Advantages of Jetting Fiber Optic Cable Over Traditional Pulling

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What
are the advantages of blowing or jetting fiber optic cable vs. traditional
pulling?

 

Pulling
and blowing are the two primary fiber installation methods. But each of these
techniques can impact the longevity, performance, and return on investment
(ROI) of a fiber optic network. If you take into account the fragility of glass
or fused silica during installation, distance to be covered, efficiency, and
costs, you may see that jetting (blowing) offers many advantages over
traditional cable-pulling techniques.

 

An
Overview of Fiber Optic Cable Installation Methods

 

• Pulling: It
involves pulling the fiber optic cable through pre-installed underground or
aerial ducts. You can pull the cable manually or using a reeling machine.
You’ll also need a pulling tape to haul the cable while measuring the distance
covered.

 

• Blowing:
With this technique, high-speed air pressure pushes fiber optic cables through
standard ductwork or microduct systems.

 

Here
are the reasons why cable jetting is superior to traditional pulling methods:

 

Minimal
Risk of Tension Damage

 

Each
brand of optical fiber
cable has a maximum tensile strength. But in pulling, there’s a risk of
straining the cable beyond its limit, which can compromise the fiber’s
performance and cut its service life. Unchecked resistance forces, such as
friction, on the sidewalls of cables and ducts, can also cause damage during a
“pulling” installation.

 

In
contrast, jetting involves little or no pulling, which significantly minimizes
strain on the fiber optic cable. You can not only configure the system’s
hydraulic pack or air-compressing equipment to control airflow inside the duct
but also monitor the conduit and fiber to minimize damage.

 

To
minimize friction during cable jetting, consider applying lubricants meant for
the method. Ducts with low-friction interior walls may also help.

 

Suitability
for Long-Haul Fiber Optic Networks

 

Pulling
isn’t the best option for placing outside plant (OSP) fiber optic cable. With
the technique, there’s always a high possibility of pulling the cable into
conduit bends. And as bend angles continue to accumulate, it becomes
increasingly difficult to optimize pull length. The bad news is that ducts for
cross-country fiber optic networks can have many bends.

 

As
such, pulling is ideal for short-distance fiber optic cable deployment.
Distance will vary from one manufacturer to another and cable jacket material
plays a role too.

 

With
high air speed blowing fiber optic installation, however, conduit bends and
undulations aren’t as much of an issue as they are with traditional
cable-pulling techniques. The blowing force doesn’t pull the cable into a duct
bend. It instead pushes it smoothly around every turn or curve.

 

In
other words, the duct route geometry doesn’t impact installation distance in
this case. Consequently, air-assisted installation lets you place fiber optic
cable thousands of feet between jetting sites. That’s why it’s suitable for OSP
fiber deployments, for example, telecommunication, CATV, and internet networks.

 

Reduced
Costs

 

Cable
jetting equipment and ductwork may be initially expensive. But you can amortize
these upfront costs depending on current needs, and your initial investment may
pay off in future savings on upgrades. For example, you don’t have to invest in
redundant higher fiber counts when you can cheaply upgrade capacity in tandem
with changing requirements. 

 

Likewise,
“pulling” is more labor-intensive than the blowing method. The technique
involves more equipment movement, and it may require the positioning of placing
tools at intermediate points and both ends of long OSP runs. Additional workers
and extra equipment translate to higher installation costs. Cable jetting
requires fewer cabling technicians, however.

 

Keep
in mind that air-assisted optical fiber installation minimizes the number of
splices needed. Cables installed this way don’t usually require
“figure-eight” looping to prevent twisting every time duct changes
direction. Since the approach has fewer intermediate-assist placement
operations, it limits the number of handholes and other access points required
along the cabling route.

 

Suitability
for Microduct Installation

 

Jetting
is very effective in pushing fiber optic cable through microducts. With the
blowing method, you can place microduct cable in continuous lengths. The
technique is most suitable for modern optical fiber cables that tend to contain
bare fibers, and sometimes reduced cladding diameters, both of which contribute
to decreased outer cable diameters.

 

The
thinner a fiber optic cable is, the larger the number of fibers you can place
in specific innerduct. As such, jetting is the best installation technique when
you wish to make the most of the available duct capacity. It also allows you to
work with small but flexible fibers that go through multiple microduct twists
and turns over long distances with near-zero bend losses.

 

Additionally,
when setting up microducts for fiber optic cable jetting, you may include redundant
ductwork to accommodate new fiber in the future as required. This way, you
avoid the unnecessary costs of placing dark fiber, which may become obsolete
sooner than anticipated.

 

Appropriate
for Removal of Old Fiber

 

Pulled
fiber optic cable may be difficult to remove when no longer needed. The
presence of old and unwanted cables in mission-critical physical pathways may
limit your ability to optimize your optical network capacity or even upgrade to
higher-performance fibers.

 

But
after installing optical fiber by cable jetting, you may easily remove it by
the same approach when necessary. You may be able to reuse the removed fiber
optic cable since the removal process is gentle enough to minimize or avoid
damage.

 

Quick
Installation

 

Cable
jetting is faster than the “pulling” method. The pushing device can
move fiber optic cable at speeds of 350 feet per minute or higher. With the
air-jetting technique, you can quickly push cables through pre-installed
innerduct or underground ductwork. But in most cases, you can only pull fiber
at a rate of 100-200 feet per minute, or even slower.  

 

Less
Disruption

 

Choose cable jetting
to upgrade your optical fiber with minimal interruption to ongoing workflows or
operations. The cable-pulling approach is more disruptive.