Underground Cable Pulling Is a Whole Different Beast

Why today's underground electric transmission projects demand a different approach to cable pulling-and to the pulling rope crews depend on.

You've done the math. You've planned the pull. You've checked the equipment. But once the line disappears into the conduit, there are still things you can't see.

And no amount of planning completely eliminates that fingers-crossed moment.

Underground cable pulling is uniquely challenging because contractors must manage pulling tension, sidewall pressure, conduit friction, bends, debris, heat, abrasion and long runs they cannot directly see. Those conditions create risk for the cable, the pulling equipment and the pulling rope, and they can turn a carefully planned installation into an expensive problem.

Crews can calculate pulling tension, sidewall pressure, bend radius, cable weight, coefficient of friction and distance before the job begins. But calculations can't perfectly account for everything waiting underground. Dirt and debris can increase friction. Conduit conditions vary. Bends add pressure. Temperature can affect the pull. Even installation quality can introduce variables that are difficult to predict.

And there are about to be a lot more pulls to plan.

Don't be caught at the end of your rope.

Why underground cable pulling is becoming more important

After decades of relatively flat electricity demand, the U.S. grid is entering a period of significant load growth.

Data centers and AI are a big part of it. So are expanding domestic manufacturing, large industrial loads and electrification. The U.S. Department of Energy's July 2026 draft National Transmission Needs Study describes the need for additional transmission infrastructure as "pressing."

Data centers alone consumed about 4.4% of U.S. electricity in 2023 and, according to Lawrence Berkeley National Laboratory, could account for approximately 6.7% to 12% by 2028.

All that new demand creates a straightforward infrastructure challenge: generating electricity is one thing. Getting more of it where it needs to go is another.

That puts greater importance on expanding and modernizing electric transmission infrastructure-and on the electrical contractors and project teams tasked with building it.

For underground electric transmission projects, that means tackling an environment that asks something very different from people, plans and equipment.

Underground isn't simply a harder pull. It's a different beast.

What makes underground cable pulling difficult?

The challenge of underground cable pulling is not one single variable. It is the combination of pulling tension, friction, bends, sidewall pressure, conduit conditions, distance and limited visibility-and the way those factors interact throughout a pull.

Start with the obvious: you can't see most of what is happening.

But limited visibility is only part of the challenge.

A bend isn't simply another turn on the way to the other end. Pulling cable around bends creates sidewall pressure, and excessive pressure can damage cable. Friction between the cable and conduit increases the pulling force required. Dirt, sand and debris can add resistance and abrasion. Offsets, neckdowns or damaged conduit can make an otherwise carefully planned underground cable installation unexpectedly difficult.

And those conditions don't conveniently take turns.

They compound.

Friction contributes to pulling tension. Bends increase sidewall pressure. Debris adds abrasion. Long runs expose the cable and pulling rope to more contact. Every trip through the conduit creates another cycle of wear on the cable pulling rope.

What factors affect an underground cable pull?

Factor	Why It Matters
Pulling tension	The force required to move cable through the run increases with weight, distance, friction and geometry.
Sidewall pressure	Cable is forced against the conduit wall at bends, creating pressure that must remain within cable limits.
Coefficient of friction	More friction between cable and conduit means more pulling force is required.
Bends and bend radius	The number, angle and radius of bends can significantly affect tension and sidewall pressure.
Conduit condition	Debris, damage, offsets and restrictions can add resistance that may not be obvious from the plan.
Pull distance	Long underground cable pulls expose the system to more friction and increase the consequences of a problem.
Temperature and environment	Environmental conditions can affect cable behavior, friction and the overall pull.
Pulling rope condition	Abrasion, repeated use and localized damage can affect pulling-rope performance over time.

That's why cable pull planning matters so much in the first place. Contractors are trying to understand and control as many variables as possible before thousands of feet of cable and pulling rope disappear somewhere they can't readily access.

The pulling rope shouldn't add another unknown.

What factors affect an underground cable pull?

A pulling rope failure during an underground cable installation can create costs far beyond the price of replacing the rope. A mid-pull failure can stop work, strand cable inside the conduit and trigger recovery work, additional equipment, idle labor, schedule changes, permitting issues or even excavation.

If a pulling rope fails somewhere inside a long underground run, the first question is simple:

Where did it break?

The questions that follow can get expensive quickly.

How do you recover it? Can you access the failure point? Can the cable be backed out? Will you need to excavate? What happens to the crew and pulling equipment already scheduled? Are street closures or permits affected? How quickly can another reel of pulling rope get to the job?

On a major underground transmission project, the price of failure can extend far beyond the price of the rope.

So experienced contractors plan accordingly.

Backup reels. Extra schedule. Additional labor. Recovery plans. Contingency budgets. In some cases, crews may add capacity or redundancy to give themselves more margin.

That isn't overplanning.

When failure is expensive, you plan for failure.

But there's a difference between preparing for the unknown and accepting every source of risk as inevitable.

What if the pulling rope could be one less thing to worry about?

When does an underground pull demand more from the pulling rope?

Conventional 12-strand, single-braid HMPE rope is a proven solution for many utility and cable-pulling applications. But demanding underground transmission projects can place different stresses on a pulling rope, including repeated abrasion, friction, high loads and multiple trips through conduit.

The issue isn't that the 12-strand single braid rope suddenly stopped working.

The question is whether the construction and expected service life of the pulling rope match the demands of the application.

Keeping backup reels on hand can get a crew moving again after a failure. Adding contingency into the schedule can soften the impact of downtime. Increasing capacity can give the team additional margin.

Those are ways to manage the consequences.

They don't change what's happening to the pulling rope inside the conduit.

For demanding underground cable pulling applications, breaking strength is only part of the equation. Contractors should also consider how the rope is constructed, how it handles abrasion and repeated contact, how its condition changes over multiple pulls and how reliably it can remain in service.

That calls for a different question:

Instead of engineering the project around the limitations of the pulling rope, what if you engineered the pulling rope around the realities of the project?

Choosing pulling rope for demanding underground cable installation

When selecting pulling rope for demanding underground cable installation, contractors should look beyond catalog breaking strength alone. Construction, abrasion resistance, repeated-use performance, service life, application-specific sizing and the condition of the rope over time can all affect project reliability.

That thinking is what led Yale Cordage to develop GlideLine.

Yale saw underground electric transmission asking conventional pulling rope to operate in a very specific set of conditions. So instead of simply adding more strength, its engineers started with the application.

GlideLine is a double-braid HMPE pulling rope built with a high-strength HMPE core and a protective HMPE jacket. Its tightly braided outer surface is designed for the friction, abrasion and repeated contact that come with traveling through conduit.

The construction is also designed to resist sawing behavior against the conduit, helping address one of the wear mechanisms that can occur during underground cable pulling.

REDLIGHT™ Technology adds a 35-foot section of high-visibility red coating that alerts operators when the pulling rope is approaching the end of the run.

These features aren't designed to make every unknown underground disappear.

There are enough variables down there already. The idea was to make the pulling rope less of one.

Then E-J Electric gave Yale the opportunity to see how that thinking would hold up in the field.

E-J Electric field test: 42 underground cable pulls

On a demanding high-voltage underground transmission project, E-J Electric completed 42 underground cable pulls with a single reel of GlideLine without a rope failure-six times the number of pulls completed before a previously trialed 12-strand HMPE pulling rope failed in the same application.

E-J Electric was working on the Champlain Hudson Power Express, a major high-voltage direct-current transmission project with demanding underground installations through and around New York City.

It was exactly the kind of work that makes contingency planning necessary: long underground cable pulls, dense urban infrastructure and a high cost if work suddenly stops.

A previously trialed 12-strand HMPE pulling rope failed after seven underground pulls.

E-J then began using 1-1/8-inch GlideLine.

The pulls averaged approximately 2,000 feet in length, with pulling tensions ranging from approximately 5,000 to 35,000 pounds.

What happened next is worth a closer look.

One reel. 42 underground pulls. Zero GlideLine rope failures.

That's six times the number of pulls completed before the previously trialed 12-strand rope failed.

And 42 wasn't when GlideLine quit.

It's when the job did.

Yale then brought samples of the used GlideLine back to its laboratory in Saco, Maine for residual break-strength testing.

Across all tested samples-including two samples with localized damage identified before testing-the rope retained an average of approximately 87% of its minimum breaking strength. When the two samples with identified localized damage were excluded, average residual strength was approximately 90% of MBS.

The point isn't simply that GlideLine completed more pulls.

It is that the pulling rope continued to perform through repeated exposure to the kinds of conditions underground transmission contractors plan around every day.

Field Test Table:

E-J Electric Field Trial	Result
Application	HV underground cable pulling
Average pull length	~2,000 ft
Pulling tension	5,000-35,000 lbs
Previous 12-strand rope	7 pulls before failure
GlideLine	42 pulls
GlideLine failures	0
Service-life improvement in this application	6× pulls

Technical Review and lab test conducted by Yale Cordage Engineer.

Underground cable pulling FAQs

What type of rope is used for underground cable pulling?

Synthetic pulling ropes, including HMPE pulling rope, are commonly used for demanding utility and underground cable-pulling applications because they can provide high strength at relatively low weight. The right pulling rope depends on the required load, pulling equipment, length of the run, conduit conditions and expected use. For repeated or particularly demanding underground pulls, contractors should also consider abrasion resistance, construction and expected service life rather than breaking strength alone.

What causes high pulling tension during an underground cable pull?

Cable pulling tension is affected by factors including cable weight, pull distance, coefficient of friction, conduit geometry, bends, pull direction and the condition of the conduit. As these factors interact across a long underground run, the amount of force required to move the cable can increase significantly. Pull planning helps contractors estimate these forces before installation begins.

What is sidewall pressure in cable pulling?

Sidewall pressure is the pressure created when a cable under tension is pulled around a bend and presses against the conduit wall. Pulling tension and bend radius both affect sidewall pressure. Excessive sidewall pressure can damage cable, which is why it is an important consideration when planning underground cable installation.

Why can pulling rope fail during underground cable installation?

Pulling rope can be exposed to high loads, abrasion, friction, repeated contact with conduit and localized damage during underground cable installation. Over multiple pulls, those conditions can affect rope condition and service life. Selecting the right rope for the application and inspecting pulling rope throughout its service life can help contractors manage that risk.

What should contractors consider when choosing underground cable pulling rope?

Contractors should consider required pulling loads, rope diameter, pulling equipment, construction, abrasion resistance, repeated-use performance, rope condition and expected service life. For demanding underground transmission work, the goal is not simply to choose a rope strong enough to complete one pull, but to select a pulling system appropriate for the conditions and project requirements.