DENVER — Denver7 cannot confirm the urban legends regarding Denver International Airport’s underground tunnels, but we got an exclusive behind-the-scenes look at what lies at the end of them.
Just north of Concourse C is the maintenance facility for the airport’s Automated Guideway Transit System (AGTS), known more commonly as the airport’s trains, which transport passengers from the terminal to their gates.
The train travels about 1.3 miles in each direction in a pinched loop layout.
“The system is incredibly complex,” said Matt Robb, senior vice president of technical operations for the airport. “They operate almost entirely on their own, using software with oversight from the super controller.”
The airport uses the company Alstom as its operations and maintenance contractor. Near the maintenance facility is a control room area where operators keep track of the trains and problems that may come up.
The oldest trains, which started running when the airport opened in 1995, have nearly 2 billion miles on them. Robb said the plan is to phase out the original cars by the end of this year and completely phase out the older designs by 2028.
After a 2018 purchase of 26 train cars with an updated design, according to Robb, the fleet will grow to 41 total cars. That allows the airport to operate a maximum of eight trains at a time instead of seven, increasing passenger capacity to about 8,000 per hour in each direction.
Robb said the cars can fit roughly 90 passengers each, but “we don't want more than 50 passengers at a time.”
“We want to ensure that they have not only a reliable level of service, but also they're comfortable going to and from their flights,” he told Denver7.
With no alternate walkway option between Concourses B and C, train maintenance becomes critical.
“So we touch every car every other day,” said Robb. “Every car undergoes a bi-daily check where it comes in, and the mechanics check vital systems to ensure everything is operating properly. Then, just like your personal vehicle, they undergo routine mileage-based maintenance.”
There are also several backups to prevent a complete failure of the system.
“There's lots of redundancies on the power side,” Robb explained. “We've got six power distribution stations. Two of those are in terminal, two of those are at B, and then two of those are here at the maintenance facility. And then we've got redundant power feeds from Xcel. There's also a huge amount of safety redundancy built in this system, from our automatic train operation to automatic train control and then automatic train protection, which is solely focused on the safety operation of the system.”
As for the cars themselves, Robb said they’re a “much more comfortable ride,” while the airport touts their energy efficiency, and that they allow for a more efficient operating schedule that moves approximately 850 more passengers to the gates every hour.
“They're a huge improvement, you can you can tell just by looking at them,” said Robb. “They've got better signage, they've got better lighting, they've got better HVAC in them… We have ‘dwell time’ in each station down to an exact science to maximize the capacity of the system.”
However, when the complex system does have issues, it can create a frustrating experience for travelers. Last week, pre-planned maintenance on the track limited the number of trains in service, just as an influx of weather-delayed flights came in late at night, leading to long delays waiting for the train and a chaotic scene.
Robb told Denver7 last week the airport “actually did make adjustments to the train schedule… to run seven trains until 10:30 p.m., which is more than we typically run. Unfortunately, we came down a little bit too early where we would have liked to extend that.”
On Friday, he said the airport now has “streamlined some of our communication protocols so that when we're faced with a similar situation in the future, we can make the right decision whether or not to defer maintenance or to go ahead and complete critical maintenance with some sort of supplemental tool for moving people.”
Read Denver7's previous coverage of DIA's train issues below
- As DIA unveils new train cars, touting their efficiency, how close is an alternative for getting to your gate?
- Train track maintenance causes delays at Denver International Airport Tuesday night
- Denver7 takes passengers' concerns to DIA officials after train delays Tuesday night
After each of these issues, viewers have asked why the airport has not yet invested in an alternative to trains, such as a pedestrian walkway. Denver7 took that question to Robb.
“Ultimately, we want to make this AGTS as reliable as we possibly can,” he replied. “We have a service level expectation of 99.86%, we want to drive that to 100%… That's why we're investing money in replacing these 30-year-old assets. That's why we're going to invest in creating more capacity for the system, and ultimately, why we're going to invest in upgrades to our guide, ways to our signaling and to our switch infrastructure.”
Last July, Denver7 asked airport CEO Phil Washington about train alternatives. He said then the “most prominent” idea being considered is “a pedestrian bridge from A to B, from B to C.”
“So we’re looking at those [ideas], we’re gonna make a call on those on whether we proceed with that probably in the next six months or so,” Washington said at the time.
Denver7 asked for an interview or response from Washington, nearly one year later, and if there is a rough estimate for what an alternative would cost. Instead, an airport spokesperson provided this statement:
"In 2022, DEN issued a Request For Information (RFI) to the industry to explore ways to add redundancy to our concourses, as well as to the desire to add capacity if possible. After receiving many great ideas, over the past year we have further studied the feasibility of one option, the addition of elevated concourse connector bridges from Concourse A to B and from B to C.
We believe redundant pedestrian access is commercially viable and offers fiscal benefits to our partners. Currently, the project is not in our Capital Improvement Plan (CIP). As we are evaluating and prioritizing projects for the next 10 years, this project will be evaluated along with DEN’s many other infrastructure needs."
As the statement says, the pedestrian bridge option has been “further studied,” but the airport is not committing to any option at this time. The airport did not include any estimate as to what a pedestrian bridge project would cost.
For now, keeping the train system running smoothly is the only option.
“Typically, our busiest week of the year is right around the Fourth of July,” said Robb. “That Sunday after the Fourth of July tends to be a peak travel day for us. So on that day, we will be running every train that we possibly can in the system.”
According to Robb, the Sunday after July 4, 2024, was the airport’s busiest day ever, with roughly 96,000 passengers screened at security.
