The completed Concourse D expansion will offer 75 percent more space for passengers and 34 new parking positions for large aircraft.

Atlanta’s airport—the busiest such thoroughfare in the world, and Georgia’s largest employer—­has embarked on a multiyear project that will enable it to better support more than 100 million passengers annually. Construction is underway to expand Concourse D even as it continues to serve passengers. A team of contractors and joint ventures are making it happen.

Opened in 1980, Hartsfield-Jackson Atlanta International Airport (ATL) boasted five original concourses. Until recently, Concourse D was the narrowest at 60 feet wide, including gates, seating areas and restaurants. The circulation corridor was only 18 feet wide but meant to accommodate as many as 5,400 passengers. The goal was to widen that space, improve the passenger experience and serve the increasing number of larger aircraft at Concourse D’s gates.

When finished in 2029, the entire Concourse D expansion, with a north and south pier, will offer a 75% increase in boarding-level square footage and 34 new parking positions for large aircraft such as the Boeing 737 Max and Airbus A321 Neo. The modernized and expanded concourse will be 99 feet wide and 288 feet long, with a ceiling that is 18 feet higher than before. It will also offer an increased seating capacity of 6,400, larger holding areas, restrooms and concessions, and more elbow room for passengers. To accommodate all this added service area, ATL requires distribution improvements to electrical and IT systems, in addition to other utilities.

Electrical contractors include Inglett & Stubbs LLC, Mableton, Ga., which is part of the joint venture ISM for building and connecting the expansion modules, and UpTime Electric Co. Inc., College Park, Ga., for voice, data and electrical modifications.

At the helm is a joint venture general contracting team known as Holder-Moody-Bryson-Sovereign. ATL credits this team for the smooth installation, said Tom Nissalke, the airport’s assistant general manager of planning and development.

From the onset, it was clear nothing about the project would be easy. Millions of passengers and thousands of planes continue to use the airport as contractors work, explained Nissalke. In fact, a maximum of only eight gates can be closed at any time during the project.

With that in mind, the contractors are constructing, transporting (across the south airfield) and installing 19 modular expansion units, one at a time. And to facilitate this process, the airport needed to reconfigure the concourse’s apron level (where the aircraft are parked, loaded, refueled and maintained) to ensure continuous operational support space. The project also requires crews to move “a tremendous number of utility runs located on the ceiling of the apron level,” Nissalke said.

Additionally, subcontractors—including the electrical contractors—were tasked with tying new services into existing ones at the concourse. That included the electric service, HVAC, security and plumbing, as well as fueling, cellular, sanitary sewer and others.

Electrical expansion will take place in a phased approach to ensure service is never interrupted.

“The electrical challenges focus on developing a second set of electrical infrastructure, tying it into the existing systems and the eventual decommissioning of the existing systems while the concourse continues to serve passengers and aircraft,” Nissalke said. While the construction was straightforward, integrating it into an operational concourse “takes complexity to a whole new level.” 

Dedicated modular fabrication area

About a mile from Concourse D, ATL established a 6-acre, modular construction site between two runway complexes, where the module-building work does not interfere with air traffic or normal gate operations.

Once each module is finished, it is transported across the airfield overnight when flight travel is typically limited.

Accomplishing the electrical portion of this effort is the ISM joint venture. One of the largest electrical contractors in the area, Inglett & Stubbs recently celebrated its 70th anniversary. For this massive, multiyear project, the company chose to create the ISM joint venture, said Tom Sapitowicz, Inglett & Stubbs’ senior project manager for prefabrication/modular systems.

Inglett & Stubbs has considerable experience at the airport, and worked on the international concourse in the last decade.

ISM has run temporary power cables to gates that feed lighting and power to boarding platforms. Once the modular units are in place, ISM will connect the system to existing infrastructure.

As of May, the first five modules were in place on the north and northeast side of the building, Sapitowicz said. The gates supported by these modules will be substantially complete and in operation in September.

Inglett & Stubbs’ electrical prefab site

Inglett & Stubbs operates multiple modular/prefabrication sites, including one in Covington, Ga., where the units’ electrical systems are built before delivery to the airport for installation in the module. Electricians are using the prefab site to build electrical and communications rooms, and the distribution frames (MDF and IDF) are brought on-site as fully contained units.

For ISM, the work itself is not unlike a standard electrical installation in a building, Sapitowicz noted. 

“Technically speaking, we’re not doing anything more with these prefab modules than building what could be a decent-sized, two-story building. We’re very familiar with prefab anyway,” he said. 

However, the timing and modular transport make this project highly memorable.

The completed units are transported about once a week on self-propelled module transporters provided by Dutch company Mammoet. Mammoet’s low-slung transport vehicles, with 80 rows of tires, carry the finished modules at 1 or 2 miles per hour, with a team of operators walking alongside. Personnel walk in front of the vehicles, while other workers follow behind to ensure no foreign objects are left behind. 

“We have to leave the runways in better condition than when we found them,” Sapitowicz said. The entire journey takes about 45 minutes, usually well after midnight.

Once the unit is in place, the existing and temporary electrical portions are decommissioned and the connection between the new modules and the existing concourse structure is coordinated.

Low-voltage and data installation

For the low-voltage systems installation, a joint venture that includes UpTime Electric is building out the Cat 6 cable network to serve the concourse’s data needs.

UpTime has been working at ATL since the airport was built, first under the name of Yukon Electric, and as UpTime since 1997. 

“We are providing the infrastructure conduit and cable tray for all of the low-voltage systems,” said Tony Cook, UpTime’s president and CEO. UpTime will also extend low-­voltage cabling to 16 boarding bridges, as well as power to the gate signs, safe gate units and potable water cabinets, Cook said.

Up, up in the Sky Club

A separate UpTime project is the Delta Sky Club, in which UpTime works for ATL Builders JV, a general contractor joint venture made up of J.E. Dunn Construction, Kansas City, Mo., and Barnsley Construction Group, Atlanta. With the expansion, Delta is opening a new Sky Club at Concourse D to provide members workspaces, food and beverages and showers. Delta currently operates two smaller Sky Clubs at the concourse, which will close when the much larger, upgraded version is finished.

UpTime’s responsibilities include the demolition and relocation of existing power systems to allow the footprint expansion of the Sky Club during the Concourse D core and shell building widening, as well as new infrastructure power to serve the Sky Club.

That effort requires some collaboration with other contractors, including ISM, which is powering the expanded concourse.

“We’ve had to coordinate with them to make sure that we’re giving them the power that they need and they’re getting it in the right location,” Sapitowicz said.

Jet bridges

A third UpTime project at ATL involves electrification of the jet bridge units that carry passengers between the aircraft and the concourse. With this project, Cook said, UpTime Electric is part of the PBB joint venture, which is made up of UpTime and the AERO Group BridgeWorks Inc., Marietta, Ga. AERO Group is providing and installing the 16 new jet bridges and UpTime is wiring them.

The complexity of working in a live airport affects the entire building crew.

“You’ve got an airport that never shuts down, so you’re limited in your staging areas—it really takes a concentrated effort,” Cook said. 

That includes a lot of night shifts to avoid disrupting the majority of the flying public. 

Additionally, he said, “You’ve got to schedule the equipment and material needs routinely, since staging areas are limited.”

When all is said and done, Concourse D will greatly enhance the customer experience while strengthening ATL’s position as a global gateway, Nissalke said. 

“Widening Concourse D will increase capacity and efficiency, as we will be able to accommodate an ever-growing number of travelers,” he said.

The project’s success may have been a matter of communication and orchestration with the existing activity at the airport.

“I think the concentrated effort [throughout the project] is for the contractors to pull together,” Cross said. “I think that will be what will stand out for us, years later, more than anything.”

Hartsfield-Jackson Atlanta international airport