DAta centers are often depicted as giant brains, but the miles of wires and cables radiating from them more closely resemble the tentacles of a large jellyfish. A single 500-acre hyperscale campus, like the one Mortenson is building in Eagle Mountain City, Utah, has more than 40 miles of channel bank needed to safely house those lines.
Mortenson is among several companies that are rethinking all the steps involved and have achieved impressive safety improvements with reduced hazards.
Duct bank sections are a series of conduits through which cables are routed. Traditionally, they are made by digging a trench, preparing the trench base, constructing formwork, and installing conduit cages before pouring concrete. The sections are often built in thick mud and the trenches often require drainage during inclement weather, extending the installation process to three to four weeks per 1,000 feet. The process is repeated again and again until the cables can be pulled through and the data center is powered and connected.
During labor-intensive work, workers are exposed to slippery conditions, trench collapse, and chemical burns from wet concrete.
Large electrical companies like Rosendin Electric And Bergelectric has addressed the issues related to the channel bank. Earthworks and utility companies such as Muller and Contech Engineered Solutions, as well as large general contractors and construction managers such as DPR and Turner Construction, also have sewer banking programs or specialized methods.
Minneapolis-based Mortenson, through its manufacturing arm BLUvera, addressed the issues in 2020, opting for off-site prefabrication and large-scale prefabrication.
Data center developer QTS had hired Mortenson for the large Utah project in Eagle Mountan City, west of Provo.
“The idea originated at the Eagle Mountain hyperscale data center,” explains Nate Haack, vice president and general manager of BLUvera. “The project team faced scheduling challenges in a crowded area – so they asked themselves, 'What if we prefabricated these elements off-site and installed them like Lego bricks?'”
Over the past five years, BLUvera has expanded its operations to produce 20-foot, 17,000-pound modular sections in off-site fabrication shops, reducing on-site labor by 56%.
The safety risks for workers have also been reduced. According to BLUvera's internal tracking data from 2024, Mortenson saw an 87% decrease in safety incidents after switching to precast. According to a company case study on the Eagle Mountain project, the practice reduced trench exposure by 60 to 70 percent. In the production halls, the teams carry out the same tasks every day. The work carried out on site includes setting channel bank supports and connecting pipes to each other.
Mortenson's off-site pre-concreting reduced exposure to wet concrete, prevented potential burns, slips or formwork collapses, and reduced the number of excavator lifts by 60%. Only one lift is required per 20 feet of duct bank, compared to 10 to 15 with a cast-in-place approach.
The process for building the data center duct bank was refined by Mortenson and involves placing concrete in an interior fabrication hall. Photo: Courtesy of Mortenson.
“In the factory environment,” explains Haack, “we are under one roof, in a controlled environment with forklift and truck lanes. The way we pour our prefabricated sewer pipe is repeated every day. So for our team members, it's rinse and repeat. They do the same job every day because they pull out every form every day.”
The defects have also decreased dramatically.
“We very rarely have one,” says Haack. “We have seen an 83% reduction in quality defects, with the most common defect being due to damage during loading and unloading of the truck.”
To minimize transportation costs and logistics, BLUvera has taken its prefabrication concept one step further and now deploys mobile factories near data center project locations. By setting them up close to the locations of use, these can be expanded very quickly.
“From a cost perspective, it is very ineffective to ship channel bank sections,” says Haack. “We sign a rental agreement, take possession of the property and produce within a month… As soon as we finish producing the products for the site, we move on to the next work.”
Mortenson currently has a mobile duct bank factory in Louisiana. “We have been there since January and will be there for another year,” says Haack. The company is working on leases for two additional mobile factories.
Marty Corrado, a retired project manager, proponent of prefabrication and author of a book about prefabrication, likes what he sees in data centers and compares it to projects he has been involved with.
In 2017, as general superintendent for JE Dunn, Corrado's team worked on an electrical contractor's prefabricated hospital duct bank at Sarah Cannon Hospital in Plano, Texas – another type of power- and data-hungry structure.
One of the goals that Mortenson says has led the construction of canal banks to eliminate as much labor as possible in the trenches is to improve safety. Photo: Courtesy of Mortenson.Electrical contractor Enterprise Solutions “dug the hole on a Monday and dug virtually the entire hole in a week,” he explains. “In the next four weeks [the team] poured the concrete for it [duct bank] Base set up, bench set up, everything tied down and inspected. “It was done in 30 days,” notes Corrado, adding, “Normally it would take us four to five months.”
Of Mortenson's innovation, Corrado says he is “so happy to see the electrical industry really starting to work efficiently.”
Haack says Mortenson has more innovations in the works. The company is preparing a new sewer bank, which it says will further reduce on-site labor by eliminating the need to be in the trench to bond the PVC pipe sections. The new system will reduce the project’s carbon footprint by “more than 30%,” he adds.
The unfolding boom in data center construction will provide many opportunities to discover what works best.