Upgrading Communications


Fiber optics chosen as optimal
solution for L&O Power Cooperative

Project Owner:
L&O Power Cooperative

Key Experience:

  • Specified and procured all the components for this project, including fiber optic cables, hand holes, equipment racks, patch panels, Ethernet switches, fiber test equipment, patch cables,
    and more
  • Locating services using GIS
  • Installation included all cable plowing, trenching, boring, and pulling required for each L&O site as well as the 4.5-mile underground project
  • Tested the functionality of the fiber network, providing sufficient data to be utilized as a baseline for future troubleshooting

Key Features:

  • Privately owned and secure high speed fiber optic data network
  • Optical ground wire (OPGW) serves as both a communications path and bonds adjacent towers to earth ground to shield the high-voltage conductors from lightning strikes
  • Detailed GIS mapping of transmission lines and underground facilities

Reliable data communications are a necessity to all industries, and the utility industry is no exception. In critical moments, dependable communications are imperative. A poor connection can be the difference between a 5-minute or an extended electrical outage. No one wants an extended outage, extra expense, or inconvenience of having to commit additional resources to what should have been a simple solution. In addition, certain scenarios can put first responders or the general public at risk.

Realizing the risks of a less-than-reliable communications network, a long-standing client of DGR Engineering (DGR), L&O Power Cooperative (L&O), was determined to improve communications on its electric transmission system. L&O has utilized wireless radios on its system since the 80s and unlicensed 900 MHz digital Ethernet wireless radios since 2005. The radio system performed well for years but was designed as a budget-friendly way to connect sites over long distances while sending limited amounts of data. The need for constant uptime, along with an exponential rise in data traffic over recent years is exceeding the technology’s limitations.

DGR engineers explored different solutions. Radio technology with more data throughput such as Wi-Fi or microwave could be deployed. Microwave radios proved econ-omically unfeasible. Standard Wi-Fi technology could not meet the distance requirements and would require additional repeater sites and devices to meet L&O’s needs. Cellular radio options were reviewed, but paying for data and exposing critical data to the outside world was seen as a last resort or backup plan. A private fiber optic network owned exclusively by L&O became the solution that met both current and future needs. Fiber is reliable, secure, and offered data capacity that exceeded L&O’s projected future needs.

DGR recommended utilizing L&O’s existing transmission lines as the backbone for their fiber network, replacing the static wire on most lines with an Optical Ground Wire (OPGW) design. OPGW is a stranded electrical conductor with a steel tube core. The steel tube is then filled with numerous fiber optic strands. L&O understood that pursuing this solution would take longer to deploy but would be in their best interest long-term. As this OPGW infrastructure is built out, L&O intends to utilize existing wireless radios for backup communication in the event the OPGW line is compromised.


As part of the capital improvements study that DGR recently performed for L&O, it was identified that many of their lines were at the end of their useful life and due for replacement. The timing of the line replacement lined up well with their need for communication infrastructure improvements. DGR was tasked by L&O to design a new transmission plant to include OPGW. The remaining lines, yet to be completed, will require existing static wires to be replaced with OPGW or installation of a new underground fiber line to connect remaining terminal sites. The OPGW will be the backbone of the L&O communications infrastructure for the foreseeable future.

With the OPGW plan in place, DGR proposed the installation of a new 4.5-mile underground fiber line to connect their headquarters building to the OPGW network.

DGR’s team determined the optimal routes, materials, and cable locating requirements. DGR also consulted with local utilities to optimally navigate rights-of-way where possible. DGR’s team acquired the necessary permits from the Iowa DOT and Lyon County. No DNR permits, encroachment agreements, or new easement acquisitions were necessary for this particular project. The route consisted of utility rights-of-way, existing utility easements, and private property owned by L&O.

Underground cable location processes are necessary for all utilities that own and operate underground facilities. After investigation of contracted locating services options, L&O ultimately decided to take on the locating responsibility themselves. With the help of precise Global Positioning System (GPS) equipment that integrated into GIS and some additional effort during installation, L&O could perform locating services, accurate to within a few inches. The Owner felt comfortable with this amount of accuracy and appreciated the simplicity of the idea. All the underground cable installed was either armored or included a tracer wire to accommodate traditional cable locating practices as well.

The team at DGR developed plans and specifications two separate contracts the construction of the underground project; one for underground cable installation and the other for fiber splicing. The scope of the installation included all rural area cable plowing, trenching, boring, and pulling required for each L&O station site as well as the 4.5-mile mainline project. The installation contractor was able to substantially complete their scope of work in approximately one week while encountering only minor issues during construction. The fiber splicing connected all the OPGW system to underground cables as well as interconnecting fiber patch panels. DGR specified and procured all the components for this project, including fiber optic cables, hand hole, pedestals, equipment racks, patch panels, Ethernet switches, test equipment, patch cables, and more.

Testing the fiber optic cable upon project completion is a key milestone for this project as well. DGR’s ability to test the functionality of the fiber network provides L&O with sufficient data to be utilized as a baseline for future troubleshooting.

The DGR team was able to perform the necessary project design, permitting, specifications and procurement, incorporation of GIS, and complete the construction on time. GIS was originally outside the scope of this project, but in the end, contributed much value in construction, mapping and locating efficiencies. The GIS team at DGR was able to quickly develop a GIS solution, and it has been an invaluable tool. Overall, the DGR team was able to complete this job on time, on budget, and overcome numerous unforeseen challenges in completing the project.