How to evaluate a fiber route, choose a construction method, and identify problems before the crew gets there
Construction prints can make a fiber route look pretty simple. The proposed path follows a road for 2,000 feet, crosses at an intersection, continues along the opposite side, and has several handholes placed along the way. There is a beginning, an end, and a line connecting the two.
Eventually, somebody has to turn that line into physical infrastructure.
Once we get into the field, that clean line has to coexist with everything already there. There may be gas and water occupying part of the available right-of-way. A large culvert may cross the proposed alignment. Driveways interrupt the route. A drainage ditch gets deeper farther down the road. The right-of-way narrows near an intersection. The proposed handhole fits on the print, but there may not be enough room to excavate it without affecting something else.
Then there is the actual construction operation. Even if there is technically enough underground space for the conduit, can we get the equipment where it needs to be? Is there enough room for a drill setup? Where will the product pipe go? Can an excavator reach the handhole location? Where will the excavated material be placed? Can traffic continue through the area? Can the crew safely work there?
None of this automatically means there is a problem with the design. The design gives us the intended route and what we are trying to build. Construction has to take that intent and figure out how to physically build it under the conditions that exist.
That is constructability.
For our purposes, constructability is taking what we intend to build and testing it against the actual conditions required to build it. That includes the existing infrastructure, available space, construction methods, equipment, access, project requirements, permits, safety considerations, restoration, and everything else that determines whether the work can actually happen.
When someone asks whether a route is constructable, we cannot answer that by looking only at the proposed fiber line. We need to understand what is around that line and what it will take to physically put something there.
The Route Tells Us Where. We Still Have to Figure Out How.
One of the first things to understand is the difference between a route and a construction method.
For underground fiber, we might use horizontal directional drilling, commonly called HDD. A drill creates an underground path between an entry and exit area so conduit or product can be installed without continuously opening the surface above it. Another section might be plowed, where specialized equipment places conduit or cable into the ground as it travels along the route. Open trench construction exposes the proposed pathway so conduit can be installed directly. In other situations, an existing conduit may provide the pathway we need.
The important part is that a single route does not necessarily have one construction method.
Imagine 2,000 feet of proposed underground construction along a roadway. The first 500 feet has usable right-of-way, manageable ground conditions, good equipment access, and relatively few utility conflicts. Farther down, the route approaches a commercial driveway that needs to remain open. After that, we encounter a large culvert. Beyond the culvert, the right-of-way opens again before eventually narrowing near an intersection filled with existing utilities.
The network still needs to travel from the beginning of the route to the end. What changed were the conditions along the way.
This is where it becomes useful to start seeing a long route as smaller constructable segments. A constructable segment is simply a portion of the route where the conditions are similar enough that we can evaluate how that particular section should be built.
A driveway might create a new segment. A culvert might create another. A major change in available right-of-way, surface, utility congestion, elevation, ground conditions, or equipment access might be another reason to stop and reevaluate the construction approach.
That does not mean every change requires a different construction method. It means that when the conditions change, we should ask whether the method still works.
First Understand What You Are Trying to Build
Before deciding whether something needs to change, we need to understand what the project is actually asking us to build.
Where does the network need to go? What conduit configuration is required? Where are the proposed handholes or other structures? What depths and separations apply? Are there requirements for conduit entry, bend radius, structure placement, restoration, or future access? Are permits, easements, right-of-way limits, environmental requirements, or owner standards controlling any part of the installation?
These requirements give us the target we are trying to hit.
This matters because a constructability review is not simply walking into the field and deciding where we would personally prefer to build the network. There may be reasons behind the design that are not obvious when we look at one location by itself.
Take a proposed handhole location. Moving it 50 feet might make excavation easier, but that handhole could be positioned there because of cable lengths, splice planning, future connections, property boundaries, permitting, or another part of the network design. Moving it may be possible, but somebody needs to understand what else that change affects and whether the person proposing the change has the authority to make it.
We need to understand the intended result before we start deciding how to accomplish it.
Then Look at What the Construction Has to Work Around
Once we know what we are trying to build, we can start looking at the existing conditions.
Existing conditions are everything already present that could affect how the proposed infrastructure is constructed.
Some are obvious. Roads, driveways, sidewalks, ditches, culverts, retaining walls, fences, landscaping, buildings, poles, waterways, and changes in elevation can all affect construction.
Other conditions are underground. Gas, electric, water, sewer, storm facilities, and existing communications can influence the horizontal alignment, depth, crossing location, and construction method.
Knowing a utility exists does not always give us enough information to make a construction decision. A locate may show us approximately where the facility is horizontally, but there are situations where we also need to know its actual depth and position. That may require exposing the facility using an approved method before we can determine how our proposed installation gets past it.
Property matters too. Open ground does not necessarily mean available ground. The usable right-of-way or easement may be much narrower than the physical space we can see.
Then we need to look beyond the space where the finished conduit will sit. We need to look at the space required to build it.
That is easy to miss.
A conduit may only occupy a few inches underground once installed. The construction operation required to put it there can consume a much larger area.
Can the Equipment Actually Perform the Work?
This deserves its own part of the constructability review because equipment setup can determine whether a construction method is feasible.
Suppose a proposed road crossing appears to be a good candidate for HDD. There is room underground for the bore, the required depth appears achievable, and the utility conflicts look manageable.
That still does not tell us whether we can drill it.
Where does the drill sit?
How much room does that particular drill and its support equipment require?
Can the drill get into the setup location?
Can it be positioned at the angle needed to establish the bore profile?
What is behind the drill?
What is beside it?
Are we sitting in the road, shoulder, ditch, private property, or somebody’s driveway?
What happens to traffic while the equipment is there?
Now look at the other end.
Where does the bore exit?
Is there enough room to expose or receive the tooling as required?
Where is the product that will be installed?
If we are pulling back a long section of conduit, where will that conduit be laid out before the pull?
Can we get it into position without blocking a road, crossing private property, bending it beyond its limits, or creating another problem?
Those questions are part of constructability. The same thinking applies to excavation.
A handhole may physically fit between two existing facilities, but that does not automatically mean we can install it there. We need enough room to excavate the hole, safely work around the excavation, handle the structure, manage spoils, bring bedding or stone into the area, connect the conduits, and restore the site afterward.
If the handhole requires mechanical equipment to set it, can that equipment reach the excavation? Can it operate there safely? Are overhead lines, traffic, slopes, fences, buildings, or other obstacles limiting the working area?
Plowing creates similar questions. There may be enough room for the finished facility, but can the plow and support equipment physically travel the proposed path? What happens when it reaches a driveway, culvert, fence, steep slope, or congested utility area?
This is an important constructability lesson:
Do not evaluate only where the infrastructure fits. Evaluate where the construction operation fits. A route can have enough space for the finished fiber and still not have enough space to build it using the method being considered.
Every Construction Method Needs Certain Conditions
Once we understand the route and existing conditions, we can start evaluating the available construction methods.
The mistake is choosing a method first and then trying to force the location to fit it. A better approach is understanding what each method requires and testing those requirements against the actual location.
For HDD, we need to think about entry and exit areas, equipment setup, existing utilities, required depths and separations, elevation changes, bore length, ground conditions, product characteristics, staging, drilling fluids, traffic, property, permits, and environmental requirements.
For open trench construction, we need usable excavation space, safe access, a way to manage spoils and materials, an understanding of existing utilities, a plan for traffic and property access, and a way to restore whatever surface we disturb.
Plowing requires enough continuous access for the equipment to move through the route, suitable ground conditions, manageable utility conflicts, and a path that is not constantly interrupted by features the equipment cannot cross.
Existing conduit presents a different set of questions. Is the conduit actually continuous? Is it usable? Is there enough capacity? Can it be accessed? Has it been proofed? Does its path get us where the network needs to go?
The questions change with the method, but the thought process stays the same: What does this method require, and do those conditions exist here?
What Is Controlling How We Can Build It?
When a section becomes difficult, I like to narrow the problem by identifying what is actually controlling our options.
A controlling condition is the feature, requirement, or limitation that has the greatest influence on how that section can be constructed.
Imagine a section with plenty of open ground. Several methods initially appear possible. Then we find gas, electric, water, and existing communications occupying much of the usable underground space. The existing utilities may now control the decision.
Another location may have very few utility conflicts but almost no place to position the necessary equipment. Equipment access and setup may control the decision.
At another location, the easiest physical route may leave the permitted right-of-way. Property now controls the decision.
Other controlling conditions can include depth, required separation, drainage, surface restoration, traffic, ground conditions, environmental requirements, safety, structure placement, project specifications, or the equipment available to perform the work.
Once we identify what is controlling the section, the conversation gets more specific. Instead of asking, “How are we going to build this?”, we can ask, “What methods still work if the equipment has to remain inside this right-of-way?” or “What options do we have if this utility occupies the depth we originally planned to use?”
Now we have a construction problem we can actually work through.
Just Because We Can Build It Does Not Mean We Should Build It That Way
There are usually several ways to get infrastructure from one point to another. The first method somebody thinks of is not automatically the best construction approach.
Suppose someone says, “We can bore it.”
They may be correct. The question now is what that bore requires.
Can we get the drill into position? Can we achieve the required profile? Can we maintain the necessary separation from existing facilities? Can we stage the product? Can we manage the drilling fluids? Are we allowed to perform the work from the available setup area? What does the permit require? What happens to traffic? What are the ground conditions? What happens if we encounter something different than expected?
Then we compare that approach with the alternatives.
Maybe another alignment reduces the utility conflicts. Maybe a combination of plowing and shorter bores makes more sense. Maybe open trench is practical in one small section. Maybe the proposed route is still the best option.
The point is not to create unnecessary alternatives. It is to make sure the selected construction approach works when we consider the whole operation, not simply whether we can physically get conduit into the ground.
That includes safety, project requirements, equipment, access, restoration, traffic, schedule, cost, and what the next construction activity needs from us.
Finding What We Do Not Know Is Part of the Job
Constructability reviews do not always end with an immediate construction decision.
Sometimes they identify missing information.
Suppose we know a gas main crosses our proposed bore, but its actual depth will determine whether the bore profile works. We do not need to guess. We have identified something that needs to be verified.
Maybe we need a pothole or other approved method of exposing the facility. Maybe we need survey information to establish the right-of-way. Maybe engineering needs to review a proposed change. Maybe the contractor needs to walk the site because the feasibility of the method depends on the equipment they intend to use. Maybe we need additional information about the ground or a clarification from the permitting authority.
Finding an unknown is useful because now the project can do something about it. This is also where timing becomes important. Imagine we discover today that we need to verify the depth of an existing gas main, and construction in that area is three weeks away. We have time to expose the facility, gather the information, evaluate the options, and make a decision before the crew reaches that section.
Now imagine discovering the same thing after the drill has arrived, traffic control is set, materials are staged, and the crew is waiting.
The physical problem did not change. The effect on the project did. This is one of the biggest reasons to think about constructability ahead of construction. We are trying to move discovery far enough ahead of the work that the project still has time to respond.
Think About the Person Who Comes After You
Constructability should not stop when we determine that the conduit can be installed.
The conduit is only one part of the network.
Fiber still needs to be placed through it. Handholes have to support cable placement and future access. Cable needs to be spliced. The installation has to be tested, documented, accepted, located in the future, maintained, and eventually repaired when something happens to it.
A construction decision can solve today’s problem and create tomorrow’s issues.
For example, we might find a way around several utility conflicts by adding unnecessary bends to the conduit route. The conduit gets installed successfully, but cable placement becomes more difficult.
A handhole might physically fit in a location but leave poor access for placing cable or performing future maintenance.
A route change may solve an immediate construction conflict while creating a problem at the next structure.
Experienced construction people often look several steps ahead because they have seen those consequences before. Someone newer to the industry can begin developing the same habit by asking a very simple question:
If we build it this way, what does the next person have to do with what we leave them? That question forces us to think beyond today’s production.
Walking a Route Is Different From Driving It
Driving a proposed route is useful. It helps us understand the overall area and see obvious conditions. It should not always be the end of the constructability review.
Some things become obvious only after getting out.
When you walk a difficult section, do not stare only at the proposed alignment. Look at the entire construction area.
Stand where the drill would actually sit.
Look toward the proposed exit.
Walk over to it.
Look back.
Where would the product be staged?
Where would an excavator sit?
How would the crew reach the handhole?
Where would the spoils go?
What happens to the driveway while we are working?
Where is traffic going?
What is draining through that ditch?
Where do the utility markings run compared with our proposed path?
What is overhead?
Where does the right-of-way end?
Then think about what happens after the conduit is installed.
You are no longer simply looking at a route. You are mentally walking through the construction operation before the construction operation happens.
That is a skill, and it gets better with repetition.
Use This on Your Project Today
Pick one section of upcoming construction and walk it before the crew gets there. It does not have to be the hardest section on the project. The goal is to practice looking at construction differently.
Start by making sure you understand what is supposed to be built and what requirements apply. Then look at everything the construction has to coexist with, including utilities, drainage, property, surfaces, structures, traffic, ground conditions, and access.
Next, consider the construction methods that could reasonably be used. For each one, picture the actual operation. Where does the equipment sit? How does it get there? Where are materials staged? How much working room is needed? What gets excavated or disturbed? How does the crew perform the work safely? What does the next activity need after this work is finished?
Then identify what is controlling your options. It may be a utility, available space, equipment access, right-of-way, depth, drainage, traffic, ground conditions, restoration, or another project requirement.
Finally, identify what you do not know. Do not fill the gap with an assumption just because you want to finish the review. Write down what needs to be verified and who needs to provide the answer.
That might mean verifying a utility depth, checking the right-of-way, reviewing a permit, talking with engineering, walking the location with the contractor, or gathering additional field information.
A useful constructability review does not have to answer every question on the spot. It should identify the questions early enough that they can be answered before they become field problems.
When you look at a print, see the intended network. When you look at the field, see the construction operation required to turn that design into something real. Then start working through the conditions that connect the two.
This is one of the standards taught in the Fiber Done Right Academy, Valor’s training library for fiber construction.
Related reading: Not Every Fiber Route Should Be Built the Same and What Directional Drilling Does.