Underground Infrastructure - May 2023 - 13

are right, multiple utilities can be placed
in the same trench, reducing costs for all
participating companies.
Two companies - Ditch Witch and
Vermeer - dominate this market and
representatives of both companies say
that trenchers are essential for installing
underground utilities.
Steve Seabolt, category manager for
Ditch Witch trenchers, and Ed Savage,
Vermeer product manager, discussed
with Underground Infrastructure
the
importance of trenchers for utility construction
today.
Have trenchless technologies
made trenching obsolete
for utility construction?
Seabolt: Trenching and other types of
open-cut methods are popular solutions
for installation of cable or pipe products
over long distances, in areas with
minimal surface obstructions. They are
also selected often for extremely short
or shallow jobs, such as a " drop " from
street to home, or for installation of a
lawn sprinkler system.
But a plow blade could strike and damage
any existing utility in its path.
Today, most project articles in industry
trade magazines tend to cover
trenchless methods, horizontal directional
drilling (HDD), pipe bursting and
various rehabilitation methods. Have
the various trenchless technologies
made trenching equipment obsolete?
The answer is a loud " No. "
Trenchers that dig a relatively narrow
trench to the depth necessary for
each type of utility, remain the fastest,
least costly method of putting utilities in
the ground. An important added benefit
trenching offers is when circumstances
Trenchers are the go-to solution
if the design of the job requires the
product be Tee'd, branched, joined, or
physically manipulated in some other
way during installation. Trenchers (and
sometimes plows) are often chosen
when there are requirements for sand to
be placed above or below the product.
Plows, in particular, are capable of
installing small-diameter pipes or cables
at a very fast pace, compared to
most other methods, and are often the
installation tool of choice when productivity
is critical. Saws, or disc trenchers,
are often selected when installing
product in solid rock or frozen ground,
especially for short or shallow distances.
Microtrenchers are chosen to cut
asphalt roadways when the roadside
easement is crowded or covered with
surface obstructions that might inhibit
setup of an HDD rig.
Savage: Horizontal directional drilling
does get a lot of attention for installing
underground utilities, but dedicated
trenchers still play a significant role in
the installation process. Trenchers and
vibratory plows are widely used to install
utilities over long distances in more
rural areas, where there are fewer restoration
requirements.
Small walk-behind trenchers and
vibratory trenchers are often used to
install electrical, telecom, water and gas
lines to homes and businesses. Mid-size
rubber tire/track trenchers and vibratory
plows are employed on longer installation
projects. Large trenchers are an
excellent option for utility jobs in challenging
rocky grounds.
Also, trenching tends to be the preferred
method for installing new utilities
on greenfield development projects,
where existing underground infrastructure
might be limited.
What factors influence whether
trenching or HDD will be used?
Seabolt: Ground conditions, depth,
distance, product being installed, padding
(beneath the pipe) or special cover
requirements like sand, surface obstructions,
desired speed, skilled labor availability
are among the considerations.
Savage: The main factor contractors
should use to determine whether to
trench or use a horizontal directional
drill is location.
In urban areas, there are typically
more above-ground obstacles like
roads, driveways and buildings that
contractors have to account for. So,
using trenchless installation methods
like horizontal directional drilling, auger
boring and piercing tools tends to
be more efficient than cutting through
hard surfaces and then repairing them.
Rural areas have fewer road intersections
and other obstacles. Trenching or
using a vibratory plow in these areas is
typically faster than using HDD alone.
Drills are still often used to make road
and river crossings.
Other factors that contractors
should think about are the utility bundle
size, installation depth and ground
conditions. These will influence the size
UndergroundInfrastructure.com | MAY 2023 13
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Underground Infrastructure - May 2023

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