Fiber Construction Overview

Construction of a fiber optic network is a complex and lengthy process.  Numerous contractors are involved and the entire process can take six to 12 months to complete, depending upon the length of the circuit, the terrain and soils, weather and other external factors.  The following discussion covers the phases of construction along overhead distribution lines.  You can see each step below:

1. Make-Ready Engineering

After an in-house autodesign of the fiber build, field engineers go to each pole to determine if any modifications are required in order to support the fiber and its associated steel strand. These engineers create design sheets showing  where to move items at the pole to create more space, as well as where poles need to be changed out to add height or strength. During this time, inspectors will “ride out” the build to ensure every member will be included in the fiber build. This phase can take two to four weeks.

2. Make-Ready Construction

Line crews will change poles, move transformers from one side of the pole to another, move wires on the pole, add new anchors to the poles, and perform other work to allow the fiber to be placed later. The make ready construction phase can take four to twelve weeks as a rule of thumb. This work has the widest variance in time of all construction phases.

3. Fiber Construction

Fiber crews place steel strand along the pole line and return to place the fiber optic cable against the steel strand. A lashing machine is used to secure the fiber to the strand. In locations where the electric is underground, the fiber optic  cable will be placed in a small plastic pipe underground by either boring or plowing. Asphalt and concrete driveways will be bored under and a pedestal may be placed next to a transformer or junction box to allow for a service drop.  Areas of disturbance are restored to their original state. Fiber construction can take four to eight weeks on a circuit.

4. Splicing

Once the strand and fiber is placed, splicers will make splices at each end and tap point. They splice the necessary cables at each point and mount the splices in enclosures secured to the distribution poles or in pedestals. The splicing  work can take another three to six weeks for the main lines.

5. Service Drop Construction

The next step is service drop construction. This work can be done in parallel with some of the earlier work, or it might be done after the main line fiber is in place. The drop crews extend the fiber from the nearest splice point to the  structure receiving service and leave coils of fiber in each location.

6. Drop Splicing

The final outdoor step in fiber construction is the splicing of the drop. The splicer connects the last length of fiber at the tap point and also mounts a network interface device (NID) at the structure with the final splice inside the NID. The service is now ready for installation.