate drill rig, drill bit type and back reamer based on the anticipated soil conditions and the total bore length.  By choosing the drill stem and length, the desired bore path depth, desired minimum cover, diameter and bend radius of the product being pulled, the software plots a proposed bore pitch, calculates setback distances, figures point to point bore paths, estimates hole volumes and calculates pullback time. The software can also provide a fluid–mixing process map that shows how much mud should be used based on soil conditions, drill unit and tooling used.

If a bore planning software package is not used, field calculations should be performed to appropriately choose the correct drill rig, drill bit and back reamer tooling requirements, desired bore path and quantity and type of drilling fluids to be utilized.

What anode should be selected for HDD installation?

MATCOR’s SPL-FBR™ Linear Anode may be suitable for some HDD installations.

MATCOR manufactures two linear anode products (SPL-FBR™ Linear Anode and the Iron Gopher™) that are both, in the right circumstances, suitable for use in HDD installations.  The installation contractor, along with the client, must carefully select the appropriate anode and the appropriate anode installation methodology.  The two generally accepted methodologies are direct pulling of the anode through the properly conditioned borehole by attaching the anode to the backreamer after the initial pilot hole has been drilled.  The second installation methodology involves pulling an HDPE pipe sleeve into the borehole, installing the anode inside the pipe, and then removing the HDPE sleeve.  The tables that follow are intended to assist the installer in selecting the appropriate anode and installation methodology.  The selection of the appropriate anode type and installation methodology is subjective based on a qualitative analysis.

Iron Gopher® Linear Anode for HDD Applications

TABLE 1 – Linear Anode Application Difficulty

EASY• Less than 200 foot pulling length
• Minimal changes in elevation
• No environmental restrictions on use of drilling muds/hole conditioners
• Installation costs and risks are low
MODERATE• 200-500 foot pulling length
• Moderate elevation change
• No environmental restrictions on use of drilling muds/hole conditioners
• Installation costs are modest and risks are low
DIFFICULT• 500-1000 foot pulling length
• Moderate elevation changes
• Some environmental restriction on use of drilling muds/hole conditioners
• Installation costs are higher and risks are moderate
EXTREME• 500+ foot pulling length
• Extreme or multiple elevation changes
• Restrictive environmental limits on use of drilling muds/hole conditioners
• Critical application with high costs and risks

TABLE 2 – Anode Selection Guidelines

 Linear Anode Application Difficulty 1
SOIL TYPE 2EASYMODERATEDIFFICULTEXTREME
Earth LoamsFBRFBR/Iron GopherIron GopherIron Gopher*
Sand/SiltFBR/Iron GopherIron GopherIron GopherIron Gopher*
ClayIron GopherIron GopherIron Gopher*Iron Gopher*
Gravel / CobleIron GopherFBR*/Iron Gopher*Iron Gopher*Iron Gopher*
RockyFBR*/Iron Gopher*FBR*/Iron Gopher*Iron Gopher*Iron Gopher*

*Anode is to be installed in HDPE sleeve that is then removed

NOTES
1Classifying the linear anode application difficulty using Table 1 is a qualitative analysis and may warrant taking into consideration other risk factors that may be appropriate. In general, the more difficult the application, the more costly the installation component, the greater the case to use the higher pulling strength Iron Gopher and the greater the incentive to use temporary HDPE sleeving to assure the lowest risk installation.
2Soil Types based on the US Department of Agriculture Soil textural classification guidelines. Earth Loams would include the broad range of Sandy Clay Loam, Loam, Silt Loam, and Clay Loam.

What contingency planning is warranted for an HDD installation?

Even with proper project planning and an experienced installation contractor, some consideration should be given to contingency plans if something unforeseen happens during the HDD boring and anode installation.

  • Are alternate bits available if needed to complete the pilot hole?
  • Is a larger boring machine available if needed?
  • If drilling is more challenging than anticipated, do we have ready access to HDPE pipe for sleeving if warranted?
  • Does the project warrant having one or more spare anode assemblies in the event of an anode breakage during installation?

While these risks can be greatly minimized with proper planning, asking these questions before mobilizing to the site can help solve problems more quickly, saving time and money.


For assistance with linear anode selection for HDD applications, MATCOR’s linear anode systems, project management or installation, please CONTACT US.

Video Demonstrates Cathodic Protection System Installation

Iron Gopher® Impressed Current Linear Anode System designed for horizontal directional drilling (HDD) is installed beneath an above ground storage tank (AST)

Chalfont, PA (May 27, 2015) – MATCOR, Inc. the trusted full-service provider of proprietary cathodic protection products, systems, and corrosion engineering solutions recently released a video showing the installation of the company’s Iron Gopher impressed current linear anode system at the site of an above ground storage tank in Texas.

Trenching to install cathodic protection systems may not be feasible for applications such as cross country pipelines, congested industrial environments and under above ground storage tanks. For these horizontal directional drilling applications, a linear anode with superior mechanical strength is required. The Iron Gopher with Kynex® technology is the only impressed current linear anode designed specifically for cathodic protection in horizontal directional drilling applications.

“As another example, Colonial Pipeline installed several thousand feet of our Iron Gopher® linear anode at an HDD project in NE Georgia,” said Ted Huck, VP of Sales for MATCOR. “With its unique design and greatly increased strength, Iron Gopher is superior to anything seen in the market for cathodic protection in HDD applications.”

Learn about MATCOR’s complete cathodic protection installation services.

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