Vacs ID Uncertain Underground
It started with one man and his pickup truck. Tom Banks’ then one-man operation was rooted in specialization. He wanted to identify the gaps in services offered by other companies and do his best to fill them.
Formed in 2001, Banks Gas Services Inc. quickly grew from one employee to nearly one hundred. Today the company is a full-fledged gas distribution contractor headquartered in the Pittsburgh area and serving gas distribution companies in Pennsylvania and Ohio.
The expanding Banks Gas workforce brought new specialty skills and services, including mainline gas and service line replacement, vacuum excavation, leak investigation and repair, corrosion protection, service abandonments and horizontal directional drilling (HDD).
“If there’s something other companies can’t do or another contractor won’t do, the project owner will usually come knocking on our door,” says Tom Banks, owner of Banks Gas Services.
This specialized approach means Banks Gas has no trouble staying busy. On any given day, Banks has a dozen or more crews out in the field. That busy schedule is a testament to the level of commitment and expertise the company brings to each project.
“We’re the smallest contractor in our area,” says Banks. “But we’re able to compete with the much larger local and national providers because we’ve adjusted to the changing demands of our customers.”
Peoples Natural Gas Project
Often the demands of customers lead to some very challenging bores. For example, Banks Gas Services has a contract with Peoples Natural Gas in Pittsburgh. A recent distribution line replacement job called for a 400-ft bore, so the crew could install a 4-in. gas line. While the job itself was pretty typical, the location of the project was what really put Banks Gas crews to the test. The line had to cross Bigelow Boulevard, a busy four-lane street on the outskirts of downtown Pittsburgh. Banks Gas faced extreme grade changes, crowded underground conditions, a tight footprint and time constraints — among other things.
“This was a very challenging installation project,” says Jim Grachen, superintendent at Banks Gas Services. “The grade changes alone — it was just ridiculous what we were able to do there.”
Time and Space Constraints
The City of Pittsburgh did not want traffic on Bigelow Boulevard disrupted for longer than necessary. Banks knows municipal planners will not hesitate to turn down a crew whose equipment is so big it requires street closures.
“A small footprint is essential for us,” he says. “Size matters in the city.”
Knowing there were strict time and space restrictions on this project, Banks Gas crews opted to use the keyhole method to locate the underground utility lines. This meant they would need limited space for the locating portion of the project, and road restoration would be minimal.
Banks Gas came to the job with a Vermeer VX100XT AIR Series Vacuum Excavator by McLaughlin and a truck-mounted core saw to expose and locate the utilities. This required only one lane of traffic to be blocked during the utility locating process.
“Our McLaughlin vacuum units are mounted on Dodge 5500 four-wheel drive chassis,” says Grachen. “That allows us to access narrow neighborhood streets in the city and to avoid disturbing traffic conditions as much as possible.”
Using the core saw, Banks Gas crews drilled a 12-in. hole in the road and lifted out the coupon, which was about 14 in. thick. They were looking for a 4-in. gas line and an 8-in. water line running along the 400-ft bore. The underground was crowded with existing utility lines, which meant a great deal of maneuvering during the actual bore.
“When we started, we had to go over a utility,” says Grachen. “By the time we got to the end of the bore, we had to go under another utility and up a steep embankment — all the while ensuring we had proper separation for the other underground lines.”
Locating is not always a quick process. Pittsburgh’s underground consists of abandoned steel and cast iron lines, and, once a line is taken off the system, it’s usually not marked on maps of existing utilities. Banks knows “one-call” utility locating systems are not always 100 percent accurate, so he sends crews out to the site a few days ahead of a job to do some scout work. It can sometimes take up to five days to locate the line they’re looking for. When locating can take that long, it becomes that much more important to take up as little space as possible.
To Banks Gas, locating using a vacuum excavator is always worth the additional step and extra time it takes to ensure they identify materials in the ground.
Backfilling Made Easier
For the Peoples Natural Gas project, the crew was able to locate the utilities quickly and reopen the lane of traffic within two hours.
Banks Gas uses air excavation whenever possible, so they are able to reuse the spoils and backfill right on the jobsite with materials excavated out of the holes. Next they replaced the 12-in. coupon into the hole and secured it using a quick-setting grout. The crew leveled and smoothed the grout around the edges, and, just like that, the lane was ready to be reopened.
“When we finished that process,” Grachen says, “the only sign of us being there was some paint marks on
Once the lane was reopened, the crew began the actual bore.
Not Your Everyday Bore
The bore required that Banks Gas set up its drill — a Vermeer D24x40 Series II Navigator HDD rig — in the embankment on the north side of Bigelow Boulevard and bore 6 ft under the four-lane road and then up a quick elevation change to a 100-ft tall rock shelf embankment at a 30 percent grade on the south side of the road.
Accurately locating the utilities in a timely manner was difficult, but the ground conditions on this project were especially problematic. The materials, aside from utility lines, that the Banks Gas crews uncovered tested their skills.
“We’re finding, at times, railroad tracks, trolley tracks, old abandoned mains made of both cast iron and bare steel,” says Grachen.
In addition to the debris, the Banks Gas crews also had to adjust to changing soil conditions. The 400-ft bore consisted of not only clay and mixed soil but also a rock shelf as they drilled gradually up the hill on the south side of the road.
Banks Gas crews also came across a substance common to the Pittsburgh area called mill slag or steel slag. Steel slag is produced during the steel-making process when the molten steel separates from the metal impurities. The substance was not considered usable by steel manufacturers, so they used to dump it in what is now the outskirts of Pittsburgh. When it solidifies, it is dense and hard, similar to rock.
“The whole city was built on this steel slag,” says Grachen. “I guarantee you, it is some of the hardest stuff you will ever drill through.”
The Banks Gas crews were able to overcome all the obstacles of this project — the changing ground conditions, the space limitation, the time constraints and the varying grades — in one shot in order to complete the bore and install the 4-in. gas line. The whole project took just under two days to complete.
Confidence in Crew, Equipment
Tackling a job like this distribution line replacement gives the impression that Banks Gas Services has been doing directional drilling projects for years. Banks doesn’t mind making it known that this is not the case.
“We’re newer to directional drilling,” he says. “We’ve been doing it for about four or five years now, so we haven’t had many challenges like this project for Peoples Natural Gas.”
Banks didn’t hesitate to accept the job, despite the complexity of the bore. He was confident in his men and his equipment. The core saw, the vacuum excavators and the directional drills Banks Gas crews use are all Vermeer models, which allowed crew members to master the equipment quickly and thoroughly — proving again how important specialization is to Banks’ business.
“The guys, in a short time, were just able to gain confidence and knowledge of the machine,” says Banks. “They drill from point A to point B. Somehow, someway we always find a way to get it done.”
Banks Gas Services Inc, March 2016 Print Issue, McLaughlin, Vermeer
Meredith Augspurger is a features writer for Two Rivers Marketing, on behalf of McLaughlin, based in Greenville, South Carolina.
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