Crews
rely on the accuracy of the Grundomat piercing
tools. Boring shots as long as 200 feet
have been successfully completed.
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Utility contractor Potelco, Sumner
WA, has embraced trenchless equipment. In fact,
the company has been using one trenchless tool in particular
for almost 20 years, the
pneumatic piercing tool. A workhorse of trenchless
technology, the piercing tool has become a mainstay at
Potelco providing solutions for a wide variety construction
applications.
Potelco’s piercing tool arsenal
numbers somewhere around
200 tools company wide. For
gas work alone crews perform as many as 150 residential
service bores in any given month. According to General
Foreman Mike Beuslinch, the tool is an important part of
daily operations throughout the company. He said, “We
couldn’t do our work
without them. It would be too costly with restoration,
the hauling off and importing of materials. We use
them for power, phone and cable, but gas is definitely
the area where we use them the most.”
According to Scott Langfeldt,
piercing tool specialist from trenchless equipment manufacturer
TT Technologies, Aurora, IL, Potelco has been utilizing
piercing tool technology for years. He said, “Potelco crews have a long
history with the piercing tool. Over that time they’ve
really gotten the most of the technology and they continue
to grow their services with it.”
Potelco, Inc. (a subsidiary of Quanta Services, Inc., Houston,
TX) was established in 1967. The full service utility
contracting firm, serves customers throughout the Northwest
in Washington, Oregon, Idaho, and Montana. Potelco has
been providing overhead power distribution and power
transmission services since the company's inception including
everything from street light maintenance and energized
system work, to huge overhead construction and mass transit
projects.
Their service offerings also
include underground power construction and maintenance.
The company plays an important role in cable replacement
throughout the region. Potelco
also performs civil construction and installation, as well
as the electrical installation. It is also one of
the regions leaders in telecommunications construction
having provided both overhead and underground telecom services
for decades. The company now has crews specializing in
the design, installation, and splicing of fiber optic cable,
for last mile operations.
Potelco
has over 250 piercing tools in its arsenal. Crews
use them in gas, electric, cable and fiber conduit
installations.
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With such a breadth of service
and operation, safety is a top concern. Potelco puts employees through extensive
safety training. However, according to Potelco Director
of Safety Brian Sabari, safety is the first thing every
crewmember focuses on when they arrive at the job site. He
said, “Everyday, crews, before they get started,
are required to do what we call a tailboard meeting which
is essentially a daily safety meeting. Crews go through
a form specific to the type of work they’re doing. The
form raises key questions about, for example, traffic control,
excavation, confined spaces and other specific topics crews
face at their job site. At that meeting, they basically
plan their day for safety on that particular project.”
In addition to safety, many of those projects rely on
the capability of the trenchless piercing tool.
According to Langfeldt, the piercing tool represents one
of the most versatile pieces of trenchless equipment
ever manufactured. He said, “It’s really
incredible if you think about it. The piercing
tool itself can be used for a variety of applications. Obviously
it is used as a boring tool, but it can also be used
as a ramming tool and a pipe bursting tool. It’s
extremely capable. For Potelco, it’s mainly
a boring tool. And successful boring is a function
of accuracy.
“While the Grundomat [piercing tool] basically works
on the same principles found in the first piercing tools,
the major improvement comes in the reciprocating head. A
piston inside of a casing generates power. The piston
drives the tool, and air drives the piston. Today’s
conventional piercing tools, as well as the Grundomat,
operate in this fashion.
“The Grundomat’s reciprocating chisel head
assembly, however, moves independently of the main casing,
creating a pilot bore for the rest of the tool body to
follow. This ultimately leads to greater bore accuracy
over conventional tools. The chisel like action helps
the tool to power through difficult soils and obstructions
without being pushed off course.”
Potelco’s crews see a wide variety of soil conditions.
Soils types include sandy loam, clay, hard-pan and pit-run. With
such a variety of soil types, crews rely on the accuracy
and dependability of their piercing tools. Accuracy is
necessary to ensure efficiency.
Beuslinch said, “We don’t typically encourage
our crews to attempt shots over 75 to 80 feet if possible. The
longer the shot the greater the potential is for inaccurate
boring. But occasionally, we get in the right soil
and the right situation and the crews can pull off a 150-
or 200-foot shot. And when they make them, they brag,
and rightfully so.”
Safety
is a major component of Potelco operations. Crews
are exposed to various safety-training programs,
including daily safety “tailboard” meetings.
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Gas work performed for Puget
Sound Energy, Bellevue, WA, represents the bulk of the
piercing tool work done by Potelco. A
recent project in Renton, WA highlights the integral role
the tool plays in gas distribution installations. According
to Beuslinch, the main line replacement was performed for
capacity reasons in a commercial district.
Beuslinch said, “The whole area was commercial. When
this new customer turned in his application for service,
the existing main was no longer sufficient to handle the
load requirements, so a new larger main needed to be installed. We
typically deal with new service and main installations,
but everyone likes main replacement installations.”
For the main replacement project
Potelco crews used two
5-inch diameter Grundomat P-130s. But according Beuslinch,
the job was originally earmarked for directional drilling. He
said, “The project in Renton was approximately 1,100
feet of gas main replacement. It was upgrading from
a 2-inch bare steel main to a 4-inch polyethylene main. It
was a hard surface job from start to finish with significant
portions under concrete sidewalks. When we looked
at the job we had 13 services that we had to test-and-tie-over
or replace completely and with the other utilities we needed
to cross, everything spaced out in 40- to 80-foot shots. It
was perfect for a piercing tool. Plus, the soil conditions
were ideal. It was basically Class B soil, no rock.”
Grundomat
piercing tools help Potlelco minimize disruption,
mitigate restoration costs and improve overall
productivity and efficiency.
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After successfully boring a
section of the project, crews would remove the tool and
pull in the new main with a weak link and pulling cable. As work progressed, crews
fused the sections of mains together, while other crewmembers
attended to connecting services and replacing others. New
service installations were also performed with piercing
tools.
Beuslinch said, “We used a 2-inch tool, a P-55. We
also have the smaller tools, P-45, 1 ¾-inch, for
the short shots, but mostly we used the 2-inch and 3-inch
diameter tools to install 5/8-inch to 2-inch services lines. Most
services were in the 40- and 80-foot range.” The
entire project was completed in seven days.
Potelco crews have improved field production and efficiency
dramatically under hard surface areas by combining trenchless
methods on projects, specifically directional drills
and piercing tools.
Beuslinch said, “By combining the tools on a project,
we can get done in a day what would normally take two or
three days. This works well with specific job layouts. For
example, we recently did one on a new main extension and
service where we used the piercing tool to install 160
feet of main and the directional drill to install 350 feet. We
were in an intersection. We needed to extend the main 160
feet to south, then 350 feet to the east. So, we
set up the drill on the 350-foot section and began drilling. Meanwhile
the rest of the crew worked from the intersection back
to the tie in point with the piercing tool. By the
time the piercing tool section was complete, the 350-foot
section was already drilled out and pulled back. We
had over 500 feet of main and an 80-foot service installed
in a day and footage is what pays.”
Trenchless Technology,
July 2007 |
