Updating Gas Service Lines in Minneapolis – Compact HDD Connects Old with New
Throughout Minnesota, and around Minneapolis specifically, natural gas service lines are being replaced. In most instances, decades-old lines are being replaced with new polyethylene lines. As the age of the service lines indicates, their location is often in the older, more established neighborhoods. Of course, those are prime locations for trenchless technology.
Michels Utility Services Inc., of Brownsville, Wisconsin, is the contractor responsible for replacing the aging gas infrastructure. Reconstruction division manager Ben Buer said that Michels crews are doing a variety of work throughout the state.
“The specifications of the work vary depending on whether it is commercial or residential,” he said. “Existing residential services are typically ½-in. lines, but sometimes we’re replacing 1-in. steel, for example. Some of the work includes moving meters outside. Other areas, include 1 ¼-in. to 4-in. diameter service lines for commercial applications, along with main line work.”
A portion of the residential work has been taking place around Lake Nokomis on the southern edge of Minneapolis. The area is comprised of eleven neighborhoods covering seven and a half square miles that encompass and celebrate the old neighborhood charm that the area is known for. With Lake Nokomis as a central feature, the area offers an abundance of recreational opportunities that make the homes and residences in the Lake Nokomis neighborhoods highly desirable.
According to Mark Dorn, trenchless specialist with trenchless equipment manufacturer TT Technologies, the compact directional drill has been having a big impact with little disruption in older neighborhoods near Minneapolis, like those around Lake Nokomis.
“With that old neighborhood charm comes narrow, uneven streets and older homes with a small footprint that make the replacements of any type of utility difficult,” Dorn said. “In addition to the challenging layout, soil conditions in the area leave much to be desired from an underground construction standpoint. With aging infrastructure in need of updating, the Grundodrill 5X compact directional drill becomes an easy choice for the area, along with a high-skill contractor like Michels.”
A History of Excellence
Michels Utility Services Inc. is part of the Michels family of companies, cumulatively one of the most dynamic contractors in the United States involved in virtually all aspects of underground and overhead construction. Michels began doing business in 1959 as a gas pipeline construction company providing construction and installation of natural gas distribution systems to Wisconsin utilities. Today, Michels employs more than 8,000 people, is licensed to work in all 50 states and has more than 50 offices and yards coast-to-coast.
Safety is a big part of what makes Michels the respected organization that it is. According to Buer, safety is the cornerstone of Michels culture, a core value extended to every job and project. “Every one of our crews is required to participate in Job Safety Analysis (JSA) tailgate meetings in the morning,” he said. “We have ‘Step Back for Safety’ after mid-day breaks and lunch. Safety is a very high priority so we follow that very closely and take it very seriously.”
In terms of training, even driller operators with experience who are new to the team go through a period of training. “Even the guys coming in that have drilling experience, I do require them to spend a designated amount of time as a third wheel doing shadow training,” Buer said. “I say, ‘Well, you drilled in phones lines for someone else and did all this other stuff, but this is how we do it.’ So we’ll go with three guys instead of two and take them through that training process. Then we’ll move them over to another drill crew for another week, so they’re just not seeing how one guy does it or one team does it. We’ll move between a couple or three teams before we start placing them out there to do the work.”
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Judging by the number of services being replaced in Minneapolis, any new drill operators will have plenty of opportunity to hone their skills on the compact directional drill.
Compact Directional Drilling Making the Big Time
Compact directional drilling has gained significant popularity over the last decade. Smaller, more powerful and capable compact directional drills have been allowing utility contractors to become even more productive in difficult, tight working conditions, much like the Lake Nokomis area in Minneapolis.
According to Dorn, there are several different criteria for what constitutes a compact directional drill. He said, “The first is power, pullback. Horizontal directional drills under 20,000 lbs of pullback are often considered compact, but sometimes it’s under 15,000 lbs. Either way, the new Grundodrill 5X provides 12,000 lbs of pullback and thrust, so that would definitely fit into compact HDD category. Another hallmark of compact drills is their jobsite maneuverability. In this latest version, the drill is easily and quickly tracked from location to location using a wireless remote control. A big improvement over other models.”
The lightweight and smaller profile of compact drills also makes them attractive for service line work. The drills can operate in tight, residential areas.
“They also tend to be narrow enough to fit through a standard yard gate. This is very useful in a residential service application,” Dorn said. “Portability is another factor. Most compact drills can be legally towed behind a 1-ton truck. Helping with productivity, there are several drilling modes incorporated into this latest compact drill, everything from manual to a fully automated drilling operation.”
On the Job
The Minnesota construction season runs from early April through mid-December. And while weather is commonly a challenge on jobsites in the state, soil conditions can be equally challenging. “Dealing with the variety of soils makes the accuracy and power of the Grundodrill 5X a significant asset. Inside and around the Twin Cities, you can encounter almost every possible soil condition,” Dorn said.
“Sandy sections, clay, rock. We literally ran it through everything we could physically drill through,” Buer said. “In the Lake Nokomis area it is predominantly sandy, but you run into a mixed bag with some rock mixed in. We do use a bentonite mixture. How much and how often depends on conditions. Sandy soils require thicker mixtures to hold the hole. But that’s drilling anywhere, you mix your mud to match the conditions.”
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In the Lake Nokomis area, Michels crews are working block-to-block replacing gas service lines. Michels is doing both replacement work and new installations, depending upon location. Crews operate as team, moving from line to line with operational precision.
“We try to move in an assembly line fashion as often as possible,” Buer said. “So that we can keep the guys as close together as possible for helping each other out and keeping the restoration crew moving close behind. So moving in that way is very efficient.”
The average distance for most of the services being installed in the Minneapolis area are 75 to 100 ft in length. A majority of the residential services lines are ½-in. medium density polyethylene (MDPE) pipe, however on commercial services crews pull back larger diameter pipe with the compact drill as well. Michels crews maintain a high level of production even in tight working conditions.
“It’s going to depend on conditions in neighborhoods. A well-seasoned crew could be completing seven services a day,” Buer said. “The objective is to get everyone back on service by the end of the day. But the drill crew itself, on a good day, can put in 1,000 feet of drilling, and have completed up to 18 service runs in a day installing lines ahead of the service crews.”
The trenchless application helps minimize disruption and keep roadways open during service work in the neighborhoods. The compact directional drill’s mobility also contributes to work site efficiency. Buer said, “Naturally we want to keep things open as much as possible for emergency vehicles, school bus, etcetera. Sometimes we will track the machine into a yard or back alley and shoot back down toward those locations. It works well for multiple different challenges that present themselves at the jobsite. The mobility definitely helps ease the pain of daily production. It does track better. And the footprint in the yards is much lighter.”
Jim Schill is a technical writer based in Mankato, Minnesota.