Potelco: Getting a Big Impact from Piercing Tools
Look in the toolbox of any successful contractor and you will see some of the reasons why they are successful. Aside from the other essentials for success, skill, dedication and commitment to quality, a contractor’s toolbox can give a keen insight into why they are successful.
Since its beginnings in the 1960s, utility contractor Potelco, Sumner WA, has seen many changes. The assortment of tools in its toolbox has changed with the times, as well as Potelco’s expanding service offerings. One tool in particular has evolved from a novelty into an essential piece of equipment—the piercing tool.
According to Gas Operations Manager Mitch Bogrand the tool is an important part of daily operations. He said, “We use pneumatic piercing tools for a wide range of applications including gas, electric and phone. For our gas service line installations we rarely use anything else. It’s just so much nicer then tearing up someone’s yard, their sprinkler system and grandma’s rose bush.”
According to Scott Langfeldt, piercing tool specialist from trenchless equipment manufacturer TT Technologies, Aurora, IL, Potelco really gets the most out of their piercing tools. He said, “The folks at Potelco are utilizing piercing tools to the utmost. Those tools are in the field day in and day out performing bore after bore. The piercing tool has unquestionably helped make Potelco one of the leading utility contractors in the United States.”
37 Years Of Service
Potelco, Inc, a subsidiary of Quanta Services, Inc., is a full service utility contracting firm, serving customers throughout the Northwest in Washington, Oregon, Idaho, and Montana. For more than 37 years, Potelco has been providing construction services to the power transmission and distribution, natural gas distribution, fiber optics, aerial and underground telecommunications industries.
With a staff of project engineers, Potelco is a design/build contractor. Potelco offers its clients comprehensive project planning including construction design, projected costs of materials and labor, and the construction of the project itself.
Bogrand said, “We specialize in designers who are field oriented and who understand how design affects construction and future maintenance of the overall project. Often those designs include the use of trenchless technology, specifically piercing tools. We own and operate over 200 of them from one and three quarters to five inches in diameter.”
Accuracy Is Key
While the principal function of the piercing tool hasn’t changed much over the last 50 years, its design has. Bogrand said, “We’ve been using piercing tools for more than a decade. The tools have really come a long way. They have become more accurate.”
According to Langfeldt, that improvement accuracy comes from improved design. He said, “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.”
On The Job Training
Potelco currently performs all the electrical power related installations for Puget Sound Energy, Bellevue, WA, as well as the new business portion of its gas division. According to Bogrand, typical crew sizes vary between two and four people. Each crew is equipped with at least two piercing tools some have three. New crewmembers receive training in the field.
Bogrand said, “We put new crewmembers with an experienced person. They seem to grab onto very quickly. It is a basic process, but there is a feel for the ground conditions and how the tool is going to run that you can only develop through experience.”
Potelco’s crews see a wide variety of soil conditions. Soils types include sandy loam, clay and rocky. With such a variety of soil types, crews rely on the accuracy and dependability of their piercing tools. Accuracy is a necessity to ensure efficiency.
Bogrand said, “Well I’ll tell you in ideal ground conditions we’ve done 200-foot bores. That’s usually in an extensively landscaped situation where we’re running tool fairly shallow in good ground conditions. If it’s running straight and true we’ll just go ahead and keep adding hose. The guys call them glory shots. Most of the time, though, typical installations range between 40 and 70 feet.”
According to Bogrand, approximately 80% of all Potelco’s piercing tool work is gas service line related. A recent gas conversion project for Puget Sound Energy in Kent, WA highlights the piercing tool’s abilities.
The project in Kent was a commercial gas service line installation for a strip mall. The Potelco crew needed to install a 300-foot, 1 1/4-inch Medium Density Polyethylene (MDPE) gas service line. The bore traveled from the mainline, under a roadway, two sidewalks and landscaped area adjacent to a parking lot, to the mall’s meter manifold.
Bogrand said, “The soil conditions in the area are very unforgiving. In addition, we had to deal with a nicely landscaped area and several changes in elevation, so we decided to divide the run into sections. The first shot went from the main under the sidewalks and the street, approximately 50 feet. After that we divided the subsequent shots into 40-foot lengths.”
The three-man Potelco crew used a 2-inch diameter Grundomat-P 55 from TT Technologies for the job. After the first shot under the road, the crew disconnected the air hose from the tool and compressor. At the launch pit a pipe pulling cable was connected to the hose and pulled into the completed bore path as the crew removed hose at the exit pit.
At that point, the exit pit became the launch pit and a new exit pit was excavated approximately 40 feet away for the next bore. Each pit measured approximately 3 feet wide and 6 feet long at varying depths throughout the run. After each bore the crew repeated the process of pulling in pipe pulling cable, connecting each section of cable together once in place.
After the series of bores to the mall was completed, the Potelco crew pulled the new 300-foot, 1 1/4-inch service in place with the pipe pulling cable. According to Bogrand each bore took approximately 20 minutes to complete. Once installed, the crew tied the line in the steel gas main using a welded service tee with a transition for plastic pipe.
Piercing Tool Praise
The piercing tool has earned a respected place in the Potelco toolbox, and for good reason according to Bogrand. “The piercing tool is absolutely essential for our business. Our productivity would definitely be lower without it. You know we’re so used to them you start taking them for granted. But if you think about it, there are just all kinds of pluses to the tool.
You can put it in the ground and get it on its way and the crew can be doing something else. The crew can be working on the tie in or something like that. It’s always moving; it’s like having another person on the crew.”
by Jim Schill
Underground Construction, October 2001